Whirlpool Range EDP EDN User Manual
For sales, parts and service, call 781-961-1660  
Installation, Operation and Maintenance Instructions  
Installation,  
Operation and  
Maintenance  
Instructions for  
Endurance  
EBP Series Modulating Combination Boiler  
(natural or propane gas)  
EDP Series Modulating Hydronic Boiler  
(natural or propane gas)  
EDN Series Modulating Boiler, non ferrous  
(natural or propane gas)  
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,  
qualified in hot water boiler installation and maintenance. Improper installation and/or operation could  
create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death.  
Improper installation and/or operation will void the warranty.  
AVERTISSEMENT  
WARNING  
Assurez-vous de bien suivres les instructions  
If the information in this manual is not  
données dans cette notice pour réduire au  
followed exactly, a fire or explosion may  
minimum le risque d’incendie ou d’explosion ou  
result causing property damage, personal  
pour éviter tout dommage matériel, toute  
injury or loss of life.  
blessure ou la mort.  
Ne pas entreposer ni utiliser d’essence ni  
Do not store or use gasoline or other  
d’autres vapeurs ou liquides inflammables dans  
flammable vapors and liquids in the vicinity  
le voisinage de cet appareil ou de tout autre  
of this or any other appliance.  
appareil.  
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  
nearby phone. Follow the gas supplier's  
instructions.  
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:  
• Ne pas tenter d’allumer d’appareils.  
• Ne touchez à aucun interrupteur. Ne pas vous  
servir des téléphones dansle bâtiment où vous  
vous trouvez.  
• Appelez immédiatement votre fournisseur de  
gaz depuis un voisin. Suivez les instructions  
du fournisseur.  
• If you cannot reach your gas supplier, call  
the fire department.  
• Si vous ne pouvez rejoindre le fournisseur de  
gaz, appelez le sservice des incendies.  
Installation and service must be performed by a  
qualified installer, service agency, or gas  
supplier.  
L’installation et l’entretien doivent être assurés par  
un installateur ou un service d’entretien qualifié ou  
par le fournisseur de gaz.  
P.O. Box 310  
Lynnfield, MA 01940  
Phone: 781-961-1660  
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Endurance  
Page 3  
intake air and the gas are metered through separate  
SECTION 1.  
General Information  
orifices before entering the combustion air blower.  
The blower forces the air/fuel mixture through the  
flame holder and into the combustion chamber. The  
mixture is ignited from the hot surface ignitor and  
burns. Hot gases are forced out between the passes of  
the heat exchanger into the flue collector. Flue gases  
are discharged into the outside atmosphere through the  
vent terminal.  
The appliance can operate with a concentric vent  
system that will provide outside air for combustion.  
Other venting arrangements can be provided for the  
appliance to include an alternative 50 equivalent feet  
maximum horizontal or condensate trapped vertical  
vent.  
1A. Introduction  
EBP - This appliance is a low pressure, direct  
vent, hot water boiler that provides priority domestic  
hot water on demand as well as hydronic space heating  
system. The unit has a twenty gallon tank which holds  
boiler water (and is not domestic water storage).  
The boiler water is kept hot at all times to  
provide immediate response to call for heat or  
domestic water. Domestic water is heated by the boiler  
water through a stainless steel plate heat exchanger.  
EDP/EDN - This appliance is a low pressure,  
direct vent, cold start hot water boiler that provides  
heat for hydronic space heating.  
Both appliances incorporate a circulating pump  
and a bypass loop, and provide circulation for the  
heating system and adequate flow for its own needs.  
It may be necessary to install a system circulator to  
achieve the required flow rate through the system.  
Both appliances feature a forced draft, premixed  
combustion system. All air for combustion is supplied  
with the gas to the burner (flame holder). Both the  
1B. Codes and Standards  
The Endurance may be a direct vent or Category  
IV Boiler. All installations must be made in  
accordance with:  
1. The National Fuel Gas Code, ANSI Z223.1 latest  
edition, or.  
2. CAN/CGA B149 “Installation Codes for Gas  
Burning appliances and Equipment” and with the  
requirements of the local utility or other  
authorities having jurisdiction. Such application  
requirements take precedence over the general  
instructions contained herein.  
All electrical wiring is to be done in accordance with:.  
1. The National Electrical Code ANSI / NFPA70  
latest edition or  
Figure 1. Combo Heating/Domestic Water (Model EBP).  
Figure 2. Heating Unit (Model EDP/EDN).  
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LAARS HEATING SYSTEMS  
Page 4  
2. The CSA standard C22.1 “Canadian Electrical  
Code - Part 1” and local codes.  
SECTION 2.  
Venting Options  
All vent installations must be made in accordance with:  
1. Part 7, Venting of Equipment of the National Fuel  
Gas Code, ANSI 223.1 latest edition, or applicable  
provisions of the local building codes or  
2A. Direct Vent Kits  
When using a direct vent kit, the appliance is a  
sealed combustion unit. All of its air is drawn in from  
the outside through the 5" outer pipe. Flue gases are  
vented through the 3" vent pipe positioned inside the  
5" intake pipe. The hot flue gases are surrounded by  
the intake flow of cooler outdoor air. This vent system  
may be installed through, and be in contact with,  
combustible materials. Except for roof vent kit (max 7'  
vertical) all venting should pitch away (down) from  
unit.  
2. CAN/CGA B149.  
When required by the jurisdiction authority, the  
installations must conform to the American Society of  
Mechanical Engineers' Safety Code for Controls and  
Safety Devices for Automatically Fired Boilers, No.  
CSD-1.  
1C. Unpacking the Appliance  
Remove all packing and tie down materials.  
Make immediate claims (to the carrier) if the  
appliance and its packaging are damaged.  
2B. Installing Direct Vent Kits  
The direct vent appliance is certified with a  
maximum of 15 linear feet (4.6m) of vent pipe and  
three sets of elbows. There are two basic vent kits  
available, together with various additional elbow and  
extension kits if required (see Figures 3 and 4).  
Detailed installation instructions are provided in the kits.  
For additional length and/or fittings, the  
1D. Locating the Appliance  
The appliance is designed for installation on  
combustible flooring, in alcoves, basements, closets,  
or utility rooms. It must not be installed on carpeting.  
IF INSTALLED IN A FINISHED AREA,  
following components are available:  
PROVISION SHOULD BE MADE FOR DRAINAGE  
OF ANY ACCIDENTAL SPILLAGE OR LEAKAGE.  
The location for the unit should be chosen with  
regard to venting dimensions, convenient access to  
piping, and accessibility for service and cleaning.  
The boiler shall be installed so that the gas  
ignition system components are protected from water  
(dripping, spraying, rain, etc.) during appliance  
operation or service (circulator replacement, control  
replacement, etc.).  
3" and 5" elbow set  
5" x 1' extensions  
5" x 2' extensions  
5" x 2' to 4' adjustable  
extensions  
3" x 1' extensions  
3" x 2' extensions  
3" x 2' to 4' adjustable  
extensions  
PartNumber2400-330  
PartNumber2400-332  
PartNumber2400-334  
PartNumber2400-336  
PartNumber2400-338  
PartNumber2400-340  
PartNumber2400-342  
2C. Locating the Vent on an Outside Wall  
The center line of the vent opening must be at  
least 16½" (419mm) above grade, outside, and at least  
13½" (343mm) from any other building opening, such  
as doors, windows, etc. Vent opening should be well  
away from shrubbery or other obstructions that would  
prevent free air flow to and from vent terminal. Do not  
terminate vent under decks, stairways, or car ports.  
NOTE: Should it be impossible to locate  
opening center line 16½" (419mm) above grade, use  
optional vent terminal extension (p/n 2400-278).  
Vent terminals must also be at least 3' (0.9m)  
above any forced air inlet located within 10' (3.0m),  
and at least 7' (2.1m) above grade when located  
adjacent to a public walkway, and cannot terminate in  
a location where condensate or vapor may be a  
nuisance, hazard, or could be a detriment to other  
equipment. Vent terminals must have a minimum  
clearance of 4' (1.2m) (6' (1.8m) in Canada)  
1E. Clearances  
The dimension and criteria in Table 1 should be  
followed when choosing the location for the unit.  
A
B
AGA/CGA  
AGA  
CGA  
in.  
152 24 610  
in.  
1
in.  
6
mm  
25  
25  
25  
25  
25  
mm  
mm  
Left Side  
Right Side  
Top Side  
Back  
1
12 305 24 610  
14 356 24 406  
1
1
9
229 12 305  
Front  
1
24 610 24 610  
Vent: Direct Vent  
Vent: Category IV  
0
3
0
0
3
0
76  
76  
A. Minimum clearance from combustible construction to  
meet AGA/CGA requirements.  
horizontally from, and in no case above or below  
electrical meters, gas meters, regulators, and relief  
equipment unless a 4' (1.2m) horizontal distance is  
maintained.  
B. Recommended clearance for accessibility and venting.  
Table 1. Clearances  
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Endurance  
Page 5  
Figure 3. Part number 2400-500 provides all of the required venting materials for appliance installations adjacent to an  
outside wall and for installation of wall mounted units. Requires minimum above unit clearance of 13" (330mm) and  
provides maximum horizontal length of 24" from unit center line to outside wall face.  
Figure 4. Part number 2400-326 for vent installations which require adjustable height and horizontal run. This kit  
provides vertical and horizontal lengths of pipe from 2' to 3½' (0.6 to 1.1m). To adapt 2400-278 (vent terminal  
extension) remove 3" screen section of telescoping piece. Companion section will directly fit extension.  
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LAARS HEATING SYSTEMS  
Page 6  
Figure 5. Part number 2400-328 provides all of the required venting materials for appliance installations that require  
adjustable horizontal run, but a short vertical run. It requires minimum above unit clearance of 13" (330mm) and  
provides for an adjustable horizontal run of 2' to 3-1/2' (0.6 to 1.1m).  
Figure 6. Part number 2400-360 provides the required venting materials for concentric through-the-roof vents. It allows  
for a vertical vent, straight off the top of the unit, from 2 to 7 feet (0.6 to 2.1m).  
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Endurance  
Page 7  
2D. Stainless Steel Single Pipe Horizontal  
and Vertical Vents - Category IV  
Stainless steel special gas Vent listed to U.L.  
Standard 1738 and U.L.C. Standard 636 may be used  
Minimum clearance from  
combustibles (vent)  
Max. flue gas temp.  
3"  
325°F  
76mm  
163°C  
Max. vent pressure  
1.5" WC  
3"  
diameter  
50 equiv. ft.  
0.4kPa  
76mm  
diameter  
15.2m  
Max. equivalent ft. of venting  
(any combination of horizontal  
or vertical)  
Figure 7. For Appliances Certified as Direct Vent.  
Max. equivalent ft. of venting  
(any combination of horizontal  
or vertical)  
100 equiv. ft. 30.5m  
4" diameter 102mm dia.  
Table 2. Appliance Venting Design Data.  
to vent all models. Vent pipe and fittings are  
manufactured to these standards by HeatFab, Inc.  
under the trade name of Saf-T Vent® and by Z-Flex™  
under the trade name of Z-Vent. Follow the Special  
Gas Vent manufacturer's instructions regarding design,  
location and assembly of the vent system.  
The appliance may be vented with any number of  
elbows or fittings provided that the maximum  
equivalent feet of venting is not exceeded. Elbows  
(90°) in the vent system shall be considered to be 5  
equivalent feet (1.5m). When vented with special gas  
vent, the appliance must not be common vented with  
any other appliance.  
Figure 8. Typical vent installation with 18" or less  
overhead clearance to outside.  
For applications requiring vertical venting  
through a roof, the above limitations apply. Vertical  
vents greater than 7' (2.1m) in length must offset a  
condensate trap tee p/n 2400-358 adjacent to the  
appliance. Utilize vent cap p/n 2400-370 to terminate  
vertical venting.  
2E. Air Source For Combustion  
(when not direct vented)  
When using Category IV venting methods the  
appliance draws all combustion air through its top and  
from the adjacent space. When locating the appliance  
in unconfined spaces in buildings, infiltration may be  
adequate to provide air for combustion and ventilation.  
However, in buildings of unusually tight construction,  
or when locating the appliance in a confined space,  
additional air should be provided and the following  
guidelines must be followed.  
Figure 9. Multiple Concentric Vent Clearances.  
When appliances are used, the concentric vent  
terminals must be at least 12" apart, edge-to-edge (see  
Figure "term").  
Do not locate the vent terminal where blockage  
by snow is a possibility, or where flue products could  
strike against building materials and cause  
degradation. If the vent terminal location chosen is  
less than 18" below an overhang, the 3" vent pipe  
must extend to the outside edge of the overhang (see  
Figure 6).  
1. If the space is in a building of unusually tight  
construction, air should be obtained from  
outdoors, or from spaces which freely connect  
with outdoors.  
2. For boilers in confined rooms, two permanent  
openings shall be provided - one within 12"  
(305mm) of the ceiling, and one within 12"  
(305mm) of the floor of each room. Each  
opening shall be at least one square inch  
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LAARS HEATING SYSTEMS  
Page 8  
gas vent to the flue outlet of the appliance. Heat-Fab  
pipe or fittings (p/n 2400-350 or 2400-352) or the male  
end of Z-Vent pipe (Z-Vent # 02 SVEPXX030) may  
be installed over the flue outlet of the Appliance (see  
Figure 10).  
2G. Securing Special Gas Vent  
Attach p/n 2400-277 with sheet metal screws to  
the 5" collar on the appliance with a short piece of 5"  
pipe or to the end of the 5" combustion air duct.  
Attach p/n 2400-372 bracket and tighten clamp. Form  
the tabs on the bracket onto the special gas vent pipe  
and secure the tabs with the 3" clamp. After the clamp  
has been tightened, fold the end of the tabs down over  
the clamp (see Figure 10).  
Figure 10. Special Gas Vent Connection.  
DO NOT use screws in any portion of the 3"  
special gas vent.  
When providing combustion air from another  
location, the connection of the 5" duct to the appliance  
must be secured with sheet metal screws.  
Each 5" joint in the 5" duct must be secured with  
sheet metal screws.  
In this type of installation, p/n 2400-372 must be  
used to secure the special gas vent at the point where it  
exits the duct. The combustion air supply should be  
protected from debris entering the duct with an  
appliance vent terminal, p/n 2400-277, as shown in  
Figure 8 or with a large mesh screen.  
Follow the special gas vent manufacturer's  
instructions for cleaning and sealing all parts before  
assembling.  
Apply ¼" bead of silicone sealer (GE108 or  
Novagard 400) to the 3" flue outlet of the appliance  
approximately 1" from the end.  
Figure 11. Non-Concentric Combustion Air Source.  
Slide 3" inner vent pipe or 1-880 adapter, when  
using outer 3" telescoping section, over the appliance  
flue outlet and push down to stop (do not force pipe  
beyond stop).  
Apply another bead of silicone around this joint  
and smooth out.  
(6.5 sq. cm) per 1,000 BTU/hr (293W) boiler  
input, but not be less than 100 square inches  
(645.2 sq. cm). These openings shall freely  
connect with areas having adequate infiltration  
from outside.  
Apply ¼" bead of silicone to subsequent 3" joints.  
An alternate, nonconcentric combustion air  
source may be installed (as shown in Figure 11),  
provided that the minimum 4" diameter combustion air  
duct does not exceed 15' (4.6m). Termination should  
include an air screen and be located in a qualified air  
space (see Section 2E) or outside.  
3. When all air is provided from outdoors, the  
confined space shall be provided with one  
opening within 12" of the ceiling. This opening  
shall connect directly, or by ducts, with outdoors  
or spaces (crawl or attic) that freely connect  
with the outdoors, and shall have a minimum free  
area of:  
a. 1 sq. in. per 3000 BTU/hr (7 cm2/kw) of the  
total input rating of all equipment located  
in the enclosure, and  
SECTION 3.  
3A. Gas Piping  
b. Not less than the sum of the areas of all  
vent connectors in the confined space.  
The appliance requires an inlet gas pressure of at  
least 4" w.c. (1.0kPa) and no greater than 13" WC  
(3.2kPa). Check with your local gas utility or supplier  
for availability of this pressure range.  
Refer to Table 3 to size the supply piping to  
minimize pressure drop between meter or regulator  
and unit.  
2F. Connecting Special Gas Vent  
to the Appliance  
Part number 2400-372 is used with a vent  
terminal (p/n 2400-277) to secure the 3 inch special  
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Endurance  
Page 9  
Capacity of Pipe  
Length  
of Pipe  
1/2"  
3/4"  
1"  
1-1/4"  
MBTU/h  
ft.  
10  
20  
30  
40  
50  
75  
100  
150  
MBTU/h  
132  
92  
MBTU/h  
278  
190  
152  
130  
115  
93  
MBTU/h  
520  
350  
285  
245  
215  
175  
150  
120  
m
3
6.1  
9.1  
12.2  
15.2  
22.9  
30.5  
45.7  
kW  
38.7  
27  
21.4  
18.5  
kW  
kW  
152.4  
102.6  
83.5  
71.8  
63  
51.3  
44  
35.2  
kW  
1050  
730  
590  
500  
440  
360  
305  
250  
81.5  
55.7  
44.5  
38.1  
33.7  
27.2  
23.1  
18.8  
307.7  
213.9  
172.9  
146.5  
128.9  
105.5  
89.4  
73  
63  
79  
64  
73.3  
Additional length to be added for each tee or bend  
ft  
ft  
ft  
ft  
m
m
m
m
1.3  
1.7  
2.2  
2.7  
0.4  
0.5  
0.7  
0.8  
Table 3.  
1. Run gas supply line in accordance with all  
applicable codes.  
2. Locate and install manual shutoff valves in  
be no higher than 120°F mixed delivery  
temperature or as local codes dictate. LAARS  
RECOMMENDS ANTI-SCALD TEMPERING  
(MIXING) VALVES (see Figure 12).  
accordance with state and local requirements.  
3. Install drip leg, ground joint union and drip cap  
to trap sediment and for test gauge access.  
4. Support all piping with proper hangers.  
5. All threaded joints should be coated with piping  
compound resistant to the action of liquefied  
petroleum gas.  
6. The boiler and its individual shutoff valve must  
be disconnected from the gas supply piping  
system during any pressure testing of that system  
at test pressures in excess of ½ psig (3.5kPa).  
7. The boiler must be isolated from the gas supply  
piping system by closing its individual manual  
shutoff valve during any pressure testing of the  
gas supply piping system at test pressures equal  
to or less than ½ psig (3.5kPa)  
2. Connect gate or shutoff valve 13 to tempering  
(mixing) valve 12 “MIX” port, and cold  
water inlet.  
3. Install supplied flow restrictor 14 ahead of  
tempering (mixing) valve tee.  
4. Connect pressure relief valve 1 (if required by  
codes), maximum 150 PSI as close to the unit as  
possible. No other valves or restrictions may be  
installed between the Endurance and the relief  
valve.  
DO NOT USE A TEMPERATURE/PRESSURE  
RELIEF VALVE AS THIS IS NOT A STORAGE  
HOT WATER HEATER.  
Note: Installations with water containing 10  
or more grains of hardness, must be installed with  
appropriate water treatment.  
8. The boiler and its gas connection must be leak  
tested before placing the boiler in operation.  
9. Purge all air from gas lines.  
3B. Domestic Water Piping (EBP only)  
1. Connect tempering (mixing) valve 12 “Hot” port  
to hot water outlet from unit. This valve should  
Figure 12. Domestic Water Piping.  
Figure 13. Domestic Water Piping With Storage Tank.  
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LAARS HEATING SYSTEMS  
Page 10  
Figure 14. EBP Domestic Water Piping with Recirculating Loop.  
bypass pipe must be installed between supply and  
return piping.  
1. EBP ONLY: Connect system supply to 1¼"  
supply connection marked “SUPPLY”.  
2. EDP/EDN ONLY: Connect 1¼" thermostatic  
union to system supply connection in direction  
designated with union.  
WARNING  
Failure to install a hot water tempering (mixing)  
valve (12) creates a scalding hazard with potential for  
serious bodily injury. Some brands of tempering  
(mixing) valves are not designed as anti-scald valves.  
Where domestic water is supplying multiple  
apartments or large whirlpool tubs, additional storage  
tank may be connected as shown in Figure 13. The  
bronze circulator shown must be connected to tank  
aquastat and must not run continuously. If the  
circulator is wired to run continuously, unit's domestic  
water flow switch will keep the unit in domestic water  
priority, and no water will be allowed to be sent to the  
heating system.  
3. Pipe the discharge of the relief valve, full size, to  
a drain or in a manner to prevent injury in the  
event of pressure relief.  
4. Install an air purger in flow supply line as shown  
in Figures 15, 16 or 17.  
5. Install automatic float type air vent on air scoops.  
6. Install a diaphragm expansion tank in boiler  
outlet piping. To ensure sufficient expansion  
volume for the hydronic system water, due to  
heat-up and cool-down during normal operation,  
a #30 or larger expansion tank must be used on  
EBP combo units.  
SECTION 4.  
Hydronic Heat Piping  
NOTE: Never install expansion tank and auto  
fill valve on return.  
7. If necessary, install a properly sized circulator  
with optional isolation valves in supply beyond  
expansion tank.  
4A. Hydronic Piping  
The appliance incorporates its own circulating  
pump and bypass loop and is capable of providing  
flow through heating zones, in addition to what it  
needs for itself. Model size 110 is capable of  
providing flow for two heating zones (up to 67 feet of  
¾" baseboard each), and model 175 is capable of  
providing flow for four heating zones (up to 67 feet of  
¾" baseboard, each).  
Caution  
All hot water pipes must be installed with a minimum  
1" (25mm) clearance from combustible materials.  
8. Connect boiler feed water supply with shut off  
valve to inlet connection of automatic fill valve.  
Locate in boiler outlet piping.  
9. If codes require, install suitable back flow  
preventer between automatic fill valve and city  
main.  
10. The appliance may be installed in single and  
multiple zone systems (using either zone valves  
EDP/EDN boilers installed in radiant (in floor)  
systems and other low mass boilers should be provided  
with a buffer/blender tank to assure a controlled  
supply temperature, and to prevent short cycling. In  
radiant systems utilizing 3-way tempering valves, a  
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Endurance  
Page 11  
Figure 15. Hydronic Piping EDP/EBP with Zone Valves.  
Figure 16. Piping, Single EDP/EBP Boiler for Multiple Temperature Systems.  
Figure 17. Piping, Model “EDP/EDN” for Radiant Floor.  
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Page 12  
Figure 18. Hydronic Piping EBP/EDP for Systems Zoned with Circulators.  
Figure 19. Hydronic Piping EDP for Low-Temp and/or Multi-Temp Systems.  
or zone circulators) in the same manner as any  
other residential boiler.  
4B. Use in a Combined Hot Water Heating  
and Chilled Water Cooling System  
When the appliance is used in connection 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 it.  
Caution  
The EBP/EDP appliance must not be direct  
connected to a heating system utilizing oxygen  
permeable tubing (see warranty). Provide a water to  
water heat exchanger between systems to prevent  
corrosion of tank or other components. Non-toxic  
heating system antifreeze may be added to the  
hydronic system provided that the concentration  
does not exceed 35% and the antifreeze contains an  
anti foamant.  
The boiler piping system of an appliance  
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.  
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Endurance  
Page 13  
2. For single zone installations: (If external pump is  
required, e.g., because of large system pressure  
drop) connect room thermostat wires to the red  
and white/red wires. Connect circulator (120  
volt, 5 amps maximum) between the blue wire  
and the white wire (neutral) (see Figure 21).  
4C. Water Quality and Treatment  
Water quality control is steadily increasing in  
importance in view of the use of modern regulation  
technology and the modern boiler designs used in  
central heating systems.  
The life of a central heating boiler can be  
severely curtailed as a result of the formation of scale  
deposits and/or corrosion products. The formation of  
such deposits should be prevented wherever possible.  
Continual water make-up is not permitted.  
A suitable water treatment should be used to  
prevent excessive scale deposits in the boiler and  
corrosion in the system.  
3. Zone Valves and Thermostats: Install external 24  
volt transformer of sufficient V.A. to power  
combined load of zone valves. Consult zone  
valve manufacturer’s instructions. Connect  
circulator (120 volt, 5 amp maximum) between  
the blue wire and the white wire (neutral) (see  
Figure 22).  
SECTION 5.  
Electrical Connections  
ENDURANCE  
FIELD WIRING BOX  
All electrical wiring must conform to local codes  
and/or the National Electric Code or Canadian  
Electrical Code, Part 1.  
The unit must be electrically grounded in  
accordance with the requirements of the authority  
having jurisdiction or, in the absence of such  
requirement, with the National Electrical Code.  
ANS/NFPA No. 70 latest edition, or the CSA Standard  
C22.1 “Canadian Electrical Code, Part 1.”  
Single pole switches, including those of safety  
control and protective devices must not be wired in a  
grounded line.  
Figure 20. Single Zone With Room Thermostat (internal  
pump provides system flow).  
All electrical connections are made in the field  
wiring box which is located on the top of the appli-  
ance, behind the right hand side of the control pod.  
NOTE: All internal electric components have  
been pre-wired. No attempt should be made to connect  
electric wires to any other location except the wiring  
box as described below.  
ENDURANCE  
FIELD WIRING BOX  
1. Main power: Connect a fused 120 volt supply  
(15 amp) to the main power switch (see  
Figure 20) (hot leg is connected directly to  
switch). Neutral leg to white wire. Ground wire  
can be connected to the grounding screw in the  
box or on the switch.  
Figure 21. Single Zone with Added Circulator(s) and  
Room Thermostat(s).  
Figure 22. Multiple Zones Utilizing Four Wire Zone Valves with (Dry) End Switches.  
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LAARS HEATING SYSTEMS  
Page 14  
4. Multi zone/Multi-relay-circulator Installations:  
Multiple circulators must not exceed 5 amps total  
when connected to blue wire (see Figure 24).  
NOTE: On zone valve systems such as Taco,  
Automag and others which do not have isolated (dry)  
contact end switches, a single pole isolating relay must  
be utilized (see Figure 23).  
NOTE: This wiring is NOT the same  
as shown by valve manufacturer.  
Figure 23. Multiple Zones with Three Wire Zone Valves (Requires Isolation Relay).  
Figure 24. Multiple Zones with Circulators and Room Thermostats.  
NOTE: This wiring required only for  
single zone applications utilizing  
clock thermostats requiring 24 volt  
power supply.  
Figure 25. Wiring for Single Zone Power Stealing Type Clock Thermostats That Require 24 VAC.  
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Endurance  
Page 15  
FOR YOUR SAFETY READ BEFORE OPERATING  
WARNING  
If you do not follow these instructions exactly, a fire or explosion  
may result, causing property damage, personal injury or loss of life.  
A. This appliance does not have a pilot. It is  
equipped with an ignition device which  
automatically lights the burner. Do not try to light  
the burner by hand.  
B. BEFORE OPERATING smell all around the  
appliance area for gas. Be sure to smell next to  
the floor because some gas is heavier than air  
and will settle on the floor.  
• If you cannot reach your gas supplier, call the  
fire department.  
C. Turn off gas shutoff valve (located above the  
combination gas control) so that the handle is  
aligned across the gas pipe. If the handle 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.  
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.  
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.  
OPERATING INSTRUCTIONS  
1. STOP! Read the safety information above on  
this label.  
4. This appliance is equipped with an ignition  
device which automatically lights the burner.  
Do not try to light the burner by hand.  
2. Set the thermostat to lowest setting.  
5. Removecontrolaccesspanel,andtopfrontcover.  
3. Turn off all electric power to the appliance.  
6. Turn gas shutoff valve clockwise  
to “off”.  
Handle will be horizontal, do not force.  
7. Wait five (5) minutes to clear out any gas. If you  
then smell gas, STOP! Follow “B” in the safety  
information above on this label. If you don't  
smell gas, go to next step.  
8. Turn gas shutoff valve counterclockwise  
“on”. Handle will be vertical.  
to  
Combination  
Gas Shutoff  
Gas Control  
Valve  
9. Replace top front cover and control access panel.  
10. Turn on all electric power to appliance, depress  
on/off button on control panel, depress black  
button on top of control panel.  
11. Set thermostat to desired setting.  
12. If the appliance will not operate, follow the  
instructions “To Turn Off Gas To Appliance” and  
call your service technician or gas supplier.  
TO TURN OFF GAS TO APPLIANCE  
1. Set the thermostat to lowest setting.  
4. Turn gas shutoff valve clockwise  
not force.  
to “off”. Do  
2. Turn off all electric power to the appliance if  
service is to be performed.  
5. Replace top front cover and control access  
panel.  
3. Remove control access panel and top front  
cover.  
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LAARS HEATING SYSTEMS  
Page 16  
PAR MESURE DE PRUDENCE, LISEZ CE QUI SUIT AVANT DE  
FAIRE FONCTIONNER L’APPAREIL  
MISE EN GARDE  
Si vous ne suivez pas ces instructions à la lettre, un incendie ou une  
explosion pourrait se produire et causer des dommages matériels,  
des blessures personnelles ou même la mort.  
A. Cet appareil n’est pas doté d’une veilleuse. Il est  
équipé d’un dispositif d’allumage qui allume  
automatiquement le brûleur. Ne tentez pas  
d’allumer le brûleur manuellement.  
B. AVANT D’UTILISER, vérifiez s’il n’y a pas  
d’odeur de gaz près de l’appareil. Vérifiez s’il n’y  
a pas d’odeur de gaz près du plancher, car le  
gaz est plus lourd que l’air et peut se déposer  
sur le plancher.  
•
Si vous ne pouvez joindre votre fournisseur  
de gaz, appelez le service des incendies.  
C. Fermez la soupape d’arrêt de gaz (située au-  
dessus de la commande de gaz multifonctions)  
de sorte que la poignée soit perpendiculaire au  
tuyau de gaz. Si vous ne pouvez tourner la  
poignée à la main, n’essayez pas de la réparer.  
Communiquez avec un technicien de service  
qualifié. Le fait de forcer ou de tenter de réparer  
la poignée pourrait causer un incendie ou une  
explosion.  
D. N’utilisez pas cet appareil si l’une des pièces a  
été plongée sous l’eau. Communiquez  
immédiatement avec un technicien de service  
qualifié afin qu’il inspecte l’appareil et remplace  
toute pièce du système de commande et toute  
commande de gaz qui aurait été plongée sous  
l’eau.  
QUE FAIRE EN CAS D’ODEUR DE GAZ  
•
•
•
N’essayez pas d’allumer n’importe quelque  
appareil que ce soit.  
Ne touchez pas à un commutateur électrique.  
N’utilisez pas le téléphone de votre résidence.  
Appelez immédiatement votre fournisseur de  
gaz en utilisant le téléphone de votre voisin.  
Suivez les instructions de votre fournisseur de  
gaz.  
NOTICE D’UTILISATION  
1. ARRÊTEZ ! Lisez l’information de sécurité ci-  
6. Faites tourner la valve de fermeture du gaz dans  
le sens des aiguilles d’une montre et mettez-la  
à «off». La poignée sera horizontale. N’employez  
pas de force.  
7. Attendez cinq (5) minutes afin que le gaz se  
dissipe. Si vous croyez sentir une odeur de gaz,  
ARRÊTEZ ! Reportez-vous aux instructions B ci-  
dessous, sur cette étiquette. S’il n’y a pas  
d’odeur de gaz, passez à la prochaine étape  
8. Faites tourner la valve de fermeture du gaz dans  
le sens contraire des aiguilles d’une montre et  
dessus, sur cette étiquette.  
2. Réglez le thermostat au réglage le plus bas.  
3. Coupez l’alimentation électrique à l’appareil.  
4. Cet appareil est doté d’un dispositif d’allumage  
qui allumera automatiquement le brûleur.  
Ne tentez pas d’allumer le brûleur manuellement.  
5. Retirez le panneau d’accès aux commandes et le  
couvercle avant qui se trouve sur le dessus.  
mettez-la  
à «on». La poignée sera verticale.  
9. Replacez le couvercle avant et le panneau d’accès  
de commandes.  
10. Rétablissez l’alimentation électrique à l’appareil,  
appuyez sur le bouton «on/off» qui se trouve sur le  
panneau de commande, appuyez sur le bouton noir  
qui se trouve sur le panneau de commande.  
11. Réglez le thermostat à la température désirée.  
12. Si l’appareil ne fonctionne pas, suivez les directives  
relatives à la fermeture de l’alimentation en gaz et  
communiquez avec votre technicien de service ou  
le fournisseur de gaz.  
Commande de gaz  
multifonctions  
Valve de fermeture  
du gaz  
FERMETURE DE L’ALIMENTATION EN GAZ  
1. Réglez le thermostat au réglage le plus bas.  
4. Faites tourner la valve de fermeture du gaz dans  
le sens des aiguilles d’une montre et mettez-la  
à «off». N’utilisez pas de force.  
2. Coupez toute alimentation électrique à l’appareil  
si celui-ci doit faire l’objet d’un entretien.  
3. Retirez le panneau d’accès aux commandes et le  
couvercle avant qui se trouve sur le dessus.  
5. Replacez le couvercle avant.  
30-414A  
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Endurance  
Page 17  
the flame of a match or candle, or smoke from a  
cigarette, cigar or pipe.  
SECTION 6.  
Boiler Start Up  
6. 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.  
7. Any improper operation of the common venting  
system should be corrected so the installation  
conforms with the  
6A. Common Vent Test  
At the time of removal of an existing boiler, the  
following steps shall be followed with each appliance  
remaining connected to the common venting system  
placed in operation, while the other appliances  
remaining connected to the common venting system  
are not in operation.  
a. National Fuel Gas Code, ANSI Z223.1  
latest edition.  
b. Can / CGA - B149.  
1. Seal any unused opening in the common venting  
system.  
2. 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.  
3. 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. Do not operate a  
summer exhaust fan. Close fireplace dampers.  
When re-sizing any portion of the common  
venting system, the common venting system should be  
re-sized to approach the minimum size as determined  
using the appropriate tables in Appendix F in the  
National Fuel Gas code, ANSI Z223.1 - latest edition,  
and/or Can/CSA B149 Installation Codes.  
6A. Common Vent Test  
Au moment du retrait d’une chaudière existante,  
les mesures suivantes doivent être prises pour chaque  
appareil toujours raccordé au système d’evacuation  
commun et qui fonctionne alors que d’autres appareils  
toujours raccordés au système d’évacuation ne  
fonctionnent pas:  
1. Sceller toutes les ouvertures non utilisées du  
système d’évacuation.  
2. Inspecter de façon visuelle le système  
d’évacuation pour déterminer la grosseur et  
l’inclinaison horiztonale qui conviennent et  
s’assurer que le système est exempt  
4. Place in operation the appliance being inspected.  
Follow the lighting instructions. Adjust  
thermostat so appliance will operate  
continuously.  
5. Test for spillage at the draft hood relief opening  
after 5 minutes of main burner operation. Use  
Message  
Identifies  
Boiler Flow Temp (Supply)  
Tank Temp  
To read or change mode  
During operation display will default to supply  
temperature. Press temperatures button repetitively.  
To sequence through three temperature indicators.  
Return Temp (Boiler Inlet)  
On  
Boiler in standby mode: will operate on call for domestic  
water or heat zone demand.  
Off  
Boiler switched OFF. Press ON/OFF button for “ON”.  
After three trials for ignition, will stand in lockout. Press  
reset on top of panel to retry.  
Lock Out - Combustion Related  
Fault Code (Three) There are 8  
different Fault Codes defined.  
Afaultcodemaybeindicatedonthedisplaypriortopushing  
the reset button or switching the on-off button or power  
switch. Observe code, and note it, for servicing.  
Sensor has detected return temperature below 39°F (4°C).  
Freeze Protection  
Figure 26. Typical Display Identification Codes.  
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LAARS HEATING SYSTEMS  
Page 18  
d’obstruction, d’étranglement, de fuite, de  
4. Purge all lines by opening vents.  
corrosion et autres défaillances qui pourraient  
présenter des risques.  
5. Close gas shutoff valve located above gas valve.  
6. Turn on 120 volt power, the display will initially  
display [---] for five seconds before displaying  
[OFF].  
3. Dans la mesure du possible, fermer toutes les  
portes et les fenêtres du bâtiment et toutes les  
portes entre l’espace, où les appareils tojours  
raccordés et les autres espaces du bâtiment.  
Mettre en marche les sécheuses, tous les  
appareils non raccordés au système d’évacuation  
commun et tous les ventilateurs d’extraction  
comme les hottes de cuisinère et les ventilateurs  
des salles de bain. S’assurer que ces ventilateurs  
fonctionnent à la vitesse maximale, Ne pas faire  
fonctionner les ventilateurs d’été. Fermer les  
registres des cheminées.  
4. Mettre l’appareil inspecté en marche. Suivre les  
instructions d’allumage. Régler le thermostat de  
façon continue.  
5. Faire fonctionner le brûleur principal pendant 5  
min ensuite déterminer si le coupe-tirage  
déborde à l’ouverture de décharge. Utiliser la  
flamme d’une allumette ou d’une chandelle ou la  
afumée d’une cigarette, d’une cigare ou d’une  
pipe.  
6. Une fois qu’il a été déterminé, selon la méthode  
indiquée ci-dessus, que chaque appareil raccordé  
au systéme d’évacuation est mis à l’air libre de  
façon adéquate. Remettre les portes et les  
fenêres, les ventilateurs, les registres de  
cheminées et les appareils au gaz à leur position  
originale.  
7. Tout mauvais fonctionnement du systéme  
d’évacuation commun devrait êvacuation  
commun devrait être corrigé de façon que  
l’installation soit conforme au National Fuel  
Gas Code, ANSI Z223.1/NFPA 54 et (ou) aux  
codes d’installation CAN/CGA-B149. Si la  
grosseur d’une section du systéme devrait être  
modifié ppour respecter les valeurs minimales  
des tableaux pertinents de l’appendice F du  
National Fuel Gas Code, ANSI Z223.1/NFPA 54  
et (ou) des codes d’installation CAN/CGA-B149.  
7. If the temperature sensor detects a temperature  
below 39°F (4°C) it will display [ICE]. The  
appliance will then be in the frost protection  
mode. The pump initially runs alone for 5 minutes  
or until the flow temperature reaches 45°F (7°C).  
(EBP ONLY: When the internal zone valve is  
manually* opened the water will be pumped to  
the space heating.) This is a good time to ensure  
that the system is fully discharged of all air and  
the water charge pressure is correct. Should the  
water temperature remain below 45°F (7°C) after  
5 minutes the appliance will start the ignition  
sequence. After three attempts to ignite the  
burner control will lock out and display [LO]  
(see Figure 25).  
8. If the display remains at [OFF], press the on/off  
button on the front panel and the reset button on  
top of the front panel. The pump and the blower  
will start, the display will then flash [  
] (boiler  
flow temperature) for 1 second intervals and the  
actual temperature (e.g., [127]) in degrees F for  
3 second intervals. The appliance will attempt to  
ignite three times after which it will lock out and  
display [LO]. The fan and the pump will then  
stop. Ensure that the system is fully discharged  
of all air and the water charge pressure is correct.  
9. Turn the main electrical supply off.  
10. EBP ONLY: Manually reset the internal zone  
valve to its normal position (manual level  
toward top of actuator).  
11. System is now ready for operation.  
6C. Firing Burner  
1. Be sure that system has been filled properly and  
is leak tight.  
2. Open gas shutoff valve.  
6B. Filling the System  
1. Open all supply and return valves.  
2. Fill heating system to minimum operating  
pressure 12 psig.  
3. Loosen screw in coin vent and allow any trapped  
air to escape. Collect any water that escapes so  
that it does not drip on the blower electronics and  
damage them. Small amounts of air that may  
remain will be purged by the internal pump.  
Tighten screw after purging.  
3. Turn on main electrical switch.  
4. If the temperature sensor detects a temperature  
below 39°F (4°C) it will display [ICE]. The  
appliance will then be in the frost protection  
mode.  
5. If the display remains at [OFF], press the on/off  
button on the front of the control panel and the  
reset button on top of the control panel.  
6. The pump and the blower will start, the display  
will show [ ] (boiler flow temperature) for  
1 second intervals and the actual temperature  
(e.g., [127]) in degrees F for 3 second intervals.  
*The “manual operation” lever located on the  
side of the valve operator requires moderate pressure  
to latch the valve open and then again to unlatch it and  
allow it to close.  
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Endurance  
Page 19  
The appliance will attempt to ignite three times,  
gallons (approx. 4-8L) of water from it. Turn off the  
if ignition is not successful, the appliance will  
lock out and display [LO]. Ignition reset is done  
by pressing the reset button on top of the control  
panel. EBP models will then operate to heat the  
transfer tank.  
main disconnect switch and unplug the pump wires,  
remove the pump motor. The pump housing need not  
be removed. The replacement pump motor should be  
installed in the reverse order from which the old pump  
motor was removed. After filling the system be sure  
the combustion chamber coil vents through the air vent  
located on top of the boiler chamber (inlet manifold  
extension).  
7. EBP ONLY: Turn on a hot water tap. This puts  
the appliance in the DHW mode.  
Caution  
7B. Gas Valve  
Should any pronounced odor of gas be detected, or  
if the gas burner does not appear to be functioning  
in a normal manner, close main shutoff valve, do not  
shut off switch, and contact your heating contractor,  
gas company, or factory representative.  
The gas valve is a 24VDC solenoid operated,  
negative pressure regulated ratio valve. The outlet  
pressure may be adjusted as described in the service  
section. It is designed to operate with supply pressures  
of 4-13 inches w.c. (1.0 to 3.2 kPa). To remove the gas  
valve, shut off 120 volt power and the gas shutoff  
valve, remove the 4 screws on the upper and lower  
flanges and disconnect the wires from the gas valve,  
the valve may now be removed. After the valve has  
been removed, replace with a new valve in the reverse  
order in which the old valve was removed. Turn on gas  
shutoff valve and 120 volt power and check boiler  
operation and gas tightness of gas valve connections.  
You MUST check flame monitoring control  
(ignition system safety shut off device).  
1. Close gas shutoff valve with burner operating.  
2. The flame indicator light will go out and blower  
will continue to run for the post purge cycle.  
Three additional attempts to light will follow  
including pre-purge, ignitor on, valve/flame on  
and post purge. Ignition will not occur as the gas  
is off. The display will eventually show [LO]  
approximately 10 seconds after the gas valve has  
closed on the third ignition attempt.  
7C. Safety Limit Switch  
The Safety Limit Switch is an automatic reset  
switch with a fixed set point of 230°F (110°C). To  
replace the switch, shut off the 120 volt power.  
Disconnect the 2 wires from the quick connects at the  
switch and remove the switch. To replace, perform the  
same operations in reverse. Turn on disconnect switch  
and check boiler.  
3. Open gas shutoff valve. Press reset button on the  
top of the control panel. The ignition sequence  
will start again and the burner will start. The  
appliance will return to its previous mode of  
operation.  
7D. Boiler Control Printed Circuit  
Board (PCB)  
6D. Mode and On/Off Buttons Operation  
The on/off button it is used to switch the  
appliance from standby [ON] to standby [OFF] and  
vice versa. It is NOT an isolation switch. The mode  
button accesses all other functions as described in  
their particular sections of this manual.  
The Integrated Boiler Control Module controls  
the ignition process, the combustion process, the  
temperature of the boiler flow and return, and the  
transfer tank temperature* and provides both domestic  
hot water* and space heating on demand.  
To do this it takes inputs from three temperature  
sensors, a domestic hot water flow switch, an overheat  
thermostat (safety limit) and an external space heating  
switch, such as a room thermostat, zone valve end  
switches or circulator relay contacts. It then controls  
the pump, blower, ignitor and gas valve sequencing.  
It constantly displays the boiler outlet  
temperature when the appliance is operating in one of  
its demand modes. It also allows the user to obtain  
information from the appliance to determine the water  
temperature at three different locations within the  
appliance and to find up to 8 previous faults stored in  
memory.  
SECTION 7.  
Maintenance and Component  
Description  
7A. Unit Pump  
The unit pump operates whenever there is a call  
for heat or hot water.  
It is a wetted-rotor type pump and should always  
be filled with water when it is operating so that it will  
cool properly.  
If a pump change is required for any reason,  
valve off the boiler and drain approximately 1 or 2  
If replacement of PCB is necessary, shut off the  
120 volt power and disconnect the wire connectors  
from the pcb. Remove the PCB from its location posts.  
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LAARS HEATING SYSTEMS  
Page 20  
Replace in reverse order ensuring that the connections  
are correct.  
storage vessel to reduce boiler cycling on small output  
heating zones and to provide additional heat for  
domestic hot water through the domestic hot water  
(DHW) plate heat exchanger.  
*EBP combination units only.  
If a tank change is necessary, access to the tank  
is possible by removing the jacket’s lower front panel.  
This is done by removing the screws that hold the  
panel at the top and lifting the panel away. Isolate the  
appliance and drain down using the drain cock at the  
base of the tank. Remove the tank sensor. Undo the  
union and the pump flange bolts that connect the tank  
to the boiler, unscrew the panel between the upper and  
lower compartments, support the upper components  
and remove the tank. Installation of the new tank is  
done in the reverse order. After installation purge all  
air from the boiler before restarting.  
7E. Ignitor / Flame Sensor Assembly  
The ignitor is a “glow bar” type ceramic  
composite device. It is energized whenever there is a  
call for heat and switched off when ignition is  
established.  
The flame sensor is a remote sensing flame rod  
which is connected directly to the circuit board “J5”  
terminal. The ignitor should read 50 to 100 ohms  
resistance when at room temperature.  
If the ignitor fails and the assembly must be  
replaced, always install a new ignitor gasket with the  
replacement assembly.  
For sequence of operation, see Section 8,  
Servicing.  
7I. Thermostatic Union (EDP/EDN)  
The thermostatic union is a 1¼" NPTF union  
which must be mounted at the flow outlet to control  
boiler temperature. The union must be installed so that  
union nut is on the boiler side of the connection. This  
insures that the thermostat is properly positioned with  
its spring facing up, toward the system. The element  
has two small bypass holes that allow some water to  
flow into the system at all times. When the boiler first  
starts and the element is closed, boiler water is re-  
circulated back to the return until the supply water  
reaches 160°F (71°C). The element then modulates  
open. If the temperature does not exceed 150°F (66°C)  
within two minutes after firing, the element is not  
functioning properly. To replace the element, shut off  
and drain the section of the system adjacent to the  
thermostatic union. Open the union and replace the  
element with a new one. The element should be  
installed so that its spring and actuator are facing the  
system side (up). Close the union, open the valves,  
refill and bleed the system. Ensure that air is venting  
from the air vent on top of the boiler chamber and it is  
left operational. Restart boiler.  
Caution  
Ignitor gets hot.  
7F. Transformer  
The control transformer accepts 120 VAC line  
voltage and provides 80 VA of 24 VAC control  
voltage for the boiler control ONLY. It is NOT  
capable of supplying control voltage for external  
devices such as zone valves, which MUST have their  
own separate power supply.  
Should the transformer require replacing, shut off  
the 120 volt power. Unplug the transformer wires from  
the PCB, unscrew the two fixing screws and remove  
the transformer.  
Fit the replacement transformer in reverse order.  
7G. Blower  
The combustion air blower is a high pressure  
centrifugal blower. It is powered by a 24VDC motor  
which is controlled by the PCB. Its speed will be  
varied according to the temperature of the boiler flow.  
If a blower change is required, turn off the 120  
volt power and unplug the wires from the blower  
motor. Remove the four nuts from the blower  
discharge flange and the four screws that secure the  
gas manifold to the gas valve. Remove the complete  
assembly. Unscrew the combustion air inlet assembly  
and register plate from the fan.  
Fit the replacement fan in reverse order, ensuring  
that all joints are made correctly and sealed.  
After replacement the combustion should be  
checked for correct air fuel ratio (see Check, Test and  
Start-Up section).  
7J. Cleaning the Boiler Coil  
The Endurance is equipped with a premixed  
combustion system. This type of combustion system  
does not create free carbon (soot) except in very rare  
instances and therefor the combustion chamber coil  
will probably never need cleaning. If cleaning is  
required, proceed as follows: valve off the boiler,  
switch off the electrical power at the disconnect  
switch, drain 1-2 gallons (4-8L) of water from the  
boiler drain, remove the flue assembly from the top of  
the boiler, remove the pump flange bolts from the top  
pump flange, disconnect the sensor wires from the  
sensors (boiler flow, return and safety limit), undo the  
union nut from the boiler flow manifold, and remove  
the four (4) screws from the bottom gas valve flange.  
The boiler assembly may now be removed from the  
jacket. After removal of the boiler assembly from the  
7H. Transfer Tank (EBP)  
The transfer tank contains approximately 20  
gallons of boiler water. It functions as an energy  
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Endurance  
Page 21  
jacket, remove the four (4) long screws that secure the  
top and bottom pans. Remove the air vent and the top  
pan. Remove the insulation retainer and the coil cover  
insulation. Clean the boiler coil with a wire brush and  
vacuum debris from the combustion chamber (avoid  
hitting the ignitor or the flame sensor with the brush  
or vacuum hose because they are fragile).  
After cleaning, assemble the parts in the reverse  
order, open isolation valves and bleed air from the  
boiler and the system. Follow the lighting instructions  
and start the boiler. Check operation.  
seconds while the [MC] indicates alternately  
and the current boiler outlet temperature.  
2. Following the prepurge cycle the ignitor will  
heat for 10 seconds while the blower continues  
to operate.  
3. The gas valve will then be energized (green  
‘GV’ LED located on the PCB next to the  
display will light) and open, gas will flow and  
ignition will occur.  
SECTION 8  
Servicing.  
8A. Sequence of Operation  
Figures 22 and 23 depict the flow paths and  
temperature sensor locations for the space heating,  
EDP/EDN, and the combined space heating and  
domestic water heating, EBP, appliances.  
The model EDP/EDN modulating boilers are  
cold start boilers that will start only on a call for heat  
from a room thermostat or zone control contact.  
During normal operation the Message Center [MC]  
LED display will indicate ‘ON’ while awaiting a call  
for heat. On a call for heat the following sequence  
will occur.  
1. (a) The internal pump will start.  
(b) After 5 seconds the blower prepurge cycle  
will start and operate for approximately 6  
Figure 27. EDP/EDN Flow Schematic.  
Figure 28. EBP Flow Schematic.  
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4. 10 seconds after establishing combustion and  
proof of flame ( via the flame rod signal to  
ground ), the ignitor will be de-energized and  
the burner will modulate to high fire for  
maximum output.  
F-?; FL2, F=?; …, FL8, F=?). The fault number in  
fault code FL1 is the most recent fault.  
8B-1. Fault Code Identification  
The following eight fault codes may be observed:  
F- Error corrected, control in auto reset time  
period (10 seconds)  
F-0 No fault has occurred  
F-1 Error occurred reading fault logic of main  
control  
F-2 Over heat thermostat has operated  
(open circuit)  
F-3 Fan fault  
F-4 Flow temperature sensor faulty  
(open or short circuited)  
F-5 Tank temperature sensor faulty  
(open or short circuited) (Combi unit only)  
F-6 Return temperature sensor faulty  
(open or short circuited)  
5. The [MC] should indicate a rapid rise in  
temperature to 150º F (1-2 min. duration).  
During this period the thermostatic union at the  
flow outlet is closed and the boiler is operating  
in the internal recirculation mode. [Service note:  
If the temperature rise is not rapid the union  
thermostat may be defective and must be  
replaced].  
6. At 150° F the thermostat will allow increased  
flow to the system and a gradual rise in  
temperature will be indicated until the  
temperature approaches the setpoint temperature  
of 180ºF. The firing rate will start to modulate  
downward until its cutoff limit is reached or the  
call for heat is satisfied.  
8B-2. Fault Correction (see also Fault  
Trees in this Section)  
The EBP modulating combination boiler will  
start from any of three input signals: (a)T-T closure  
for space heating. (b)A demand for domestic hot  
water, signaled by water flow activation of the water  
flow switch. (c)A call for heat from the minimum  
tank temperature sensor at 158°F (tank charge mode).  
In tank charge mode the red LED located below the  
green LED on the PCB will be lit. In modes (b) and  
(c) which are priority modes, the internal anti-  
condensing valve will be closed. On a T-T call for  
heat the valve will remain closed until the priority  
modes are satisfied.  
[Service note: as with the thermostatic union in  
the EDP/EDN models, the anti-condensing valve  
prevents condensation on the combustion chamber  
coil and must be in the closed position when the coil  
inlet (F6) indicates a temperature below 130°F].  
F-1 Switch off boiler and restart. If F-1 repeats,  
replace PCB  
F-2 The overheat thermostat (safety limit)  
opens at 230°F. Observe boiler operation if  
the boiler shuts off before the  
indicates 225°F (107°C) replace safety  
limit. If the temperature rises rapidly and  
the safety limit operates, the internal pump  
is not operating. Refer to the wiring  
diagrams and check for voltage (120V)  
acrosstheterminalsonthePCBmarkedPMP.  
a. If there is no voltage, and the PCB  
display does not indicate on or off,  
replace PCB  
b. If there is voltage, the pump or wiring  
is defective.  
F-3 Attempt to start the boiler. Check  
combustion air blower operation. If F-3 is  
indicated again, replace blower.  
F-4 Check for damaged wiring or poor  
connection at sensor plug. If they are OK  
disconnect the sensor plug and check the  
resistance across the sensor terminals. The  
resistance of a good sensor is 10,000 ohms  
@ 77°F (25°C). Replace sensor if  
resistance is less than 500 or more than  
20,000 ohms.  
8B. Trouble Shooting - Fault Codes  
The Endurance boiler is controlled by a Pactrol  
integrated boiler control (PCB) which provides eight  
fault codes with eight memories. To obtain fault  
messages press-in on the message center fault button  
until the first fault code (FLI) is displayed.  
If a thermistor error occurs, it will appear on the  
LED upon power-up. The memory does not need to  
be accessed. Memory fault codes are for error  
history only. All thermistor faults will show as “F”  
codes on the LED, and will never cause the LED to  
read “LO”. (Note that the unit is shipped with error  
codes already in memory, and an error code that is  
shown in memory upon start-up of a new unit is from  
manufacturing testing.)  
F-5 Correct in the same manner as F-4.  
F-6 Correct in the same manner as F-4.  
8B-3. Resolving Lockouts (LO)  
(The memory does not need to be accessed.  
Memory fault codes are for error history only. All  
thermistor faults will show as “F” codes on the  
LED, and will never cause the LED to read “LO”.  
There are many causes for lockouts. The five  
most common causes are: (1) poor combustion,  
The last recorded fault will appear e.g. F-4 (flow  
thermister faulty - open or shorted). The control will  
then sequence through all eight memories, indicating  
alternately the fault number and the fault code (FL1,  
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Page 23  
POWER UP  
FAULT TREE  
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Page 24  
IGNITION FAULT TREE  
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Page 25  
SPACE HEATING  
FAULT TREE  
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Page 26  
DOMESTIC HOT WATER  
FAULT TREE (EBP ONLY)  
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Page 27  
BOILER TEMPERATURE  
FAULT TREE  
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Page 28  
(2) poor flame sensor signal, (3) inadequate gas  
supply, (4) ignitor failure, (5) blocked or  
contaminated air source.  
MEASUREMENTS AT HIGH FIRE  
NATURAL GAS  
% CO2  
MAX INPUT  
BTU/H  
9.0 - 9.6  
1. Poor Combustion: Poor combustion should be  
suspected if there is a strong flue gas odor. The  
odor may result from either an improper gas/air  
ration (high or low CO2) or contamination of the  
combustion air supply. If an improper gas/air  
ratio is suspected refer to “gas valve calibration  
(offset adjustment)” on page 25. If  
175,270  
OFFSET  
IN W.C.  
(-0.01 to -.10)  
LP GAS  
% CO2  
MAX INPUT  
BTU/H  
9.7 - 10.1  
175,270  
contamination of the air source is suspected refer  
to (5) below.  
OFFSET  
IN W.C.  
(-0.01 to -.10)  
2. Poor flame sensor signal: The boiler control  
board will lockout if the flame sensor is  
Table 4. EBP/EDP 175.  
grounded or if the flame signal it receives is less  
than 1 mA dc. To check for a grounded sensor,  
remove the flame sensor wire (yellow) from the  
boiler control board and check for continuity  
between the yellow wire terminal and the  
combustion chamber bottom pan. If there is  
continuity, the flame sensor is grounded. An  
alternate way to check for grounding of the  
flame sensor is to check the ohms resistance  
between the yellow wire terminal and the  
combustion chamber bottom pan, using a meter  
set for at least 100,000 ohms. The resistance  
must be more than 250,000 ohms (some  
technicians have been confused by meters which  
report infinite resistance with what appears to  
them as double zeros; an infinite resistance  
reading means there is no grounding of the flame  
sensor.) If there is continuity, or the ohms  
resistance is less than 250,000 ohms, debris or  
moisture in the combustion chamber may be the  
cause. To correct, carefully remove the ignitor  
and flame sensor assembly. Look for debris on  
the assembly where the flame rod exits the  
ceramic tube. If debris exists, remove it. If this  
area is clean, insert a pencil or other round  
object into the flame sensor hole in the bottom  
combustion chamber pan and roll it around to  
clear any debris that may exist inside the  
combustion chamber. Replace the ignitor/flame  
sensor assembly, reconnect the yellow wire on  
the PCB and start the boiler. If lockout persists,  
check the flame signal. To check the flame  
signal, disconnect the yellow wire from the  
flame sensor, connect a meter, set for microamps  
(mA) DC, between the flame sensor connector  
and the yellow wire connector. Start the boiler. If  
the meter reading is less than 1.00 mA DC, see  
(3) “poor combustion” below. (Check for air  
leaks at air inlet to blower.)  
Figure 29.  
Figure 30. Jumper Wiring for Test and Calibration.  
cycle. Approximately 20 seconds after the start  
of the cycle, the GV LED on the PCB should  
light. If it does not, reset the boiler and check for  
24 VAC at the plug on the PCB. If the voltage is  
less than 20 VAC, and transformer voltage is 24  
VAC replace the PCB. If the voltage is correct,  
connect a pressure gauge to the offset pressure  
port on the gas valve. Reset the boiler and  
3. Inadequate gas supply: Before proceeding,  
ensure that the gas supply has not been shutoff  
or the LP tank (LP boilers) is not empty. Then,  
reset the boiler and observe the operational  
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Page 29  
Caution  
ATTENTION  
Label all wires prior to disconnection when servicing  
controls. Wiring errors can cause improper and  
dangerous operation.  
Au moment de l’entretien des commandes,  
étiquetez tous les fils avant de les débrancher. Les  
erreurs de câblage peuvent nuire au bon  
fonctionnement et être dangereuses.  
Verify proper operation after operation servicing.  
S’assurer que l’apperiel fonctionne adéquatement  
une fois l’entretien terminé.  
Figure 31. EDP/EDN Wiring Diagram.  
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Page 30  
Caution  
ATTENTION  
Au moment de l’entretien des commandes,  
étiquetez tous les fils avant de les débrancher. Les  
erreurs de câblage peuvent nuire au bon  
fonctionnement et être dangereuses.  
Label all wires prior to disconnection when servicing  
controls. Wiring errors can cause improper and  
dangerous operation.  
Verify proper operation after operation servicing.  
S’assurer que l’apperiel fonctionne adéquatement  
une fois l’entretien terminé.  
Figure 32. EBP Wiring Diagram.  
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Page 31  
observe the offset pressure at startup and after 20  
The CO2 values shown in Table 4 should be  
seconds. The pressure will be ~ -2 in. w.c. at  
startup (during prepurge) and should become  
less negative (-0.1 in. w.c.) when the gas valve  
opens and gas flow starts. If the pressure remains  
at ~ -2 in. w.c. throughout the cycle replace the  
gas valve.  
achieved when the unit is in high fire. To manually fix  
the unit in high fire, locate the four-pin connector on  
the bottom left of the control board, and jumper the  
middle two terminals together (see Figure 29). NOTE:  
For EBP (combination heat & hot water) units, when  
the unit is in “tank charge” mode it will stay in high  
fire, whether manually jumpered or not.  
Note: During the prepurge cycle, the gauge will  
indicate several in. W.C. negative pressure.  
Adjust the CO2 and/or offset pressure to the  
values shown in Table 4.  
When adjusting the offset pressure, the CO2 will  
reduce as the offset pressure is adjusted more  
negative. FINAL ADJUSTMENT OF THE  
OFFSET PRESSURE MUST ALWAYS RESULT  
IN A NEGATIVE PRESSURE UPON  
4. Ignitor failure: If the boiler goes through a  
normal start cycle but combustion does not  
occur, ignitor failure should be suspected.  
Check the ignitor by unplugging the ignitor plug  
and measuring the ignitor resistance. It should be  
50-100 (W) ohms. If the resistance is not 50-100  
ohms (W), replace the ignitor. If the resistance is  
correct, reset the boiler and check for 120 VAC  
at the ignitor plug during the start cycle. If there  
is no voltage, replace the PCB or faulty ignitor  
wires.  
COMPLETION.  
5. Blocked or contaminated air source: Before  
proceeding, ensure that the vent terminal (Direct  
Vent installations) or the air inlet (Category IV  
installations) is not obstructed. In general, only  
direct vent installations have the potential for  
cross contamination (flue products entering the  
combustion air stream) of the combustion air  
source. This may be caused by leaky joints in the  
3" flue pipe located inside the 5" combustion air  
pipe. If this is suspected, remove the front panel  
from the appliance, reset the boiler and allow it  
to go through a normal cycle. If during this cycle  
there is no flue odor, repair the leaky joints in  
the flue pipe.  
SECTION 10.  
Symptom Evaluations  
10A. Delayed ignition  
Possible Causes  
a. High lockup pressure (LP boilers) - occurs on  
start-up.  
b. Gas valve regulation problem - occurs on start-up.  
c. Incorrect gas orifice (Natural gas orifice in an LP  
boiler) - occurs on start up  
d. Defective burner - occurs on startup or at burner  
shutdown.  
High lock up pressure is the most common cause  
of delayed ignitions on LP fueled boilers. It may result  
from an improper second stage regulator selection or  
from a faulty regulator.  
SECTION 9.  
Gas Valve Calibration  
9A. Gas Valve Calibration  
Lock up can be detected by measuring the gas  
supply pressure to the boiler at the inlet pressure tap  
on the gas valve. The gas supply to the boiler must be  
shut off before making this connection. Use a water  
manometer or pressure gauge with a scale reading of  
at least 25 in. w. c. or 15 oz/in2. Loosen the screw in  
the gas valve pressure port one full turn and install a  
hose from the pressure gauge over the pressure port.  
Turn on the gas supply. The ENDURANCE boiler is  
designed to operate with supply pressures of 4-13 in.  
w. c. (2.3 - 7.5 oz/ in²). If the supply pressure exceeds  
13 in. w. c. (7.5 oz/ in²) with the boiler not operating it  
is possible that this may be the cause of delayed  
ignitions and the pressure must be reset to ~ 9 in. w. c.  
(5.2 oz/ in2). Restart the boiler and then switch it off  
again. Lock up pressures must be measured when the  
boiler is not operating and preferably immediately  
after boiler shutdown. If the gas pressure again  
exceeds the allowable values, correct the lock up  
problem.  
(offset adjustment)  
If poor combustion is suspected because of a  
strong exhaust smell, pulsation in the exhaust, or  
nuisance flame failure lockouts (shown as “LO” on  
LED), the gas valve offset pressure and exhaust CO2  
should be checked and adjusted, if required. A  
magnehelic pressure gauge (with 0.1 in. w.c.  
divisions) and a CO2 tester are required for this  
adjustment.  
Note: Direct vent installations may experience  
poor combustion that results from cross contamination  
of the combustion air source. Check for cross  
contamination before attempting offset pressure  
adjustment (see Section 8B-3.5).  
CO2 sampling may be taken at the exhaust  
terminal or at the sample port on the 3” exhaust  
located inside the front panel top cover. See Figure 28  
for the location of the offset pressure port and offset  
adjustment.  
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Page 32  
Gas valve regulation problems can also cause  
delayed ignitions. See “Gas valve calibration”.  
Incorrect gas orifice – Check orifice size.  
The CO2 & O2 readings may be influenced by  
cross contamination. Suspect cross contamination if  
the noise returns when the front panel is replaced.  
Boiling (kettling) may occur at boiler discharge  
temperatures from 170°F to 210°F. The temperature  
at which it starts will vary from one installation to  
another. The primary cause of the problem is poor  
heat transfer on the inside of the boiler coil. This may  
be caused by foaming due to excessive concentration  
of antifreeze in the system or by scaling from the  
boiler water due to hardness of make up water.  
Plumbing antifreezes should never be used in a  
boiler system. Only boiler antifreezes, with effective  
antifoamants, are appropriate for the ENDURANCE  
boilers.  
A defective burner can cause a delayed ignition  
during operation or at shutdown. If the gas supply  
pressure is proper the gas valve is functioning  
properly and the gas orifice is correct, the burner  
should be inspected. To inspect it, remove the  
blower. The burner is retained by the blower and it  
will drop out of the bottom of the chamber when the  
blower is removed. There should be no distortion or  
perforations in the burner other than the punched  
holes. Replace if indicated.  
10B. Short Cycling  
Note: The concentration of appropriate  
Possible causes  
antifreeze should be always be kept as low as possible  
to minimize its effect on heat transfer and efficiency.  
The method for eliminating the boiling noise is  
the same regardless of the cause. However, if  
antifreeze in the system is suspected of being the  
cause, the concentration (<35%) and type should be  
investigated.  
a. Reduced system flow - EDP  
b. Thermostatic union (EDP) or anti-condensing  
valve not opening (EBP).  
c. T-T wires cross connected (jumped) – improper  
installation - EBP or EDP/EDN  
d. Leakage of flue products into the combustion air  
stream – Direct Vent Installations only, see  
Moisture  
Although it is not a primary cause of lockouts,  
moisture in the combustion chamber may cause  
lockouts by weakening the flame signal to the boiler  
control. It should be suspected if the boiler  
temperature does not rise above 160°F during long  
periods of operation. This condition can be caused by  
a defective thermostat in the thermostatic union of  
EDN or EDP boilers (or the omission of the  
thermostatic union at installation) or failure of the  
anticondensing valve in the EBP (combi) boilers.  
Moisture can also get into the combustion chamber  
through an incorrectly pitched or incorrectly installed  
flue pipe (pitched back toward the boiler without a  
condensate trap). The flue assembly of EBP, EDN and  
EDP boilers installed as Direct Vent boilers should  
always pitch down from the boiler.  
Section 8B-3, Resolving Lockouts (LO), item (5).  
10C. Noisy Operation  
There are two principal sources of noisy  
operation:  
a. Combustion - high pitched noise - whistle or  
hoot.  
b. Boiling (kettling) - lower frequency noise which  
varies with temperature - moan.  
Many times it is difficult to determine the source  
of the noise or if it is combustion related or boiling  
related. Combustion noises always have the same  
frequency; however, their volume may change from  
the time that the burner first fires to the time that it  
shuts off. A boiling noise is identified by rapidly  
raising or lowering the system water pressure while  
the noise is present. A change in the pitch or intensity  
of the noise indicates a boiling problem.  
10D. Insufficient Hot Water (EBP only)  
Possible cause:  
Combustion noise occurs at any boiler  
a. No flow restrictor (supplied with unit - field  
installed)  
discharge temperature and is heard the loudest at the  
flue outlet (especially on units that are sidewall  
vented). There are two basic causes for the noise, rich  
mixture (high CO2 or low O2) or cross contamination.  
The mixture is determined by measuring the percent  
O2 or CO2 in the flue products. O2 readings lower than  
4½ % or CO2 readings higher than 9¼ % (natural gas)  
and 10.8% (LP) will often cause combustion related  
noise. The rich mixture could be caused by the mis-  
calibration of the gas valve (offset adjustment) or by  
the gas orifice size. To eliminate the noise; first, check  
the gas valve calibration. If it is correct, install a  
smaller gas orifice so that the O2 will rise above 4½%  
or the CO2 will drop to 8½% (natural) or 9½% (LP).  
b. Water flow switch failure  
c. Mixing valve setting or failure  
d. Domestic hot water (DHW) heat exchanger  
contamination  
The most common cause for insufficient hot  
water complaints results from failure to install a flow  
restrictor. The absence of a flow restrictor allows  
water to pass through the heat exchanger at a greater  
rate than the boiler output is capable of heating to the  
desired temperature.  
Failure of the water flow switch to operate  
during a hot water draw prevents boiler water from  
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Page 33  
flowing through the DHW heat exchanger and  
therefor the DHW will not be heated.  
systems (mostly magnesium), cause slime on the  
inside of the heat exchanger and prevent adequate heat  
transfer. These minerals must be filtered out by a  
special incoming water filter or by the addition of an  
inhibitor to protect the coil and provide acceptable  
water quality. Minerals may be removed when  
necessary by flushing the coil with a cleaner such as  
“Unlime®” or “Sizzle®”.  
To test the switch, place a temporary jumper  
across the back of the connector on the PCB (see  
wiring diagrams for connector location). If the internal  
pump operates and there is DHW generated then the  
water flow switch is faulty and must be replaced.  
Note: Switch orientation is critical for proper switch  
operation, The identification plate on the switch must  
face up and the arrow on the plate must point in the  
direction of flow.  
Failure of the mixing valve will allow cold water  
to be mixed with the hot water from the DHW heat  
exchanger during a DHW draw regardless of the  
setting of the mixing valve or the temperature of the  
water leaving the DHW heat exchanger. The failure  
can be detected by observing the temperature of the  
three pipes connected to the mixing valve. If the  
“mix” temperature is luke warm or cool and the “hot”  
temperature is hot and the “cold” temperature is cold  
then the mixing valve is either faulty or incorrectly  
adjusted and must be replaced or adjusted.  
10E. High Gas Consumption  
Boilers operating with an improper air/fuel ratio  
are very inefficient and consequently, have very high  
gas consumption. Because efficiency is high when the  
CO2 is high, boilers operating with low CO2  
(especially LP boilers) consume more gas. Adjust the  
CO2 or O2 for optimum efficiency. If no combustion  
analyzing equipment (CO2 or O2) is available then a  
proper adjustment of the air/fuel ratio (CO2) can not  
be accomplished. However, by briefly sniffing the flue  
gases it is possible to determine if the CO2 or O2 is  
within the proper range. There is no significant flue  
gas odor when combustion is proper. A strong  
piercing smell indicates poor combustion and  
generally a lean mixture (low CO2). Check gas valve  
calibration (offset adjustment) and adjust if indicated.  
Do not attempt to correct combustion by reorificing  
without an O2 or CO2 kit.  
DHW heat exchanger scaling may occur in some  
areas of the country where there are high  
concentrations of minerals in the water. These  
minerals may cause fouling of the DHW heat  
exchanger over an extended period of time (lime build  
up). Other minerals, which react more quickly in well  
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Page 34  
Description  
Part  
Number  
SECTION 11.  
Parts Identification  
18. GASKET, BLOWER  
19. WATER FLOW SWITCH  
2400-540  
2400-542  
Description  
Part  
Number  
20. BOILER CONTROL (BEHIND PANEL) (EBP) 2400-546  
21. GAS VALVE, HONEYWELL,  
NEG. REG. PRESSURE  
22. SAFETY LIMIT, 230 °F  
23. SENSOR, TANK ( EBP ONLY )  
24. SENSOR, BOILER FLOW  
25. SENSOR, BOILER RETURN  
2400-548  
2400-550  
2400-552  
2400-554  
2400-556  
1. PAN, COMBUSTION CHAMBER T0P  
2. PAN, COMBUSTION CHAMBER BOTTOM  
3. INSULATION, COIL COVER  
4. INSULATION, BOILER COIL  
5. COIL, BOILER, EBP/EDP/EDN 110 (ASSY.) 2400-510  
6. COIL, BOILER, EBP/EDP/EDN 175 (ASSY.) 2400-512  
2400-502  
2400-504  
2400-506  
2400-508  
26. THERMOSTATIC UNION EDP (NOT SHOWN)2400-030  
27. GAS SHUTOFF VALVE  
28. PUMP, EBP/EDP 110  
29. PUMP, EBP/EDP 175  
30. GASKETS, PUMP FLANGE  
31. RESET SWITCH  
32. HEAT EXCHANGER, DOM. HOT WATER  
33. GASKETS, DHW HEAT EXCHANGER  
34. BUTTON, ON/OFF (PART OF 2400-546)  
35. BUTTON, TEMP/MESSAGE  
(PART OF 2400-546)  
36. GAUGE, PRESSURE (NOT SHOWN)  
37. PRESSURE RELIEF VALVE  
(30 PSIG, NOT SHOWN)  
2400-560  
2400-592  
2400-386  
2400-566  
2400-568  
2400-570  
2400-572  
-
7. GASKET, BURNER  
8. BURNER, EBP/EDP/EDN 110  
(GASKETS INCLUDED)  
9. BURNER, EBP/EDP/EDN 175  
(GASKETS INCLUDED)  
10. TRANSFER TANK  
11. BOILER DRAIN (BEHIND PANEL-EBP)  
12. BLOWER, COMBUSTION AIR  
(GASKETS INCLUDED)  
13. IGNITOR/FLAME SENSOR  
(GASKET INCLUDED)  
2400-514  
2400-516  
2400-518  
2400-520  
2400-522  
2400-524  
-
2400-574  
2400-526  
2400-528  
1-592  
14. GASKET, IGNITOR/FLAME SENSOR  
15. COIN VENT  
2400-112  
38. BOILER CONTROL (BEHIND PANEL)  
(EDP/EDN)  
39. PUMP, EDN 110  
40. PUMP, EDN 175  
41. THERMOSTATIC UNION EDN (NOT SHOWN)47-026  
42. TRANSFORMER (NOT SHOWN) 2400-562  
16. COMBUSTION AIR INLET,  
ADJUSTABLE, KIT  
2400-558  
2400-388  
2400-388  
2400-142  
2400-538  
17. VALVE, ANTI CONDENSING,  
REPAIR KIT  
Model EDP/EDN  
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Endurance  
Page 35  
Model EBP  
Boiler Drain  
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As an Energy Star® Partner,  
Laars has determined that this  
product meets the Energy Star®  
guidelines for energy efficiency.  
P.O. Box 310  
Lynnfield, MA 01940  
Phone: 781-961-1660  
Fax: 781-334-2541  
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