SERVICE HANDBOOK
FOR
STANDARD RESIDENTIAL
GAS WATER HEATERS
(NON POWER VENTED MODELS)
Printed in the USA 0604
$15.00
Part Number STC-080
This service handbook addresses service issues associated with Standard Residential Gas
Water Heaters. Includes C-3 Flammable Vapor Technology.
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
Tools Required:
•
Phillips head screw driver
•
•
•
•
•
•
•
•
•
•
•
3/8, 7/16, ¾ inch open end wrenches
3/16 inch Allen wrench
11/16 inch – 6 point – socket – for anode removal
set of marked drill bits
electrical multimeter
gas pressure gauge or monometer
water pressure gauge
thermometer
tubing cutter if pilot tube is to be replaced
hose – to drain tank
container – to measure gallons per minute flow
MISCELLANEOUS INFORMATION
Draw efficiency is the quantity of hot water available to the consumer before the outlet water
temperature decreases 25 degrees F. A 40 gallon water heater will typically provide 70% (28
gallons) of this “usable” hot water. The burner is allowed to operate during this test. Incoming,
cold water mixes the remaining stored water below this 25 degree limitation.
Energy Factor is an indicator of the combined thermal efficiency and standby efficiency of a
water heater. The higher the energy factor, the more efficient the water heater will be.
Recovery rate is the amount of water that is heated to a set temperature, per hour. An
example might be that a water heater has a recovery rate of 30 gallons of water per hour at 80
degree F. (Fahrenheit) temperature rise.
“R” Value is a measure of the resistance of a substance to heat flow.
Thermal efficiency is approximately the amount of generated BTU (British Thermal Units),
which enters the water. A percentage of the total BTU passes out through the vent piping.
Temperature rise is the increase in the temperature from its coldest “inlet” water temperature
to the desired hot (outlet) setting. Typically this is assumed to be 40 degrees entering water;
120 degrees desired stored water or 80 degrees “temperature rise.”
Standby efficiency – the water heater’s ability to contain heat in the tank. A minimum of tank
water heat loss per hour is desired.
Sample: temperature change = Btu/h loss/ square foot of tank surface
“R” value
Water cannot (for all practical purposes) be compressed.
Water expands when it is heated.
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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Water Hammer – is a concussion of moving water against the sides of a containing pipe or
vessel on a sudden stoppage of flow.
EX: 1/2 “copper pipe, 5GPM flow (7.2ft/sec.) – stop. Pressure rise of approximately 412 PSI.
3/4” copper pipe, 5GPM flow (3.3ft/sec) – stop. Pressure rise of approximately 188 PSI
Minerals and gases will separate from water as temperature increases.
Formulas:
Btu (British Thermal Unit) is the heat required to raise 1 pound of water 1°F
1 BTU = 252 cal = 0.252 kcal
1 cal = 4.187 Joules
BTU X 1.055 = Kilo Joules
BTU divided by 3,413 = Kilowatts
To convert from Fahrenheit to Centigrade: (° F – 32) times 5/9, or .556, equals degrees C.
One gallon of (120° F, 49°C) water weighs approximately 8.25 pounds.
Pounds X .45359 = Kilogram
Gallons X 3.7854 = Liters
% of Hot = (Mixed Temp. – Cold) divided by (Hot Temp. – Cold)
% Thermal Efficiency = (GPH X 8.25 X Temp. Rise X 1.0) divided by BTU/H Input
Btu Output = GPH X 8.25 X Temp. Rise X 1.0
GPH = (BTU/H Input X % Eff.) divided by (Temp. Rise X 8.25)
One cubic foot of Natural Gas contains about 1000 BTU of heat.
One “therm” is equal to 100,000 BTU
One cubic foot of Propane Gas contains about 2500 BTU of heat.
One gallon of Propane gas contains about 91,250 BTU of heat.
One pound of Propane gas contains about 21,600 BTU of heat.
One pound of gas pressure is equal to 27.7 inches water column pressure
Inches of Water Column X .036091 = PSI
Inches of Water Column X .073483 = Inches of Mercury (Hg.)
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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Centimeters = Inches X 2.54
MM (millimeters) = Inches X 25.4
Meters = Inches X .0254
Doubling the diameter of a pipe will increase its flow capacity (approximately) 5.3 times.
CONSTRUCTION:
Tank is constructed of steel.
The inside of the tank is constructed of a glass lining bonded to the steel. This prevents
water to metal contact and rusting of the tank.
An anode rod will be installed within the tank. The hex-head plug end of the anode is visible
on the top of the water heater. This metal rod offers secondary protection of the tank against
corrosion where the application of glass is not possible (threaded tank openings). These areas
will have small areas of water to metal contact.
All water heaters will contain at least one thermostat (to operate the heater) and one high
limit (to prevent water temperatures approaching the “steam” level).
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INSTALLATION OF RESIDENTIAL GAS WATER HEATER
Water
Exhaust Vent to
Shut Off
Outside of Building
Valve
Union
Union
Expansion Tank
Pressurize to Equal
Supply Water
Pressure
See Manual and
Labels For Installation
Clearances
Temperature And
Pressure Relief
Valve – Do Not
Reuse Old Valve.
Typical Model
and Rating
Plate Location
Temperature and
pressure relief valve
tube piped to within 6”
of drain.
Maximum Gas Supply
13.8” W.C. or ½ PSI
Minimum
Thermostat –
4.5” W.C. –Natural Gas
11.0” W.C. Propane Gas
recommended starting
point - 120°F.
Safety Pan – Piped to
Drain
Drain
Air Is Drawn In For
Combustion. Keep
area clean and free
from flammables and
flammable vapors
Inner and
Outer Doors –
Reinstall After
Lighting Pilot.
Installation Must Follow Local Codes and Instruction Manual Guidelines
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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RESIDENTAL GAS WATER HEATER SERVICE
This portion of this manual applies to the Operations and Servicing of Residential Gas, Tank
Type, Water Heaters, which are vented atmospherically and use a thermocouple as their
electrical source.
Control: There is one control on this style of water heater. The control has a main gas
regulator, pilot gas regulator, on-off-pilot knob, controls water temperature, has a temperature
adjustment knob, and a high water temperature limit safety.
σ(delta)
Note: The word “Hot”
may or may not be
present on the control
knob
6
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Residential Gas – continued
Burner: The burner assembly consists of the main burner, main burner orifice, main burner
gas supply tube, pilot burner, pilot burner orifice, pilot burner gas supply tube and thermocouple.
The pilot burner remains on once it is manually lit. When incoming cold water activates the
thermostat, gas flows to the main burner. The pilot flame ignites this gas. The main flame
burns until the tank reaches set temperature then the thermostat interrupts this main gas flow.
AFTER HAVING CONFIRMED THAT THE WATER HEATER HAS BEEN INSTALLED
PER THE INSTALLATION MANUAL INSTRUCTIONS:
Normal Operation
Electrical: The Pilot Flame heats the end of a thermocouple. As the thermocouple is heated,
it generates a small (cannot be detected without an electrical meter) electrical current to the
bottom of the control valve. This current powers the electromagnet and holds open the safety
valve as long as the pilot flame is heating the thermocouple. DANGER! If the pilot is
extinguished, it can take up to 180 seconds for the thermocouple to cool sufficiently to close the
safety valve.
See also C3 technology product information beginning on page 15 .
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Residential Gas – continued
Temperature: Two metal probes mounted
onto the back of the control are immersed
inside the tank water. One probe (the
shorter) acts as a temperature high limit. If
water gets excessively hot, a sensor within
the probe opens, interrupts the small
electrical current to the gas valve, and gas
flow through the control is interrupted. If this
safety sensor opens, the entire control must
be replaced.
The longer probe contains a metal rod that
expands and contracts as water temperature
around the probe cools and heats. As the
rod expands, it pushes against a lever
actuated gas valve. If the regulator is
pushed sufficiently, gas flow is interrupted to
the main burner. Adjusting the temperature
dial changes the distance the rod must
expand or contract to open or close the gas
valve.
Gas: When you prepare to light the pilot,
you are instructed to turn the top
knob to the pilot position and depress
the knob. When the knob is
depressed gas will flow to the pilot
burner only. You then have to
(manually) ignite this pilot gas. When
the pilot is lit, the flame must heat the
thermocouple until it generates
sufficient electricity to the gas valve
to allow you to release the knob while
gas continues to flow to the pilot.
When the top knob is turned to the
“ON” position, gas is also available to
the main burner if the thermostat calls
for heat.
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Residential Gas - continued
Water Flow: When a hot water faucet is opened, water pressure from the well tank or street
main forces cold water into the water heater. This pushes hot water out of the tank.
Operation: A residential water heater is not a precise operating appliance. Because the water
heater relies on the expansion and contraction of a metal rod, when the thermostat dial is set at
an indicated setting (“▲” is recommended as a starting setting. This is approximately 120
degrees F.) The heater may shut off at 110 to 130° F. The heater will consistently shut off at
this same temperature. For this same reason, water temperature may drop 15 - 25° F, around
the temperature probe, before the main burner is activated. Keep in mind that hot water in the
upper part of the tank will probably be very near the “shut off” temperature of the control while
incoming cold water drops the water temperature around the thermostat probe. Also, short
repeating heating cycles caused by small hot water uses can cause temperatures at the point of
use to exceed the thermostat setting by up to 30° F.
Setting Approximate Temperature (°F) Time To Produce 2nd & 3rd
Degree Burns on Adult Skin
120° ± 10°
130° ± 10°
140° ± 10°
150° ± 10°
160° ± 10°
5 Minutes
30 Seconds
5 Seconds
Hot (▲)
A
B
C
1.5 Seconds
Under 1 Second
Very Hot
9
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Residential Gas - continued
Service:
Air: A gas burning appliance requires the oxygen contained in 12.5 cubic feet of air (at sea
level) for every 1000 BTU of heat that is generated. If your water heater has a BTU per hour
input of 40,000 BTU then a minimum of 500 (40 times 12.5) cubic feet of clean air must be
available. This oxygen will mix with the gas for a clean, blue flame in the burner chamber and
provide dilution air for flue products.
(Enters
Here)
12.5
Cubic
Feet of
Air
1,000
BTU
Fuel
+
=
(Enters Here)
Do not forget that your gas (or oil) furnace and gas clothes dryer also require a like amount of
air.
When calculating air supply provisions, also consider the presence of whole house exhaust fans
or other exhaust fans competing for the same air supply.
Air must be allowed to enter the heater chamber from the base of the heater and also enter the
flue vent from below the draft hood. Do not block these areas with insulation blankets or
obstructions lying around the base of the heater.
Lack of Oxygen: If a sufficient supply of oxygen (air) is not available for combustion and
dilution, the result will be:
•
•
•
Pilot outage
Yellow burner flame
Sooting water heater
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State Water Heater
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
•
•
Possible carbon monoxide
Smell of burnt gas in the room
Residential Gas – continued
The instruction manual gives guidelines under “Air Requirements” and “Unconfined “ or
“Confined Space” sections. If you want to test for a lack of air:
1. Turn on every appliance and fan that exhausts air from the utility room and/or house.
Make sure all windows and doors are closed, as well as chimney dampers.
2. Open a hot water faucet so that the main burner will ignite
3. Remove the outer door of the water heater – not the inner door
4. Monitor the flame characteristics for several minutes
If the flame begins to “yellow” open a door or window, to the outdoors, to see if additional air
corrects this back to blue. If it does, the room needs more air supply. Perform draft test at draft
hood of water heater with match or smoke source to verify.
Testing with
Gas
Pressure
Gauge
Pilot Gas
Pressure
Test
Manifold
Gas Pressure
Test
Gas pressure checks are done with flowing gas.
Supply gas pressure checks are taken ahead of the gas control and as close to the heater
as possible.
Pilot gas pressure checks are taken by using fitting adapters to tap into the pilot gas tubing.
Manifold (main burner) gas pressure is measured using the Allen wrench tap on the
bottom of the control valve.
Desired gas pressures will be noted on the gas valve label.
If …
… then
supply gas pressure is under desired pressure
setting
•
increase supply gas pressure regulator
setting and,
•
•
•
increase supply gas piping size.
add gas pressure regulator.
reduce setting on existing regulator.
supply gas pressure is over desired pressure
pilot gas pressure is more than +/- .3 inch
W.C. from desired
replace the control valve.
manifold gas pressure is more than +/- .3 inch replace the control valve.
W.C. from desired
Additional considerations when pilot or main burner flames are too large or too small:
•
•
Incorrect orifice
Dirt in orifice or gas supply tubing
11
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Residential Gas - continued
Sooting causes:
If …
… then
the burner is clean but the chamber and/or flue check for lack of supply air.
are sooted
the main burner, chamber and flue are sooted check the following:
•
•
•
•
•
•
incorrect orifice
excessive gas pressure
loose main burner
cross threaded orifice
gas control valve gas seepage
loose gas connection in burner assembly.
Electrical Testing
This type of water heater has its own electrical
generating system.
When two dissimilar metals are joined together
and this joint is heated, a small, electrical current
will be produced. A thermocouple uses this
science.
TO GROUND
Thermocouple output test
Procedures/Conditions:
Meter set for DC millivolt testing
Test from lower ECO (emergency cut off or energy cut off) solder joint to ground.
Note: If pilot will not stay lit, manually hold the top knob down in the pilot position. This allows
gas to flow to the pilot. Light the pilot and continue to hold this knob down while conducting the
test.
If …
… then
reading test of at least 13 mV is not present
•
check that flame contacts end of
thermocouple
•
replace thermocouple.
reading test of at least 13 mV is present
continue to next test.
12
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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Residential Gas - continued
Electrical Testing– continued
Millivolt dropout test through copper magnet winding and ECO (Emergency Cut Off)
Procedure: Move meter probe to upper ECO solder joint and ground
If …
… then
replace the control valve.
replace the control valve.
reading of at least 10 mV is not present
reading of more than 10 mV is present but,
gas to the pilot shuts off each time knob is
released
Safety drop out test –
The safety gas shutoff should interrupt gas through
the valve when mV current drops to 1-3 mV.
Procedures:
Meter still connected to upper ECO solder joint and
ground.
Turn Top Knob to “off” position
Millivolt output will decrease as thermocouple cools
TO GROUND
If…
… then
replace the control valve.
internal safety does not activate between 1
and 3 mV (you will hear a “click” inside the
valve)
*internal safety does activate between 1 and valve is within tolerance and will interrupt gas
3 mV flow if pilot looses heat or ECO opens.
*Note: A “click” sound should be heard from the valve as the main gas interrupter snaps up to
the “closed” position.
Condensation
Flue gas products contain moisture. If these flue gas products are cooled to their “dew point”,
they become visible moisture – condensation.
Flue gas may become cooled by:
•
•
Cold supply air temperatures
Cool surfaces – generally, if tank water temperatures drop below 110°F, the flue pipe
surface and/or bottom tank head will be cool enough to cause condensation.
Increased combustion efficiency – higher thermal efficiency means that an increased
amount of heat is transferring from the flue gas into the water. If you transfer
(approximately) 87.5%, or more, the moisture in the flue gas will condense.
•
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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Residential Gas – continued
Condensation is a mild acid – it will corrode steel
Condensation is usually noted when:
•
•
•
•
water dripping is heard (only) while the main burner is on,
there is “water” around the heater just after the heater has been operating,
there are small, black or red granules on the main burner or top of the heater or
corroded jacket or vent piping is noted.
If …
… then
any of the above conditions exist
•
•
•
raise the supply air temperature or
increase stored water temperature or
increase the size of the tank
You would not wish to lower combustion
efficiency – this would waste gas. Use
materials (stainless steel, PVC etc.) that
will not be affected by the condensation
Suggested Multiple Heater Water Piping Required For
Proper Operation of Top Connect Models
Installed in accordance with local codes.
TEMPERATURE/PRESSURE RELIEF VALVES
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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Residential Gas – continued
Exhaust Venting Notes
Follow current National Fuel Gas Code requirements for proper installation.
“D” – Typically, same or larger diameter as Draft
Hood outlet
“L” – Horizontal piping slopes upward ¼” per foot
from heater to chimney or vertical vent
Length of horizontal not more than 75% of “H”
“H” – Not less than 5 feet
Maximize vertical distance to first elbow
FLAMMABLE VAPOR IGNITION RESISTANT (FVIR) DESIGN
This section will address the changes brought about by the introduction of FVIR compliant
products. Other than items mentioned here, the construction, installation, and service will
remain the same as discussed in the primary handbook.
The FVIR acronym stands for "Flammable Vapor Ignition Resistant." The State products are
based on "Corderite Combustion Containment" known as “C3 Technology™” . The C3
Technology design features a sealed (from non designated air intake openings) combustion
chamber and a "flame arrestor" component.
This class of residential gas water heaters meet the new ANSI standards and testing protocols
(ANSI Z21.10.1) established to deal with the accidental or unintended ignition of flammable
vapors, such as those emitted by gasoline. Virtually all gas-fired, atmospherically vented,
residential water heaters manufactured in the United States with BTU ratings of 75,000 or less
are required to meet this new ANSI standard effective July 1,2003. The current implementation
schedule for C3 TECHNOLOGY compliant residential gas-fired products is shown in the
following table. These dates are subject to change.
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IMPLEMENTATION ANTICIPATED
CLASS OF PRODUCTS
CATEGORY
INTRODUCTION
INCLUDED IN THIS CATEGORY
July 1, 2003
30, 40, and 50 gallon atmospheric vented.
Phase I
(July 1, 2004* Can.) (Manufactured housing models are excluded.)
30, 40, and 50 gallon power-vented models.
January 1, 2005*
Phase II
Phase III
(Manufactured housing models are excluded.)
All other gas-fired models with inputs of 75,000 BTU
July 1, 2005*
or less.
* Subject to change. This supplement addresses the July1, 2003 compliant products.
In addition to the standard water heater design discussed in the main service handbook, the C3
Technology design also includes:
•
•
•
A LDO (Lint Dust and Oil) screen over the combustion air intake
A Flame Arrestor
A combustion chamber Thermal Cut Off (TCO) limit
An additional tool for these products might be a vacuum cleaner with both blowing and
vacuuming capabilities. Also include the long, narrow crevice accessory.
LDO SCREEN (LINT, DUST, OIL) SCREEN(S)
An easy to clean screen designed to minimize lint, dust and oil based contaminants from being
drawn into the “Flame Arrestor” along with make up – combustion - air. There may be one or
two of these screens. The LDO screen must be installed with the arrows on the right and left
side facing up to function properly. (The arrows are located on two mounting tabs on each side
of the screen).
Service:
Inspect the LDO screen(s) regularly. Clean or wash as necessary.
Pulling the tab located in the middle of the screen will remove the screen. Reinstall the clean
screen by inserting the end tabs into the jack with the arrows pointing up.
Possible Service issues associated with a blocked screen:
•
•
•
Poor combustion – yellow flame, possible sooting
Pilot outage resulting from a lack of oxygen
Pilot outage resulting from to increased combustion chamber temperature below the
main burner. This may open the automatic reset, thermal cut off switch (TCO).
16
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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FLAME ARRESTOR
Made from Corderite, a fireproof ceramic material, the flame arrestor is built into the base of
the water heater. Combustion air is drawn in through the LDO screen (s). After entering the
bottom area of the water heater, this air passes up through the small ports of the flame
arrestor and into the combustion chamber.
In the event flammable vapors are introduced accidentally into the combustion chamber, the
flame arrestor is designed so any flames burn off the top surface of the arrestor and cannot
escape down through the arrestor. The arrestor works somewhat like a check valve.
Service:
Inspect the bottom ports of the flame arrestor by removing the LDO screen (s) and using
a mirror and flashlight. Clean the ports if necessary by vacuuming the bottom of the
arrestor.
Inspect the top of the flame arrestor by removing the inner door and burner assembly.
Lift the heat shield located on the bottom of the chamber. Inspect with the mirror and
flashlight. Vacuum or blow down any blocking material. If you blow down through the
ports, be certain to also vacuum below the arrestor.
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If there has been a flammable vapor ignition, a qualified service agent needs to inspect
the arrestor for cracks. The arrestor is not a replaceable part – the heater would need to
be replaced.
Possible service issues associated with the flame arrestor.
•
•
Poor combustion – yellow flame, sooting, possible carbon monoxide production.
Pilot outage due to lack of oxygen. Continued pilot outage or finding that the LDO
screen(s) is heavily blocked would warrant inspection of the flame arrestor.
Pilot outage due to increased combustion chamber temperatures below the main burner.
This may open the automatic reset, thermal cut off switch (TCO).
•
•
The flame arrestor having contained a flammable vapor ignition. The TCO will open and
the chamber and arrestor should be inspected by a qualified service agent.
COMBUSTION CHAMBER TEMPERATURE SENSOR
The C3 Technology water heaters will come equipped with a thermal cutoff (TCO)
device that is integral with the thermocouple. Temperature cutoff points range from
160°C to 200°C depending on model. The TCO is an automatic reset thermal switch.
When activated it will open the thermocouple circuit and shut off the main and pilot
burner gas flow. The pilot would have to be relit after the TCO has had sufficient time to
cool down (sensor is below 120 degrees F).
In addition to printing the temperature setting on the TCO, a label located near the gas
valve attachment end of the thermocouple notes the temperature setting of the TCO.
The TCO performs two primary functions:
•
In the event of flammable vapor ignition inside the combustion chamber, it
senses the corresponding increase in temperature and shuts off gas flow to the
main and pilot burners.
•
If excessive temperatures inside the combustion chamber indicate poor
combustion due to a clogged LDO screen or inadequate air for combustion, the
TCO will shut off gas flow to the main and pilot burners.
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RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
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SERVICE:
There is no routine service associated with the TCO. The standard thermocouple millivolt output
checks described in this service handbook still apply. Millivolt readings indicate that the TCO is
closed. An open TCO (within a cool chamber) would indicate that the assembly must be
replaced.
The TCO is an integral part of the thermocouple and not replaceable as a separate item. A pilot
burner assembly must be reinstalled. On repeated calls of no hot water or pilot outage, a
clogged/dirty LDO screen might be the cause and should be checked. Keep in mind this TCO
will shut off the pilot and main burner when activated.
With the different cutoff temperature set-points of TCO devices for different model water
heaters, it is important that the correct part is used when replacement of the pilot burner
assembly is necessary.
Possible service issues associated with the Thermal Cut Off switch being opened:
•
Pilot outage due to increased combustion chamber temperatures below the main burner.
This may open the automatic reset, thermal cut off switch (TCO).
•
The flame arrestor having contained a flammable vapor ignition. The TCO will open and
the chamber and arrestor should be inspected by a qualified service agent.
ONE PIECE PILOT BURNER ASSEMBLY
C3 Technology models feature a "one piece" pilot burner assembly. There are five main
components that make up this pilot assembly:
1. Thermocouple with integral Thermal Cut Off switch (TCO).
2. Pilot burner w/orifice and tubing
3. Piezo igniter cable
4. Pilot assembly seal/grommet (orange).
5. An inner door gasket (white) will also be included.
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To replace a pilot assembly:
Turn off the gas supply
Disconnect the piezo cable from the piezo button (connection near gas control
valve).
1.
2.
3.
Disconnect the pilot tubing, thermocouple and main burner tube from the bottom of
the gas control valve.
4.
5.
6.
7.
8.
Remove (2) 3/8 inch nuts securing the inner door.
Remove the entire burner assembly.
Remove screw securing pilot burner assembly to pilot mounting bracket.
Remove pilot assembly - with orange gasket – from the back side of the inner door.
Reinsert new pilot assembly into back side of inner door. Wetting the orange gasket
may help in securing the gasket into place.
9.
Reattach the new pilot assembly to the pilot mounting bracket.
10.
Inspect/replace the white, inner door gasket before making the connections to the
bottom of the gas control valve.
11.
12.
13.
14.
Reattach the piezo cable to the piezo button.
Remount the inner door.
Follow the pilot lighting instructions including gas and gasket leak checks.
Install the outer door.
SEALED COMBUSTION CHAMBER
The combustion chamber is factory sealed around the flame arrestor and the upper and lower
perimeter of the chamber. Access for service is provided through an inner door as with current
product. However, this inner door is now sealed with; a door gasket, a pilot assembly grommet
type seal, and a main burner tube boot/sleeve type seal.
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The three seals on the inner door should be checked every time any service is performed. The
sight glass should be checked to insure it is not damaged or missing. The pilot tube and
thermocouple routing should be straight (not bent at an angle close to the surface of the seal) as
it passes through the pilot assembly seal.
A "five point inner door seal inspection" is outlined below:
Five point inner door seal inspection:
1. Inner door gasket condition and fit.
2. Main burner tube seal condition and fit.
3. Pilot assembly seal condition and fit.
4. Sight glass, condition; present, not broken or cracked.
5. Straight routing of the thermocouple and pilot burner tube through the pilot assembly
seal.
These are all critical to maintaining the C3 TECHNOLOGY integrity of the combustion
chamber.
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PIEZO IGNITER
C3 TECHNOLOGY models will feature a Piezo igniter to light the pilot burner. The push button
switch will be located on the top of the gas control valve. There will be a plug connector
between the push button and the igniter wire which is part of the pilot burner assembly.
Important Service Reminder
Any time service is performed on C3 TECHNOLOGY product the Five Point Inner Door Seal
Inspection outlined in the Sealed Combustion Chamber section should be performed and the
LDO Screen (s) should be inspected for proper installation (arrows up) and cleaned before
leaving.
Other features
All C3 TECHNOLOGY models will feature Green Choice by having a low NOx (nitrous oxide)
burner which meets SCAQMD rule 1121. All C3 TECHNOLOGY models will have a brass drain
valve standard.
See the “Technical Bulletins Section “ of this manual for explanations of:
Water Hammer
Mineral Buildup
Aluminum Hydroxide
Condensation
Discolored Water
Smelly Water
Chlorination Process
Lack of hot water
Thermal Expansion
Temperature and Pressure Relief Valve Operation
Parts Replacement – The parts on these models may change due to improvements/changes
in the products. To order the current, correct replacement part for your model gas water heater,
you must know the model number and (complete) serial number of your water heater. This
information will be located on a black and white label, on the front of your water heater. This
label will also display a star within a circle (the CSA symbol).
To order parts, contact your local State Water Heater Contractor or Distributor,
phone State parts at 800-821-2018 or contact State on Web site
“www.statewaterheaters.com”
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WHY WATER HEATER TANKS LEAK
WHAT
Water
Pressure
WHY
PREVENTION
A Temperature and Pressure Relief
Valve limits pressure to a
maximum.
Adding a Thermal Expansion Tank
limits pressure to near supply water
pressure.
Water expands when it is heated
(Thermal Expansion). Water
cannot be compressed.
Excessive Pressure in the tank
causes failure of joints, welds or
gaskets.
Condensation) Products of combustion contain
moisture. As the combustion
products cool the moisture
becomes liquid – carbonic acid.
The acid attacks the metal.
Higher efficiency water heaters
have cooler gases.
Install a water heater with capacity
to minimize significant stored water
temperature drop during usage.
Store water at a higher temperature
– install a mixing valve to reduce
danger of scalding.
Recommended water storage
temperatures create cooler
surfaces.
Contaminated Bleaches, floor waxes,
Supply the heater with clean air.
“Direct Vent” water heaters use air
from outside of the building for
Air
detergents, salt and many other
household products contain
chemicals which, when drawn into combustion.
contact with a flame (a gas water
heater uses 12 cubic feet of air for
each 1000 BTU of heat
generated). When these
chemical vapors or dusts come
into contact with a flame or
electrical contact, various acids
form. These acids attack the
metal.
Soft Water
Soft water minimizes mineral
buildup within the tank. Minimal
minerals maintain the water
heater at high efficiency but may
also expose interior surfaces to
corrosion. Mineral buildup in
some heaters prevents them
leaking while greatly reducing
efficiency.
A metal “Anode” rod within the tank
helps to prevent internal corrosion.
Maintain the self sacrificing “anode”
rod by inspecting the rod annually
and replacing when large “gouges”
appear in its surface.
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WHY WATER HEATER TANKS LEAK -
WATER CONDITIONS
Continued
WHAT
WHY
PREVENTION
“Hard” Water
“Hard” water contains minerals.
As water is heated the minerals
separate from the water and
attach to hot surfaces within the
tank. In gas water heaters, these
minerals “insulate” the heat
transfer surfaces conducting heat
from the burner through to the
water. These surfaces become
hotter than if they were clean.
Hotter surfaces mean more
expansion and contraction of the
metal as the burner cycles on and
off. The metal or weld joints
crack.
“Flush” the sand from the tank every 6
months.
Delime the tank interior yearly.
Install a water softener in hard water
areas. These should be adjusted
according to manufacturer’s
recommendations, typically for 5 grains
hardness.
Water
Temperature
Begin with a water heater setting of
120°F (49°C) and increase only as
necessary.
Purchasing a proper sized tank will
minimize burner or element operation
when only small quantities of hot water
are used.
Water stored at 160°F (72 °C)
may be twice as corrosive as
water stored at 140°F (60°C)
Each time the burner or elements
cycle on and off, a small amount
of metal expansion and
contraction take place. As
bending a piece of wire back and
forth will break the wire, this
expansion and contraction will
eventually crack tank joints or
welds.
Usage
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TECHNICAL BULLETIN - 11
WATER HAMMER
Water hammer is the destructive forces, pounding noises and vibration in a piping
GENERAL
system when water flowing through a pipeline is stopped abruptly. When water
hammer occurs, a high intensity pressure wave travels back through the piping
system until it reaches a point of some relief. The shock wave will then surge back
and forth between the point of relief and the point of stoppage until the destructive
energy is dissipated in the piping system. The violent action accounts for “banging”,
“thumping”, and/or intense vibration in the pipe line. Although noise is generally
associated with the occurrence of water hammer, it can occur without audible sound
or noise. Quick closure always causes some degree of shock with or without noise.
The common cause of water hammer is single lever faucets (sinks/lavatories) or
automatic solenoid valves (dishwashers, washing machines, etc.). The speed of the
valve closure time is directly related to the intensity of the surge pressure.
The damage from water hammer can manifest itself in a number of ways. The most
common are:
EFFECTS
•
Expanded Tank Shell - This can be demonstrated by measuring the circumference at
various locations along the shell. Pressures in excess of the maximum design working
pressure can cause permanent deformation of the shell.
•
Collapsed Flue Tube - This will choke off the ability to vent the products of combustion
causing the flame and/or combustion to spill out from the combustion chamber. Often
this will occur where thinning of the flue tube walls has occurred due to contamination
of the combustion air or because of excessive condensation.
•
Inverted or Deformed Tank Heads - Often this accompanies collapsed flues, but one
or both heads can be deformed.
The only effective means of control is to install water hammer arrestors. These
devices have diaphragms, which separate an air chamber from the water in the piping
system. As the shock wave reaches this device, the air chamber absorbs the shock.
Arrestors should be located as close as possible to the source of the shock wave.
THE FIX
NOTES
Since water hammer exposes the equipment to pressures in excess of its design
limits, failures caused by water hammer are not eligible for warranty consideration.
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TECHNICAL BULLETIN - 13
MINERAL BUILD-UP
•
Rumbling
•
Crackling
•
Popping
SYMPTOMS
CAUSE
With the advent of high input and larger storage tanks in both commercial and
residential heaters, deliming has become a necessity of modern maintenance.
Lime (CaCO3), is the most notable factor when discussing water hardness.
Lime is present in every water system to some degree across the entire
United States. Since lime is inversely soluble [the more you heat, the more
lime comes out], higher usage, excessive hardness, and increased heating
surface can lead to a high incidence of “limed-up” heaters.
Symptoms often include a popping of water trapped under lime deposits or
the sizzling of water trapped next to elements, boiling it to steam.
Treatment of a “limed-up“ heater is relatively simple. Since CaCO3 is a base,
the easiest way to dissolve it so it can be flushed from the heater is with an
acid. The most commonly used is phosphoric acid at a food-grade level.
THE FIX
Two common treatments available from State are Mag-Erad® and Un-Lime®.
Any well-stocked plumbing supply house should have a deliming solution
available.
The directions on the product should be followed explicitly.
For additional information and instructions in deliming water heaters and
boilers, please refer to the following pamphlets available from State:
NOTES
•
Why? When & How: To Remove Water Scale from Tank Type Water
Heaters
•
•
•
The Mag-Erad® Method of Cleaning Gas Fired Water Heaters
Up-N-Down™ Transfer Kit
All About Deliming Coil Type Water Heaters
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TECHNICAL BULLETIN - 14
ALUMINUM HYDROXIDE
“Crackling”, “gurgling”, or “popping” noises from new water heaters (installed less than
six months).
SYMPTOMS
In a few isolated parts of the United States where the water supply has a relatively high pH (8+),
CAUSE
water conditions will react with the aluminum anode to form excessive amounts of aluminum
hydroxide on the anode and in the bottom of the tank. Aluminum hydroxide looks like “jelly
beads” or a green, blue or gray gel like substance in the heater drain or at faucet aerators.
This procedure should only be performed by someone with abilities equal to a licensed
tradesman. Aluminum hydroxide can be removed by using one of the methods outlined.
THE FIX
If tank is new with no lime build-up to any degree:
1
2
3
4
Turn off the heater.
Remove the anode.
Flush the tank thoroughly with water.
Replace the aluminum anode (identifiable by smooth surface on plug) with magnesium
anode (identifiable by weld bead on plug).
If the tank is new with lime build-up to any degree:
1
2
3
4
Turn off the heater.
Drain the heater.
Remove the anode.
Add UN-LIME to the tank.
20-40 gallon models (use 3 gallons of UN-LIME)
41-65 gallon models (use 5 gallons of UN-LIME)
66-100 gallon models (use 7 gallons of UN-LIME)
(On electric models, be certain the lower element is immersed in solution.)
5
Heat the UN-LIME to a temperature between 140°F to 160°F.
•
GAS - Heat for 7 to 10 minutes.
6
7
8
9
Shut off the water heater.
Allow the heated UN-LIME to stand for up to 12 minutes.
Drain and flush the tank. Caution: UN-LIME will still be hot.
Replace the original aluminum anode with a magnesium anode.
10 Fill the system with water.
11 Turn heater fuel “ON”.
NOTE
Since aluminum hydroxide is a product of a chemical reaction dependent on the water condition,
any treatment is not considered warranty related.
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TECHNICAL BULLETIN - 21
DISCOLORED WATER
Rusty, brown, black, or yellow water appearing in the hot water.
SYMPTOMS
Complaints of discolored water are commonly blamed on water heaters and
CAUSE
storage tanks, but in fact, it is a rare occurrence for today’s high quality glass
lined tanks to have a lining failure significant enough to allow water to contact
enough bare metal to discolor the contents of even a small tank.
The most common cause of “rusty” water is a non-toxic iron reducing bacteria,
scientifically termed Crenothrix, Leptothrix, and Gallionella. Iron bacteria is
commonly found in soil, water wells, water treatment plants and water
distribution piping systems where soluble iron exceeds 0.2 ppm, higher levels
make conditions even more favorable. Soluble iron in the water provides food
for the bacteria. Rusty discolored water is the end result of the bacteria feeding
process. Water heaters and storage tanks usually require new anode rods as
presence of iron bacteria contributes to premature anode failure.
The requirements for the bacteria to thrive are:
•
•
•
Elevated level of iron and manganese in the water
Water with little or no dissolved oxygen
Temperatures below 138°F
Items that can increase the potential for this bacteria are:
•
•
•
Water softeners
Well water
Long periods of no water movement
The simplest treatment available is shock-chlorination of the system. This is a
surface treatment, and often requires repeated trials in heavily infected
systems. The chlorination of a system requires that you follow each step
explicitly to avoid an un-treated portion of the piping system from reinfecting
another part. See Bulletin 23 for the chlorination procedure.
TREATMENT
Since rusty water is caused by a bacteria presence and is not caused by the
water heater, any treatment would not be considered warranty related.
NOTE
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TECHNICAL BULLETIN - 22
SMELLY WATER
The most common cause of “smelly water” is a non-toxic sulfate reducing
CAUSE
bacteria, scientifically termed Divibrio Sulfurcans. This bacterium often enters
the water system through construction or a break in ground piping. The
bacteria create the energy it needs to survive by converting sulfate (SO4) to
hydrogen sulfide (H2S) gas you smell in the water.
Hydrogen sulfide gas is distinctive because of its rotten egg-like stench. Its
presence can severely affect the taste as well as the odor of the water.
Occasionally these bacteria can be accompanied by black deposits, the result
of pipe and fitting corrosion. In extremely high concentrations, hydrogen
sulfide gas can be toxic though the gas is detectable long before harmful
levels are reached.
The requirements for the bacteria to thrive are: a) an elevated level of sulfur in
the water, b) activated hydrogen from cathodic reactions within the tank, c)
water with little or no dissolved oxygen, d) and temperatures below 138°F.
Items that can increase the potential for these bacteria are: a) water
softeners, b) well water, c) and long periods of no water movement.
Other factors that may contribute to smelly water:
•
•
•
•
•
Chlorides of Magnesium and Calcium leave a bitter taste.
Chloride of Sodium produces a salty taste.
Sulfates (50 ppm) give a medicinal taste.
Carbon Dioxide in low pH water gives fizzy water.
Iron and tannic waters also give a bad taste and odor.
The simplest treatment available is the shock-chlorination of the system. This
is a surface treatment, and often requires repeated trials in heavily infected
systems. The chlorination of a system requires that you follow each step
explicitly to avoid an un-treated portion of the piping system from reinfecting
another part. See Bulletin 23 for the chlorination procedure. Longer lasting
solutions include chlorination or aeration of the water supply.
TREATMENT
Since smelly water is caused by a bacteria presence and is not caused by the
water heater, any treatment would not be considered warranty related.
NOTE
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TECHNICAL BULLETIN - 23
CHLORINATION PROCEDURE
The chlorination procedure is used to eliminate various bacteria that
accumulate and grow in water heaters. These bacteria often cause odorous
or discolored water conditions.
CAUSE
PROCEDURE
Please read the steps of the chlorination procedure prior to beginning. If you
feel uncomfortable performing any of these steps, contact a service person to
perform this procedure for you.
STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
Turn off the gas supply to the tank.
Turn off the cold water supply valve to the tank.
Open a nearby hot water faucet to relieve the vacuum.
Drain all the water from the tank (a water-hose may be needed).
Remove the anode rod(s), and close the drain valve.
Using a funnel in the anode opening add one gallon of household chlorine
bleach (e.g. Clorox or Purex) for every 25 gallons of tank capacity.
Reinstall anode rod(s) after inspecting and replacing as needed.
Open cold water supply valve and refill the system. Then draw the water to
every hot water fixture, until the smell of chlorine is detected. Operate dish
and clothes washers until a noticeable amount of the chlorine is detected as
well. All hot water lines must receive treatment.
STEP 7
STEP 8
STEP 9
STEP 10
Leave the chlorine solution undisturbed for one hour or more.
After the contact time has elapsed, drain the tank according to steps #2, #3, &
#4.
STEP 11
Close the drain valve and refill the tank. Allow the tank to sit for 15 minutes.
Repeat steps #2, #3, and #4. Continue to flush the tank if the water is
discolored or contains a chlorine odor.
STEP 12
STEP 13
Close the drain valve and refill the tank. Flush all chlorine from the piping by
opening every hot water outlet/ appliance.
Return hot water heating system to service by following the recommended
start-up procedure posted on the unit or in the manual.
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TECHNICAL BULLETIN - 35
NOT ENOUGH HOT WATER - GAS
Not enough hot water complaints are becoming more frequent in the water heater
CAUSE
industry. This increase was triggered when changes required by our regulatory
agencies were implemented. For example, heaters are now factory preset at a
lower temperature and inlet tubes have been shortened. While lower temperatures
settings reduce the burn rate, and shorter dip tubes guard against stacking, both
affect the amount of hot water a water heater can supply. The following test will
help determine if a water heater is supplying the intended amount of hot water and
will help pinpoint any problems that exist.
Please read all the steps of the test prior to beginning. If you feel uncomfortable
performing any of these steps, contact a service person to conduct this test for you.
TEST
STEP 1
At the faucet nearest to the water heater, time (in seconds) how long it takes to fill a
1 gallon bucket (flow rate).
Gallon per minute (gpm) = 60 seconds / seconds to fill a 1 gallon bucket
If the bucket fills in: 10 sec = 6 gpm
12 sec = 5 gpm
15 sec = 4 gpm
20 sec = 3 gpm
24 sec = 2.5 gpm
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
STEP 7
Turn thermostat dial on the water heater so the arrow points to “A” position.
Run about 15 gallons of hot water from the nearest faucet. Shut water off.
Water heater should complete heating 15 gallons in approximately 20-35 minutes.
At a nearby faucet using a candy thermometer, measure the hot water temperature.
The temperature should fall between 120°F to 140°F.
Continue running the hot water until 60% of the tank capacity is depleted:
CAPACITY
30 gallons
40 gallons
50 gallons
75 gallons
100 gallons
DEPLETE
18 gallons
24 gallons
30 gallons
45 gallons
60 gallons
STEP 8
STEP 9
At the same faucet using a candy thermometer, measure the water temperature.
The temperature should be about 30°F below the temperature in step 6.
Step 6 - if the temperature was not within range, check the thermostat.
Step 9 - if more than 30 °F was lost, check the dip tube.
THE FIX
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TECHNICAL BULLETIN - 45
THERMAL EXPANSION
•
•
•
•
•
Effects are only noticeable after hot water use followed by periods of no water use.
Relief valve drips during any recovery cycle when no hot or cold water is used.
Hot water pipes creak while heater is recovering and all valves are closed.
Tanks or other components of the water supply system fail prematurely.
A metallic creaking noise might actually be heard in the location of the heater as the
pressure is relieved and the stretched tank returns to a natural shape.
Faucets drips during any recovery cycle when no hot or cold water is used.
SYMPTOMS
•
Water surges when a valve is first open and then pressure drops.
The water in a water heating system expands when it is heated and has a greater
volume. Since water will not compress (like air), system designers must include
provisions for thermal expansion. (Water in a closed tank at 50 psi, when heated just
10 degrees, will reach a pressure of 250 psi).
CAUSE
Many water supply systems have check valves at the water meter to prevent any
possible contamination of the public water supply by the accidental back-flow of
contaminated water into the supply mains. These check valves are often required by
code, and some cities are even installing the check valves. They serve a useful
purpose. Do not remove them!
The use of pressure reducing valves (PRV) is another cause. PRVs are designed to
conserve water and prolong fixture life. Many PRVs also act as very effective check
valves. Again, do not remove them!
Water softeners in the system may also act as back-flow preventers.
Follow these easy steps to diagnose thermal expansion:
•
Turn the heater thermostat all the way down, and install a water pressure gauge
with dead hand (part #4798) on the drain valve. Open the drain valve, so the gauge
reads system pressure.
TEST
•
Open a hot water tap and allow 15% to 20% of the tanks volume to run out. Shut
off the drain valve and make sure that no other fixture in the system, hot or cold, is
open. Make sure that outside fixtures, if they are on the same system, are turned
off too. Any water leaks or use will make the test meaningless.
•
•
Check the water pressure gauge, and turn the pointer so it lines up with the
pressure indicating needle. Turn the thermostat back up to its normal position, so
the heater cycles on. Watch the pressure gauge.
If the system is closed, the pressure will start to climb steadily and rapidly. A small
amount of thermal expansion control may be built into the system because of
trapped air pockets or a water hammer arrestor. In that case the pressure will
increase slightly, hold steady for a short time and then rapidly increase. The
temperature and pressure relief valve (T&P) or PRV should open and release water
once the pressure reaches the maximum setting on the valve. The valve will close
once the pressure falls below the pressure setting of the valve.
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The ideal fix involves the use of a pressure reducing valve if supply pressures are
THE FIX
above 60 to 70 psi, and a properly sized expansion tank. The PRV reduces supply
pressures to 40 to 60 psi allowing an economically priced and sized expansion tank to
be used. The PRV also offers the benefit of saving water and prolonging the life of
water flow valves. The PRV is not required if the system already has one or if high
supply pressures are desired.
The PRV is installed between the check valve and the water heating system. The
expansion tank is installed between the PRV and the water heating system. Follow the
manufacturers’ instructions for installing the expansion tank.
Run the thermal expansion check again. The pressure should increase only slightly
then hold steady throughout the recovery cycle. The expanded water is flowing back
from the heater and into the pressurized storage bladder of the expansion tank. Air
pressure will force this water out of the expansion tank into the supply once usage
resumes.
DO NOT DEPEND ON THE T&P VALVE TO HANDLE THERMAL EXPANSION! The
T&P valve, according to the makers of those valves, was designed as an emergency
relief device only. The T&P could be subject to reduced effectiveness or failure.
FIGURE
Thermal expansion of water, if not compensated for in system design, will lead to the
early failure of components. These failures are not covered by the manufacturer’s
warranty, so it is extremely important that everyone be aware of the causes, symptoms
and solutions to thermal expansion in a closed water heating system.
WARNING
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TECHNICAL BULLETIN - 52
LEAKING TEMPERATURE AND PRESSURE RELIEF VALVE
•
•
•
•
Water seeping around the relief valve tank connection
SYMPTOMS
GENERAL
Leakage at the threaded portion of the relief valve connection
Intermittent weeping and/or dribbling from the relief valve
Large volume of hot water sporadically discharged from the relief valve
The temperature and pressure relief valve (T & P) is a safety device limiting temperature and
pressure levels in a water heater. Each T & P has both a temperature and pressure rating.
Normally, the temperature and pressure relief valve will have a temperature rating for 210°F. A
probe (part of the relief valve) extends into the tank measuring the stored water temperature.
This probe must be within the top six inches of the water heater. However, if the water heater’s
thermostat malfunctions, higher than normal water temperatures could be produced. Once the
probe senses a temperature exceeding its temperature rating, the relief valve will open to full
capacity releasing “very hot” water until the temperature is below its reset temperature.
The pressure rating on the relief valve should be the same or less than the certified working
pressure of the tank (generally 150 psi) and be below the lowest pressure rating of any system
components. It is not acceptable to install a relief valve that exceeds the maximum working
pressure of the water heater. Once the pressure in the tank reaches the valve’s pressure rating,
it will slightly open relieving the pressure. Relieving of pressure can be noted as “dribbling” or
“weeping” water from the relief valve.
If an incorrectly sized temperature and pressure relief valve is installed, the warranty will be
void.
•
•
•
Seeping at the spud of the water heater - Spuds are welded to the tank and are not
repairable. The heater should be replaced.
Leakage at the threaded relief valve connection - Remove relief valve and reseal
connection.
Intermittent weeping and/or dribbling at the relief valve - The relief valve relieves water
slowly when actuating on pressure. A closed system can cause pressure to increase in the
system. This condition is called thermal expansion. For additional information regarding
thermal expansion please see Bulletin 45.
THE FIX
•
Large volume of hot water sporadically discharged from the relief valve - The relief valve
relieves water quickly when actuating on temperature. The only cause of this problem is a
malfunctioning thermostat.
34
State Water Heater
© 2004
Technical Training Department
Ashland city, TN
Download from Www.Somanuals.com. All Manuals Search And Download.
To order additional copies of this Service Handbook and to view
other service and presentation literature and CDs that are
available from State Water Heaters:
Telephone 1-800-821-2017, Fax number 800-644-9306 or visit our
web site at www.statewaterheaters.com
For additional information or assistance in servicing you’re
State water heater, visit our web site or telephone the Technical
Information Department at 1-800-365-0024
This Service Handbook was prepared by the Technical Training Department,
Ashland City, TN.
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