MODELS HW 300, 399, 420, 520, 610, 670
GAS-FIRED COMMERCIAL COPPER BOILERS FOR
HYDRONIC HEATING AND HOT WATER SUPPLY
UP-FLOW MODELS
• INSTALLATION • OPERATION • MAINTENANCE • LIMITED WARRANTY
• INDOOR ONLY
WARNING: If the information in this manual
is not followed exactly, a fire or explosion
may result causing property damage,
personal injury or death.
— Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instructions.
• If you cannot reach your gas supplier,
call the fire department.
— Installation and service must be
500 Tennessee Waltz Parkway
performed by a qualified installer,
service agency or the gas supplier.
Ashland City, TN 37015
PLACE THESE INSTRUCTIONS ADJACENT TO BOILER AND
NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE
PRINTED 0210
317693-000
GENERAL SAFETY
3
TABLE OF CONTENTS
SAFE INSTALLATION, USE AND SERVICE.......................................................................................................................................................................... 2
GENERAL SAFETY................................................................................................................................................................................................................ 3
TABLE OF CONTENTS.......................................................................................................................................................................................................... 4
DIMENSIONS AND CAPACITY DATA.................................................................................................................................................................................... 5
INTRODUCTION.................................................................................................................................................................................................................... 7
Grounding Instructions ................................................................................................................................................................................................... 7
Correct Gas.................................................................................................................................................................................................................... 7
Precautions .................................................................................................................................................................................................................... 7
Liquid Petroleum Gas Models ........................................................................................................................................................................................ 7
High Altitude Installations ............................................................................................................................................................................................... 7
CONTROLS AND FUNCTION................................................................................................................................................................................................ 8
High Limit ....................................................................................................................................................................................................................... 8
Intermittent Ignition Control Module ............................................................................................................................................................................... 8
Thermal Balancer........................................................................................................................................................................................................... 9
Auto Reset High Limit Control........................................................................................................................................................................................ 9
Safety Flow Switch......................................................................................................................................................................................................... 9
Safety Relief Valves...................................................................................................................................................................................................... 10
Tank Temperature Control.............................................................................................................................................................................................11
Thermometers (not installed) ....................................................................................................................................................................................... 12
DRAIN VALVE ...................................................................................................................................................................................................................... 12
GENERAL ............................................................................................................................................................................................................................ 12
Required Ability ............................................................................................................................................................................................................ 12
Location........................................................................................................................................................................................................................ 12
Air Requirements.......................................................................................................................................................................................................... 13
Chemical Vapor Corrosion............................................................................................................................................................................................ 13
Installation Clearances................................................................................................................................................................................................. 14
Leveling........................................................................................................................................................................................................................ 14
System Connections .................................................................................................................................................................................................... 14
VENTING ............................................................................................................................................................................................................................. 14
Venting the Boiler ......................................................................................................................................................................................................... 14
Venting Maintenance.................................................................................................................................................................................................... 16
Venting Sidewall........................................................................................................................................................................................................... 16
Venting System ............................................................................................................................................................................................................ 16
Venting Tables.............................................................................................................................................................................................................. 17
SYSTEM INSTALLATIONS .................................................................................................................................................................................................. 18
Installations .................................................................................................................................................................................................................. 18
Conventional ........................................................................................................................................................................................................ 18
Linear Temp.......................................................................................................................................................................................................... 18
Water Supply Line................................................................................................................................................................................................ 19
Expansion Tank.................................................................................................................................................................................................... 19
Vent Valves........................................................................................................................................................................................................... 20
Manifold Headers................................................................................................................................................................................................. 20
Cooling Piping ...................................................................................................................................................................................................... 20
Circulating Pump.................................................................................................................................................................................................. 20
Gas Connections.......................................................................................................................................................................................................... 20
Gas Supply Line Purging and Sizing............................................................................................................................................................................ 21
Gas Pressure Regulators............................................................................................................................................................................................. 22
WIRING ................................................................................................................................................................................................................................ 23
WIRING DIAGRAMS....................................................................................................................................................................................................... 24-33
PIPING ............................................................................................................................................................................................................................ 34-39
OPERATION AND START-UP INSTRUCTIONS.................................................................................................................................................................. 39
Important ...................................................................................................................................................................................................................... 39
Filling the System......................................................................................................................................................................................................... 39
Pilot Alignment and Main Burner.......................................................................................................................................................................................... 39
Lighting Instructions ................................................................................................................................................................................................ 43-44
Checking and Adjusting Input....................................................................................................................................................................................... 41
Operating Sequence .................................................................................................................................................................................................... 42
REMOVAL OF EXISTING BOILER FROM A COMMON VENTING SYSTEM ..................................................................................................................... 45
GENERAL MAINTENANCE ................................................................................................................................................................................................. 45
Cleaning and Flushing Instructions ...................................................................................................................................................................................... 46
PRE TROUBLESHOOTING................................................................................................................................................................................................. 46
TROUBLESHOOTING .................................................................................................................................................................................................... 47-54
LIMITED WARRANTY.......................................................................................................................................................................................................... 55
4
DIMENSIONS AND CAPACITY DATA
EXTRA OPENING
FOR THERMOMETER
AND RELIEF VALVE
HW-520, 610
AND HW--670
TABLE 1
MODELS
DIMENSIONS IN INCHES
PROPANE
HW-610/670
NATURAL
HW-610/670
HW-300
HW-399
HW-420
HW-520
A
B
C
D
E
F
G
H
J
Overall height
Height to Top of Jacket
Floor to Center Line Water Inlet
Diameter of Jacket
Floor to Center Line Water Outlet
Draft Diverter Outlet Diameter
Floor to Center Line Gas Inlet
Overall Depth
65 (1651)
57-1/8 (1451) 57-1/8 (1451) 68-5/16 (1735)
67 (1702)
64-3/4 (1645)
43-1/4 (1099) 45-1/8 (1146) 45-1/8 (1146) 56-1/4 (1429) 56-1/4 (1429) 56-1/4 (1429)
36 (914)
25-1/4 (641)
12 (305)
8 (203)
16-1/2 (419)
29-5/8 (753)
9 (229)
14 (356)
1-1/4
1-1/4
38-3/4 (984) 38-3/4 (984)
46 (1168)
27 (686)
12 (305)
10 (254)
18 (457)
46 (1168)
27 (686)
12 (305)
12 (305)
18 (457)
36-1/2 (927)
9 (229)
11 (279)
2
46 (1168)
27 (686)
12 (305)
12 (305)
18 (457)
36-1/2 (927)
9 (229)
11 (279)
2
27 (686)
12 (305)
10 (254)
27 (686)
12 (305)
10 (254)
16-3/4 (425) 16-3/4 (425)
31-1/2 (800) 31-1/2 (800) 36-1/2 (927)
Support Height
9 (229)
14 (356)
1-1/2
1-1/2
1
9 (229)
14 (356)
1-1/2
1-1/2
1
9 (229)
11 (279)
K
L
Width of Control String (approx.)
Pipe Size of Water Inlet (NPT)
Pipe Size of Water Outlet (NPT)
Pipe Size of Gas Inlet (NPT)
Control String Plus 1/2 Jacket Diameter (approx.) 26-5/8 (676)
Horizontal Length between Water Inlet and Outlet 5-3/8 (137)
2
2
1
M
N
P
S
T
2
1
2
1
3/4
27-1/2 (699) 27-1/2 (699) 24-1/2 (622)
24-1/2 (622)
5-3/4 (146)
7 (178)
361 (164)
24-1/2 (622)
5-3/4 (146)
7 (178)
361 (164)
5-1/2 (140)
5 (127)
5-1/2 (140)
5 (127)
5-3/4 (146)
7 (178)
Control String from Jacket
Approximate shipping weight lbs. (Kilograms)
5 (127)
240 (109)
291 (132)
291 (132)
361 (164)
NOTE: All dimensions in inches (millimeters) except pipe size which is NPT
5
TABLE 2, RECOVERY CAPACITIES
Input
Model
°F
20
40
50
60
70
80
BTUH (kW)
°C
11.1
22.2
27.7
33.3
38.8
44.4
GPH
LPH
GPH
LPH
GPH
LPH
GPH
LPH
GPH
LPH
GPH
LPH
1439
5448
1914
7245
2014
7627
2494
9443
2926
11077
3165
11985
719
576
2179
765
480
1816
638
411
1556
547
360
1362
478
HW 300
HW 399
HW 420
HW 520
HW 610
HW 670
300,000 (88)
399,000 (117)
420,000 (123)
520,000 (152)
610,000 (179)
660,000 (193)
2724
957
3623
1007
3813
1247
4721
1463
5538
1583
5992
2898
806
2415
671
2070
576
1811
504
3051
998
2542
831
2179
713
1907
624
3777
1170
4431
1266
4794
3148
975
2698
836
2361
731
3692
1055
3995
3165
904
2769
791
3424
2996
COMPONENT LOCATION
FIGURE 1.
6
INTRODUCTION
This design complies with the current edition of the ANSI Z21.13 IF THE BOILER HAS BEEN EXPOSED TO FLOODING, IT
low-pressure boiler standard.
MUST BE REPLACED.
Compliance under this standard implies that when the boiler LIQUEFIED PETROLEUM GAS MODELS
underwent test, the gas manifold and control assembly provided
on the boiler met safe lighting and other performance criteria.
Boilers for propane or liquefied petroleum gas (LPG) are different
from natural gas models. A natural gas boiler will not function
Detailed installation diagrams are found in this manual. These safely on LP gas and no attempt should be made to convert a
diagrams will serve to provide the installer a reference for the boiler from natural gas to LP gas.
materials and methods of piping necessary. It is essential that
all water, gas piping and wiring be installed as shown on the LP gas must be used with great caution. It is highly
diagrams. You should thoroughly read and understand this manual explosive and heavier than air. It collects first in the low
before installation and/or operation of this boiler.
areas making its odor difficult to detect at nose level.
If LP gas is present or even suspected, do not attempt
The factory warranty will be void if the boiler(s) have been to find the cause yourself. Leave the building, leaving
improperly installed or operated.
doors open to ventilate, then call your gas supplier or
service agent. Keep area clear until a service call has
In addition to these instructions, the boiler(s) shall be installed been made.
in accordance with those installation regulations in force in the
local area where the installation is to be made. These shall be At times you may not be able to smell an LP gas leak.
carefully followed in all cases. Authorities having jurisdiction One cause is odor fade, which is a loss of the chemical
should be consulted before installations are made.
odorant that gives LP gas its distinctive smell. Another
cause can be your physical condition, such as having
In the absence of local codes, the installation must comply with the a cold or diminishing sense of smell with age. For
current editions, as follows:
these reasons, the use of a propane gas detector is
recommended.
In the United States:
The National Fuel Gas Code, ANSI Z223.1/NFPA 54 and the IF YOU EXPERIENCE AN OUT OF GAS SITUATION, DO
National Electric Code, NFPA 70.
NOT TRY TO RELIGHT APPLIANCES YOURSELF. Call
your local service agent. Only trained LP professionals
should conduct the required safety checks in accordance
In Canada:
Installation Code CAN/CSAB149.1 and Canadian Electrical Code, with industry standards.
CSA C22.1.
HIGH ALTITUDE INSTALLATIONS
GROUNDING INSTRUCTIONS
This boiler must be grounded in accordance with the National Electrical
Code, Canadian Electrical Code and/or local codes. Correct wiring is
imperative for proper operation.
This boiler must be connected to a grounded metal, permanent
wiring system, or an equipment grounding conductor must be run
with the circuit conductors and connected to the equipment grounding
terminal or lead on the boiler.
CORRECT GAS
MAKE SURE THE GAS ON WHICH THE BOILER WILL
OPERATE IS THE SAME AS THAT SPECIFIED ON THE
BOILER RATING PLATE. DO NOT INSTALL THE BOILER IF
EQUIPPED FOR A DIFFERENT TYPE OF GAS — CONSULT
YOUR SUPPLIER.
PRECAUTIONS
IF THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT
OPERATE UNTIL ALL CORRECTIVE STEPS HAVE BEEN
MADE BY A QUALIFIED SERVICEMAN:
1. EXPOSURE TO FIRE.
2. IF DAMAGED.
Rated inputs are suitable up to 2000 feet (610 m) elevation.
Consult the factory for installation at altitudes over 2000
feet (610 m).
3. FIRING WITHOUT WATER.
4. SOOTING.
7
HIGH ALTITUDE INSTALLATIONS
IN CANADA
Ratings specified by manufacturers for most boilers apply for
elevations up to 2000 feet (600 m). For elevations above 2000 feet
(600 m) ratings must be reduced by a rate of 4% for each 1000 feet
(300 m) above sea level.
Acceptance of these models for use at altitudes above 2000 feet
(600 m) is based on field test of the individual installation by the
provincial/state authority having jurisdiction.
Example: If a boiler is rated at 610,000 Btu/hr. at sea level, to operate
the boiler at 5000 feet (1500 m) it must be derated by 20% (4% x 5)
to a new rating of 488,000 Btu/hr.
IN THE U.S.A.
A. O. Smith does build some models specifically for high altitude
service. Please check the rating plate before making changes.
WARNING
INSTALLATIONS ABOVE 2000 FEET REQUIRE REPLACEMENT
OF THE BURNER ORIFICES IN ACCORDANCE WITH THE
CURRENT EDITION OF THE NATIONAL FUEL GAS CODE
(ANSI Z223.1). FAILURE TO REPLACE THE ORIFICES WILL
RESULT IN IMPROPERAND INEFFICIENT OPERATION OF THE
APPLIANCE RESULTING IN THE PRODUCTION OF INCREASED
LEVELS OF CARBON MONOXIDE GAS IN EXCESS OF SAFE
LIMITS WHICH COULD RESULT IN SERIOUS PERSONAL
INJURY OR DEATH.
The input reduction is primarily achieved by reducing the size
of the main burner orifices. To do this, the main burner orifices
require replacement with orifices sized for the particular
installation elevation. When ordering, be sure to state the model
number and the altitude of the location where the boiler is being
installed.
Upon field deration of the boiler, adjustment to the gas pressure
regulator is required. See CHECKING AND ADJUSTING
THE INPUT in this manual for inlet and manifold pressure
requirements. Also, due to the input rating reduction required at
high altitudes, the output rating of the appliance is also reduced
For specific orifice requirements, please refer to the appropriate
section of the National Fuel Gas Code ANSI Z223.1.
You should contact your gas supplier for any specific changes which and should be compensated for in the sizing of the equipment
may be required in your area.
for applications.
CONTROLS AND FUNCTION
AUTO RESET HIGH LIMIT
3. Opens the pilot valve.
The high limit is a safety device wired in series with the
ignition system. Set the high limit control to approximately 100F
above the maximum designed system temperature. If the
boiler outlet water temperature should exceed the high
limit setting, the main gas valve will close but the circulator
will continue to operate. Maximum adjustable setting is 1150C
(239°F) cut-out with a 30C (50F) to 250C (450F) adjustable
differential, see Figure 2.
4. Discontinues ignition spark when the pilot flame is established.
The S-8600 control used on propane gas models provides
safety lockout if the pilot fails to ignite within the pilot flame
establishing period. The S-8600 control used on natural
gas models continues trial for ignition until pilot flame
is established.
5. After proof of pilot flame, opens then main valve.
6. On a power loss, shuts the heater down. When power is restored
it will begin a new ignition cycle.
7. On a loss of flame, shuts off main gas and starts trial for pilot ignition.
PLEASE SEE TROUBLESHOOTING SECTION FOR MORE
INFORMATION.
FIGURE 2.
INTERMITTENT IGNITION CONTROL MODULE
The Honeywell S-8600 control module contains the electronic
components of the system and also serves as a control wiring system
for the controls mounted on the heater. The control module performs
the following functions:
1. Checks for safe-start by sensing for a false flame condition on
start-up.
S-8600 INTERMITTENT IGNITION
CONTROL MODULE (IID)
2. Generates a potential of 15,000 volts for spark ignition of the
pilot burner.
FIGURE 3.
8
THERMAL BALANCER
Figure 4 shows the internal wiring of the thermal balancer. The
device may be tested after disconnecting the four leads from their
respective terminals on the unit.
1. Apply a test light to the yellow and red leads.
• The lamp should light as the contact in this circuit is normally
closed when the resistor is cool.
HIGH LIMIT SWITCH
2. Apply a light to the black and yellow leads.
FIGURE 5.
•
The lamp should not light as the contact in this circuit is normally
open when the resistor is cool.
SAFETY FLOW SWITCH
3. Remove the test light.
The safety flow switch is a safety device which must be installed at
the water outlet of the unit to prevent main burner operation in the
event of inadequate water flow through the unit.
4. Apply 120 volts to the white and red leads which power the 1900
ohm resistor. After a warming period the contacts of the thermal
balancer should operate.
An accessory package containing a safety flow switch is available
for this application.
5. Remove the test light.
This switch may be mounted in a horizontal pipe line or a vertical
pipe line with upward water flow. Do not install the switch where the
water flow is downward.
6. Apply the test light as described in steps 1 and 2.
For proper performance mount the switch in a section of pipe where
thereisastraightrunofatleast5pipediametersoneachsideoftheflow
switch (i.e. do not locate adjacent to valves, elbows, orifices, etc.).
While the resistor is still warm the lamp indications should be the
opposite as described previously.
The flow switch shall be mounted in a standard 1-1/2" x 1-1/2" x 1"
tee for a 1-1/2" pipe application. For larger pipe sizes use a reducing
tee in order to keep the switch as close to the pipe as possible. Install
the flow switch in the branch (top) opening of the reducing tee and
provide adequate paddle length in the flow stream. For example in
a 2" pipe installation use a 2" x 2" x 1" reducing tee. For 2", or 3"
pipe use paddle segments as supplied. For other pipe sizes (i.e.
1-1/4", 1-1/2" and 2-1/2") trim the paddle to the proper pipe size, see
Figure 6 on page 10. If a standard tee is used, install a face or hex
bushing in the top opening. The paddle must be adjusted or trimmed
to the size of the pipe in which it will be installed.
FIGURE 4.
MANUAL RESET HIGH LIMIT
CAUTION
Any part of the paddle must not touch the pipe or any restrictions in
the pipe. Screw the flow switch in position so the flat of the paddle
is at right angles to the flow. The arrow on the side case must point
in the direction of the flow.
This boiler is equipped with a manual reset high limit switch,
located under the small cover on the side of the jacket, see
Figure 5. This device provides positive shutdown of the
boiler in the event of boiler or system malfunction. Should the
surface temperature of the copper tubing heat exchanger
reach 250°F (120°C), the high limit switch will activate,
the gas valve will close, the pilot and main burners will be
extinguished. If the high limit switch should shut off unit, check
the following conditions:
TABLE 3 - SAFETY FLOW SWITCH
Minimum Pipe Rate
Contacts Closed
(Flow)
Contacts Open
(No Flow)
Model Number
GPM
5.8
LPM
22.0
28.4
28.4
GPM
3.7
LPM
14.0
18.9
18.9
•
•
•
No water in boiler.
HW-300
HW-399
Restricted water flow through the boiler.
7.5
5.0
Improper wiring (boiler firing without circulator
operating).
HW-420
7.5
5.0
HW-520
13.7
13.7
51.9
51.9
9.5
9.5
36.0
36.0
•
Pump failure.
HW-610/670
After correcting failure condition remove the protector switch cover
and push the reset button. The high limit switch may be reset after The safety flow switch may be field adjusted to obtain higher
the coil surface cools to 6°F (3.3°C) below the trip setting.
minimum flow rates than those shown in table 3.
9
To adjust the flow rate setting:
CAUTION
The switch is factory set at approximately the minimum flow rate, see
Table 3 on page 9. It must not be set lower than the factory setting as
this may result in the switch failing to return at 'no flow' condition.
1. Remove the flow switch cover.
2. For higher flow rate - turn the range adjusting screw clockwise.
4. Replace flow switch cover. Where units are installed in multiples,
each boiler must be individually protected by a safety flow switch.
3. For lower flow rate - turn the range adjusting screw
counterclockwise.
CAUTION
Paddle must be trimmed at the dotted arc. It must not touch the pipe or have any restriction when installed.
FIGURE 6.
SAFETY RELIEF VALVES
FROM THE SIZE OF THE VALVE OUTLET AND IT MUST NOT
CONTAIN ANY VALVES BETWEEN THE BOILER AND THE
RELIEF VALVE OR THE RELIEF VALVE AND THE DRAIN EXIT.
IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS
IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH
AREAS WHERE FREEZING CONDITIONS MIGHT OCCUR. DO
NOT THREAD OR CAP THE DRAIN LINE EXIT. RESTRICTING
OR BLOCKING A DRAIN LINE WILL DEFEAT THE PURPOSE OF
THE RELIEF VALVEAND MAY CREATEAN UNSAFE CONDITION.
INSTALLADRAIN LINE WITHADOWNWARD SLOPE SUCH THAT
IT NATURALLY DRAINS ITSELF.
Your local code authority may have other specific relief valve
requirements not covered below.
WARNING
THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID
EXCESSIVE PRESSURE OR TEMPERATURE INTO THE STEAM
RANGE WHICH MAY CAUSE SCALDING AT FIXTURES, TANK
EXPLOSION, SYSTEM OR BOILER DAMAGE.
TOAVOID SCALDING OR WATER DAMAGEADRAIN LINE MUST
BE CONNECTED TO A RELIEF VALVE TO DIRECT DISCHARGE If any safety relief valve is replaced, the replacement valve must comply
TOASAFE LOCATION. ADRAIN LINE MUST NOT BE REDUCED with the current editions of the ASME Boiler and Pressure Vessel
10
Code, Section IV or CSAB51, as applicable. Select a relief valve with TANK TEMPERATURE CONTROL
a discharge NOT less than the boiler input, and a pressure rating NOT
exceeding the working pressure of any component in the system.
The water temperature in the storage tank is controlled by the Tank
Temperature Control. The sensing element is mounted inside the
A. O. Smith supplies a 125 psi relief valve for hot water supply systems hot water storage tank.
and 50 psi relief valve for space heating application.
DANGER
AnASMEratedtemperatureandpressurereliefvalvemustbeinstalled
HOT WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHERAND LAUNDRY USE CAN CAUSE SCALD BURNS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THE TEMPERATURE AT WHICH INJURY OCCURS VARIES
WITH THE PERSON’S AGE AND TIME OF EXPOSURE. THE
SLOWER RESPONSE TIME OF CHILDREN,AGED OR DISABLED
PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW
SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW
THEIROWNBATHWATER. NEVERLEAVEACHILDORDISABLED
PERSON UNATTENDED IN A BATHTUB OR SHOWER.
on each and every water storage tank in a hot water supply system.
The storage tank temperature and pressure (T & P) relief valve must
comply with the applicable contruction provisions of the Standard
for Relief valves and Automatic Gas Shutoff Devices for Hot Water
Supply Systems, Z21.22 - CSA 4.4. The T & P valve must be of the
automatic reset type and not embody a single-use type of fusible
plug, cartridge or linkage.
The T & P relief valve should have a maximum temperature rating
of 100°C (210°F), a pressure rating NOT exceeding the lowest
rated working pressure of any system component, and a discharge
capacity exceeding the total input of the water boilers supplying
water to the storage tank.
Locate the T & P relief valve (a) in the top of the storage tank or (b)
in the side of the tank on centerline within upper 6 inches from the
top of the tank. See Figures 28 to 33, Pages 34 to 38. Tapping shall
be threaded in accordance with the latest version of the Standard for
Pipe Threads, General Purpose (inch), ANSI/ASME B.120.1.
Mark location with a class III Label. See ANSI Z21.10.1, Part 1,
Marking, See CAN/CSA B149.
The tank temperature control is adjustable from 100°F (37.7°C) to
220°F (104.4°C). It is recommended that lower water temperatures
be used to avoid the risk of scalding. It is further recommended, in all
cases, that the water temperature be set for the lowest temperature
which satisfies the user’s hot water needs. This will also provide the
most energy efficient operation of the water heater and minimize
scale formation.
THE WATER HEATER SHOULD BE LOCATED INANAREAWHERE
THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET
TEMPERATURES. SETTING THE WATER TEMPERATURE AT
120°F (49°C) WILLREDUCETHE RISK OF SCALDS. Some states or
provinces require settings at specific lower temperatures. Below you
will find listed the approximate time-to-burn relationship for normal
adult skin. Valves for reducing point-of-use temperature by mixing
cold and hot water are available. Also available are inexpensive
devices that attach to faucets to limit hot water temperatures. Contact
a licensed plumber or the local plumbing authority.
11
THERMOMETERS
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
Water Temperature
Thermometers should be obtained and field installed as shown
in the installation diagrams.
OVER: 170°F (77°C)
160°F (71°C)
150°F (65°C)
140°F (60°C)
130°F (54°C)
120°F (49°C)
Nearly Instantaneous
About 1/2 second
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
Thermometers are installed in the system as a means
of detecting a possible liming condition in the boiler.
An increase of 5°F (3°C) over the normal temperature
rise through the boiler is an indication that lime is
present. The term "temperature rise" designates
the difference between the boiler inlet and outlet water
temperature.
USE ANTI-SCALD VALVE(S) in the hot water system to reduce
the risks of scalds at points of use such as lavatories, sinks
and bathing facilities.
An increase of 5°F (3°C) above the recorded temperature
rise may signify a liming condition in the coils or heat
exc hanger. Refer to C LE A NI NG A N D FLUS HI NG
section of this manual for deliming instructions.
A change in water temperature in the storage tank lower than
the Tank Temperature Control setting will cause the sensor to
close its contacts and consequently energize the boiler.
Record temperature rise at initial start-up for future
reference.
If the Tank Temperature Control is out of calibration, replace it
with a new one; do not attempt to fix this control.
DRAIN VALVE (Not Supplied)
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL
VALVE TO THE APPLIANCE.
A drain valve must be obtained and installed on each boiler
and tank for draining purposes, see installation diagrams in
this manual.
GENERAL
REQUIRED ABILITY
CONNECTIONSWILLNOTRESULTINDAMAGETOTHEADJACENT
AREA OR TO LOWER FLOORS OF THE STRUCTURE.
Installation or service of this boiler requires ability equivalent to that
of a licensed tradesman in the field involved. Plumbing, air supply, WHEN SUCH LOCATIONS CANNOT BE AVOIDED, A METAL
venting, gas supply and electrical work are required.
DRAIN PAN SHOULD BE INSTALLED UNDER THE BOILER. Such
pans should be fabricated with sides at least 60mm (2-1/2") deep,
with length and width at least 50mm (2") greater than the diameter
of the boiler and must be piped to an adequate drain. The pan must
not restrict combustion air flow.
LOCATION
When installing the boiler, consideration must be given to proper
location. Location selected should be as close to the stack or chimney
as practicable with adequate air supply and as centralized with the
piping system as possible. This location should also be such that the
WARNING
KEEPINGBOILERAREACLEARANDFREEFROMCOMBUSTIBLE
gas ignition system components are protected from water (dripping, MATERIALS, GASOLINEAND OTHER FLAMMABLE VAPORSAND
LIQUIDS.
spraying, etc.) during appliance operation and service (circulator
replacement, control replacement, etc.).
WARNING
THE BOILER MUST NOT BE INSTALLED ON CARPETING.
THERE IS A RISK IN USING FUEL BURNING APPLIANCES
SUCH AS BOILERS IN ROOMS OR AREAS WHERE GASOLINE,
OTHER FLAMMABLE LIQUIDS OR ENGINE DRIVEN EQUIPMENT
OR VEHICLES ARE STORED, OPERATED OR REPAIRED.
FLAMMABLE VAPORS ARE HEAVY AND TRAVEL ALONG THE
FLOORANDMAYBEIGNITEDBYTHEIGNITERORMAINBURNER
FLAMES CAUSING FIRE OR EXPLOSION. SOME LOCALCODES
THE BOILER SHOULD NOT BE LOCATED IN AN AREA WHERE
IT WILL BE SUBJECT TO FREEZING.
LOCATE IT NEAR A FLOOR DRAIN. THE BOILER SHOULD BE
LOCATED INANAREAWHERE LEAKAGE FROMTHE BOILER OR
12
PERMIT OPERATION OF GAS APPLIANCES IF INSTALLED If the confined space is within a building of tight construction,
18 INCHES OR MORE ABOVE THE FLOOR. THIS MAY
REDUCE THE RISK IF LOCATION IN SUCH AN AREA CANNOT
BE AVOIDED.
air for combustion, ventilation, and draft hood dilution must be
obtained from outdoors. When directly communicating with the
outdoors or communicating with the outdoors through vertical
ducts, two permanent openings, located in the above manner,
shall be provided. Each opening shall have a free area of not
less than one square inch per 4000 Btuh of the total input of
all appliances in the enclosure. If horizontal ducts are used,
each opening shall have a free area of not less than one
square inch per 2000 Btuh of the total input of all appliances
in the enclosure.
WARNING
FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY
OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST
NEVER BE PLACED ON OR ADJACENT TO THE BOILER.
OPEN CONTAINERS OF FLAMMABLE MATERIAL MUST
NOT BE STORED OR USED IN THE SAME ROOM WITH
THE BOILER.
(b) Canadian Installations
A hot water boiler installed above radiation level or as required
by the authority having jurisdiction, must be provided with a low
water cutoff device at the time of boiler installation.
Ventilation of the space occupied by the boiler(s) shall be
provided by an opening for ventilation air at the highest practical
point communicating with outdoors. The total cross-sectional
area shall be at least 10% of the area of the combustion air
opening but in no case shall the cross-sectional area be less
than 10 square inches (6500 mm2).
AIR REQUIREMENTS
Provisions for combustion and ventilation air in accordance
with the current edition of the National Fuel Gas
Code, ANSI Z223.1, CAN/CSA B149.1, Installation
C o d e s , o r a p p l i c a b l e p r o v i s i o n s o f t h e l o c a l
building codes.
In additional to the above, there shall be permanent air supply
opening(s) having a cross-sectional area of not less than 1
square inch per 7,000 BTUH (310 mm2/KW) up to and including
1,000,000 BTUH plus 1 square inch per 14,000 BTU in excess
of 1,000,000 BTUH. This opening(s) shall be located at, or
ducted to, a point neither more than 18" (450 mm) nor less
than 6 inches (150 mm) above the floor level.
Provisions for vent, bleed and gas relief lines (when applicable).
Keep appliance area free of combustible or flammable liquids.
Do not obstruct the flow of combustion or ventilating air.
Where power vented equipment is used in the same room as the
boiler, sufficient air openings must be supplied.
WARNING
FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR
COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY
OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION
PRODUCTS RESULTING IN AIR CONTAMINATION THAT
MAY BE HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN
WILL RESULT IN A YELLOW, LUMINOUS BURNER FLAME,
CAUSING CARBONING OR SOOTING OF THE COMBUSTION
CHAMBER, BURNERS AND FLUE TUBES AND CREATES A
RISK OF ASPHYXIATION.
UNDERSIZED OPENINGS MAY RESULT IN INSUFFICIENT AIR
FOR COMBUSTION.
WHERE AN EXHAUST FAN IS INSTALLED IN THE SAME ROOM
WITH A BOILER, SUFFICIENT OPENINGS FOR AIR MUST BE
PROVIDED IN THE WALLS.
UNDERSIZED OPENINGS WILL CAUSE AIR TO BE DRAWN
INTO THE ROOM THROUGH THE CHIMNEY, CAUSING POOR
COMBUSTION. SOOTING MAY RESULT WITH AN INCREASED
RISK O F ASPHYXIATION.
Unconfined Space
In buildings of conventional frame, brick or stone construction,
unconfined spaces may provide adequate air for combustion, and
draft hood dilution.
CHEMICAL VAPOR CORROSION
WARNING
If the unconfined space is within a building of tight construction
(buildings using the following construction: weather stripping,
heavy insulation, caulking, vapor barrier, etc.) air for combustion,
ventilation, and draft hood dilution must be obtained from
outdoors or spaces freely communicating with the outdoors. The
installation instructions for confined spaces in tightly constructed
buildings must be followed to ensure adequate air supply.
CORROSION OF THE FLUEWAYS AND VENT SYSTEM
MAY OCCUR IF AIR FOR COMBUSTION CONTAINS
C E R TA I N C H E M I C A L VA P O R S W H I C H B R E A K
DOWN INTO ACIDS AT HIGH TEMPERATURE. SUCH
CORROSION MAY RESULT IN FAILURE AND RISK OF
ASPHYXIATION.
Water boiler corrosion and component failure can be caused
by the heating and breakdown of airborne chemical vapors.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium
and sodium chloride, waxes, and process chemicals are typical
compounds which are corrosive. These materials are corrosive
at very low concentration levels with little or no odor to reveal
their presence. Products of this sort must not be stored near
the boiler. Also, air which is brought in contact with the water
boiler should not contain any of these chemicals. If necessary,
uncontaminated air should be obtained from remote or outside
sources.
Confined Space
(a) U. S. Installations
Whendrawingcombustionanddilutionairfrominsideaconventionally
constructed building to a confined space, such a space shall be
provided with two permanent openings, ONE WITHIN 12 INCHES
OF THE ENCLOSURE TOPAND ONE WITHIN 12 INCHES OF THE
ENCLOSURE BOTTOM. Each opening shall have a free area of at
least one square inch per 1000 Btuh of the total input of all appliances
in the enclosure, but not less than 100 square inches.
13
INSTALLATION CLEARANCES
Sufficient area should be provided at the front and rear of the unit
for proper servicing. Clearances of 24 inches (609.4mm) in the
rear and 48 inches (1,219mm) in the front are required by code.
In a utility room installation, the door shall be wide enough to allow
the boiler to enter or to permit the replacement of another appliance
such as a water heater.
These boilers are approved for installation on combustible flooring
in an alcove with minimum clearance to combustibles of:
TABLE 4
LEVELING
HW
300
HW
399
HW
420
HW
520
HW
610 & 670
Each unit should be checked after installation to be certain that it is level.
TOP
SIDES
REAR
VENT
28" (711.2) 32" (812.8) 24" (609.6) 24" (609.6) 24" (609.6)
6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6)
6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6)
6" (152.4) 6" (152.4) 6" (152.4) 6" (152.4) 6" (152.4)
If the unit is not level, insert metal shims under the legs of the unit
to correct this condition.
SYSTEM CONNECTIONS
The system installation must conform to these instructions
and to the requirements of the local code authority having
Two inch (50.8mm) clearance is allowable from combustible jurisdiction. Good practice requires that all heavy piping be
construction for hot water pipes.
supported.
A TYPICAL BOILER INSTALLATION
FIGURE 7.
VENTING
current edition of the National Fuel Gas Code, ANSI Z223.1, or
CAN/CSA B149.1, Installation Codes, or applicable provisions
of the local building codes.
VENTING THE BOILER - STANDARD VENTING
WARNING
THE INSTRUCTIONS IN THIS SECTION ON VENTING
THE BOILER MUST BE FOLLOWED TO AVOID CHOKED
COMBUSTION OR RECIRCULATION OF FLUE GASES.
SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE
AND ASPHYXIATION.
Vent connectors serving appliances vented by natural draft shall
not be connected into any portion of mechanical draft systems
operating under positive pressure.
The minimum distance from adjacent public walkways, adjacent
buildings, openable windows and building openings shall not be
less than those values specified in the National Fuel Gas Code,
ANSI Z223.1 and/or CAN/CSA B149.1, Installation Codes;
TYPE B VENTING MAY BE USED WITH THESE BOILERS. ALL
LOCAL UTILITY REGULATIONS ON VENTING SHOULD BE
FOLLOWED.
For boilers for connection to gas vents or chimneys, vent sizing, Stack or chimney must be a minimum height of 12" (305mm)
installation and termination shall be in accordance with the
above the annual snow fall to prevent blockage.
14
Building materials must not come in contact with combustion Vent connectors serving appliances vented by natural draft shall not
products from stack or chimney, due to the degradating properties be connected into any portion of mechanical draft systems operating
of flue products.
under positive pressure.
Flue products must have a minimum clearance of 4 feet (1.22m) 3. CONNECTING BOILER TO A COMMON VENT
horizontally from, and in no case above or below, unless a 4-foot
(1.22m) horizontal distance is maintained, from electric meters, gas Do not connect the boiler to a common vent or chimney with solid
meters, regulators and relief equipment.
fuel burning equipment. This practice is prohibited by many local
building codes as is the practice of venting gas fired equipment to
CAN/CSA B149.1, Installation Code specifies a 6 foot horizontal the duct work of ventilation systems.
vent terminal clearance to gas and electric meters and relief devices
(this clearance is specified as 4 feet in the U.S. under the National Where a separate vent connection is not available and the vent pipe
Fuel Gas Code,ANSI/Z223.1). Therefore instruction, which specifies from the boiler must be connected to a common vent with oil burning
compliancewiththe4footclearance,asappliesintheU.S.only,andthe equipment, the vent pipe should enter the common vent or chimney
CAN/CSA B149.1 Installation Code applies in Canada.
at a point ABOVE the flue pipe from the oil fired unit.
1. DRAFT HOOD
Where two or more appliances vent into a common vent connector
or manifold, the area of the common vent or vent connector should
at least equal the area of the largest vent connector plus 50% of the
areas of the additional draft hood outlets.
The draft hood furnished with this boiler must be installed without
alteration. Provision must be made if the boiler is installed in confined
space or a small boiler room to accommodate draft hood spillage and
avoid risks described above. The upper air opening called for in the
AIR REQUIREMENTS section of this manual is for this purpose.
When removing a boiler from a system with a common vent, use
the following steps:
2. VENT CONNECTION
Be sure the other appliances connected to the common vent are
not in operation.
Size and install proper size vent pipe. Do not reduce pipe size to
less than that of the draft hood outlet.
Seal any unused openings in the common venting system.
Horizontal runs of vent pipe shall be securely supported by
adequately placed (approximately every 4 feet or 1 meter), non-
combustible hangers and/or slip joints suitable for the weight
and design of the materials employed to prevent sagging and
to maintain a minimum upward slope of 1/4" (21mm/m) per foot
from the boiler to the vent terminals, see Figure 8. Dampers or
other obstructions must not be installed in the vent. Be sure
that the vent pipe does not extend beyond the inside wall of
the chimney.
Visually inspect the venting system for proper size and horizontal pitch
and determine there is no blockage or restriction, leakage, corrosion
and other deficiencies which could cause an unsafe condition.
WARNING
Ensure sufficient supply and ventilation air. Under no circumstances
should the equipment room where the boiler is installed ever be under
negative pressure. Insufficient air supply can interfere with combustion
and ventilation of this boiler resulting in unsafe conditions.
Insofar as is practical, close all building doors and windows and
all doors between the space in which the appliances remaining
connected to the common venting system are located and other
spaces of the building. Turn on clothes dryers and any appliance not
connected to the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they will operate
at maximum speed. Close fireplace dampers.
Place in operation the appliance being inspected. Follow the
lighting instructions. Adjust thermostat so appliance will operate
continuously.
Test for spillage at the draft hood relief opening after five minutes of
main burner operation. Use the flame of a match or candle.
VENT PIPE INSTALLATION
FIGURE 8.
After it has been determined that each appliance remaining connected
to the common venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, fireplace dampers and
any other gas burning appliance to their previous conditions of use.
Where a continuous or intermittent back draft is found to exist the
cause must be determined and corrected. A special vent cap may
be required. If the back draft cannot be corrected by the normal
methods or if a suitable draft cannot be obtained, a blower type
flue gas exhauster may be employed to ensure proper venting and
correct combustion if permitted by local codes.
Any improper operation of the common venting system should be
corrected so the installation conforms with the current edition of
CAN/CSA B149.1 (current edition). When resizing any portion of
the common venting system, the common venting system should
WARNING
FAILURE TO CORRECT BACK DRAFTS WILL CAUSE AIR be resized to approach the minimum size as determined using the
CONTAMINATION AND UNSAFE CONDITIONS.
appropriate tables in CAN/CSA B149.1.
15
4. MULTIPLE VENT TABLE
1. Turn off the electrical power (main manual gas shutoff and pilot
valves, if applicable).
Table 5 on page 17 has been compiled to show the material
sizes in a Type B doublewall combined vent system. Refer to
CAN/CSAB149 .1 (current edition), or theASHRAE 1983 Equipment
Volume for further information.
Allow boiler parts and vent to cool before disassembly.
2. Remove the boiler draft diverter and vent pipe running to the chimney.
•
Check parts and chimney for obstructions and clean as necessary.
A combined vent system is one in which two or more boilers at one
level are attached to a common vent.
3. Remove burner from boiler and other metal parts as required to
clean and vacuum the heat exchanger and combustion coils.
In order to use table 5, the connector rise and total vent height must
be known. Connector rise is vertical distance from the draft hood outlet
to the point where the manifold connection is made. Total vent height
is the least vertical distance from a draft hood outlet to the top of the
vent. Local codes or utility requirements often govern termination
height. ULC listed doublewall gas vents, up through 24" (610mm)
diameter, can be installed in heated and unheated areas and can
pass through floors, ceilings, partitions, walls and roofs, provided
the required one inch clearance is observed. These vents should be
installed in accordance with CAN/CSA B149.1 (current edition).
•
Refer to parts list supplied with this manual for disassembly aid.
4. Reinstall the parts removed in steps 2 and 3.
•
Besuretheventpipehasaminimumupwardpitchofonequarter
inch per foot of length (21mm/m) and is sealed as necessary.
5. Restore electrical power and gas supply to boiler.
•
Place boiler in operation by following the lighting instructions
in this manual.
•
Check for gas leaks and proper boiler and vent operation.
EXAMPLE SHOWING USE OF THE HW-610 COMBINED VENT
SIZING TABLE
VENTING - SIDEWALL (OPTIONAL) POWER VENT SYSTEM
If you are installing the optional Power Vent Kit, refer to your
HW Power Vent Kit Installation Instructions for proper wiring
and installation procedures. Contact your local A. O. Smith
representative for details.
VENTING SYSTEM
HAVE VENTING SYSTEM CHECKED EVERY SIX MONTHS FOR
OBSTRUCTIONS AND/OR DETERIORATION IN VENT PIPING.
A. Insofar as is practical, close all doors, windows and air inlets to
the building. Turn on all exhaust fans (range hood, bathroom
exhaust, etc.) so they will operate at their maximum speed.
Close fireplace dampers.
B. After allowing appliance to operate for five minutes, test for
spillage at the draft hood relief opening.
C. “CHECKING THE DRAFT. Operate vent connected gas utilization
equipmentforseveralminutesandchecktoseethatthecombustion
products are going up the chimney or gas vent properly by passing
a lighted match or taper around the edge of the relief opening of
the draft hood. If the chimney or gas vent is drawing properly, the
match flame will be drawn into the draft hood. If not, the combustion
products will tend to extinguish this flame. IF THE COMBUSTION
PRODUCTS ARE ESCAPING FROM THE RELIEF OPENING OF
THE DRAFTHOOD, DO NOTOPERATETHE EQUIPMENTUNTIL
PROPERADJUSTMENT OR REPAIRSARE MADE TO PROVIDE
ADEQUATE DRAFT THROUGH THE CHIMNEY OR GAS VENT.”
FIGURE 9.
VENTING MAINTENANCE - STANDARD VENTING
It is recommended that the heating surfaces and vent piping of
the appliance be checked every six months for dust, deterioration
and carbon deposits. Remove all soot or other obstructions from
chimney and flue which will retard free draft. Replace any damaged
or deteriorated parts of the venting system.
D. Next, turn on all other fuel burning appliances within the same
room so they will operate at their full input.
Qualified servicers should follow this procedure when the boiler’s
external heating surfaces and vent pipe need cleaning.
Repeat step C above, checking the draft on each appliance.
CAUTION
DO NOT USE A NYLON BRUSH OR OTHER STATIC CREATING
MATERIAL TO CLEAN DUST AND CARBON DEPOSITS FROM
HEATING SURFACES AND VENT.
SUCH DEPOSITS ARE FLAMMABLE AND MAY BE IGNITED BY
STATIC ELECTRICITY. USE A METAL BRUSH TO MINIMIZE THE
DANGER OF EXPLOSION.
FIGURE 10.
16
TABLE 5, COMBINED VENT SIZING TABLES
MODEL HW-610 BOILER
MODEL HW-300 BOILER
Input: 610,000 Btuh
Draft Hood Outlet 12"
Input: 300,000 Btuh
Draft Hood Outlet 8"
Required Connector or Smoke Pipe Diameter
Required Connector or Smoke Pipe Diameter
Total Vent Height (Measured in Feet Above Draft Hood)
Total Vent Height (Measured in Feet Above Draft Hood)
Connector
Rise in Feet
Connector
Rise in Feet
10
15
20
30
40
50
60
80
100
10
15
20
30
40
50
60
80
100
Connector Diameter (in Inches)
Connector Diameter (in Inches)
1
2
3
16
14
14
12
14
14
14
12
14
14
12
12
14
14
12
12
14
14
12
12
14
12
12
12
14
12
12
12
14
12
12
12
14
12
12
12
1
2
3
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
4 or more
4 or more
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
Total Input
Btuh x 1000
Total Input
Btuh x 1000
10
100
10
100
2
3
4
5
6
7
8
9
1220
1830
2440
3050
3660
4270
4880
5490
6100
6710
7320
18
22
26
28
32
34
36
38
40
42
44
18
20
24
26
28
32
34
36
38
38
42
16
20
22
26
28
30
32
34
36
38
38
16
18
20
24
26
28
30
30
32
34
36
14
18
20
22
24
26
28
30
30
32
34
14
16
18
22
24
24
26
28
30
30
32
14
16
18
20
22
24
26
28
28
28
32
14
16
18
20
22
22
24
26
26
28
30
14
14
16
18
20
22
24
24
26
26
28
2
3
4
600
900
1200
14
16
18
12
14
16
12
14
16
12
14
14
10
12
14
10
12
14
10
12
14
10
12
12
10
12
12
MODEL HW-399 BOILER
Draft Hood Outlet 10"
Required Connector or Smoke Pipe Diameter
Input: 399,000 Btuh
10
11
12
Total Vent Height (Measured in Feet Above Draft Hood)
Connector
Rise in Feet
10
15
20
30
40
50
60
80
100
Connector Diameter (in Inches)
1
2
3
12
12
12
10
12
12
10
10
12
12
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
MODEL HW-670 BOILER
Input: 660,000 or 670,000 Btuh
Required Connector or Smoke Pipe Diameter
Draft Hood Outlet 12"
4 or more
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
Total Input
Btuh x 1000
Total Vent Height (Measured in Feet Above Draft Hood)
10
100
Connector
Rise in Feet
10
15
20
30
40
50
60
80
100
Connector Diameter (in Inches)
2
3
4
798
1197
1596
14
18
20
14
16
20
14
16
18
12
14
16
12
14
16
12
14
16
12
14
14
12
14
14
12
12
14
1
2
3
16
14
14
12
14
14
14
12
14
14
12
12
14
14
12
12
14
14
12
12
14
12
12
12
14
12
12
12
14
12
12
12
14
12
12
12
4 or more
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
MODEL HW-420 BOILER
Total Input
Btuh x 1000
10
100
Input: 420,000 Btuh
Draft Hood Outlet 10"
Required Connector or Smoke Pipe Diameter
2
3
4
5
6
7
8
9
1220
1830
2440
3050
3660
4270
4880
5490
6100
6710
7320
18
22
26
28
32
34
36
38
40
42
46
18
20
24
26
28
32
34
36
38
38
44
16
20
22
26
28
30
32
34
36
38
40
16
18
20
24
26
28
30
30
32
34
38
14
18
20
22
24
26
28
30
30
32
36
14
16
18
22
24
24
26
28
30
30
34
14
16
18
20
22
24
26
28
28
28
34
14
16
18
20
22
22
24
26
26
28
32
14
14
16
18
20
22
24
24
26
26
30
Total Vent Height (Measured in Feet Above Draft Hood)
Connector
Rise in Feet
10
15
20
30
40
50
60
80
100
Connector Diameter (in Inches)
1
2
3
12
12
12
10
12
12
10
10
12
12
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
12
10
10
10
4 or more
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
Total Input
Btuh x 1000
10
11
12
10
100
2
3
4
840
1260
1680
14
18
20
14
16
20
14
16
18
12
14
16
12
14
16
12
14
16
12
14
14
12
14
14
12
12
14
Known:
(5) model HW-610 boilers. (See illustration).
Connector rise - 2' (Note 1' is minimum). Total vent
height 30'.
MODEL HW-520 BOILER
Input: 520,000 Btuh
Draft Hood Outlet 10"
Required Connector or Smoke Pipe Diameter
Total Vent Height (Measured in Feet Above Draft Hood)
Connector
Rise in Feet
10
15
20
30
40
50
60
80
100
Connector Diameter (in Inches)
Problem:
Determine diameter of connector, manifold and
common vent.
1
2
3
14
12
12
12
14
12
12
12
14
12
12
12
12
12
12
12
12
12
10
10
12
12
10
10
12
12
10
10
12
12
10
10
12
12
10
10
4 or more
Procedure: Enter the top of the HW-610 table (total vent height)
at 30' and the side at 2' (connector rise). A 14"
connector diameter is indicated for each connector
rise.
Total Vent Height (Measured in Feet Above Draft Hood)
15 20 30 40 50 60 80
Manifold and Common Vent Diameter (in Inches)
Number
if Units
Combined
Total Input
Btuh x 1000
10
100
2
3
4
5
6
7
8
1040
1560
2080
2600
3120
3640
4160
16
20
22
26
28
30
32
16
18
22
24
26
28
30
14
18
20
22
24
26
28
14
16
18
20
22
24
26
14
16
18
20
22
24
24
14
14
18
18
20
22
24
12
14
16
18
20
22
22
12
14
16
18
18
20
22
12
14
14
18
18
20
20
To determine the manifold and common vent size, enter table on this
page (total vent height) at 30 and the side at 5 boilers. A manifold
diameter of 24" (610 mm) is indicated.
17
SYSTEM INSTALLATIONS
1. CONVENTIONAL INSTALLATIONS
All modern hydronic type boilers are exceptionally fast heating units.
The low water volumes in relation to firing rates require special
attention to water flow rates for smooth, efficient operation. These
considerations for the A. O. Smith copper heat exchanger boilers
are covered below.
Conventional 200F (100C) drop in systems for a fully loaded boiler
will maintain the following approximate flow rates:
MODELS
GPM (LPM)
HW-300
HW-399
HW-420
HW-520
HW-610/670
23 (87)
30 (114)
35 (132)
39 (148)
46 (175)
Figure 7 on page 14 shows a typical installation of the boiler with pipe
sizing and circulator selected by the installer to provide adequate
water flow whenever the boiler is firing.
ONE BOILER INSTALLED
INDEPENDENT OF THE PRIMARY SYSTEM
FIGURE 11.
In a system with several large zones of which any might be smaller
than approximately 1/3 of the system should include a hydronic
balancer as shown in Figure 7. The balancer connects between
the system supply and the return line before the circulator inlet.
Adjustment of the balancing cock should permit adequate boiler flow
rate when only the smallest zone is in operation.
Total heating requirements for the building can be supplied by a
series of boiler loops all connecting to a common pipe joining the
system supply and return mains. The supply and return branches of
each boiler loop must join the common pipe only a short nipple length
apart. The different sets of branches should be installed reasonably
close together, but not necessarily to the short nipple length as
required for the supply and return of each set. These branches may
be made with tees or with welded connections.
Attention should be given to balancing inputs and water flow rates
where wide variations of system flow rates can occur.
The installer is reminded that the total boiler flow rates need not
match the system flow rate.
Therecommendedminimumflowratesthatwillresultinapproximately
500F (300C) temperature rise across the boiler are as follows:
TABLE 6.
PUMP AND PIPE SIZING DATA
MODELS
GPM (LPM)
(PIPING FROM TEES IN MAIN TO BOILER BRANCHES)
HW-300
HW-399
HW-420
HW-520
HW-610
HW-670
9 (34)
12 (45)
14 (53)
16 (61)
18 (69)
20 (76)
Model
Temp. Rise °F (°C) G.P.M. *Pump Size Pipe Size
20 (10)
30 (15)
30 (15)
40 (20)
20 (10)
35 (15)
40 (20)
40 (20)
20 (10)
35 (15)
40 (20)
40 (20)
20 (10)
20 (10)
35 (17)
40 (20)
20 (10)
30 (15)
35 (17)
40 (20)
23
15
15
11
30
20
15
15
32
21
16
16
39
26
23
20
51
34
29
25
1-1/2" PR
150
2"
1-1/2"
1-1/4"
1"
HW-300
125
100
60-13
1-1/2" HV
150
If system flow rate is unknown, or if zoning creates extreme variations
in flow rates, the boiler should be installed as shown in Figure 11 on
this page for A. O. Smith LINEAR-TEMP installations.
2"
1-1/2"
1-1/2"
1-1/4"
2"
1-1/2"
1-1/2"
1-1/4"
2-1/2"
2"
1-1/2"
1-1/2"
3"
2-1/2"
2"
HW-399
HW-420
125
2. LINEAR-TEMP INSTALLATIONS
60-13
1-1/2" HV
150
A. New Installations
125
A. O. Smith LINEAR-TEMP systems have been designed to provide
efficient, trouble-free operation of the boiler sizes covered in this
manual with any of the following conditions:
2-1/2"
1-1/2" HV
1-1/2" HV
150
60-13
2-1/2"
2"
HW-520
a. Unknown system flow rate
b. Varying flow rate as with zoned systems
c. Multiple boiler installations
HW-610/670
1-1/2" HV
1-1/2"
Figure 11 on this page shows piping and accessory arrangement
for a boiler pumped independent of the primary system mains. Pipe
sizing and boiler loop pump selection data are shown in Table 6 for
several different temperature rises across the boilers.
NOTE: Pipe loop sizes and pump selections based on
50 equivalent feet of pipe and fittings.
*All pump sizes listed are B & G model numbers.
18
NO.
SUGGESTED ITEMS FOR INSTALLATION
Short pipe nipple and pair of boiler loop tees in piping
1
between system supply and return. One set per each group
of boilers.
2
3
4
5
6
Boiler pipe loop. See piping sizing data.
Boiler circulator. See pump sizing data.
Thermometer.
Theraltimeter.
Plug cock to control flow rate.
Safety flow switches. For interlock with other systems or
instead of low water cutoff.
7
8
Relief valve.
With one -300, -399 or -420 item 9 is - sensing element of
remote control.
With a group of -300's, -399's or -420's, item 9 is - for 1st
boiler, the sensing element as above. For additional boilers,
install a 2nd limit control if required by local codes. With
any -520, -610 or 670 boilers, install 2nd limit control here if
required by local code.
BOILER INLET - OUTLET SIZES
HW-300 - 1-1/4", HW-399 - 1-1/2", HW-420 - 1-1/2",
HW-520 & HW-610 - 2".
HW-300 - 1-1/4", HW-399 - 1-1/2", HW-420 - 1-1/2", HW-520
& HW-670 - 2".
SCHEMATIC OF THE LINEAR-TEMP® SYSTEM
9
FIGURE 12.
Supply and return headers of the old system should be connected
to the boiler loop with a pair of tees set close together. The boiler
loop pump and the boiler(s) should be wired to operate only when
any of the system pumps are in operation. The number of zone
pumps that may be in operation at any particular time will take
their required flow rate out from the first tee in the boiler piping.
This water will be circulated through the proper branches from
the supply header to the zones calling for heat. The water will be
brought back to the return header and then into the second tee in
the boiler pipe loop. There will be no conflict between the boiler
pump and the zone pumps when the two tees in the boiler loop
are placed close together.
10
10
MINIMUM BRANCH SIZES TO BOILERS
HW-300 - 1-1/4"
HW-520, 610 (Single boiler
11 HW-399 - 1-1/2"
per pump) 2"
HW-420 - 1-1/2"
HW-300 - 1-1/4"
11 HW-399 - 1-1/2"
HW-520, 670 (Single boiler
per pump) 2"
Normal use of flow control valves is required to prevent cross
circulation of zones as with any multiple pump system. Flow control
is not required on boiler circuit.
HW-420 - 1-1/2"
Flow control valve. Required only if flow rate of system
12 primary is excessive for size of boiler branch tees or if chilled
water main is above boilers.
13 System supply temperature thermometer.
Attention should be given to balancing gas inputs and water flow
rates. Large systems with multiple boilers should include main water
temperature control (with or without outdoor reset) to stage the boilers
on and off in relation to the load on the system.
Boiler headers for three (3) boilers can be larger than pipe
loop, if desired, to aid in balancing.
14
3. WATER SUPPLY LINE
These boilers can be used ONLY in a forced circulation hot water
The system flow rate is selected to give the desired system heating system. Since most forced circulation systems will be of
the closed type, install the water supply line as shown on piping
diagrams, Figure 7 to 11 on pages 14 and 18.
temperature drop - depending on the design criteria.
The boiler generator flow rates, on the other hand, should be
selected to give the temperature rise through the generator that is
both economical and offers the best generator efficiency.
Fast filling of large pipe, old radiator installations and pressure
purging of series loop systems (where high pressures are not
available) requires bypassing of the pressure reducing valve.
Generally, pressure purging is not possible with a well pump system.
High point air venting is essential.
The boiler temperature rise is normally between 100C and 200C (200F
and 400F). The system temperature that will be introduced to the
boiler (inlet temperature) plus the selected boiler temperature rise
selected from PUMP AND PIPE SIZING DATA should not exceed
the high limit control setting of 1150C (2400F).
If the system is of the open type, a pressure reducing valve
will not be required as the water supply to the system will be
controlled by a manually operated valve. An overhead surge
tank is required.
There should be a relation of the minimum system load to the size
boiler selected as the first firing or base boiler. This will stabilize
operation during minimum load periods.
4. EXPANSION TANK
CAUTION
A closed system will exist if a check valve (without bypass), pressure
reducing valve (without bypass), or a water meter (without bypass) is
installed in the cold water line between the water heater and street
main (or well).
B. Commercial Boiler Replacements
Application of LINEAR-TEMP® to a commercial boiler replacement
with an old multiple pump installation is an excellent way to modernize
the system. The A. O. Smith boiler(s) should be installed on a pipe
loop with a separate circulating pump selected from PUMP AND
PIPE SIZING DATA TABLE.
Excessive pressure may develop causing premature tank failure or
intermittent relief valve operation. This is not a warranty failure. An
expansion tank or a similar device may be required in the inlet supply
line between the appliance and the meter or valve to compensate for
the thermal expansion of water under supply pressure, see Figure 7
on page 14.
Figure 12 shows a line drawing of how the system headers should be
connected to the pipe loop installed with the replacement boiler(s).
Make-up water connections and accessories are not shown.
An air separator as shown in the piping diagrams is recommended
especially for modern commercial hydronic systems.
19
5. VENT VALVES
If the boiler is connected to chilled water piping or its heating coils
are exposed to refrigerated air, the boiler piping system must be
equipped with flow valves or other automatic means to prevent gravity
circulation through the boiler during the cooling cycle.
It is recommended that automatic, loose key or screwdriver type
vent valves be installed at each convector or radiator.
6. MANIFOLD HEADERS
8. CIRCULATING PUMP
Split systems with individual supply and return lines from the boiler
room should normally have this piping connected to supply and
return manifold headers near the boiler. To achieve good water
distribution with maximum pressure drop for several circuits,
CONSTANT CIRCULATING PUMP OPERATION OF THE BOILER
VOIDS THE WARRANTY. Constant water flow through the unit
manifolds of at least 2-1/2" (64mm) diameter are suggested on will “wash” away the copper’s natural protective coating. This is
HW-399, HW-420, HW-520, HW-610 and HW-670 units. HW-300
units should have 1-1/2" (38mm) diameter manifolds.
called velocity erosion. This erosion is not as great a problem when
intermittent circulating operation is used per the recommended
installation procedure. Constant circulation of water through the
building’s system main is permissible as long as the water does not
constantly flow through the boiler. Only all bronze or stainless steel
circulators are to be used with the unit when it is installed in HOT
WATER SUPPLY SYSTEMS.
The circuits should be spaced on the header at a minimum of
3" (76mm) center to center. Install a balancing cock in each return line.
Manifold headers are recommended for split systems with or without
zone valves and also those installations with zone circulators. If the
system is to be split at remote points, good practice requires special
attention be given to main pipe sizing to allow balancing of water flow.
The boiler piping system of a hot water boiler connected to heating
coils located in air handling units where they may be exposed to
refrigerated air circulation must be equipped with flow control valves or
other automatic means to prevent gravity circulation of the boiler water
during the cooling cycle.
7. COOLING PIPING
When the boiler is used in conjunction with a refrigeration system it
must be installed so that the chilled medium is piped in parallel with
the boiler with appropriate valves to prevent the chilled medium from
entering the boiler, see Figure 13.
A TYPICAL CIRCULATING PUMP
Water temperature in the heating system must be reduced to less
than 1000F (38°C) before cooling system is started, or damage to
the chiller unit may occur.
FIGURE 14.
Although each circulator that requires oiling is oiled and operated by
the manufacturer, ITMUSTBE OILEDAGAIN BEFORE OPERATED.
Oil the three oil cups (2 on the motor, 1 on the pump) as instructed
on the oil tube supplied with the unit, see Figure 14 on this page.
Thereafter, during the heating season, lubricate the three oil cups at
least once every four months. Combination heating-cooling systems
should be lubricated every four months year ‘round.
Use 2 or 3 teaspoonsful in bearing oil cups or 12 drops in the motor
oil cups, see Figure 14 on this page. Use No. 20 non-detergent
motor oil.
SCHEMATIC SHOWING PROPER PIPING ISOLATION
OF THE BOILER FROM THE CHILLER
FIGURE 13.
Follow the same oiling procedure if a replacement circulator is
installed into the system.
GAS CONNECTIONS
WHEN LOCAL CODES REQUIRE A MAIN MANUAL SHUTOFF
VALVE OUTSIDE THE BOILER JACKET, A SUITABLE MAIN
MANUALSHUTOFF VALVE MUST BE INSTALLED INALOCATION
COMPLYING WITH THOSE CODES.
WARNING
THIS BOILER IS NOT INTENDED TO OPERATE AT GAS SUPPLY
PRESSURE OTHER THAN SHOWN ON THE RATING PLATE.
EXPOSURE TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE
DAMAGE TO GAS VALVES WHICH CAN RESULT IN FIRE OR
EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH AS
THROUGH IMPROPER TESTING OF GAS LINES OR EMERGENCY
MALFUNCTIONOFTHESUPPLYSYSTEM,THEGASVALVESMUSTBE
CHECKEDFORSAFEOPERATION. MAKESURETHATTHEOUTSIDE
VENTS ON THE SUPPLY REGULATORS AND THE SAFETY VENT
VALVESAREPROTECTEDAGAINSTBLOCKAGE. THESEAREPARTS
OFTHEGASSUPPLYSYSTEM, NOTTHEBOILER. VENTBLOCKAGE
MAY OCCUR DURING ICE BUILD-UP OR SNOW STORMS.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE
CERTIFIED FOR GAS SERVICE.
BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS
PIPE IS CLEAN ON THE INSIDE.
20
Use table 7, or CAN/CSA B149.1 (current edition) to
size iron pipe or equivalent gas supply line. Table 7
is based on a pressure drop of 0.3 inches of water and
a specific gravity of 0.60 approximately that of natural
gas. (LP gas has an S.G. of about 1.53). If the service pressure
is five inches water column or less, use one pipe size larger in
order to minimize pressure drop in the line.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS
SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED DRIP
LEG or sediment trap) MUST BE INCORPORATED IN THE
PIPING, see Figure 1 on page 6. The dirt leg must be readily
accessible and not subject to freezing conditions. INSTALL IN
ACCORDANCE WITH RECOMMENDATIONS OF SERVING
GAS SUPPLIERS. (Refer to National Fuel Gas Code, ANSI
Z223.1 or CAN/CSA-B 149.1 Installation Codes.
TABLE 7.
To prevent damage, care must be taken not to apply too
much torque when attaching gas supply pipe to the gas valve
gas inlet.
MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER
HOUR (BASED UPON A PRESSURE DROP OF 0.3 INCH
WATER COLUMN AND 0.6 SPECIFIC GRAVITY GAS)
Fittings and unions in the gas line must be the metal to
metal type.
Distance
from Gas
Nominal Iron Pipe Size (Inches)
Meter
Apply joint compounds (pipe dope) sparingly and only to the
male threads of pipe joints. Do not apply compound to the first
two threads. Use compounds resistant to the action of liquefied
petroleum gases.
1/2 3/4
1
1 1/4 1 1/2
2
2 1/2
3
4
10 (3)
20 (6)
132 278 520 1,050 1,600 3,050 4,800 8,500 17,500
92 190 350 730 1,100 2,100 3,300 5,900 12,000
73 152 285 590 890 1,650 2,700 4,700 9,700
63 130 245 500 760 1,450 2,300 4,100 8,300
56 115 215 440 670 1,270 2,000 3,600 7,400
50 105 195 400 610 1,150 1,850 3,250 6,800
30 (9)
40(12)
50 (15)
60 (18)
70 (21)
80 (24)
90 (27)
100 (30)
125 (38)
150 (45)
175 (53)
200 (60)
THE BOILER AND ITS GAS CONNECTIONS MUST BE LEAK
TESTED BEFORE PLACING THE BOILER IN OPERATION.
Use soap and water solution or other material acceptable for
the purpose in locating gas leaks. DO NOT USE MATCHES,
CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR
THIS PURPOSE.
46
43
40
38
34
31
28
26
96 180 370 560 1,050 1,700 3,000 6,200
90 170 350 530 990 1,600 2,800 5,800
84 160 320 490 930 1,500 2,600 5,400
79 150 305 460 870 1,400 2,500 5,100
72 130 275 410 780 1,250 2,200 4,500
64 120 250 380 710 1,130 2,000 4,100
59 110 225 350 650 1,050 1,850 3,800
DISCONNECT THE BOILER AND ITS MAIN MANUAL
GAS SHUTOFF VALVE FROM THE GAS SUPPLY PIPING
SYSTEM DURING ANY PRESSURE TESTING OF THE GAS
SUPPLY SYSTEM OVER 1/2 PSIG (3.5kPa). THE GAS SUPPLY
LINE MUST BE CAPPED WHEN NOT CONNECTED TO
THE BOILER.
55 100 210 320 610
980 1,700 3,500
*The heating value of Natural Gas is approximately 1,050 Btu/Ft.3.
Propane (LP) Gas has a heating value of approximately 2,500 Btu/Ft3.
1 cu. meter=35.31 cu. feet.
THE BOILER MUST BE ISOLATED FROM THE GAS SUPPLY
PIPING SYSTEM BY CLOSING ITS MAIN MANUAL GAS
SHUTOFF VALVE DURING ANY PRESSURE TESTING OF
THE GAS SUPPLY PIPING SYSTEM AT TEST PRESSURES
EQUAL TO OR LESS THAN 1/2 PSIG (3.5kPa).
Where it is necessary to use more than the average number of pipe
fittings i.e. elbows, tees, and valves in gas supply line, use a pipe
larger than specified to compensate for increased pressure drop.
2B. SIZING GAS SUPPLY LINE (For multiples of over three boilers of
same size or for multiple installations of two or more mixed sizes).
PURGING AND SIZING
Capacities in cubic feet per hour of 0.60 specific gravity gas for
different sizes and lengths are shown in table 7. No additional
allowance is necessary for an ordinary number of fittings.
Gas line purging is required with new piping or systems in which
air has entered.
CAUTION
Applications of the gravity factor converts the figures given in table
7 to capacities with another gas of different specific gravity. Such
application is accomplished by multiplying the capacities given in
table 7 by the multipliers shown in table 8 on page 22.
PURGING SHOULD BE PERFORMED BY PERSONS
EXPERIENCED IN THIS TYPE GAS SERVICE TOAVOID RISK OF
FIRE OR EXPLOSION. PURGE DISCHARGE MUST NOT ENTER
CONFINEDAREAS OR SPACES WHERE IGNITION CAN OCCUR.
THEAREAMUST BE WELLVENTILATEDANDALLSOURCES OF
IGNITION MUST BE INACTIVATED OR REMOVED.
To determine the size of each section of gas piping in a system within
the range of table 7 proceed as follows:
1. CORRECT GAS
•
Determine the gas demand of each appliance to be attached
to the piping system. When table 7 is to be used to select the
piping size, calculate the gas demand in terms of cubic feet
per hour for each piping system outlet. The gas demand for
an appliance can be found by dividing its heat input rate by
the gas’s heating value.
Make sure the gas on which the boiler will operate is the same as
that specified on the boiler rating plate. Do not install the boiler if
equipped for a different type gas — consult your supplier.
2A. SIZING GAS SUPPLY LINE (For single boiler installations
and for installations of multiples of two or three of same
size boilers).
•
Obtain or determine the length of piping from the gas meter or
service regulator to the appliance(s).
21
•
•
In table 7 on page 21, select the row showing the distance to
the most remote outlet or the next longer distance if the table
does not give the exact length. This is the only distance used in
determining the size of any section of gas piping. If the gravity
factor is to be applied, the values in the selected row of table 7
are multiplied by the appropriate multiplier from table 8.
TABLE 8.
MULTIPLIERS TO BE USED WITH TABLE 7 WHEN APPLYING
THE GRAVITY FACTOR TO OTHER THAN .60 SPECIFIC GRAVITY
Specific
Gravity
.35
Specific
Gravity
1.00
Multiplier
Multiplier
1.31
1.23
1.16
1.10
1.04
1.00
.96
.93
.90
.87
.84
.78
.74
.71
.68
.66
.63
.61
.59
.58
.56
.55
.54
Total the gas demands of all appliances on the piping system.
Enter table 7, on the left hand side, at the row equal to or just
exceeding the distance to the most remote outlet. Select the
pipe size in the row with a capacity equal to or just exceeding
the total gas demand. This is the required main gas supply line
size leading away from the gas meter or regulator. To determine
the pipe size required for each branch outlet leading away from
the main supply line, determine the gas demand for that outlet.
Enter table 7 on the same row, and select the branch pipe
size for a capacity equal to or just exceeding the demand at
that outlet. The main line can be resized for a lesser capacity
after each branch outlet, since the gas demand is reduced.
Total the gas demands of all remaining appliances branching
off downstream on the main gas line. Re-enter table 8 in the
same row and select the appropriate pipe size with adequate
capacity. Repeat the branch sizing and main line re-sizing for
any remaining appliances in the system.
.40
.45
.50
.55
1.10
1.20
1.30
1.40
*.60 (Nat.)
.65
*1.50 (Prop.)
1.60
.70
.75
.80
.85
1.70
1.80
1.90
*2.00 (Butane)
2.10
.90
.82
*Use these correction factors if exact specific gravity of the gas is not known.
GAS PRESSURE REGULATORS
The gas pressure regulator is included in the combination gas valve,
Figure 15, and is set to operate on the gas specified on the boiler
model and rating plate.
GROUND
TERMINALS (2)
GAS VALVE KNOB
PRESSURE REGULATOR
ADJUSTMENT
INLET
PILOT
OUTLET
PILOT ADJUSTMENT
(UNDER CAP SCREW)
GAS
CONTROL
OUTLET
PILOT SUPPLY
PILOT ADJUSTMENT
UNDER SCREW
EXAMPLE
FIGURE 15.
Job Condition:
Periodically check main burner, Figure 34 on page 39, and pilot
flame, Figure 35 on page 40, for proper operation. This should
be checked every six months.
Determining the required gas pipe size for a system composed of two
HW-420 boilers and two HW-610 boilers to be installed as a multiple
group, 50 lineal feet from meter. Gas to be used has a .60 specific
gravity and heating value of 1,000 Btu per cubic foot.
Do not subject the gas valve to inlet gas pressures of more than 14"
W.C. (1/2 P.S.I.). If higher gas pressures are encountered, a service
regulator is necessary.
Solution:
2 HW-420 Boilers
2 HW-610 Boilers
=
=
840,000 Btuh
1,220,000 Btuh
TABLE 9.
CORRECT MANIFOLD PRESSURE FOR FULL
BOILER INPUT (IN INCHES OF WATER COLUMN)
Total Btuh Input
Total Btuh Input
=
=
2,060,000 Btuh
Model
Number
HW-300
Rated
Input
Manifold Pressure
Natural Propane
3.5 10.0
2,060,000 Btuh = 2,060 cf/h
1,000
300,000
Btu per Cubic Foot of Gas
HW-399
HW-420
399,000
420,000
520,000
610,000
660,000
670,000
3.2
3.5
3.5
3.5
3.5
9.5
With a cubic foot per hour demand of 2,060 and with 50 lineal
feet of gas supply line, table 7 shows a pipe size of 3" (76mm)
is required.
10.0
10.0
10.0
HW-520
HW-610
HW-670 Nat.
HW-670 Prop.
NOTE: For other than .60 specific gravity, apply multiplier factor as
shown in table 8.
10.0
22
Adjustment, if required, is performed as follows:
5. Set primary system temperature control dial (thermostat) to
lowest setting.
1. Set primary system temperature control dial (thermostat) at
lowest setting so that boiler will not call for heat.
6. Remove pressure gauge and replace sealing plug.
2. Attach a pressure gauge to the tapping in the control string
elbow.
7. Set primary system temperature control dial (thermostat) to
desired setting.
3. Reset primary system temperature control dial (thermostat) to
highest setting. Main burner will now ignite.
WARNING
DONOTINCREASEGASPRESSUREABOVETHATSPECIFIED
ON THE RATING PLATE, AS OVERFIRING WILL RESULT IN
DAMAGE TO THE BOILER, AS WELL AS INCREASED RISK
OF FIRE, SOOTING AND ASPHYXIATION.
4. With main burner firing, adjust pressure, if necessary, by turning
pressure regulator adjusting screw with a screwdriver.
•
•
Clockwise to increase pressure.
If gas pressure regulator cannot be adjusted to correct pressure with
sufficient gas pressure at the valve, replace with new gas valve.
Counterclockwise to decrease pressure.
WIRING
WIRING CONNECTIONS
The electrical connections must be made so that the circulator will
operate before the gas valve opens. At no time may the controlling
system allow the burner to fire when there is no water flow through
the boilers.
CAUTION
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING ERRORS CAN CAUSE
IMPROPER AND DANGEROUS OPERATION. VERIFY PROPER
OPERATION AFTER SERVICING.
Refer to the diagrams in Figures 16 and 17 on pages 24 and
25 for proper wiring sequence with conventional single boiler
installations.
1. CONVENTIONAL INSTALLATIONS
The THERMAL BALANCER shown is factory included by
A. O. Smith. This device serves as a pump shutdown delay switch to
balance the rising boiler water temperature to system temperature
before the pump stops. Overshooting of boiler temperature is
prevented and stack loss after shutdown is negligible.
ALLELECTRICALWORK MUSTBE INSTALLED INACCORDANCE
WITH NATIONAL ELECTRICAL CODE, ANSI/NFPA 70 AND/
OR THE CANADIAN ELECTRICAL CODE, PART 1, CSA C22.1,
ELECTRICAL CODE AND MUST CONFORM TO LOCAL
REGULATIONS.
WARNING
The boiler, when installed, must be electrically bonded to ground in AN ELECTRICAL GROUND IS REQUIRED TO REDUCE RISK OF
accordance with the requirements of the authority having jurisdiction ELECTRIC SHOCK OR POSSIBLE ELECTROCUTION. Make the
or, in the absence of such requirements, with the National Electrical ground connection to the screw provided in the electrical supply
Code, ANSI/NFPA 70 and/or the Canadian Electrical Code Part 1, junction box on the boiler.
CSA C22.1, Electrical Code.
IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED WITH THE
STRICT ADHERENCE TO PIPING AND WIRING DIAGRAMS IS APPLIANCE, MUST BE REPLACED, IT MUST BE REPLACED
REQUIRED TO PREVENT CONSTANT PUMP OPERATION WHEN WITH TYPE 1050C WIRE OR ITS EQUIVALENT, EXCEPT FOR
SYSTEM TEMPERATURE CONTROLIS SATISFIED. OTHERWISE THE FLAME SENSOR AND IGNITION CABLE WHICH ARE 2500C
THE WARRANTY IS VOID AS STIPULATED IN THE LIMITED AND WIRES CONNECTED TO THE COIL PROTECTOR WHICH
WARRANTY ON THE INSTRUCTIONS MANUAL.
ARE 2000C.
23
HW 300 TO 670
I.I.D. SYSTEM
CONNECTION DIAGRAM
120 VAC 60 HZ
L1 (HOT) L2 (NEUTRAL)
GND
4 X 4 JUNCTION BOX
WITH TERMINAL STRIP
IGNITION
MODULE
WHITE
GAS VALVE
MV
** FUSED
DISCONNECT
SWITCH
THERMAL
BALANCER
BROWN
WHITE
MV
MV/PV
PV
MV/PV
PV
W
4
YELLOW
3
1
TRANSFORMER
Y
B
120/24V
** WATER PUMP
WHITE
RED
24V GND
24V
2
HIGH
LIMIT
GND
R
** TANK TEMP
PROBE
SPARK
BLACK
COM NO
COIL
LIMIT
TO
PILOT
** SAFETY FLOW
SWITCH (REQUIRED)
SCHEMATIC DIAGRAM
L1 (HOT)
L2 (NEUTRAL)
120 VAC 60 HZ
FUSED
DISCONNECT
SWITCH
THERMAL
BALANCER
GND
WATER PUMP
TANK TEMP
PROBE
SAFETY FLOW
SWITCH
120V
24V
HIGH LIMIT
COIL
LIMIT
IGNITION MODULE
CHASSIS
GROUND
MV
PV
MV/PV
IGNITOR WIRE TO
PILOT
GAS VALVE
%%UWIRING
** THESE COMPONENTS
ARE NOT FACTORY
INSTALLED AND MUST BE
SUPPLIED BY THE
INSTALLER.
NOTE: IF REPLACING ANY FACTORY WIRING, USE
TYPE 105°C WIRE OR EQUIVALENT, EXCEPT FOR
THE IGNITION WIRE WHICH USES 250°C WIRE
AND THE COIL LIMIT WHICH USES 200°C WIRE.
BY FACTORY
BY INSTALLER
192359-000 Rev. 3
SINGLE STAGE I.I.D. - HONEYWELL GAS VALVE
HW (300 thru 670). (NATURAL AND PROPANE GAS) - U.S. & CANADA
FIGURE 16.
24
TYPICAL WIRING DIAGRAM (IID SYSTEM) FOR SINGLE BOILER LINEAR-TEMP® INSTALLATION
FIGURE 17.
2. LINEAR-TEMP INSTALLATIONS
building is not under control of space temperature thermostats. A
single bulb outdoor sensing control will prevent overheating of halls,
Control for these systems is decided mainly by the type of building stairways or other uncontrolled areas. There are occasions when
system controlling that is desired. A single boiler installation might outdoor temperatures are temporarily too warm for even a moderate
be controlled directly from space temperature thermostat(s). amount of heating in these areas.
Multiple boiler installations are more effective when the boilers are
sequenced in and out of operation by some form of main water Space temperature controlling can be varied to meet the building
temperature controller. With one to three boilers, individual controls requirements. Either the single thermostat, as shown, or multiple
set at progressive temperatures may be used. For more than three zone thermostats should control a common relay. This relay
or four boilers, a step controller is recommended.
controls electric power to the system primary circulator and
to the main water temperature controller. This provides for
Individual boiler controls, or the separate stages of a step controller, water movement in the system before the main temperature
should fire a boiler and also start the boiler loop circulator whenever controller can start the secondary circulating pump or fire
the first boiler of a group supplied by that boiler loop is fired. Some the boiler.
large installations may require the firing of more than one boiler
per stage.
Figure 17 shows a typical wiring diagram for a single boiler space
heating installation. The boiler may be controlled by a main
The system or primary circulator may or may not be controlled temperature controller as shown or may include outdoor reset
by the boiler sequencer. When this pump is operated through if desired.
the first switch of any type of step controller, care should be
taken to determine if a motor starter is needed due to insufficient Figure 18 on page 26 shows a layout for various choices of controls
switch capacity.
often found in commercial heating. These layouts are not intended
to be wiring diagrams and only show the relation of one device to
If the primary pump is controlled by a manual switch or any other another in the system.
controllers, the electric current supply to the boiler group should
be through the primary pump controller. The fast response of Figure 18 is a typical layout of controls for two boilers with one
A. O. Smith boilers eliminates any need to maintain boiler circulator and including optional outdoor reset and thermal balancer.
temperature when the system is satisfied. Wiring should always If a secondary circulator is used with each boiler, arrangement for
prevent firing of boiler(s) when there is no water flow in the mains. boiler no. 2 will be as shown for boiler no. 1.
Installation diagrams show flow switches in the outlet piping from Commercial size installations are always best when designed to
each boiler as good protection against any boiler being fired when individual building requirements.
the boiler loop circulator is not in operation. These flow switches
will also serve as protection if there is a loss of water.
The layout in figure 18 is typical of many combination possibilities to
meet the requirements of different buildings. Brand names of controls
Outdoor vent systems will normally require an automatic shutdown shown are suggestions and not directly related to any particular type
control if there is a continuous recirculating main and/or if the entire of system. THESE LAYOUTS ARE NOT WIRING DIAGRAMS.
25
NOTE:
3. Outdoor thermostat required if building controls do not provide
automatic shutdown of reset controls during warm weather.
Boilers and Secondary Circulator are Controlled by
• Dual Bulb, Dual Switch Controller
1. Building temperature controls supply electric power to building
circulator.
2. Main flow switch proves main water flow before energizing
sequencing and resetting controls.
Staging and Outdoor Reset of Main Water Temperature
CONTROL APPLICATION DIAGRAM - TWO BOILER LINEAR-TEMP® INSTALLATION WITH TWO CIRCULATORS
FIGURE 18.
NOTE:
Boilers and Secondary Circulator are Controlled by
1. Building temperature controls supply electric power to building circulator.
2. Main flow switch proves main water flow before energizing • One Dual Bulb, Dual Switch Mechanical Controller and
sequencing and resetting controls.
• One Dual Bulb, single Switch Mechanical Controller
3. Outdoor thermostat required if building controls do not provide
automatic shutdown of reset controls during warm weather.
Sequencing and Outdoor Reset of Main Water Temperature.
CONTROL APPLICATION DIAGRAM - THREE BOILER LINEAR-TEMP® INSTALLATION WITH THREE CIRCULATORS
FIGURE 19.
26
NOTE:
1. Building temperature controls supply electric
power to building circulator.
2. Main flow switch proves main water flow before
energizing sequencing and resetting controls.
3. Outdoor thermostat required if building controls do
not provide automatic shutdown of reset controls
during warm weather.
Boilers and Secondary
Circulator are Controlled by
Dual Bulb, Dual Switch Controller
Staging and Outdoor Reset of
Main Water Temperature
CONTROL APPLICATION DIAGRAM - FOUR BOILER LINEAR-TEMP® INSTALLATION WITH TWO CIRCULATORS
FIGURE 20.
27
CER-TEMP 80 - 1 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION
CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS
FIGURE 21.
CER-TEMP 80 - 1 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION
U.S. MODELS, JUCNTION BOX W/4 TERMINALS
FIGURE 22.
FIGURE 23.
28
CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION
CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS
FIGURE 24.
29
SCHEMATIC
CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS
FIGURE 25.
30
CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION CONNECTION DIAGRAM
(FOR HOT WATER SUPPLY APPLICATION)
U.S. MODELS, JUNCTION BOX W/4 TERMINALS
FIGURE 26.
31
CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION SCHEMATIC DIAGRAM
(FOR HOT WATER SUPPLY APPLICATION)
U.S. MODELS, JUNCTION BOX W/4 TERMINALS
FIGURE 27.
32
PIPING
ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR ONE HW-670 UP-FLOW MODEL
COMMERCIAL BOILER WITH VERTICAL TANK
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE
TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE
CONTROL WARNING ON PAGE 11. IF HIGHER PREHEAT
TEMPERATURESARE NECESSARY TO OBTAINADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
IMPORTANT
THE INSTALLATION OF SAFETYFLOW SWITCHAS SHOWN IS REQUIREDTO PROTECTTHE BOILER IN CASE OF WATER SERVICE
INTERRUPTION OR CIRCULATOR FAILURE.
+
PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD
CONFORM TO LOCAL CODES.
GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.
PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.
*
** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.
WIRING - FIGURES 16 and 17 on
pages 24 and 25.
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
Pipe Size
(Inches)
B & G
Pump
Size
Model
Number
*Armstrong
Pump Size
HW-300
HW-399
1-1/4"
1-1/2"
1-1/2"
1-1/2"
2"
125
S-25 1-1/4"
H-32 1-1/2"
H-32 1-1/2"
H-32 1-1/2"
S-35
1-1/2" HV
1-1/2" HV
1-1/2" HV
2"
HW-420
HW-520
HW-610/670
* Assumes 50 equivalent feet of piping or less.
FIGURE 28.
33
ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR ONE HW-670 UP-FLOW MODEL
COMMERCIAL BOILER WITH HORIZONTAL TANK
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE
TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE
CONTROL WARNING ON PAGE 11. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITC
IS REQUIRED TO PROTECT THE BOILER IN CA
SERVICE INTERRUPTION OR CIRCULATOR F
+
PIPING AND FITTINGS BETWEEN GATE
BOILERS SHOULD BE BRASS OR BRO
PIPING SHOULD CONFORM TO LOCAL C
GATE VALVES ARE SHOWN FOR SERVIC
HOWEVER, LOCAL CODES SHALL GOVERN T
*
PRESSURE RELIEF VALVE RATING S
EXCEED PRESSURE CAPACITY OF ANY
IN THE SYSTEM.
** INSTALL THERMOMETER AND PRESSU
OPENINGS PROVIDED ON HW-520, HW-6
WIRING - FIGURES 16 and 17 on
pages 24 and 25.
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
Pipe Size
(Inches)
B & G
Pump
Size
Model
Number
*Armstrong
Pump Size
HW-300
HW-399
1-1/4"
1-1/2"
1-1/2"
1-1/2"
2"
125
S-25 1-1/4"
H-32 1-1/2"
H-32 1-1/2"
H-32 1-1/2"
S-35
1-1/2" HV
1-1/2" HV
1-1/2" HV
2"
HW-420
HW-520
HW-610/670
* Assumes 50 equivalent feet of piping or less.
FIGURE 29.
34
TWO HW-399's, HW-420's, HW-520's, HW-610's or HW-670's UP-FLOW MODEL
COMMERCIAL BOILER WITH VERTICAL TANK, CER-TEMP 80
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS
REQUIRED TO PROTECTTHE BOILER IN CASE OF WATER SERVICE
INTERRUPTION OR CIRCULATOR FAILURE.
+
PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS
SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD
CONFORM TO LOCAL CODES.
GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER,
OVERN THEIR USAGE.
F VALVE RATING SHOULD NOT EXCEED
ITY OF ANY COMPONENT IN THE SYSTEM.
ETERAND PRESSURE RELIEF IN OPENINGS
520, HW-610 & HW-670.
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE
AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 11. IF
HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED
TO FIXTURES.
WIRING - FIGURES 21 to 27 on
pages 28 to 32.
HEATERS SPACED 30" APART
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
B & G
Pipe Size
Model
Number
*Armstrong
Pump Size
Pump
Size
(Inches)
A
B
HW-300
HW-399
2"
2"
1-1/2"
1-1/2"
1-1/2"
1-1/2"
1-1/2"
2"
2"
S-35
S-35
HW-420
2"
2"
S-35
HW-520
2"
2"
S-35
HW-610/670
2-1/2"
2-1/2"
S-45 2-1/2"
* Assumes 50 equivalent feet of piping or less.
FIGURE 30.
35
TWO HW-300's, HW-399's, HW-420's, HW-520's, HW-610's OR HW-670's UP-FLOW MODEL
COMMERCIAL BOILER WITH HORIZONTAL TANK
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN
IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER
SERVICE INTERRUPTION OR CIRCULATOR FAILURE.
+
PIPING AND FITTINGS BETWEEN GATE VALVES AND
BOILERS
PIPING SH
GATE VALVES
HOWEVER, LOC
*
PRESSUR
EXCEED P
IN THE SYS
** INSTALL T
OPENINGS
WIRING - FIGURES 21 to 27 on
pages 28 to 32.
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT
FIXTURES.SEETANKTEMPERATURECONTROLWARNINGONPAGE11.IFHIGHER
PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER
OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
B & G
Pipe Size
Model
Number
*Armstrong
Pump Size
Pump
Size
(Inches)
A
B
HW-300
HW-399
2"
2"
1-1/2"
1-1/2"
1-1/2"
1-1/2"
1-1/2"
2"
2"
S-35
S-35
HW-420
2"
2"
S-35
HW-520
2"
2"
S-35
HW-610/670
2-1/2"
2-1/2"
S-45 2-1/2"
* Assumes 50 equivalent feet of piping or less.
FIGURE 31.
36
THREE HW-520's, HW-610's OR HW-670's UP-FLOW MODEL
COMMERCIAL BOILER WITH VERTICAL TANK, CER-TEMP 80
WIRING - FIGURES 21 to 27 on
pages 28 to 32.
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT
FIXTURES.SEETANKTEMPERATURECONTROLWARNINGONPAGE11.IFHIGHER
PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER
OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED
TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR
CIRCULATOR FAILURE.
+
PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE
BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.
GATE VALVESARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCALCODES
SHALL GOVERN THEIR USAGE.
*
PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE
CAPACITY OF ANY COMPONENT IN THE SYSTEM.
** INSTALLTHERMOMETERAND PRESSURE RELIEF IN OPENINGS PROVIDED
ON HW-520, HW-610 & HW-670.
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
B & G
Pipe Size
Model
Number
*Armstrong
Pump Size
Pump
Size
(Inches)
A
B
HW-520
2-1/2"
3"
1-1/2"
1-1/2"
2"
S-45 2-1/2"
HW-610/670
3" HD-3
S-46
* Assumes 50 equivalent feet of piping or less.
FIGURE 32.
37
THREE HW-520's, HW-610's OR HW-670's UP-FLOW MODEL
COMMERCIAL BOILER WITH HORIZONTAL TANK, CER-TEMP 80
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT
FIXTURES. SEETANKTEMPERATURECONTROLWARNING. IFHIGHERPREHEAT
TEMPERATURESARE NECESSARY TO OBTAINADEQUATE BOOSTER OUTPUT,
ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED
TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR
CIRCULATOR FAILURE.
+
PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE
BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.
GATE VALVESARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCALCODES
SHALL GOVERN THEIR USAGE.
*
PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE
CAPACITY OF ANY COMPONENT IN THE SYSTEM.
** INSTALLTHERMOMETERAND PRESSURE RELIEF IN OPENINGS PROVIDED
ON HW-520, HW-610 & HW-670.
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum
Pipe Size
(Inches)
B & G
Pump
Size
Model
*Armstrong
Number
Pump Size
WIRING - FIGURES 21 to 27 on
pages 28 to 32.
A
2-1/2"
3"
B
HW-520
1-1/2"
1-1/2"
2"
S-45 2-1/2"
HEATERS SPACED 24" APART
HW-610/670
3" HD-3
S-46
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
* Assumes 50 equivalent feet of piping or less.
FIGURE 33.
38
OPERATION AND START-UP INSTRUCTIONS
WARNING
CAUTION
After placing boiler into operation, the ignition system safety shutoff
device must be tested by the following test method.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY
FAIL TO SHUT OFF, DO NOT TURN OFF OR DISCONNECT
THE ELECTRICAL SUPPLY TO THE PUMP. INSTEAD,
SHUTOFF THE GAS SUPPLY AT A LOCATION EXTERNAL TO
THE APPLIANCE.
1. Reset High Limit Temperature Control to lowest setting.
(See figure 2 on page 8).
2. Reset System Controller to maximum setting, causing a call for heat
and allowing unit to run until High Limit Temperature Control trips.
PILOT AND MAIN BURNER
To maintain safe operation of the boiler, check the pilot and the main
burner once every six months for proper flame characteristics.
3. Resetting the High Limit Temperature Control to a higher setting,
unit should run.
1. MAIN BURNER
4. Reset System Controller and High Limit Temperature Control to
desired temperature. If unit fails to run, see Trouble-Shooting in
this manual.
The main burner, Figure 34, should display the following
characteristics:
Before operating the boiler, the entire system must be filled with
water, purged of air and checked for leaks. Do not use Stop Leak
or other boiler compounds. The gas piping should also be leak
tested.
•
•
•
Provide complete combustion of gas.
Cause rapid ignition and carryover of flame across entire burner.
Give reasonably quiet operation during ignition, burning and
extinction.
Any safety devices including low water cutoffs used in conjunction
with this boiler should receive periodic (every six months) inspection
to assure proper operation. A low water cutoff device of the float
type should be flushed every six months. All relief valves should be
inspected and manually operated at least twice a year.
•
Cause no excessive lifting of flame from burner ports.
If the proceeding burner characteristics are not evident, check for
accumulation of lint or other foreign material that restricts or blocks
the air openings to the burner or boiler.
IMPORTANT
IT IS RECOMMENDED THAT A QUALIFIED PERSON PERFORM
THE INITIAL FIRING OF THE BOILER. AT THIS TIME THE
USER SHOULD NOT HESITATE TO ASK THE INDIVIDUAL
ANY QUESTIONS WHICH HE MAY HAVE IN REGARD TO THE
OPERATION AND MAINTENANCE OF THE UNIT.
Also check for good flow of combustion and ventilating air to the unit.
Maintain a clear area around the boiler at all times.
FILLING THE SYSTEM
1. Fast fill system through bypass until pressure approaches
desired system pressure. Close bypass valve and permit
pressure to be established by the pressure reducing valve.
FIGURE 34.
2. Vent all high points in system to purge system of air.
The boiler should be periodically inspected by a qualified servicer
for continuous safe operation.
If pressure bleeding of system is desired, install valves as shown in
Figure 7 on page 14.
Qualified servicers should follow this procedure when the boiler’s
burners need cleaning.
Wherecastironradiationandmotorizedvalvesareused, conventional
system pressure and installation practices should be followed.
1. Turn off the electrical power and close the main manual gas
shutoff valve. See L&O instructions on pages 43 and 44.
Provisions should be made to permit manual venting of radiators
or convectors.
•
Allow boiler parts to cool before disassembly.
PRECAUTIONS
2. Remove main burner manifold assembly from boiler.
If the unit is exposed to the following, do not operate boiler until all
corrective steps have been made by a qualified serviceman:
•
Refer to parts list supplied with this manual for
disassembly aid.
1. Flooding to level of burner or controls or higher.
2. Exposure to fire.
3. If damaged.
4. Firing without water.
5. Sooting.
3. Remove any loose foreign material such as dust or lint with
a vacuum. Check all ports, orifices, and air openings for
blockage. Dislodge any foreign material causing blockage.
Remove any soot or carbon deposits with a rag making sure
to remove any lint left on burner by vacuuming again.
39
4. Reinstall the burner manifold assembly on boiler.
5. Restore electrical power and gas supply to boiler.
Check for good terminal connection at the sensing probe at the pilot
burner assembly if pilot does not light.
Check for electrical power to the valve. If electrical power and gas
are present at the valve and the pilot does not operate when system
calls for heat, replace valve.
•
Put the boiler back in operation by following the lighting
instructions in this manual or on the lighting and
operating label on the boiler. See pages 43 - 44.
5. Low gas pressure
•
Check for gas leaks and proper boiler and vent operation.
• Adjust pilot flame by means of the pilot gas adjustment
located in the gas valve.
2. PILOT BURNER - ELECTRONIC IGNITION
To establish pilot flame without main burner operation, it will be
necessary to perform the following steps:
• The pilot flame should envelop 3/8 to 1/2 inch of the tip
of the thermocouple. Remove pilot adjustment cover
screw, Figure 36. Turn inner adjustment screw or pilot
adjustingvalveclockwisetodecrease, orcounterclockwise
to increase pilot flame. Be sure to replace cover screw on
combination gas valve after adjustment to prevent
possible gas leakage.
Servicing of the pilot burner (every six months) includes
keeping pilot shield (not shown) free of lint, cleaning the burner
head, the primary air opening and the orifice of the pilot burner,
Figure 35.
1. Open fused disconnect switch or shut off electrical power
to the boiler.
2. Disconnect wire from MV wire on valve.
GROUND
TERMINALS (2)
3. Close fused disconnect switch to restore electrical power
to the boiler.
GAS VALVE KNOB
PRESSURE REGULATOR
ADJUSTMENT
INLET
PILOT
OUTLET
The pilot will now ignite provided the system is calling for heat.
4. Adjust pilot flame.
PILOT ADJUSTMENT
(UNDER CAP SCREW)
GAS
CONTROL
To adjust the pilot flame, remove the cap screw from the pilot
adjusting screw (Figure 36) and turn to deliver a sufficient
flame at the pilot burner to cover 3/8" to 1/2" (10-12mm) of
the sensing probe tip. See Figure 35.
OUTLET
PILOT SUPPLY
PILOT ADJUSTMENT
UNDER SCREW
FIGURE 36.
6. Clogged pilot burner orifice.
• Clean or replace orifice. A clogged orifice will restrict
gas flow and result in low thermocouple output.
7. Incorrect orifice.
• Replace. The Orifice size is stamped on the
wrench flats.
8. Clogged primary air opening.
• Restricted air passages will soften the pilot
flame and result in poor thermocouple flame
impingement.
FIGURE 35.
40
CHECKING AND ADJUSTING THE INPUT
7. Repeat steps 7 thru 11 of the OPERATING INSTRUCTIONS.
The boiler will resume normal operation.
1. Follow steps 1 thru 6 of the OPERATING INSTRUCTIONS.
When the boiler is operating at full capacity, or full gas input,
it should consume 1 cu. ft. of gas in approximately the time
indicated in table 10.
2. Attach a pressure gauge or a manometer to the manifold
pressure tapping and refer to table 10 for correct manifold
pressure.
3. Follow steps 7 thru 11 of the OPERATING INSTRUCTIONS.
TABLE 10.
CONSUMPTION RATE
(Refer to Operating at Full Input or Full Capacity)
4. Use this formula to “clock” the meter. Be sure that other gas
consuming appliances are not ON during this interval.
3600 x H = Btuh
Time to Consume 1 cu. ft. of gas (seconds)
Heating
T
Btuh = The approximate actual input rate.
Type Gas
Value
T =
H =
Time in seconds to burn one cubic foot of gas.
Heating value of the fuel gas in Btu per cubic foot of gas.
HW-
300
HW-
399
HW-
420
HW-
520
HW-
610
HW-
670
Btu/Ft.
EXAMPLE:
Natural
1050
2500
12.6
30.0
9.5
9.0
7.3
6.2
5.7
T = 9.0 seconds/ft3
Propane
22.6
21.4
17.3
14.8
13.4
H = 1050 Btu/ft3(natural gas)
Btuh = ?
Gas flow through meter:
3600 x 1050 = 420,000 Btuh
9.0
IMPORTANT
UNDER NO CIRCUMSTANCES SHOULD THE GAS INPUT
EXCEED THE INPUT SHOWN ON THE BOILER MODEL AND
RATING PLATE. OVERFIRING COULD RESULT IN DAMAGE
OR SOOTING OF THE BOILER. Minor variances from input
on rating plate can be corrected by adjustment of gas pressure
regulators described in GAS PRESSURE REGULATORS section
of this manual.
Small changes in the input rate may be made by adjusting the
manifold pressure, see GAS PRESSURE REGULATORS. Under
no circumstances should you exceed the maximum input rate
for the boiler given in table 2 on page 6.
5. Repeat steps 1 thru 6 of the OPERATING INSTRUCTIONS.
6. Remove the pressure gauge or manometer from the manifold
pressure tapping. Replace the screw-in plug in the manifold
pressure tap.
The inlet gas pressure must not exceed or be less than the values
shown on rating plate.
41
START
THERMOSTAT (CONTROLLER) CALLS FOR HEAT
STAGE 1
TRIAL FOR
IGNITION
SPARK GENERATOR POWERED
First valve (pilot) operator opens
PILOT BURNER OPERATION
Pilot burner lights.
Module senses
flame current.
Pilot burner does not light
Module
Response
S-8600M
After 15 sec. ignition
shut-down. 5 minute
time delay before re-try.
S-8600H
After 15 sec. ignition
system locks out
must be manually reset.
STAGE 2
MAIN BURNER
OPERATION
FLAME CURRENT SENSED
• Spark generator off.
• Second valve operator (main) opens.
POWER INTERRUPTION
System shuts off, restarts
when power is restored.
MAIN BURNER OPERATION
Module monitors pilot flame current.
PILOT FLAME FAILURE
Main valve closes.
Module starts trial for
ignition.
THERMOSTAT (CONTROLLER) SATISFIED
Valves close, pilot and main burners are off.
END
42
LIGHTING AND OPERATING INSTRUCTIONS NATURAL AND PROPANE FOR HW300 - HW399
FOR YOUR SAFETY READ BEFORE LIGHTING
If you do not follow these instructions exactly,a
fire or explosion may result causing property damage, personal
:
WARNING
injury or loss of life.
FLAMMABLE
WHAT TO DO IF YOU SMELL GAS
WARNING: HOT WATER CAN PRODUCE
DO NOT TRY TO LIGHT ANY APPLIANCE.
3rd DEGREE BURNS IN 6 SECONDS AT
140O F. (60O C).
DO NOT TOUCH ANY ELECTRIC SWITCH;
DO NOT USE ANY PHONE IN YOUR BUILDING
IMMEDIATELY CALL YOUR GAS SUPPLIER FROM
A NEIGHBOR'S PHONE. FOLLOW THE GAS
SUPPLIER'S INSTRUCTIONS.
IF YOU CANNOT REACH YOUR GAS SUPPLIER,
CALL THE FIRE DEPARTMENT.
IN CASE OF POWER FAILURE DO NOT ATTEMPT
TO OPERATE APPLIANCE. IMPROPER INSTALLATION,
ADJUSTMENT, ALTERATION, SERVICE OR MAINTENANCE
CAN CAUSE PROPERTY DAMAGE, PERSONAL INJURY
OR LOSS OF LIFE. REFER TO THE USER'S
INFORMATION MANUAL PROVIDED WITH THIS
APPLIANCE. INSTALLATION AND SERVICE MUST BE
PERFORMED BY A QUALIFIED INSTALLER, SERVICE
AGENCY OR THE GAS SUPPLIER.
C.
D.
USE ONLY YOUR HAND TO TURN THE GAS
CONTROL KNOB. NEVER USE TOOLS. IF THE
KNOB WILL NOT TURN BY HAND, DON'T TRY
TO REPAIR IT. CALL A QUALIFIED SERVICE
TECHNICIAN. FORCE OR ATTEMPTED
THIS APPLIANCE IS EQUIPPED WITH AN IGNITION
DEVICE WHICH AUTOMATICALLY LIGHTS THE PILOT.
DO NOT TRY TO LIGHT THE PILOT BY HAND.
A.
B.
REPAIR MAY RESULT IN A FIRE OR EXPLOSION.
DO NOT USE THIS APPLIANCE IF ANY PART
HAS BEEN UNDER WATER. IMMEDIATELY CALL
A QUALIFIED SERVICE TECHNICIAN TO
INSPECT THE APPLIANCE AND TO REPLACE
ANY PART OF THE CONTROL SYSTEM AND ANY
GAS CONTROL WHICH HAS BEEN UNDER WATER.
BEFORE OPERATING: SMELL ALL AROUND THE APPLI-
ANCE AREA FOR GAS. BE SURE TO SMELL NEXT TO
THE FLOOR BECAUSE SOME GAS IS HEAVIER THAN
AIR AND WILL SETTLE ON THE FLOOR.
FIGURE “C”
GAS VALVE
FIGURE "A"
FIGURE "B"
HANDLE “OFF”
POSITION
PILOT
CONTROL KNOB
ON
ON
FIGURE “D”
HANDLE “ON”
POSITION
OFF
OFF
PILOT
"OFF" POSITION
PILOT FIRING VALVE
"ON" POSITION
HONEYWELL GAS VALVE
LIGHTING INSTRUCTIONS
7. TURN TOP KNOB OF GAS CONTROL COUNTER-
CLOCKWISE TO "ON" (FIG. B). OPEN PILOT
1.
STOP! READ THE SAFETY INFORMATION
ABOVE ON THIS LABEL.
MANUAL VALVES, COUNTER-CLOCKWISE
FIGURE “D”
8. TURN ON ALL ELECTRIC POWER TO THE
APPLIANCE.
9. SET SYSTEM TEMPERATURE CONTROLLER
TO DESIRED SETTING.
10. WHEN CONTROLLER CALLS FOR HEAT, THE
.
2. MAKE SURE BOILER AND SYSTEM ARE FILLED
WITH WATER AND ALL AIR HAS BEEN EXPELLED
FROM APPLIANCE.
3. TURN OFF ALL ELECTRIC POWER TO THE
APPLIANCE. SET SYSTEM TEMPERATURE
CONTROLLER TO LOWEST SETTING. PURGE ALL
GAS LINES OF AIR.
CIRCULATING PUMP WILL OPERATE AND THE
PILOT BURNER WILL BE SPARK IGNITED. GAS
CONTROL WILL OPEN AND MAIN BURNER WILL
THEN IGNITE. NOTE: IF PILOT FAILS TO IGNITE,
TURN OFF APPLIANCE AND CONSULT YOUR
"INSTALLATION AND USER'S MANUAL" FOR
ADJUSTMENTS AND TROUBLE SHOOTING.
4. DO NOT ATTEMPT TO LIGHT THE PILOT BY HAND
5. REFER TO DIAGRAMS ABOVE. TURN TOP KNOB OF
GAS CONTROL & PILOT VALVE (FIG. “C”)
CLOCKWISE
, TO "OFF" POSITION (FIG. “A”)
6. WAIT FIVE (5) MINUTES TO CLEAR OUT
ANY GAS. THEN SMELL FOR GAS, INCLUDING
NEAR THE FLOOR. IF YOU SMELL GAS,
STOP! FOLLOW "B" IN THE SAFETY
11. IF THE APPLIANCE WILL NOT OPERATE, FOLLOW
THE INSTRUCTIONS "TO TURN OFF GAS TO
APPLIANCE" AND CALL YOUR SERVICE
TECHNICIAN OR GAS SUPPLIER.
INFORMATION ABOVE ON THIS LABEL. IF YOU
DON'T SMELL GAS, GO TO THE NEXT STEP.
TO TURN OFF GAS TO APPLIANCE
A.
B.
SET THE SYSTEM CONTROLLER TO THE
C. TURN TOP KNOB OF GAS CONTROL VALVE
LOWEST SETTING.
CLOCKWISE
CLOSE FIRINGAND PILOT MANUAL VALVES,
CLOCKWISE . SEEABOVE.
TO "OFF" POSITION SEE, (FIG.A).
TURN OFF ELECTRICA L POWER
TO APPLIANCE.
211686-000 REV. XX
43
LIGHTING AND OPERATING INSTRUCTIONS (NATURAL AND PROPANE GAS WITH I.I.D.)
FOR YOUR SAFETY READ BEFORE OPERATING
If you do not follow these instructions exactly, a
fire or explosion may result causing property damage, personal
WARNING:
injury or loss of life.
FLAMMABLE
A.THIS APPLIANCE IS EQUIPPED WITH AN IGNITION
DEVICE WHICH AUTOMATICALLY LIGHTS THE PILOT.
DO NOT TRY TO LIGHT THE PILOT BY HAND.
C.USE ONLY YOUR HAND TO TURN THE GAS CONTROL
KNOB. NEVER USE TOOLS. IF THE KNOB WILL NOT
TURN BY HAND, DON’T TRY TO REPAIR IT. CALL A
QUALIFIED SERVICE TECHNICIAN. FORCE OR
ATTEMPTED REPAIR MAY RESULT IN A FIRE OR
EXPLOSION.
B.BEFORE LIGHTING: SMELL ALL AROUND THE
APPLIANCE AREA FOR GAS. BE SURE TO SMELL
NEXT TOTHE FLOOR BECAUSE SOME GAS IS HEAVIER
THAN AIR AND WILL SETTLE ON THE FLOOR.
D.DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN
UNDER WATER. IMMEDIATELY CALL A QUALIFIED
SERVICE TECHNICIAN TO INSPECT THE APPLIANCE
AND TO REPLACE ANY PART OF THE CONTROL
SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN
UNDER WATER.
WHAT TO DO IF YOU SMELL GAS
DO NOT TRY TO LIGHT ANY APPLIANCE.
DO NOT TOUCH ANY ELECTRIC SWITCH.
DO NOT USE ANY PHONE IN YOUR BUILDING.
IMMEDIATELY CALL YOUR GAS SUPPLIER FROM
A NEIGHBOR’S PHONE. FOLLOW THE GAS
SUPPLIER’S INSTRUCTIONS.
IF YOU CANNOT REACH YOUR GAS
SUPPLIER, CALL THE FIRE DEPARTMENT.
E. DO NOT OPERATE APPLIANCE UNLESS UNIT IS FILLED
WITH WATER AND INLET LINES ARE FULLY OPEN.
FIGURE “C”
GAS VALVE
CONTROL KNOB
FIGURE “C”
FIGURE “D”
HANDLE “OFF”
POSITION
PILOT
FIGURE "B"
FIGURE "A"
FIGURE “D”
ON
ON
HANDLE “ON”
POSITION
PILOT
OFF
OFF
HANDLE “OFF” HANDLE “ON”
POSITION POSITION
"OFF" POSITION "ON" POSITION
HONEYWELL GAS VALVE
MANUAL SHUTOFF VALVE
PILOT FIRING VALVE
OPERATING INSTRUCTIONS
11. SET THERMOSTAT TO DESIRED SETTING. PILOT
BURNER WILLBE IGNITED BYELECTRONIC SPARK.
1.
STOP! READ THE SAFETY INFORMATION
ABOVE ON THIS LABEL.
12. LOCATE PEEP HOLE IN FRONT OF THE PILOT
BURNER. MAKE SURE PILOT IS BURNING.
2. SET THE THERMOSTAT TO LOWEST SETTING.
3. TURN OFF ALL ELECTRIC POWER TO THE
APPLIANCE.
4. THIS APPLIANCE IS EQUIPPED WITH AN IGNITION
DEVICE WHICH AUTOMATICALLY LIGHTS THE
PILOT. DO NOT TRY TO LIGHT THE PILOT BY HAND.
ADVISORY: THERE IS A FIFTEEN (15) SECOND TRIAL
PERIOD FOR PILOT IGNITION WHICH IS TIME ENOUGH
FOR IGNITION WHEN AIR HAS BEEN BLED FROM GAS
LINES PRIOR TO IGNITIION ATTEMPT. IF PILOT FAILS
TO IGNITE AND YOU SUSPECT THAT IT IS DUE TO AIR
IN THE LINES, CLOSE PILOT MANUAL VALVE AND
REPEAT LIGHTING PROCEDURE STEPS 1 THRU 12
5. REFER TO DIAGRAMS ABOVE. TURN TOP KNOB OF
GAS CONTROL CLOCKWISE
POSITION (FIG. A)
, TO "OFF"
13. WITH PILOT FLAME ESTABLISHED, TURN MANUAL
SHUT OFF VALVE CLOCKWISE TO “ON” (FIG D),
TO ALLOW GAS TO REACH MAIN BURNER. NOTE:
6. TURN MANUAL SHUTOFF VALVE COUNTERCLOCK-
WISE TO “OFF” (FIG C). TURN PILOT MANUAL VALVE
COUNTERCLOCKWISE
TO “OFF” (FIG E).
THE REDUNDANT MAIN COMBINATION VALVE WILL
ALREADY BE OPEN, AND MAIN BURNER WILL IGNITE.
ADVISORY: IF MAIN BURNER FAILS TO IGNITE, MAKE
SURE PILOT IS BURNING. IF THE APPLIANCE WILL
NOT OPERATE, FOLLOW THE INSTRUCTIONS BELOW
ON THIS LABEL “TO TURN OFF GAS TO APPLIANCE”
AND CALL YOUR SERVICE TECHNICIAN OR GAS
SUPPLIER.
7. WAIT FIVE (5) MINUTES TO CLEAR OUT ANY GAS.
THEN SMELL FOR GAS, INCLUDING NEAR THE
FLOOR. IF YOU SMELL GAS, STOP! FOLLOW
"B" IN THE SAFETY INFORMATION ABOVE ON THIS
LABEL. IF YOU DON'T SMELL GAS, GO TO THE NEXT STEP
8. TURN TOP KNOB OF GAS CONTROL COUNTER-
CLOCKWISE
TO “ON” (FIG B).
MAIN BURNER
PILOT BURNER
9. TURN PILOT FIRING VALVE CLOCKWISE
(FIG F).
TO “ON”
10. TURN ON ALL ELECTRIC POWER TO THE APPLIANCE
TO TURN OFF GAS TO APPLIANCE
1. T URN OFF ALL ELECTRICAL POWER TO APPLIANCE.
2. T URN TOP KNOB OF GAS CONTRO L VALVE CLOCKWISE
TO “OFF”. (FIG. “A”)
3. T URN MAIN FIRING VALVE COUNTER CLOCKWISE
T URN PILO T FIRING VALVE COUNTERCLOCKWISE
4. SET T HE THERMOSTAT TO LOWWEST SETTING.
TO “OFF” (FIG. C), AND
TO “OFF” (FIG “E”).
210135-000 REV 02
44
REMOVAL OF EXISTING BOILER FROM A COMMON VENTING SYSTEM
At the time of removal of an existing boiler, the following steps Place in operation the appliance being inspected. Follow the
shall be followed with each appliance remaining connected to lighting instructions. Adjust thermostat so appliance will operate
the common venting system placed in operation, while the other continuously.
appliances remaining connected to the common venting system
are not in operation.
Test for spillage at the draft hood relief opening after 5 minutes of
main burner operation. Use the flame of a match or candle, or smoke
from a cigarette, cigar or pipe.
Seal any unused openings in the common venting system.
Visually inspect the venting system for proper size and horizontal After it has been determined that each appliance remaining
pitch and determine there is no blockage or restriction, leakage, connected to the common venting system properly vents when tested
corrosion and other deficiencies which could cause an unsafe as outlined above, return doors, windows, exhaust fans, fireplace
condition.
dampers and any other gas-burning appliance to their previous
condition of use.
Insofar as is practical, close all building doors and windows and
all doors between the space in which the appliances remaining Any improper operation of the common venting system should be
connected to the common venting system are located and other correctedsotheinstallationconformswiththeNationalFuelGasCode,
spaces of the building. Turn on clothes dryers and any appliance ANSIZ223.1and/orCAN/CSAB149, InstallationCodes. Whenresizing
not connected to the common venting system. Turn on any exhaust any portion of the common venting system, the common venting system
fans, such as range hoods and bathroom exhausts, so they will should be resized to approach the minimum size as determined using
operate at maximum speed. Do not operate a summer exhaust fan. the appropriate tables in Appendix F in the National Fuel Gas Code,
Close fireplace dampers.
ANSI Z223.1 and/or CAN/CSA B149 Installation Codes.
GENERAL MAINTENANCE
These boilers are designed to give many years of efficient and MANUAL RESET HIGH LIMIT SWITCH CONTINUITY TEST
satisfactory service when properly operated and maintained.
Do not depress the switch reset button prior to testing. With the
To assure continued good performance, the following
unit cold, disconnect the leads from the switch. With a multimeter
recommendations are made.
place a probe on each side of the switch. If the meter reads zero
the switch is good. If you receive an infinite or OL signal, the reason
could be:
The area around the unit should be kept clean and free from lint and
debris. Sweeping the floor around the boiler should be done carefully.
This will reduce the dust and dirt which may enter the burner and
pilot air passages, causing improper combustion and sooting.
1. Protector switch contacts open.
•
Depress reset button on switch (switch cannot be reset until
water temperature in the boiler coils drop below 200°F). Meter
should read zero.
THE FLOW OF COMBUSTION AND VENTILATION AIR TO THE
BOILER MUST NOT BE OBSTRUCTED.
2. Defective switch or bad leads.
•
With leads attached, depress the switch button. If the meter does
not read zero, the switch is defective and must be replaced.
THE BOILER AREA MUST BE KEPT CLEAR AND FREE
FROM COMBUSTIBLE MATERIALS, GASOLINE, AND OTHER
FLAMMABLE VAPORS AND LIQUIDS.
RELIEF VALVE
Any safety devices including low water cutoffs used in conjunction
with this boiler should receive periodic (every six months) inspection
to assure proper operation. A low water cutoff device of the float
type should be flushed every six months. All relief valves should be
inspected and manually operated at least twice a year. More frequent
inspections may be necessary depending on water conditions.
The safety relief valve should be opened at least twice a year to
check its working condition. This will aid in assuring proper pressure
relief protection. Lift the lever at the top of the valve several times
until the valve seats properly and operate freely.
DANGER
THE WATER PASSING OUT OF THE VALVE DURING CHECKING
OPERATION MAY BE EXTREMELY HOT. BEFORE OPERATING
RELIEF VALVE MAKE SURE DRAIN LINE IS INSTALLED TO
DIRECT DISCHARGE TOASAFE LOCATION SUCHASAN OPEN
DRAIN, TO AVOID SCALDING OR WATER DAMAGE.
Periodic checks, at least twice a year, should be made for water
and/or gas leaks.
More frequent inspections may be necessary depending on
water conditions.
The boiler mounted gas and electrical controls have been designed to
give both dependable service and long life. However, malfunction can
occur, as with any piece of equipment. It is therefore recommended
that all components be checked periodically by a qualified serviceman
for proper operation.
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN THE MANUAL GAS CONTROL VALVE TO
THE APPLIANCE.
45
CLEANING AND FLUSHING INSTRUCTIONS
Pipe joint compounds, soldering paste, grease on tubing and
INTERNAL CONTAMINANTS
pipe all tend to contaminate a system.
Failure to flush contaminates from a system can cause solids
to form on the inside of boiler exchangers, create excessive
amounts of air and other gases to block circulation, foul
various system accessories and even deteriorate circulation
seals and impellers.
The hydronic system must be internally cleaned and flushed
after a new or replacement boiler has been installed to remove
contaminants that may have accumulated during installation.
This is doubly important when a replacement boiler is installed
into an existing system where Stop Leak or other boiler additives
have been used.
It is recommended that after installation, the boiler and system
when filled should include the proper percentage of cleaning
solution related to approximate water volume of the system. Fire
and circulate for about one hour and then flush clean with fresh
water. Commercial grease removing solutions are available
from your distributor.
Failure to clean and flush the system can produce acid
concentrations that become corrosive, cause gases to form
that block water circulation or lead to formation of deposits on
the boiler surfaces, any of which could result in damage to the
system and circulator.
HOT WATER SUPPLY BOILERS PREVENTIVE MAINTENANCE
All hot water heating systems should be completely flushed with
a grease removing solution to assure trouble-tree operation.
For care of the HW water system please refer to the A. O. Smith
Users Information Manual supplied with the Boiler.
PRE-TROUBLESHOOTING
Before any extensive troubleshooting, perform the following:
–
Voltage (24 vac) is supplied by transformer.
Ensure that:
–
Appliance is wired according to wiring diagram.
–
–
Voltage (120 vac) is supplied to the appliance.
Note: Cross wiring the 24 volt circuit of the relay will short the
transformer.
System control (tank temperature control, thermostat, etc.)
is calling for appliance operation (call for heat).
–
–
All wire terminals/connectors are firmly attached to valves,
modules, switches, limit controls, etc.
–
–
Other contacts (switches) are closed (relay, low water cutoff,
flow switch, coil protector, pressure switch, etc.).
For LP models only check for possible lockout condition of
the the ignition module.
Gas supply pressure is within the maximum and minimum
operating ranges listed on the appliance rating plate/label.
46
TROUBLESHOOTING
CER-TEMP 80 RECOVERY SYSTEM CHECKOUT PROCEDURE
Use this checkout for Cer-Temp 80 Recovery Systems. (For hot water supply application only)
System Operation
Checkout Sequence
Cause
Remedy
Replace.
Contact
Incorrect
Tank temperature control
(thermostat) defective.
Pump and burner remain
on.
System wiring is
incorrect.
Circulating pump and
Correct wiring.
Correct wiring.
Set tank temperature burner shut off.
control (thermostat) 20°F
Pump wired for
continuous operation.
Circulating pump on.
Burner on.
(10°C) below tank water With thermal balancer,
temperature.
pump off delay of
approximately 2 minutes.
Gas valve stuck or
defective.
Correct or replace
valve.
System wiring is
incorrect.
Correct wiring.
High limit control set too
low.
Replace. (If problem
proven to be at this
control by applying
jumper to terminals.)
High limit control
differential too wide.
System wiring is
incorrect.
Circulating pump on.
Correct wiring.
Coil protector switch has Remove control cover,
Set tank temperature
activated.
depress reset button.
control (thermostat) 20°F Circulating pump and
(10°C) above tank water burner on.
temperature.
Gas valve or wiring
defective.
Check wiring. Repair or
replace valve.
Power off or system
wiring is incorrect.
Check power supply
and wiring.
Circulating pump and
burner off.
Tank temperature control
(thermostat) defective.
Replace.
System wiring is
incorrect.
Burner on.
Correct wiring.
High limit control
defective, or set too high
(max. should be set at
200°F).
Boiler outlet temperature
Circulating pump on.
Circulating pump and
burner on.
Replace.
exceeds 210°F (100°C).
Set tank temperature
control (thermostat)
for desired water
temperature.
System maintains desired
water temperature.
47
CHECKING HONEYWELL S-8600H OR S-8610M
INTERMITTENT IGNITION CONTROLS
NO SPARK AT PILOT BURNER
Turn off gas supply.
NO
Replace ignition module.
Is voltage (24 Vac) across the 24 V terminals
on module during “Call for heat”?
YES
Is voltage (24 Vac) across the PV & MV/PV terminals on
“call for heat”?
YES
NO
NOTE: S8610M will automatically reset every 5 minutes. S8600H
pilot valve will be de-energized if module goes into lockout
condition. Reset system by turning electrical power off or by
turning system controller to off or down below "call for heat". Wait
one minute, then turn system on.
YES
Turn on gas supply.
Turn on power supply.
Turn off power supply.
Is ignition cable firmly plugged into pilot
assembly and module?
NO
NO
Securely connect cable
and/or ground wire.
Is ground wire firmly attached to pilot assembly and GND terminal
on module?
YES
Replace pilot burner
and/or ground wire.
Are ignition cable and ground wire in good condition
(not brittle, burnt or cracked)?
YES
Ensure ground strap is the closest metal to the igniter/sensor
rod (electrode) to prevent the spark from shorting out to other
metal parts (pilot screen, pilot shield, etc.).
NO
NO
Carefully bend downward
top of ground strap
to achieve 1/8”
Ignition cable must not touch metal surfaces or current
carrying wires.
spark gap.
Is there a 1/8” gap between ground strap and electrode?
YES
Is the ceramic insulator surrounding the electrode
cracked or broken?
Replace Ignition
Module.
YES
Replace pilot burner assembly.
48
CHECKING HONEYWELL S8600H OR S-8610M
INTERMITTENT IGNITION CONTROLS
SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT
Ensure all manual shutoff valves are fully open; all filters are
clean; all gas connections are gas tight; pilot tubing is not
damaged, obstructed or kinked; and pilot orifice is unclogged.
Check for air in gas line, purge (bleed) line if necessary.
YES
NO
NO
Are the wires securely attached to the pilot operator on the gas
control and to the PV & MV/PV terminals on the ignition module?
Attach wires firmly.
YES
Install a pressure gauge in the pilot tubing line between the
gas control and the pilot burner assembly. Ensure that the pilot
adjustment screw (under cap) is adjusted to a position that will
permit gas to flow.
Replace gas valve.
Is pilot gas flowing during ignition attempt?
YES
Turn on power supply.
Turn off power supply.
YES
Is ignition cable firmly plugged into pilot assembly and module?
NO
Securely connect
cable and/or ground
wire.
Is ground wire firmly attached to pilot assembly and GND
terminal on module?
YES
NO
Replace pilot burner
and/or ground wire.
Are ignition cable and ground wire in good condition (not brittle, burnt, or cracked)?
YES
Ensure ground strap is the closest metal to the igniter/sensor
rod (electrode) to prevent the spark from shorting out to
other metal parts (pilot screen, pilot shield, etc.).
Carefully bend down-
wards top of ground
strap to achieve
NO
Ignition cable must not touch metal surfaces or current
carrying wires.
1/8” spark gap.
Is there a 1/8” gap between ground strap and electrode?
YES
NO
Is ceramic insulator surrounding the electrode in good
Replace pilot burner.
condition (not cracked or broken)?
YES
NO
Replace ignition
module.
Is there excessive draft conditions that may cause pilot
burner ignition problems?
YES
Correct draft problems in a manner that would ensure
adequate combustion and ventilation air and proper
pilot burner performance.
49
CHECKING HONEYWELL S-8600H OR S8610M
INTERMITTENT IGNITION CONTROLS
PILOT BURNER LIGHTS BUT MAIN BURNER DOES NOT LIGHT
Correct the situation by consulting the
installation or user’s manual on how to
adjust pilot flame.
NO
NO
Does the pilot flame cover 3/8” to 1/2”
of ingniter/sensor rod?
YES
Replace
ignition
module.
NO
Does spark stay on for more than
15 seconds after the pilot is “proven” (lit)?
Is voltage (24 Vac) across terminals
MV & MV/PV?
YES
Are the wires securely attached to the main
valve operator on the gas control and to
terminals MV & MV/PV on ignition module?
Attach
wires
firmly.
NO
YES
YES
Replace main gas valve.
Ensure the ground wire and ignition cable are
separate from each other (prevents shorting
out).
NO
Replace pilot burner
and/or ground wire.
Are they in good condition (not brittle, burnt or
cracked)?
YES
NO
NO
Is the ceramic insulator surrounding the
igniter/sensor rod in good condition
(not broken or cracked)?
Replace pilot burner.
YES
Is the igniter/sensor rod in good
condition (not worn, corroded, sooted
or damaged)?
Clean rod or replace
pilot burner if necessary.
YES
Replace ignition module.
50
CHECKING HONEYWELL S8600H OR S-8610M
INTERMITTENT IGNITION CONTROLS
NO SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT
Turn off gas supply.
Fix connection and/or
NO
Is there a good connection between terminals?
tighten module to the
appliance.
Is module securely attached to appliance for good ground
connection?
YES
NO
NO
Check the circuit providing
24 VAC.
Is voltage (24VAC) across transformer positive terminal and
GND with "call for heat"?
YES
Is voltage (24VAC) across ignition module terminals 24 Volt and
GND on "call for heater"?
Replace ignition module.
NOTE: (For LP models only) Pilot Valve will be de-energized
if module goes into lockout condition. Reset system by turning
electrical power off or by turning system controller down below
"call for heat". Wait one minute then turn system on.
Turn on gas supply and/or
power supply.
YES
Turn off power supply.
NO
NO
Securely connect cable
and/or ground wire.
Is high voltage cable assembly firmly plugged into module?
Is pilot ground wire firmly attached to the pilot assembly and
GND terminal on module?
YES
Replace pilot burner
and/or ground wire.
Are high voltage cable and ground wire in good condition (not
brittle, burnt or cracked)?
YES
Make sure pilot flame spreader (hood) is the closest metal to
the electrode to prevent the spark from shorting out to other metal
parts (pilot screen, pilot shield, etc).
Carefully bend down-
wards top of ground
strap to achieve
NO
NO
High voltage cable must not touch metal surfaces or current
carrying wires.
1/8” spark gap.
Is there a 7/64" spark gap between the tip (edge) of the hood and
electrode, and is the gap located in the pilot gas stream?
YES
Is the ceramic insulator surrounding the electrode in good
condition (not cracked or broken)?
Replace ignition module.
YES
Replace pilot burner assembly.
51
The following procedures are provided as a general guide.
Table 11
Any module should be replaced if it does not perform properly on
checkout or troubleshooting.
Yellow LED Flame Codes
Yellow LED
Flash Codea
Recommended
Service Action
Indicates
In addition, replace any module if it is wet or looks like it has ever
been wet.
Heartbeat
Normal Flame Signal
not applicable
Weak Flame Signal-
Sytem will operate
reliably but flame
signal is less than
LED STATUS AND TROUBLESHOOTING
The control has two LEDs; one for flame sensing and one for
system status:
Perform routine
maintenance to
assure optimum
flame signal.
desired.
2
NOTE: This indication
may flash temporarily
during or shortly
after lightoff on some
applications.
Marginal Flame Signal
(less than 1.1µA)-
System may not
operate reliably over
time.
Check gas supply,
pilot burner, flame
sense wiring,
Service call
1
recommended.
contamination of
flame rod, burner
NOTE: This indication ground connection.
may flash temporarily
during or shortly
after lightoff on some
applications.
FIGURE 37.
Location of LEDs.
No Flame or Flame
Signal below minimum
threshold for system
OFF
not applicable
•
•
Flame LED (Yellow)
– Indicates flame presence and strength. See Table 11.
operation.
aFlash Code Descriptions:
Status LED (Green)
- Heartbeat: Constant 1/2 second bright 1/2 second dim cycles.
- The flash code number signifies that the LED flashes X times
at 2Hz, remains off for two seconds, and then repeats the
sequence.
– Indicates system operation status and error conditions. See
Table 12 and Table 13 on pages 53 and 54 for status specific
to each model.
52
Table 12.
Continuous Retry Models C, M, E, and K Only - Green LED Status Codes
Green LED
Flash Code
(X+Y)a
Indicates
No "Call for Heat"
Next System Action
not applicable
Recommended Service Action
none
OFF
Flash Fast
Heartbeat
Startup - Flame sense calibration
Normal operation
not applicable
not applicable
none
none
If system fails to light on next trial
for ignition check gas supply, pilot
burner, spark and flame sense
wiring, flame rod contaminated
or out of position, burner ground
connection.
5 minute Retry Delay
- Pilot flame not detected during trial
for ignition
Initiate new trial for ignition after
retry delay completed.
2
3
4
If system fails to light on next trial
for ignition, check gas supply,
code will remain through the ignition pilot burner, flame sense wiring,
Initiate new trial for ignition. Flash
Recycle
- Flame failed during run
trial until flame is proved.
contamination of flame rod, burner
ground connection.
If situation self corrects within 10
seconds, control returns to normal
sequence. If flame out of sequence
remains longer than 10 seconds,
Check for pilot flame. Replace gas
valve if pilot flame is present. If no
pilot flame, cycle "Call for Heat." If
Flame sensed out of sequence
Flame sense leakage to ground
control goes to Flash code 6+4 (see error repeats, replace control.
below).
Check flame sense lead wire for
Control remains in wait mode. When damage or shorting. Check that
the fault corrects, control resumes
normal operation after a one minute
delay.
flame rod is in proper position.
7
8
Check flame rod ceramic for cracks,
damage or tracking.
Control remains in wait mode. When Check transformer and AC line for
the fault corrects, control resumes proper input voltage to the control.
normal operation after a one minute Check with full system load on the
Low secondary voltage supply-
(below 15.5 Vac)
delay.
transformer.
Check gas supply line, pilot burner,
spark and flame sense wiring, flame
rod contaminated or out of position,
burner ground connection.
5 minute Retry Delay
- On every third retry on the same
"Call for Heat"
Initiate new trial for ignition after
retry delay completed.
6+2
6+3
Check gas supply, pilot burner, flame
sense wiring, contamination of flame
rod, burner ground connection.
On every 6th flame failure during run 5 minute retry delay, then initiate
on the same "Call for Heat"
new trial for ignition.
Control waits until flame is no
longer sensed and then goes to
soft lockout. Flash code continues.
Control auto resets from soft lockout
after one hour.
Check for pilot flame. Replace gas
valve if pilot flame present. If no pilot
flame, cycle "Call for Heat." If error
repeats, replace control.
Flame sensed out of sequence-
longer than 10 seconds
6+4
ON
Soft lockout due to error detected
during self check sequences
Control auto resets from soft lockout Reset by cycling "Call for Heat." If
after one hour. error repeats, replace the control.
aFlash Code Descriptions:
- Flash Fast: rapid blinking.
- Heartbeat: Constant 1/2 second bright 1/2 second dim cycles.
- A single flash code number signifies that the LED flashes X times at 2Hz, remains off for two seconds, and then repeats the
sequence.
- X+Y flash codes signify that the LED flashes X times at 2Hz, remains off for two seconds, flashes Y times at 2Hz, remains off for three
seconds, and then repeats the sequence.
53
Table 13.
Lockout Models B, H, D and J Only - Green LED Status Codes
Green LED
Flash Code
(X+Y)a
Indicates
No "Call for Heat"
Next System Action
not applicable
Recommended Service Action
none
OFF
Flash Fast
Heartbeat
Startup - Flame sense calibration
Normal operation
not applicable
not applicable
none
none
If system fails to light on next trial
for ignition, check gas supply,
code will remain through the ignition pilot burner, flame sense wiring,
Initiate new trial for ignition. Flash
Recycle
- Flame failed during run
3
trial until flame is proved.
contamination of flame rod, burner
ground connection.
If situation self corrects within 10
seconds, control returns to normal
sequence. If flame out of sequence
remains longer than 10 seconds,
control goes to Flash code 6+4 (see error repeats, replace control.
below).
Check for pilot flame. Replace gas
valve if pilot flame is present. If no
pilot flame, cycle "Call for Heat." If
4
Flame sensed out of sequence
Flame sense leakage to ground
Check flame sense lead wire for
Control remains in wait mode. When damage or shorting. Check that
the fault corrects, control resumes
normal operation after a one minute
delay.
flame rod is in proper position.
7
8
Check flame rod ceramic for cracks,
damage or tracking.
Control remains in wait mode. When Check transformer and AC line for
the fault corrects, control resumes proper input voltage to the control.
normal operation after a one minute Check with full system load on the
Low secondary voltage supply-
(below 15.5 Vac)
delay.
transformer.
Check gas supply line, pilot burner,
spark and flame sense wiring, flame
rod contaminated or out of position,
burner ground connection.
Failed trial for ignition resulting in
lockout
Remain in lockout until "Call for
Heat" is cycled.
6+2
6+3
More than 5 flame failures during run
on the same "Call for Heat" resulting
in lockout
Check gas supply, pilot burner, flame
sense wiring, contamination of flame
rod, burner ground connection.
Remain in lockout until "Call for
Heat" is cycled.
Control waits until flame is no
longer sensed and then goes to
soft lockout. Flash code continues.
Control auto resets from soft lockout
after one hour.
Check for pilot flame. Replace gas
valve if pilot flame present. If no pilot
flame, cycle "Call for Heat." If error
repeats, replace control.
Flame sensed out of sequence-
longer than 10 seconds
6+4
ON
Soft lockout due to error detected
during self check sequences
Control auto resets from soft lockout Reset by cycling "Call for Heat." If
after one hour. error repeats, replace the control.
aFlash Code Descriptions:
- Flash Fast: rapid blinking.
- Heartbeat: Constant 1/2 second bright 1/2 second dim cycles.
- A single flash code number signifies that the LED flashes X times at 2Hz, remains off for two seconds, and then repeats the
sequence.
- X+Y flash codes signify that the LED flashes X times at 2Hz, remains off for two seconds, flashes Y times at 2Hz, remains off for three
seconds, and then repeats the sequence.
54
LIMITED WARRANTY
A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this boiler.
1. If within TEN years after initial installation of the boiler, a heat exchanger, coil or gas burner shall prove upon examination by the warrantor to be
defective in material or workmanship, the warrantor, at his option will exchange or repair such part or portion. This term is reduced to FIVE years if
this boiler is used for water heating purposes other than hydronic space heating.
a. This warranty is extended to the owner for all other parts or portion during the FIRST year following initial installation of this boiler.
b. The warranty on the repair or replacement of the part or portion will be limited to the unexpired term of the original warranty.
2. CONDITIONS AND EXCEPTIONS
This warranty shall apply only when the boiler is installed in accordance with local plumbing and building codes, ordinances and regulations, the
printed instructions provided with it and good industry practices. In addition, an appropriately sized safety relief valve certified to the ASME Boiler and
Pressure Vessel Code must have been installed and fresh, clean water used for filling and make-up purposes.
a. This warranty shall apply only when the boiler is:
(1) used at temperatures not exceeding the maximum setting of its operative and/or high limit control;
(2) used at water pressure not exceeding the working pressure shown on the boiler;
(3) used when filled with potable water, free to circulate at all times and with the heat exchanger(s) and coil(s) free of damaging scale deposits;
(4) in a non-corrosive and non-contaminated atmosphere;
(5) owned by the original purchaser;
(6) in it's original installation location;
(7) is sized in accordance with proper sizing techniques for commercial boilers;
(8) bearing a rating plate which has not been altered, defaced or removed except as required by the warrantor;
(9) fired at the factory rated input using the fuel stated on the rating plate;
(10) maintained in accordance with the instructions printed in the manual included with the boiler;
(11) in the United States, its territories or possessions, and Canada;
(12) with an intermittent circulating action and with the pump and burner operating together.
(13) in an indoor installation only.
b. Any accident to the boiler, any misuse, abuse (including freezing) or alteration of it, any operation of it in a modified form, or any attempt to repair
leaks in the coil or heat exchanger will void this warranty.
3. SERVICE AND REPAIR EXPENSE
Under this limited warranty the warrantor will provide only a replacement part. The owner is responsible for all other costs. Such costs may include
but are not limited to:
a. Labor charges for service, removal, repair or reinstallation of the component part;
b. Shipping, delivery, handling, and administrative charges for forwarding the replacement part from the nearest distributor and returning the
claimed defective part to such distributor.
c. All cost necessary or incidental for any materials and/or permits required for installation of the replacement.
4. LIMITATION ON IMPLIED WARRANTIES
Implied warranties, including any warranty of merchantability imposed on the sale of this boiler under state law are limited to one (1) year duration
for the boiler or any of its parts. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply
to you.
5. CLAIM PROCEDURE
Any claim under this warranty should be initiated with the dealer who sold the boiler, or with any other dealer handling the warrantor’s products. If this
is not practicable, the owner should contact:
U. S. Customers
Canadian Customers
A. O. Smith Corporation
500 Tennessee Waltz Parkway
Ashland City, TN 37015
Telephone: 1-800-323-2636
A. O. Smith Enterprises Ltd.
P. O. Box, 310 - 768 Erie Street
Stratford, Ontario N5A 6T3
Telephone: 1-800-265-8520
a. The warrantor will only honor replacement with identical or similar parts thereof which are manufactured or distributed by the warrantor.
b. Dealer replacements are made subject to in-warranty validation by warrantor.
6. DISCLAIMERS
NO OTHER EXPRESS WARRANTY HAS BEEN OR WILL BE MADE IN BEHALF OF THE WARRANTOR WITH RESPECT TO THE MERCHANT-
ABILITY OF THE BOILER OR THE INSTALLATION, OPERATION, REPAIR OR REPLACEMENT OF THE BOILER. THE WARRANTOR SHALL NOT
BE RESPONSIBLE FOR WATER DAMAGE, LOSS OF USE OF THE UNIT, INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL PROPERTY,
OR OTHER CONSEQUENTIAL DAMAGE. THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE OF THIS WARRANTY OR OTHERWISE FOR
DAMAGE TO ANY PERSONS OR PROPERTY, WHETHER DIRECT OR INDIRECT, AND WHETHER ARISING IN CONTRACT OR TORT.
a. Some states or provinces do not allow the exclusion or limitation of the incidental or consequential damage, so the above limitations or exclusions
may not apply to you.
b. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
Fill in the following for your own reference. Keep it. Registration is not a condition of warranty. The model and serial number are found on the
boiler’s rating plate.
Owner ___________________________________________________________________________________________________________________
Installation Address _________________________________________________________________________________________________________
City and State/Province _________________________________________________________Postal/Zip Code _______________________________
Date Installed _________________________________ Model No. ___________________________
Serial No.________________________
Dealer’s Name ____________________________________________________________________ Phone No. _______________________________
Dealer’s Address ___________________________________________________________________________________________________________
FILL IN DATA AND KEEP FOR FUTURE REFERENCE
55
500 Tennessee Waltz Parkway, Ashland City, TN 37015
Technical Support: 800-527-1953 • Parts: 800-433-2545 • Fax: 800-644-9306
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