Lochinvar Crest FBN 2500 Owner's manual

This manual must only be used by
a qualified heating installer / service
technician. Read all instructions,
including this manual along with
the Crest Installation and Operation
Manual, and the Crest Service Manual,
before installing. Perform steps in the
order given. Failure to comply could
result in severe personal injury, death,
or substantial property damage.
WARNING
Save this manual for future reference.
FBD-SUP_100161023_2000004585 Rev E
Dual Fuel Supplemental Manual
Models: FBD 2.5 - 6.0

2
CONTENTS
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
DANGER
WARNING
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
HAZARD DEFINITIONS .................................................... 2
PLEASE READ BEFORE PROCEEDING ........................ 3
THE CREST -- HOW IT WORKS ...................................... 4
RATINGS........................................................................... 5
1. GAS CONNECTIONS
Assemble/Install Proof of Closure (FBD 6000 Model Only) 6
• Assemble Proof of Closure Valve..................................7
• Assemble High & Low Gas Pressure Switch Assembly 7
• Wiring for the High & Low Gas Pressure Switch...........8
• Wiring for the Proof of Closure Valve............................8
Check Inlet Gas Supply ..................................................... 9
Gas Pressure ................................................................... 10
Gas Valve Replacement ................................................. 10
2. START-UP
Start the Boiler ................................................................. 11
Check System and Boiler..................................................11
Operating Instructions...................................................... 12
Check Flame and Combustion......................................... 13
Dual Fuel Switching Instructions ................................ 13-14
3. DIAGRAMS.............................................................15-22
Revision Notes.................................................. Back Cover

Dual Fuel Supplemental Manual
Please read before proceeding
Installer – Read all instructions, including
this manual, the Crest Installation and
Operation Manual and the Crest Service
Manual, before installing. Perform steps
in the order given.
User – This manual is for use only
by a qualified heating installer/
service technician. Refer to the User’s
Information Manual for your reference.
Have this boiler serviced/inspected by
a qualified service technician, at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
Failure to adhere to the guidelines on this
page can result in severe personal injury,
death, or substantial property damage.
When servicing boiler –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
Consider piping and installation when
determining boiler location.
Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by
the consignee.
Factory warranty (shipped with unit) does
not apply to units improperly installed or
improperly operated.
3
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
This appliance MUST NOT be installed in
any location where gasoline or flammable
vapors are likely to be present.
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 near by phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
• Installation and service must be
performed by a qualified installer,
service agency, or the gas supplier.
WARNING
NOTICE
WARNING
WARNING

Dual Fuel Supplemental Manual
4
The Crest Dual Fuel - How it works...
1. Propane gas connection
The propane gas connection pipe is a threaded black iron pipe
connection. This pipe should be connected to the incoming gas
supply to deliver propane gas to the boiler.
2. Natural gas connection
The natural gas connection pipe is a threaded black iron pipe
connection. This pipe should be connected to the incoming gas
supply to deliver natural gas to the boiler.
3. Fuel selection switch
Switches the unit between natural and propane gas.
4. Natural gas indicator light (green)
Indicates that natural gas operation has been selected.
5. Propane gas indicator light (red)
Indicates that propane gas operation has been selected.
6. Small natural gas valve (Valve 1 Natural)
The small natural gas valve senses the negative pressure
created by the blowers, allowing gas to flow only if the gas
valves are powered and combustion air is flowing.
7. Small propane valve (Valve 1 Propane)
The small propane gas valve senses the negative pressure
created by the blowers, allowing gas to flow only if the gas
valves are powered and combustion air is flowing.
8. Large natural gas valve (Valve 2 Natural)
The large natural gas valve senses the negative pressure created
by the blowers, allowing gas to flow only if the gas valves are
powered and combustion air is flowing.
9. Large propane gas valve (Valve 2 Propane)
The large propane gas valve senses the negative pressure created
bytheblowers,allowinggastoflowonlyifthegas valves are powered
and combustion air is flowing.
10. Natural shutoff valve
The natural shutoff valve is used to isolate the boiler gas
train from the gas supply.
11. Propane shutoff valve
The propane shutoff valve is used to isolate the boiler gas
train from the gas supply.
12. Natural ball valve (Valve 1)
The ball valve for natural valve 1 is used to isolate natural valve 1
from the propane gas supply.
13. Propane ball valve (Valve 1)
The ball valve for propane valve 1 is used to isolate propane valve 1
from the natural gas supply.
14. Natural ball valve (Valve 2)
The ball valve for natural valve 2 is used to isolate natural valve 2
from the propane gas supply.
15. Propane ball valve (Valve 2)
The ball valve for propane valve 2 is used to isolate propane valve 2
from the natural gas supply.
16. Proof of closure valve
An additional safety shutoff valve with proof of closure contacts is
used on the Crest 6.0 model only.
IMG00061
14
11
10
8
9
15
12
6
7
13
IMG00064
3
4
5
IMG00555
MODELS 4.0 - 5.0
MODELS 2.5 - 3.5
34
5
16
MODEL 6.0
Models FBD 2.5 - 6.0
IMG00062
1
2
Front View Left Side (inside unit)

Dual Fuel Supplemental Manual
Ratings
Crest
AHRI Rating
Model Number
Note: Change “N” to
“L” for L.P. gas models.
Input
MBH
(Notes 4 - 8)
Min Max
Gross
Output
MBH
(Note 1)
Net
AHRI
Ratings
Water,
MBH
(Note 2)
FB(N,L,D)2500 125 2500 2300 2000
FB(N,L,D)3000 150 3000 2760 2400
FB(N,L,D)3500 200 / 290 3500 3220 2800
FB(N,L,D)4000 335 / 435 4000 3720 4043
FB(N,L,D)5000 500 / 833 5000 4650 3235
FB(N,L,D)6000* 600 / 950 6000 5520 4800
UNIT EQUIPPED FOR
HIGH ALTITUDE
3,000 FT. TO 12,000 FT.
Figure A High Altitude Label Location 5
Other Specifications
Appliance
Water
Content
Gallons
Pipe
Size
Outlet
Pipe
Size
Inlet
Gas Inlet
Size
Air
Size
Vent
Size
(Note 3)
Weight
w/Water
(lbs.)
161 4" 4" 2" 8" 9" 3650
181 4" 4" 2" 10" 10" 4125
215 4" 4" 2" 10" 10" 4750
291 4" 4" 2 1/2" 12" 12" 6500
380 4" 4" 2 1/2" 14" 14" 8000
380 6" 6" 2 1/2" 14" 14" 8000
Maximum allowed working pressure is located on the rating plate.
NOTICE
Notes:
1. The ratings are based on standard test procedures
prescribed by the United States Department of Energy.
2. Net AHRI ratings are based on net installed radiation of
sufficient quantity for the requirements of the building
and nothing need be added for normal piping and pickup.
Ratings are based on a piping and pickup allowance of
1.15.
3. Crest boilers require special gas venting. Use only
the vent materials and methods specified in the Crest
Installation and Operation Manual.
4. Standard Crest boilers are equipped to operate from sea
level to 4,500 feet only. The boiler will de-rate by 2.2%
for each 1,000 feet above sea level up to 4,500 feet.
5. High altitude Crest Models 2.5, 3.0 and 3.5 are equipped
to operate from 3,000 to 12,000 feet only. e boiler will
de-rate by 1.4% for each 1,000 feet above sea level up to
5,500 feet and 1.8% for each 1,000 feet above 5,500 feet.
e operation given in this manual remains the same as
the standard boilers. A high altitude label (as shown in
FIG A.) is also axed to the unit.
De-rate values are based on proper combustion
calibration and CO2 ’s adjusted to the recommended
levels.
*For high altitude models the minimum input is 700 MBH (natural) and 1000 MBH (LP).
6. High altitude Crest Models 4.0 and 5.0 will not de-rate up to
5,500 feet.
7. e high altitude Crest 6.0 model will de-rate by 2.0% for
each 1000 feet above sea level up to 5,500 feet.
8. For Crest Models 4.0, 5.0 and 6.0, installations above 5,500
feet contact the factory.
9. Ratings have been conrmed by the Hydronics Section of
AHRI.

6
The ship loose kit inside the FBD6000 Dual Fuel contains
parts required for assembly to the propane inlet gas train prior
to connection to the incoming propane gas line. Reference
FIG. 1-1 along with Table 1A for the required assembly order
and identification of parts. Use pipe sealant approved for
use with propane gas on all primary joints. Thread tape is
recommended on all 1/8" pipe joints for the high and low gas
pressure switches.
Assemble/install proof of closure
valve (FBD 6000 model only)
1 Gas connections
Dual Fuel Supplemental Manual
NOTICE Before installing your FBD6000 boiler
YOU MUST install the LP proof of
closure assembly provided in the ship
loose kit with the unit.
Table 1A Ship Loose Kit Components
Kit Components
Material / Part No. Description QTY.
100134332 Tee, 1/8 NPT, CLS 150, BLK, Straight 2
100134403 Nipple, 1/8 NPT, X Close, SCH40 BLK 1
100134379 Bushing, HEX, 1/4 X 1/8 NPT, SCH40, BLK 1
100134327 Elbow, Street 90, 1/8 NPT, SCH40, BLK 1
100135488 Plug, HEX, 1/8 NPT, Brass 1
100134398 Nipple, 1/8 NPT X 2", SCH40, BLK 1
100161647 Switch, Pressure, 27" WC 1
100166123 Switch, Pressure, 3" WC 1
100273736 Valve, Actuator, Proof of Closure 1
100273737 Valve, Proof of Closure 1
100173738 Valve, Ball, 2-1/2, THRD, NPT 1
100134284 Nipple, 2-1/2 X Close, SCH40, BLK 1
100134241 Nipple, 2-1/2" NPT X 6" SCH40, BLK 1
100163145 Bushing, Wire, 7/8 1
100280830 Harness, Dual Fuel, GPS/POC Switch 1
100134283 Union, 2-1/2 NPT, SCH40, BLK 1
Failure to apply pipe sealing compound
as detailed in this manual can result in
severe personal injury, death, or substantial
property damage.
WARNING
Figure 1-1 Proof of Closure Part Identification
DIR #2000540611 00
NIPPLE 2 1/2” X 6”
NIPPLE 2 1/2 X CLOSE
SHUTOFF VALVE
UNION
Labels on the top panel of the unit will identify the type of
gas for each of the two (2) inlet gas trains (see FIG. 1-2).
Verify this with the corresponding labels attached to the
gas trains inside the boiler. The natural gas train will have
a proof of closure valve already installed inside the boiler.
Figure 1-2 Labels Located on the Top Panel of the
Unit
DIR #2000540605 00
PROPANE
LABEL
NATURAL
LABEL
PROPANE
LABEL
NATURAL
LABEL
INSIDE UNIT
Note: Reference Table 1A.

7
1 Gas connections (continued)
Dual Fuel Supplemental Manual
Figure 1-3 Proof of Closure Valve Orientation
Reference FIG. 1-1 for assembly of the proof of closure valve.
Note: DO NOT install the actuator portion of the proof of
closure assembly at this time. Verify that when installing the
proof of closure valve the directional arrow located on the valve
body is pointing toward the boiler inlet gas piping (FIG. 1-3).
Orient the proof of closure valve as shown in FIG. 1-3.
Assemble proof of closure valve
1. Remove the upper most pressure plug from the proof of
closure valve body. Install high and low gas pressure
assembly as shown in FIG. 1-4.
2. With the proof of closure actuator body oriented as shown
in FIG. 1-5, loosen the two (2) screws to remove the metal
access plate.
3. Remove the two (2) knockouts on the actuator (FIG. 1-5).
Be sure to remove any parts of the knockout that may
remain inside the actuator assembly.
4. Attach the proof of closure actuator to the proof of closure
valve using the two (2) set screws which are part of the
actuator assembly (FIG. 1-6). Make certain the actuator is
fully seated to the valve body, see FIG. 1-6.
Assemble the high and low gas pressure switch
assembly
Figure 1-6 Attach Proof of Closure Actuator to the Proof
of Closure Valve
PLUG FOR THE
GAS PRESSURE
SWITCHES
TO BOILER
INLET
DIR #2000540612 00
REMOVE UPPER MOST
PRESSURE PLUG
BUSHING
ELBOW
NIPPLE
PRESSURE
SWITCH
TEE
PRESSURE
SWITCH
TEE
BRASS PLUG
NIPPLE
Figure 1-4 High and Low Gas Pressure Switch Assembly
Figure 1-5 Remove Cover and Knockouts for Wiring
LOOSEN SCREWS
TO REMOVE OUTER
COVER
REMOVE KNOCKOUTS (THIS SIDE)
FRONT SET SCREW
BOTTOM SET SCREW
FULLY SEAT TO
VALVE BODY
PROOF OF CLOSURE
ACTUATOR

8
1 Gas connections
Dual Fuel Supplemental Manual
1. Using the wire harness included in the ship loose kit, connect the 4-pin connector to the mating connector located on the
top panel of the boiler.
2. Connect the BROWN and ORANGE wires to the (lower) low gas pressure switch.
3. Connect the BLUE and ORANGE wires to the (upper) high gas pressure switch.
4. Insert a 7/8” bushing into the knockout opening nearest the proof of closure switch in the actuator assembly.
5. Feed the two (2) BROWN wires from the pressure switch harness through the bushing and attach the “C” and “NC”
terminals of the switch.
Wiring for the high and low gas pressure switches and proof of closure switch (reference FIG. 1-7)
Figure 1-7 High and Low Gas Pressure Switch Wire Harness
BR
T/BK
PROOF
OF
CLOSURE
SWITCH
LP
LGPS-LP
O BL/BK
BR
O
HGPS-LP
CONNECT TO PLUG
ON OUTER TOP PANEL
BK
12
W
C
NC
NO
C
NC
NO
BUSHING
1. Wiring and conduit for the 120V power to the actuator is attached to the outer top panel of the boiler.
3. Check and trim (if necessary) the conduit used to route the power wires from the top panel of the unit to the actuator
assembly.
3. Attach the 90° conduit to the knockout opening nearest the power connections in the proof of closure actuator assembly.
4. Connect the BLACK wire to “1” and the WHITE wire to “2” as shown in FIG. 1-8.
5. Replace the metal access plate removed in Step #2 of the Assemble the High and Low Gas Pressure Switches Section.
Wiring for the proof of closure valve 120V power (reference FIG. 1-8)
Figure 1-8 Proof of Closure Valve Wire Harness
DIR #2000540659 00
BK
PROOF OF
CLOSURE
VALVE-LP
12
W
C
NC
NO
C
NC
NO
TOP PANEL
CONDUIT

9
Table 1B Natural Gas Pipe Size Chart
The gas piping must be sized for the proper flow and length of
pipe, to avoid excessive pressure drop. Both the gas meter and
the gas regulator must be properly sized for the total gas load.
If you experience a pressure drop greater than 1 inch w.c.
(249 Pa), the meter, regulator, or gas line is undersized or in
need of service. Perform the steps below when checking inlet
gas supply:
1. Turn the main power switch to the “OFF” position.
2. Shut off gas supply at the manual gas valve in the gas
piping to the appliance.
3. Remove the 1/8" pipe plug on the flange to the factory
supplied gas shutoff valve and install a suitable 1/8"
fitting (field supplied) for the manometer tubing. Place the
tubing of the manometer over the tap once the 1/8"
fitting is installed as shown in FIG.’s 1-9 and 1-10.
4. Slowly turn on the gas supply at the factory installed
manual gas valve.
5. Turn the power switch to the “ON” position.
6. Adjust the temperature set point on the control panel of
the SMART TOUCH control module to call for heat or
utilize Service Mode, see page 13 of this manual.
7. Observe the gas supply pressure as the burner fires at
100% of rated input. Percent of burner input will be
displayed on the Modulation Screen.
8. Ensure inlet pressure is within specified range.
Minimum and maximum gas supply pressures are
specified in this section of the manual.
9. If gas supply pressure is within normal range and no
adjustments are needed, proceed on to Step 11.
10. If the gas pressure is out of range, contact the gas utility,
gas supplier, qualified installer or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
11. Turn the power switch to the “OFF” position.
12. Shut off the gas supply at the manual gas valve in the gas
piping to the appliance.
13. Remove the manometer from the pressure tap on top of
the gas valve. Remove the 1/8" (3 mm) field supplied
fitting and reinstall the pipe plug removed in Step 3.
DO NOT adjust or attempt to measure gas
valve outlet pressure. Attempting to alter
or measure the gas valve outlet pressure
could result in damage to the valve, causing
potential severe personal injury, death, or
substantial property damage.
WARNING
Check inlet gas supply
1 Gas connections (continued)
Dual Fuel Supplemental Manual
The Dual Fuel Crest is equipped with
two (2) inlet gas connections. Each
connection must be checked to ensure
proper operation.
NOTICE
TABLE - 1B
Capacity of Schedule 40 Metallic Pipe in Cubic Feet of Natural Gas Per Hour
(based on .60 specific gravity, 0.30" w.c. pressure drop)
Pipe
Size
(Inches)
Length of Pipe in Straight Feet
10 20 30 40 50 60 70 80 90 100 125 150 175 200
1/2 131 90 72 62 55 N/A N/A N/A N/A N/A N/A N/A N/A N/A
3/4 273 188 151 129 114 104 95 89 83 79 70 63 58 N/A
1 514 353 284 243 215 195 179 167 157 148 131 119 109 102
1 1/4 1,060 726 583 499 442 400 368 343 322 304 269 244 224 209
1 1/2 1,580 1,090 873 747 662 600 552 514 482 455 403 366 336 313
2 3,050 2,090 1,680 1,440 1,280 1,160 1,060 989 928 877 777 704 648 602
2 1/2 4,860 3,340 2,680 2,290 2,030 1,840 1,690 1,580 1,480 1,400 1,240 1,120 1,030 960
3 8,580 5,900 4,740 4,050 3,590 3,260 3,000 2,790 2,610 2,470 2,190 1,980 1,820 1,700
4 17,500 12,000 9,660 8,270 7,330 6,640 6,110 5,680 5,330 5,040 4,460 4,050 3,720 3,460

Dual Fuel Supplemental Manual
WARNING Do not check for gas leaks with an open
flame -- use the bubble test. Failure to
use the bubble test or check for gas leaks
can cause severe personal injury, death, or
substantial property damage.
14. Turn on the gas supply at the manual gas valve.
15. Turn the power switch to the “ON” position.
16. Adjust the temperature set point on the control panel of
the SMART TOUCH control module to the desired
water temperature so the appliance will call for heat.
17. Check burner performance by cycling the system while
you observe burner response. The burner should ignite
promptly. Flame pattern should be stable. Turn system
off and allow burner to cool, then cycle burner again to
ensure proper ignition and flame characteristics.
18. Repeat Steps 1 - 17 for both natural and LP gas supply.
Ignition problems are especially noticeable in NEW LP
installations and also in empty tank situations. This can
also occur when a utility company shuts off service to an
area to provide maintenance to their lines.
Gas valve replacement
The gas valve MUST NOT be replaced with a
conventional gas valve under any circumstances. As
an additional safety feature, the gas valves have flanged
connections to the venturis and blowers.
Figure 1-9 Inlet Gas Supply Check_Natural
DO NOT adjust or attempt to
measure gas valve outlet pressure.
Attempting to alter or measure
the gas valve outlet pressure could
result in damage to the valve,
causing potential severe personal
injury, death, or substantial property
damage.
Failure to follow all precautions
could result in fire, explosion, or
death!
WARNING
WARNING
1 Gas connections
Gas Pressure
The gas pressure must remain between 4 inches w.c. (.99 kPa)
minimum and 14 inches w.c. (3.5 kPa) maximum for Natural
gas and between 4 inches w.c. (.99 kPa) minimum and 14
inches w.c. (3.5 kPa) maximum for LP gas during standby
(static) mode and while in operating (dynamic) mode. If an
in-line regulator is used, it must be a minimum of 10 feet (3 m)
from the Crest boiler. It is very important that the gas line is
properly purged by the gas supplier or utility company. Failure
to properly purge the lines or improper line sizing, will result
in ignition failure.
Figure 1-10 Inlet Gas Supply Check_Propane
IMG00065
10

11
Dual Fuel Supplemental Manual
2 Start-up
Final checks before starting the boiler
Read the Crest Service Manual to familiarize yourself
with SMART TOUCH control module operation. Read
this manual, page 9 for proper steps to start boiler.
Verify the boiler and system are full of water and all
system components are correctly set for operation.
Verify the preparation procedures of Section 9 of the
Crest Installation and Operation Manual have been
completed.
Verify electrical connections are correct and securely
attached.
Inspectvent pipingand airpiping forsigns ofdeterioration
from corrosion, physical damage or sagging. Verify air
piping and vent piping are intact and correctly installed
per this manual.
Start the boiler
1. Read and follow the Operating instructions in FIG. 2-1,
page 12.
If boiler does not start correctly
1. Check for loose connections, blown fuse or service switch
off?
2. Is external limit control (if used) open? Is boiler water
temperature above 200°F (93°C)?
3. Is the boiler receiving a call for heat?
4. Is gas turned on at meter and boiler?
5. Is incoming gas pressure less than 4 inches w.c. (.99 kPa)?
If none of the above corrects the problem, refer to the
Troubleshooting Section of the Crest Service Manual.
Check system and boiler
Check water piping
1. Check system piping for leaks. If found, shut down the
boiler and repair immediately. (See WARNINGS in
the Crest Installation and Operation Manual (startup)
regarding failure to repair leaks.)
2. Vent any remaining air from the system using manual
vents. Air in the system will interfere with circulation
and cause heat distribution problems and noise.
Check vent piping and air piping
1. Check for gastight seal at every connection, seam of air
piping, and vent piping.
Venting system must be sealed gastight
to prevent flue gas spillage and carbon
monoxide emissions, which will result in
severe personal injury or death.
Check gas piping
1. Check around the boiler for gas odor following the
procedure in the Crest Installation and Operation
Manual (connecting gas supply piping).
If you discover evidence of any gas leak,
shut down the boiler at once. Find the
leak source with a bubble test and repair
immediately. Do not start the boiler again
until corrected. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
WARNING
WARNING

12
Dual Fuel Supplemental Manual
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. BEFOR E OP ER ATING smell all ar ound
the app liance area fo r gas. Be sure to
smell next to the floor because some gas
is heavier than air and will settle on the
floor.
WHAT TO DO IF YOU SMELL GAS
•D o no t tr y to light an y appl iance.
•Do not touch any electric switch; do
not use any phone i n your b ui ldi ng .
•Immediately call your gas supplier from a
neighbor ’s phone. Fol lo w the gas supp lier’s
instructions.
•If yo u can not reach you r ga s sup pl ier , ca ll
the fire department.
C. Use only your hand to turn the gas control knob.
Never use tools. If the handle will not turn by
hand , do n’t try to repair i t, call a qualified service
technician. Force or attempted repair may
result in a fire or expl osion.
D. Do not use this appliance if any part has b e en
unde r water. Immediately call a qual ified
ser vice tech n ician to inspect the applianc e and
to replace any part of the control system and
any ga s control which has been under water.
OPERATING INSTRUCTIONS
1. STOP! Read the safety information
above on this label.
2. Set the thermostat to lowest setting.
3. Turn off all electric power to the
app lianc e.
4. T his appliance is equipped with an
ignition device which automatically lights
the burner. Do not try to light the burner
by ha nd .
5. Remove front door.
6. Turn gas shutoff valve counterclockwise
to “ OFF”. H an dle wil l be pe rp en dicu lar to
pipe. Do not force.
7. Wait five (5) minutes to clear out any gas.
If you then smell gas, STO P ! Follow “B”
in the safety information above this label.
If you don’t smell gas, go to next step.
8. Tur n g as sh utoff val ve clo ckwise to “ ON”.
Handle will be parallel to pipe.
9. Instal l fr ont door.
10. Turn on all electric power to appliance.
11. Set ther mo stat to desired setting.
12. If the appl iance w ill n ot op er ate, fol low th e
instr uctions “T o Turn Off Ga s T o Appliance ” and
call your service technician or gas supplier.
TO TURN OFF GAS TO APPLIANCE
1. Set the thermostat to lowest setting.
2. T urn off all electric power to the appl iance
if se rvice i s to be pe rf or me d.
3. Remove front door.
4. Turn gas shut off valve counterclockwise to
“OFF”. Handle will be perpendicular to pipe.
Do not force.
5. Instal l fr ont door.
L BL2 005 3 REV B
Figure 2-1 Operating Instructions
2 Start-up

Dual Fuel Supplemental Manual
2 Start-up (continued)
Table 2A Flue Products Chart
8. After Gas Valve 1 is set, repeat the same procedure for the
second gas train by selecting Set Gas Valve 2 - High on the
Service Screen.
9. Once the heater analysis is complete, test the safety shutoff
device by turning the manual shutoff valve to the OFF
position and ensuring that the heater shuts down and
registers an alarm. Open the manual shutoff valve and reset
the control.
10. Repeat the same procedure for propane gas. Reference the
Dual Fuel Switching Instructions on pages 10 and 11 of this
manual.
11. Turn the main power off to the boiler and replace the
flue temperature sensor into the flue pipe connection.
12. Place the boiler back into normal operation.
You must replace the flue gas temperature
sensor to prevent flue gas spillage into the
room. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
WARNING
Check flame and combustion
1. Turn the main power off to the boiler by placing
the “On/Off” switch in the OFF position.
2. Remove the flue temperature sensor from the flue
collector. Note: Combustion measurements will
be made at this point.
3. Turn the main power on to the boiler by placing
the “On/Off” switch in the ON position.
4. Navigate to the Service Maintenance Screen from
the Home Screen by pressing the SETUP button,
enter the installer password, and then using the
scrolling menu feature on the left side, scroll down
to the SERVICE MAINTENANCE button.
5. On the Service Maintenance Screen place heater
into Service Mode by selecting the START button,
then selecting Set Gas Valve 1 - High.
6. Insert the probe from a combustion analyzer into
the hole left by the removal of the flue temperature
sensor.
7. Once the heat exchanger has modulated up to
rate, measure the combustion. The values should
be in the range listed in Table 2A. CO levels
should be less than 200 ppm for a properly
installed unit. If the combustion is not within
range reference the Troubleshooting Section in
the Crest Service Manual for possible causes and
corrective actions.
NOTICE A flame and combustion check
must be performed on natural gas
and then repeated on propane.
Dual fuel switching instructions
1. Turn the main power off to the boiler by placing the
“On/Off” switch in the OFF position (FIG.’s 2-2A and
2-2B).
2. Using the fuel selector switch (FIG.’s 2-2A and 2-2B),
select the desired fuel.
Figure 2-2A Fuel Selector Switch - Models 2.5 - 3.5
IMG00063
NATURAL PROPANE
DETAIL
IMG00064
MAIN POWER
SWITCH
NATURAL PERSONALITY I.D. PROPANE PERSONALITY I.D.
FUEL SELECTION
SWITCH
Flue
Products Natural Gas
Units 1.5 2.0 2.5 3.0 3.5 4.0 5.0 6.0 ALL
Gas
Valve
CO2 (%) CO2 (%) CO2 (%) CO2 (%) CO2 (%) CO2 (%) CO2 (%) CO2 (%) O2 (%)
Valve 1
High 4.8 4.6 5.2 4.5 4.9 5.4 6.2 5.9 14.2 - 9.2
Valve 1
Low 1.1 1.4 1.7 1.4 1.4 1.9 2.8 2.7 19.0-15.6
Valve 2
High 8.2 8.4 8.1 8.1 8.4 8.7 8.9 9.5 6.9 - 4.8
Valve 2
Low 7.8 7.6 7.5 7.1 7.4 8.8 8.1 8.2 8.9 - 4.9
Propane
Valve 1
High 5.4 5.6 6.1 5.7 6.4 6.6 7.3 7.6 13.0 - 9.5
Valve 1
Low 1.4 1.6 2 1.8 2 2.8 4.8 4.3 19.2-13.3
Valve 2
High 10.7 10.5 10 9.8 10.2 11 10.2 11.3 6.3 - 3.8
Valve 2
Low 8.7 8.5 9.1 8.7 8.7 10.8 9.7 9.9 8.3 - 4.1
**All set points should be within +/- 0.2%**
13

14
Dual Fuel Supplemental Manual
2 Start-up
3. Turn off all ball valves (3 total) for the fuel not in use (FIG. 2-3).
Figure 2-3 Ball Valves
NATURAL
PROPANE
IMG00061
4. Turn on the ball valves for the ones in use (3 total).
5. Turn the main power ON.
6. Using the Touch Screen, accept the appropriate personality
identification as shown in FIG. 2-4.
Figure 2-4 Personality Plug Screen
Figure 2-2B Fuel Selector Switch - Models 4.0 - 6.0
IMG00063
NATURAL PROPANE
DETAIL
MAIN POWER
SWITCH
NATURAL
PERSONALITY I.D.
PROPANE
PERSONALITY I.D.
FUEL SELECTION
SWITCH
IMG00555

15
Dual Fuel Supplemental Manual
-T
132
1245
3
231
12 45
3
M
1
2
3
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or C.S.A. in Canada.
2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same wire gauge (AWG) and rated for a
minimum of 105°C. Exceptions: Replacement high voltage spark lead and ribbon cables must be purchased from the factory. Use of a non-approved spark lead
or ribbon cables can lead to operational problems which could result in non-repairable damage to the integrated controller or other components.
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper connector block locations when using
diagrams to troubleshoot unit.
100267551 REV A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CN1-12
CN1-5
CN1-10
CN1-11
CN1-6
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
CN1-4
17
CN3-6
CN6-2
CN3-7
CN3-14
CN6-1
CN3-13
CN3-12
CN3-11
CN3-10
CN3-9
CN3-8
CN6-3
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
CN3-1
CN3-2
CN3-5
CN3-3
X3-2
X3-4
X6-1
X6-11
X3-1
X6-2
X6-14
X6-10
X6-13
X6-4
X3-3
X7-8
X7-7
X8-14
X8-13
X8-12
X8-11
X8-15
X8-5
X8-6
X8-16
X8-7
X8-17
X8-18
X8-1
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAY COIL
AUX
SWITCH 1
AUX
SWITCH 2
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
OUT
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMP IN
SHIELD
SHIELD
A
B
CASCADE
R
R
RO
RO
LB
KB
RB
R
Y
RO
HIGH LIMIT
SWITCH
R
R
X6-1
X6-2
X6-3
YG
R
RP
BAS
LB
R
LB
R
RB
W
RO
W/RO
P
W
LB
KB
J3-5
J3-4
J3-6
LWCO
BOARD
J3-3
J3-2
J2-1
J2-2
X6-3
RO
KB/RO
KB/RO
TEST
SWITCH
LWCO
PROBE
RO
RO
LWCO RESET
X6-5
X6-15
BLOWER PROVING SWITCH (LARGE)
RO
X6-12
BLOWER PROVING SWITCH (SMALL)
T
X13-1
BLOCKED FLUE SWITCH
RP
X6-6
BLOCKED DRAIN SWITCH
KB
ENABLE
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
INLET SENSOR
OUTLET SENSOR (S9)
OUTLET SENSOR (S1)
FLUE SENSOR
FLUE SENSOR (S10)
PRE-MIX SENSOR 1 (S11)
PRE-MIX SENSOR 1 (S13)
PRE-MIX SENSOR 2 (S12)
PRE-MIX SENSOR 2 (S14)
R
W
X4-1
X4-2
X4-3
X8-20
X8-10
X5-8
X5-7
X5-3
X5-9
X5-2
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
X5-1
"X5"
BLOCK WIRING
IS MODEL
DEPENDENT
KB
T
LB
W/R
R
W
YG
YG
RB
T
X10-1
X1-3
X10-4
X1-1
X1-12
X1-2
X1-4
X10-2
X10-5
X10-3
X10-6
X1-6
LN
GND
120V
SUPPLY
ON/OFF
SWITCH
GND
SMALL
PROPANE
VALVE
LARGE
PROPANE
VALVE
KB
W
RP
T
RO
LB
R
LB
X6-18
X6-8
X1-8
G
X6-9
X6-17
SMALL
BLOWER
RELAY
LARGE
BLOWER
RELAY
X2-4
X13-2
X13-3
BLOWER
(SMALL)
BLOWER
(LARGE)
R
KB
YG
W
T
T
KB/W
T
KB
W/KB W/G
R/W
BK/W
X2-3
X1-7
X1-10
X1-5
FLAME SENSE 2
FLAME SENSE 1
SPARK
GENERATOR SPARK ROD
X2-5
FLUE DAMPER
TRANSFORMER
X13-4
FLUE DAMPER
24V
TRANSFORMER
LB
R
R
R
P
KB
LB
Y
RO
BL
Y
BK
X1-2
X1-3
X1-1
INTEGRATED CONTROL
LARGE CONNECTION BOARD
SMALL CONNECTION BOARD
JUNCTION
BOX
X11
X4
USB
INTERFACE
BOILER PUMP
CONTACTOR
SYSTEM PUMP
CONTACTOR
DHW PUMP
CONTACTOR
KB
HIGH VOLTAGE
LOW VOLTAGE
120 VAC
1.5A EACH MAX
RO
OR BR
OR
GPS3
GPS2
CAM
SWITCH
PROPANE LGPS
NATURAL LGPS
CAM SWITCH
SMALL
NATURAL
VALVE
LARGE
NATURAL
VALVE
OR/BK
OR/W
CAM
SWITCH
CAM
SWITCH
R/BK
R/W
CAM
SWITCH
PROPANE LIGHT
NATURAL LIGHT
CN3-4
KB/Y
E
GND
LG CON BRD
WIFI
DONGLE
SW1
J2
843
J9
J17
J23
J12
J11
J8
USB CABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
R
J6 J7
COMMUNICATION
CONTROL BOARD
OPTIONAL
ETHERNET CABLE
PR
GY
24V
CN6-3
CN6-1
CN6-2 BAS
DISCONNECT POWER
BEFORE SERVICING
!
BOX DEPICT S
DUAL SENSOR
SINGLE HOUSING
BOX DEPICTS
OPTIONAL ITEMS
WARNING
LCD
DISPLAY
Y LB
-T
-T
-T
-T
-T
-T
-T
-T
3 Diagrams
Figure 3-1 Wiring Diagram_2.5 - 3.5 Models

16
Dual Fuel Supplemental Manual
PRE-MIX SENSOR 1 (S11)
FLUE SENSOR (S10)
FLUE SENSOR
OUTLET SENSOR (S1)
-T
-T
-T
-T
-T
-T
-T
-T
PRE-MIX SENSOR 2 (S14)
PRE-MIX SENSOR 2 (S12)
PRE-MIX SENSOR 1 (S13)
OUTLET SENSOR (S9)
1.5A EACH MAX
WARNING
OUT
100267529 REV A
JUNCTION BOX
TERMINAL STRIP
120V SUPPLY "L"
TERMINAL STRIP
120V SUPPLY "N"
120VAC NEUTRAL
INTEGRATED CONTROL
ON/OFF
SWITCH
F2
3.15 A
F4
5.0 A SYSTEM PUMP
RELAY
BOILER PUMP
RELAY
DHW PUMP
RELAY
X1-1
X1-2
X1-4
X1-8
X2-4
SMALL BLOWER RELAY
LARGE BLOWER RELAY
SMALL GAS
VALVE RELAY
LARGE GAS
VALVE RELAY
X1-6
2-01X1-01X
X10-3
SMALL GAS
VALVE RELAY
LARGE GAS
VALVE RELAY X10-6
X10-5
X10-4
TERMINAL STRIP
SYSTEM PUMP
CONTACTOR
BOLIER PUMP
CONTACTOR
DHW PUMP
CONTACTOR
SMALL BLOWER
RELAY
LARGE BLOWER
RELAY
SMALL BLOWER
LARGE BLOWER
X6-10
X13-4
X6-1
X2-5
21
321
3
BAS
X1-1 X1-2
X1-3
FLUE DAMPER
TRANSFORMER
12
3
24V
TRANSFORMER
FLUE DAMPER
X6-3
X1-12
X1-3
LWCO
BOARD
TEST
SWITCH
LWCO
PROBE
LWCO RESET
J3-6
J3-3
J2-1
J2-2
J3-5
J3-2
J3-4
X6-5
X6-15
X6-12
X13-1
X6-6
X3-3
X3-4
X3-1
X3-2
X6-11
X6-2
X6-14
INTEGRATED
CONTROL
BLOWER PROVING
SWITCH (LARGE)
BLOWER PROVING
SWITCH (SMALL)
BLOCKED FLUE
SWITCH
BLOCKED DRAIN
SWITCH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAY COIL
AUX
SWITCH 1
AUX
SWITCH 2
ENABLE
R
W
SMALL
CONNECTION BOARD
CN1-4
CN1-5
CN1-6
CN1-12
CN1-10
X6-13
X6-4
CN1-11
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
HIGH LIMIT
SWITCH
X1-3
X1-7
X1-10
X2-5
FLAME
SENSE 2
FLAME
SENSE 1
SPARK
GENERATOR
SPARK
ROD
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
X6-17
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMP IN
SHIELD
SHIELD
A
B
CASCADE
LARGE
CONNECTION BOARD
CN6-1
CN3-6
CN3-7
CN3-14
CN3-13
CN3-11
CN3-9
CN3-8
CN3-1
CN3-2
CN3-3
CN3-4
CN6-2
CN6-3
CN3-10
CN3-12
BAS
X4-1
X4-2
X4-3
X6-3
X6-1
X6-2
X8-20
X8-10
X7-8
X8-13
X8-14
X8-12
INTEGRATED
CONTROL
X8-5
X8-15
X7-7
X8-11
X8-6
X8-16
X8-7
X8-17
X8-1
-T
INLET SENSOR
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
GROUND
X6-18
X6-9
M
X6-8
X13-2
X13-3
1
2
4
5
1
2
4
5
SMALL BLOWER
LARGE BLOWER
X11
X4
X5-1
X5-7
X5-2
X5-8
X5-3
X5-9
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
HIGH VOLTAGE
LOW VOLTAGE
OPTIONAL ITEMS
DUAL SENSOR
DISCONNECT POWER
non-repairable damage to the integrated controller or other components.
BEFORE SERVICING
CN6-2
3. Actual connector block locations may vary from those show n on diagrams. Refer to actual components for proper connector blo ck
SINGLE HOUSING
120 VAC
locations when using diagrams to troubleshoot unit.
USB
INTERFACE
"X5"
BLOCK WIRING
IS MODEL
DEPENDANT
CAM
SWITCH
PROPANE LIGHT
NATURAL LIGHT
NATURAL LGPS
PROPANE LGPS
CAM SWITCH
GPS2 GPS3
PROPANE
NATURAL
PROPANE
NATURAL
CN3-4
X8-1
OPTIONAL
ETHERNET CABLE
E
GND
WIFI
DONGLE
RIBBON CABLE
SW1
J2
843
J6
J9
J17
J23
J12
J11
LG CON BRD
J8
LCD
DISPLAY
USB CABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
J7
BAS
CN6-1
CN6-3
24V
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or
C.S.A. in Canada.
2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same wi re gauge
(AWG) and rated for a minimum of 105°C. Exceptions: Replacement high voltage spark lead and ribbon cables must be purchased
from the factory. Use of a non-approved spark lead or ribbon cables can lead to operational problems which could result in
BOX DEPICTS
BOX DEPICTS
!
3 Diagrams
Figure 3-2 Ladder Diagram_2.5 - 3.5 Models

17
Dual Fuel Supplemental Manual
PRE-MIX SENSOR 1 (S11)
PRE-MIX SENSOR 1 (S13)
PRE-MIX SENSOR 2 (S12)
-T
-T
-T
-T
-T
-T
-T
-T
OUTLET SENSOR(S9)
OUTLET SENSOR (S1)
FLUE SENSOR
FLUE SENSOR(S10)
PRE-MIX SENSOR 2 (S14)
BOX DEPICTS
OPTIONAL ITEMS
BOX DEPICTS
DUAL SENSOR
SINGLE HOUSING
WARNING
DISCONNECT POWER
BEFORE SERVICING
!
1.5A EACHMAX
VALVE
LARGE
-T
1
2
5
43
2
1
4
3
diagramsto troubleshoot unit.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CN1-12
CN1-5
CN1-10
CN1-11
CN1-6
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
CN1-4
17
CN3-6
CN6-2
CN3-7
CN3-14
CN6-1
CN3-13
CN3-12
CN3-11
CN3-10
CN3-9
CN3-8
CN6-3
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
CN3-1
CN3-2
CN3-5
CN3-3
X3-2
X3-4
X6-1
X6-11
X3-1
X6-2
X6-14
X6-10
X6-13
X6-4
X3-3
X7-8
X7-7
X8-14
X8-13
X8-12
X8-11
X8-15
X8-5
X8-6
X8-16
X8-7
X8-17
X8-18
X8-1
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAY COIL
AUX
SWITCH 1
AUX
SWITCH 2
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
OUT
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEMSUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMP IN
SHIELD
SHIELD
A
B
CASCADE
R
R
OR
OR
BL
BK
BR
R
Y
OR
HIGHLIMIT
SWITCH
R
R
X6-1
X6-2
X6-3
GY
R
PR
BAS
BL
R
BL
R
BR
W
OR
OR/W
P
W
BL
BK
Y/BK
J3-5
J3-4
J3-6
LWCO
BOARD
J3-3
J3-2
J2-1
J2-2
X6-3
OR
OR/BK
OR/BK
TEST
SWITCH
LWCO
PROBE
OR
OR
LWCO RESET
X6-5
X6-15
BLOWER PROVING SWITCH(LARGE)
OR
X6-12
BLOWER PROVING SWITCH (SMALL)
T
X13-1
BLOCKED FLUE SWITCH
PR
X6-6
BLOCKED DRAIN SWITCH
BK
ENABLE
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
INLET SENSOR
R
W
X4-1
X4-2
X4-3
X8-20
X8-10
X5-8
X5-7
X5-3
X5-9
X5-2
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
X5-1
BK
T
BL
R/W
R
W
GY
GY
BR
T
X10-1
X1-3
X10-4
X1-1
X1-12
X1-2
X1-4
X10-2
X10-5
X10-3
X10-6
X1-6
ON/OFF
SWITCH
GND
BK
W
PR
T
OR
X6-18
X6-8
X1-8
G
X6-9
X6-17
X2-4
X13-2
X13-3
BLOWER
(SMALL)
BLOWER
(LARGE)
R
BK
GY
W
W/BK
T
M
T
GN
R/W
BK/W
X2-3
X1-7
X1-10
X1-5
FLAMESENSE 2
FLAMESENSE 1
SPARK
GENERATORSPARK ROD
X2-5
FLUE DAMPER
TRANSFORMER
X13-4
FLUEDAMPER
24V
TRANSFORMER
BL
R
R
R
P
BK
BL
Y
OR
BLY
BK
X1-2
X1-3
X1-1
INTEGRATED CONTROL
LARGE CONNECTION BOARD
SMALL CONNECTION BOARD
JUNCTION
BOX
X11
X4
USB
INTERFACE
BOILERPUMP
CONTACTOR
SYSTEMPUMP
CONTACTOR
DHWPUMP
CONTACTOR
BK
HIGH VOLTAGE
LOW VOLTAGE
120 VAC
100267530REVC
R2
RBL
R1
R2
L1 L2 L3
208V 3Ø
R1
N
CN3-4
OR BR
OR
GPS3GPS2
CAM
SWITCH
PROPANE LGPS
NATURALLGPS
"X5"
BLOCK WIRING
IS MODEL
DEPENDENT
CAM SWITCH
CAM
SWITCH
PROPANE LIGHT
NATURAL LIGHT
SMALL
PROPANE
T
Y
PROPANE
VALVE
SMALL
NATURAL
VALVE
LARGE
NATURAL
VALVE
OR/BK
OR/W
CAM
SWITCH
CAM
SWITCH
R/BK
R/W
X10-3
E
GND
LGCON BRD
WIFI
DONGLE
SW1
J2
843
J9
J17
J23
J12
J11
J8
USBCABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
LCD
DISPLAY
R
J6J7
COMMUNICATION
CONTROL BOARD
OPTIONAL
ETHERNET CABLE
PR
GY
24V
CN6-3
CN6-1
CN6-2 BAS
123
12345
12 3
Notes:
1. All wiringmust beinstalled inaccordancewith: local, state, provincialandnationalcoderequirements per either N.E.C. inUSA orC.S.A. inCanada.
2. If anyoriginalequipmentwire as suppliedwith theappliancemustbe replaced, it must bereplacedwith wire havingsamewi re gauge(AWG) andrated for a
minimumof 105°C. Exceptions: Replacementhighvoltagespark l eadandribboncablesmustbepurchasedfromthefactory.Useof a non-approvedspark lead
or ribbon cablescanleadto operationalproblemswhichcouldre sult innon-repairabledamageto theintegratedcontrolleror o ther components.
3. Actualconnectorblocklocations may vary from thoseshown on d
iagrams.Refer to actualcomponents for proper connector bloc
klocationswhenusing
BL
3 Diagrams (continued)
Figure 3-3 Wiring Diagram_4.0 Model

18
Dual Fuel Supplemental Manual
OUTLETSENSOR (S1)
-T
-T
-T
-T
-T
-T
-T
-T
FLUE SENSOR
PRE-MIXSENSOR 2 (S14)
PRE-MIX SENSOR 2 (S12)
PRE-MIXSENSOR 1 (S13)
PRE-MIX SENSOR 1(S11)
FLUE SENSOR (S10)
OUTLET SENSOR (S9)
1.5A EACH MAX
WARNING
L2
L1
JUNCTION BOX
TERMINAL STRIP
208V 3
O
SUPPLY
TERMINAL STRIP
208V SUPPLY "N"
NEUTRAL
INTEGRATED CONTROL
ON/OFF
SWITCH
F2
3.15 A
F4
5.0 A SYSTEM PUMP
RELAY
BOILER PUMP
RELAY
DHW PUMP
RELAY
X1-1
X1-2
X1-4
X1-8
X2-4
SMALL BLOWER RELAY
LARGE BLOWER CONTACTOR
SMALL GAS
VALVE RELAY
LARGE GAS
VALVE RELAY
X1-6
X10-1 X10-2
X10-3
SMALL GAS
VALVE RELAY
LARGEGAS
VALVE RELAYX10-6
X10-5
X10-4
TERMINALSTRIP
SYSTEM PUMP
CONTACTOR
BOILER PUMP
CONTACTOR
DHW PUMP
CONTACTOR
SMALL BLOWER
RELAY
LARGE BLOWER
CONTACTOR
SMALL BLOWER
LARGE BLOWER
X6-10
X13-4
X6-1
X2-5
21
3
BAS
2
-
1
X
1
-1X
X1-3
FLUEDAMPER
TRANSFORMER
12
3
24V
TRANSFORMER
FLUE DAMPER
X6-3
X1-12
X1-3
LWCO
BOARD
TEST
SWITCH
LWCO
PROBE
LWCO RESET
J3-6
J3-3
J2-1
J2-2
J3-5
J3-2
J3-4
X6-5
X6-15
X6-12
X13-1
X6-6
X3-3
X3-4
X3-1
X3-2
X6-11
X6-2
X6-14
INTEGRATED
CONTROL
BLOWER PROVING
SWITCH (LARGE)
BLOWER PROVING
SWITCH (SMALL)
BLOCKEDFLUE
SWITCH
BLOCKED DRAIN
SWITCH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAYCOIL
AUX
SWITCH 1
AUX
SWITCH 2
ENABLE
R
W
SMALL
CONNECTION BOARD
CN1-4
CN1-5
CN1-6
CN1-12
CN1-10
X6-13
X6-4
CN1-11
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
HIGHLIMIT
SWITCH
X1-3
X1-7
X1-10
X2-5
FLAME
SENSE 2
FLAME
SENSE 1
SPARK
GENERATOR
SPARK
ROD
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
OUT
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMPIN
SHIELD
SHIELD
A
B
CASCADE
LARGE
CONNECTION BOARD
CN6-1
CN3-6
CN3-7
CN3-14
CN3-13
CN3-11
CN3-9
CN3-8
CN3-1
CN3-2
CN3-3
CN3-4
CN6-2
CN6-3
CN3-10
CN3-12
BAS
X4-1
X4-2
X4-3
X6-3
X6-1
X6-2
X8-20
X8-10
X7-8
X8-13
X8-14
X8-12
INTEGRATED
CONTROL
X8-5
X8-15
X7-7
X8-11
X8-6
X8-16
X8-7
X8-17
X8-18
-T
INLET SENSOR
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
GROUND
X6-18
X6-9
X6-17
X6-8
X13-2
X13-3
1
4
2
5
1
4
2
5
SMALL BLOWER
LARGEBLOWER
X11
X4
X5-1
X5-7
X5-2
X5-8
X5-3
X5-9
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
HIGH VOLTAGE
LOW VOLTAGE
L3
M
OPTIONAL ITEMS
DUAL SENSOR
DISCONNECT POWER
which could result in non-repairable damage to the integrated controller or other components.
BEFORE SERVICING
CN6-2
120 VAC
connector blocklocations when using diagrams to troubleshoot unit.
USB
INTERFACE
1
2
3
4
100267528REV A
X8-10
X8-1
CN3-4
PROPANE
NATURAL
PROPANE
NATURAL
CAM
SWITCH
PROPANE LIGHT
NATURALLIGHT
NATURAL LGPS
PROPANE LGPS
CAM SWITCH
GPS2 GPS3
"X5"
BLOCK WIRING
ISMODEL
DEPENDENT
OPTIONAL
ETHERNET CABLE
E
GND
WIFI
DONGLE
RIBBONCABLE
SW1
J2
843
J6
J9
J17
J23
J12
J11
LG CONBRD
J8
LCD
DISPLAY
USBCABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
J7
BAS
CN6-1
CN6-3
24V
SINGLE HOUSING
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper
Notes:
1. All wiring must be installed in accordance with: local, s
tate, provincial and national code requirementsper either N.E.C.
in USAor C.S.A.in Canada.
2. Ifany original equipmentwireas supplied with the applianc e must be replaced, it must be replaced with wire having same
wire gauge (AWG) and rated for a minimum of 105°C.E xceptions: Replacement high voltage spark lead and ribbon cables
must be purchased from the factory. Use of a non-approved sparklead or ribbon cables can lead to operational problems
BOX DEPICTS
BOX DEPICTS
!
3 Diagrams
Figure 3-4 Ladder Diagram_4.0 Model

19
Dual Fuel Supplemental Manual
-T
M
1
2
3
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or C.S.A. in Canada.
2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same wire gauge (AWG) and rated for a
minimum of 105°C. Exceptions: Replacement high vo ltage spark lead and ribbon cables must be purchased from the factory. Use of a non-approved spark lead
or ribbon cables can lead to operational problems which could result in non-repairable damage to the integrated controller or other components.
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper connector block locations when using
diagrams to troubleshoot unit.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CN1-12
CN1-5
CN1-10
CN1-11
CN1-6
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
CN1-4
17
CN3-6
CN6-2
CN3-7
CN3-14
CN6-1
CN3-13
CN3-12
CN3-11
CN3-10
CN3-9
CN3-8
CN6-3
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
CN3-1
CN3-2
CN3-5
CN3-3
X3-2
X3-4
X6-1
X6-11
X3-1
X6-2
X6-14
X6-10
X6-13
X6-4
X3-3
X7-8
X7-7
X8-14
X8-13
X8-12
X8-11
X8-15
X8-5
X8-6
X8-16
X8-7
X8-17
X8-18
X8-1
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAY COIL
AUX
SWITCH 1
AUX
SWITCH 2
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
OUT
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMP IN
SHIELD
SHIELD
A
B
CASCADE
R
R
RO
RO
LB
KB
RB
R
Y
RO
HIGH LIMIT
SWITCH
R
R
X6-1
X6-2
X6-3
YG
R
RP
BAS
LB
R
LB
R
RB
W
RO
W/RO
P
W
LB
KB
KB/Y
J3-5
J3-4
J3-6
LWCO
BOARD
J3-3
J3-2
J2-1
J2-2
X6-3
RO
KB/RO
KB/RO
TEST
SWITCH
LWCO
PROBE
RO
RO
LWCO RESET
X6-5
X6-15
BLOWER PROVING
SWITCH (LARGE)
RO
X6-12
BLOWER PROVING
SWITCH (SMALL)
T
X13-1
BLOCKED FLUE
SWITCH
RP
X6-6
BLOCKED DRAIN
SWITCH
KB
ENABLE
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
INLET SENSOR
OUTLET SENSOR (S9)
OUTLET SENSOR (S1)
FLUE SENSOR
FLUE SENSOR (S10)
PRE-MIX SENSOR 1 (S11)
PRE-MIX SENSOR 1 (S13)
PRE-MIX SENSOR 2 (S12)
PRE-MIX SENSOR 2 (S14)
R
W
X4-1
X4-2
X4-3
X8-20
X8-10
X5-8
X5-7
X5-3
X5-9
X5-2
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
X5-1
KB
T
LB
W/R
R
W
YG
YG
RB
T
X10-1
X1-3
X10-4
X1-1
X1-12
X1-2
X1-4
X10-2
X10-5
X10-3
X10-6
X1-6
ON/OFF
SWITCH
GND
KB
W
RP
T
RO
X6-18
X6-8
X1-8
G
X6-17
X2-4
X13-2
X13-3
BLOWER
(SMALL)
BLOWER
(LARGE)
R
KB
YG
W
T
T
KB/W
T
NG
R/W
BK/W
X2-3
X1-7
X1-10
X1-5
FLAME SENSE 2
FLAME SENSE 1
SPARK
GENERATOR SPARK ROD
X2-5
FLUE DAMPER
TRANSFORMER
X13-4
FLUE DAMPER
24V
TRANSFORMER
LB
R
R
R
P
KB
LB
Y
RO
BL Y
BK
X1-2
X1-3
X1-1
INTEGRATED CONTROL
LARGE CONNECTION BOARD
SMALL CONNECTION BOARD
JUNCTION
BOX
X11
USB
INTERFACE
BOILER PUMP
CONTACTOR
SYSTEM PUMP
CONTACTOR
DHW PUMP
CONTACTOR
KB
HIGH VOLTAGE
LOW VOLTAGE
120 VAC
1.5A EACH MAX
1R
2R
RBL
1R
2R
L1 L2 L3
208V 3 
N
231
1245
3


231
1245
3
100267552 REV A
CN3-4
SMALL
PROPANE
VALVE
LARGE
PROPANE
VALVE
LB
R
LB
RO
SMALL
NATURAL
VALVE
LARGE
NATURAL
VALVE
OR/BK
OR/W
CAM
SWITCH
CAM
SWITCH
R/BK
R/W
CAM SWITCH
CAM
SWITCH
PROPANE LIGHT
NATURAL LIGHT
OR BR
OR
GPS3
GPS2
CAM
SWITCH
PROPANE LGPS
NATURAL LGPS
E
GND
LG CON BRD
WIFI
DONGLE
SW1
J2
843
J9
J17
J23
J12
J11
J8
USB CABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
R
J6 J7
COMMUNICATION
CONTROL BOARD
OPTIONAL
ETHERNET CABLE
PR
GY
24V
CN6-3
CN6-1
CN6-2 BAS
X4
X6-9
"X5"
BLOCK WIRING
IS MODEL
DEPENDENT
DISCONNECT POWER
BEFORE SERVICING
!
BOX DEPICTS
DUAL SENSOR
SINGLE HOUSING
BOX DEPICTS
OPTIONAL ITEMS
WARNING
-T
-T
-T
-T
-T
-T
-T
-T
LCD
DISPLAY
LB
Y
3 Diagrams (continued)
Figure 3-5 Wiring Diagram_5.0 Model

20
Dual Fuel Supplemental Manual
OUTLET SENSOR (S1)
PRE-MIX SENSOR 2 (S12)
PRE-MIX SENSOR 2 (S14)
PRE-MIX SENSOR 1 (S13)
PRE-MIX SENSOR 1 (S11)
FLUE SENSOR (S10)
FLUE SENSOR
OUTLET SENSOR (S9)
-T
-T
-T
-T
-T
-T
-T
-T
1.5A EACH MAX
WARNING
M
L1 L2
JUNCTION BOX
TERMINAL STRIP
208V 3Ø SUPPLY
TERMINAL STRIP
208V SUPPLY "N"
NEUTRAL
INTEGRATED CONTROL
ON/OFF
SWITCH
F2
3.15 A
F4
5.0 A SYSTEM PUMP
RELAY
BOILER PUMP
RELAY
DHW PUMP
RELAY
X1-1
X1-2
X1-4
X1-8
X2-4 SMALL BLOWER CONTACTOR
LARGE BLOWER CONTACTOR
SMALL GAS
VALVE RELAY
LARGE GAS
VALVE RELAY
X1-6
X10-1 X10-2
X10-3
SMALL GAS
VALVE RELAY
LARGE GAS
VALVE RELAY X10-6
X10-5
X10-4
TERMINAL STRIP
SYSTEM PUMP
CONTACTOR
BOILER PUMP
CONTACTOR
DHW PUMP
CONTACTOR
SMALL BLOWER
CONTACTOR
LARGE BLOWER
CONTACTOR
SMALL BLOWER
LARGE BLOWER
X6-10
X13-4
X6-1
X2-5
4
BAS
2-1X1-1X
X1-3
FLUE DAMPER
TRANSFORMER
12
3
24V
TRANSFORMER
FLUE DAMPER
X6-3
X1-12
X1-3
LWCO
BOARD
TEST
SWITCH
LWCO
PROBE
LWCO RESET
J3-6
J3-3
J2-1
J2-2
J3-5
J3-2
J3-4
X6-5
X6-15
X6-12
X13-1
X6-6
X3-3
X3-4
X3-1
X3-2
X6-11
X6-2
X6-14
INTEGRATED
CONTROL
BLOWER PROVING
SWITCH (LARGE)
BLOWER PROVING
SWITCH (SMALL)
BLOCKED FLUE
SWITCH
BLOCKED DRAIN
SWITCH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
ALARM
CONTACTS
RUN-TIME
CONTACTS
TANK
THERMOSTAT
LOUVER
PROVING
24 VAC LOUVER
RELAY COIL
AUX
SWITCH 1
AUX
SWITCH 2
ENABLE
R
W
SMALL
CONNECTION BOARD
CN1-4
CN1-5
CN1-6
CN1-12
CN1-10
X6-13
X6-4
CN1-11
CN1-9
CN1-8
CN1-7
CN1-1
CN1-2
CN1-3
HIGH LIMIT
SWITCH
X1-3
X1-7
X1-10
X2-5
FLAME
SENSE 2
FLAME
SENSE 1
SPARK
GENERATOR
SPARK
ROD
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
SHIELD
SHIELD
A
B
MODBUS
OPTION
+
-
-
+
RATE
OUT
BOILER
PUMP OUT
SYSTEM RETURN
SENSOR
SYSTEM SUPPLY
SENSOR
0-10V
0-10V
TANK
SENSOR
OUTDOOR
SENSOR
+
+
-
-
0-10V
0-10V
BMS
IN
SYSTEM
PUMP IN
SHIELD
SHIELD
A
B
CASCADE
LARGE
CONNECTION BOARD
CN6-1
CN3-6
CN3-7
CN3-14
CN3-13
CN3-11
CN3-9
CN3-8
CN3-1
CN3-2
CN3-3
CN3-4
CN6-2
CN6-3
CN3-10
CN3-12
BAS
X4-1
X4-2
X4-3
X6-3
X6-1
X6-2
X8-20
X8-10
X7-8
X8-13
X8-14
X8-12
INTEGRATED
CONTROL
X8-5
X8-15
X7-7
X8-11
X8-6
X8-16
X8-7
X8-17
X8-18
-T
INLET SENSOR
X8-3
X8-8
X8-2
X8-4
X8-9
X7-1
X7-5
X7-2
X7-6
GROUND
X6-18
X6-9
X6-17
X6-8
X13-2
X13-3
1
2
4
5
1
2
4
5
SMALL BLOWER
LARGE BLOWER
X11
X4
X5-1
X5-7
X5-2
X5-8
X5-3
X5-9
X5-4
X5-10
X5-5
X5-41
X5-6
X5-12
HIGH VOLTAGE
ITEMS
BOX DEPICTS
!
BEFORE SERVICING
CN6-2
SINGLE HOUSING
which could result in non-repairable damage to the integrated controller or other components.
24V
LOW VOLTAGE
120 VAC
connector block locations when using diagrams to troubleshoot unit.
USB
INTERFACE
1
2
3
4
1
2
3
100267527 REV A
X8-1
CN3-4
PROPANE
NATURAL
PROPANE
NATURAL
"X5"
BLOCK WIRING
IS MODEL
DEPENDENT
CAM
SWITCH
PROPANE LIGHT
NATURAL LIGHT
NATURAL LGPS
PROPANE LGPS
CAM SWITCH
GPS2 GPS3
OPTIONAL
ETHERNET CABLE
E
GND
WIFI
DONGLE
RIBBON CABLE
SW1
J2
843
J6
J9
J17
J23
J12
J11
LG CON BRD
J8
LCD
DISPLAY
USB CABLE
OPTIONAL USB/WIFI
EXTENSION CABLE
J10
J7
BAS
CN6-1
CN6-3
DISCONNECT POWER
DUAL SENSOR
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C.
in USA or C.S.A. in Canada.
2. If any original equipment wire as supplied with the applianc e must be replaced, it must be replaced with wire having same
wire gauge (AWG) and rated for a minimum of 105°C. E xceptions: Replacement high voltage spark lead and ribbon cables
must be purchased from the factory. Use of a non-approved spark lead or ribbon cables can lead to operational problems
BOX DEPICTS
OPTIONAL
L3
3 Diagrams
Figure 3-6 Ladder Diagram_5.0 Model