Thermo Products Burner 100n User Manual

TWO STAGE CONDENSING GAS FURNACE  
INSTALLATION AND OPERATION MANUAL  
MODELS:  
FOR USE WITH NATURAL GAS OR LP GAS (PROPANE)  
CHX3-75N  
CHX3-100N  
CHX3-125N  
CDX3-75N  
CDX3-100N  
CDX3-125N  
: IF YOU DO NOT FOLLOW THE SAFETY PRECAUTIONS BELOW AND IN THIS  
MANUAL, A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL  
INJURY, OR LOSS OF LIFE.  
DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN THE  
VICINITY OF THIS OR ANY OTHER APPLIANCE.  
WHAT TO DO IF YOU SMELL GAS:  
DO NOT TRY TO LIGHT ANY APPLIANCE.  
DO NOT TOUCH ANY ELECTRICAL SWITCH; DO NOT USE ANY PHONE IN YOUR BUILDING.  
LEAVE THE BUILDING IMMEDIATELY.  
IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR’S PHONE. FOLLOW THE GAS  
SUPPLIER’S INSTRUCTIONS.  
IF YOU CANNOT REACH YOUR GAS SUPPLIER; CALL THE FIRE DEPARTMENT.  
INSTALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED INSTALLER, SERVICE  
AGENCY OR THE GAS SUPPLIER. (REFERRED TO IN THESE INSTRUCTIONS AS A QUALIFIED  
HEATING CONTRACTOR).  
PLEASE READ THESE INSTRUCTIONS PRIOR TO INSTALLATION, INITIAL FIRING, AND BEFORE  
PERFORMING ANY SERVICE OR MAINTENANCE. THESE INSTRUCTIONS MUST BE LEFT WITH  
THE HOMEOWNER AND SHOULD BE RETAINED FOR FUTURE REFERENCE BY QUALIFIED  
SERVICE PERSONNEL.  
THERMO PRODUCTS, LLC.  
BOX 217  
NORTH JUDSON, IN 46366  
PHONE: (574) 896-2133  
MADE IN USA  
MG-1035  
ECN 5222-MA 110815  
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All installations and services must be performed by qualified service personnel.  
This and the previous page contain reproductions of the various warning and instruction labels placed on  
the Thermo Pride Two Stage Condensing Gas Furnaces. Please read and comply with the contents of  
these labels.  
The following safety information should be read, understood, and followed by the installer.  
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 a hot  
surface igniter that 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 base of unit because some gas is  
heavier than air and will settle on the floor or ground.  
WHAT TO DO IF YOU SMELL GAS  
? Do not try to light any appliance.  
? Do not touch any electric switch; do not use any phone in your  
building.  
? Immediately call your gas supplier from a neighbor's phone.  
Follow the gas supplier's instructions.  
? If you cannot reach your gas supplier, call the fire department.  
C. Use only your hand to move the gas control switch. Never use tools.  
If the switch will not move by hand, don't try to repair it, call a  
qualified service technician. Force or attempted repair may result in  
a fire or explosion.  
D. Do not use this appliance if any part has been underwater.  
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 underwater.  
1. STOP! Read the safety information above on this label.  
2. Set the thermostat to the lowest setting.  
3. Turn off all electric power to the appliance.  
4. This appliance is equipped with a hot surface igniter that  
automatically lights the burner. Do not try to light the burner by  
hand.  
5. Move the gas control switch to the "OFF" position.  
6. Wait five (5) minutes to clear out any gas. Then smell for gas,  
including near the floor or ground. If you smell gas, STOP! Follow  
"B" in the safety information above on this label. If you don't smell  
gas, go to the next step.  
7. Move the gas control switch to the "ON" position.  
8. Turn on all electric power to the appliance.  
9. Set thermostat to desired setting, and, if equipped, set the operating  
mode to "HEAT".  
10.If appliance will not operate, follow the instructions "To Turn Off  
Gas To Appliance" and call your service technician or gas supplier.  
1. Set thermostat to lowest setting, and, if equipped, set the operating  
mode to "COOL" or "OFF".  
2. If service is to be performed, turn off all electric power to the  
appliance.  
3. To turn off gas control valve, remove the burner compartment cover.  
4. Move the gas control switch to the "OFF" position.  
5. Replace the burner compartment cover.  
390540  
ii  
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All installations and services must be performed by qualified service personnel.  
1. Use only with type of gas approved for this furnace. Refer to furnace rating plate.  
2. Connect this furnace to an approved vent system only. Combustion products must be carried  
outdoors. Refer to Section III, D thru H, of this manual.  
The following pages contain various warnings and cautions found throughout the Thermo Pride  
Highboy and Dual Poise Two Stage Condensing Gas Furnace Manual. Please read and comply  
with the statements below.  
: This furnace is not to be used for temporary heating of buildings or structures under  
construction.  
: These high efficiency condensing furnaces are not certified for and shall not be  
vented into a standard or any type of chimney.  
: These furnaces may not be common vented with any other appliance.  
: The vent and air intake elbows must be kept away from bushes, shrubs or any  
vegetation that may restrict the flow of flue products. It must also be kept clear of any leaves,  
weeds or other combustible materials. Keep the vent hood clear of snow. Avoid locating the  
terminals in areas where standing water or condensate drippage may be a problem.  
: This CHX3/CDX3 furnace has been designed to be installed as a direct vent system.  
The failure to install the vent/air intake system as specified in these instructions will void the heat  
exchanger warranty and may result in property damage, personal injury or loss of life.  
: Outside combustion air must not come from an area that is directly adjacent to a  
pool, hot tub or spa. Measures should be taken to prevent the entry of corrosive chemicals or  
vapors to the combustion and ventilation air supply. Such chemicals include but are not limited to  
chlorinated and/or fluorinated hydrocarbons such as found in refrigerants, aerosol propellants,  
dry cleaning fluids, degreasers and removers. Other harmful compounds may come from  
bleaches, air fresheners or mastics. Vapors from such products can form acid compounds when  
burned in a gas flame. Should acid compounds form in your furnace; it may reduce the life of the  
furnace.  
: Because of the potential of odorant fade, a gas leak may not be detected by smell. If  
this furnace is installed below grade, contact your gas supplier for a gas detector.  
: Turn off power to furnace before it is placed into service. The gas piping system  
must have been leak tested by a qualified heating contractor.  
: It may be necessary to purge the air out of the gas line for initial start-up of the  
furnace after installation. This should be done by a qualified heating contractor. If excessive gas  
escapes when purging the gas supply at the union, allow the area to ventilate for at least 15  
minutes before attempting to start the furnace. LP gas is especially dangerous because the  
specific gravity of LP gas allows it to accumulate at floor level at a dangerous concentration. For  
remainder of operating instructions, reference Users Information Manual.  
: Heat exchanger oil will burn off on initial firing creating an unpleasant odor. To  
prevent this odor from occurring more than once, it is suggested that:  
1. A window(s) be opened.  
2. The thermostat set at highest setting.  
3. The furnace remain running at conditions 1&2 for 30 minutes or until odor has dissipated.  
iii  
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All installations and services must be performed by qualified service personnel.  
: The CHX3/CDX3 furnace models are sealed combustion design, which does not  
require an air shutter adjustment (air shutters are not used) for proper flame characteristics.  
Burner box access cover must always be secured with all screws in place and tightened before  
operating furnace.  
: Personal injury or property damage could result from repair or service of this  
furnace by anyone other than a qualified heating contractor. Only the homeowner/user routine  
maintenance described in the Users Information Manual may be performed by the user.  
iv  
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INDEX  
SECTION  
BEGINNING PAGE  
I.  
SAFETY INFORMATION  
i
II.  
III.  
FURNACE SPECIFICATIONS  
GENERAL INSTALLATION  
1
6
A. CODES AND CLEARANCES  
6
B. FURNACE LOCATION  
7
B1.CDX3 HORIZONTAL APPLICATION  
C. REPLACING EXISTING FURNACE FROM A COMMON VENT  
D. GENERAL REQUIREMENTS FOR VENTING CHX3/CDX3  
E. SIDEWALL VENTING  
E1. SINGLE PIPE (SIDEWALL) VENTING OPTION  
F. INSTALLATION OF OUTSIDE VENT/AIR INTAKE TERMS.  
G. CONNECTING FURNACE TO ROOF VENT/AIR TERMS.  
H. CONNECTING FURNACE TO VENT/AIR INTAKE TERMS.  
I. CONDENSATE DRAIN LINE & TRAP ASSY.  
J. GENERAL GAS PIPING  
J1. REQUIREMENTS AND SIZING OF DUCTWORK  
K. FILTERS  
L. WIRING  
STARTING THE UNIT  
A. SEQUENCE OF OPERATIONS  
7
9
9
11  
15  
15  
17  
18  
23  
26  
27  
30  
32  
36  
36  
39  
70  
47  
47  
48  
IV.  
B. INITIAL START-UP  
C. MEASURING AND ADJUSTING HEAT INPUT RATE  
D. FURNACE CHECKOUT PROCEDURE  
INSTALLER’S INSTRUCTIONS TO USER  
TROUBLESHOOTING  
V.  
VI.  
APPENDIX – A  
APPENDIX – B  
WARRANTY  
REPLACEMENT PARTS LIST  
WIRING DIAGRAMS  
55  
59  
61  
v
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II. FURNACE SPECIFICATIONS  
CHX3 SERIES  
MODEL NO.  
BTU/HR INPUT (High fire/ Low fire)  
CHX3-75  
75,000 / 52,000  
CHX3-100  
100,000 /  
70,000  
CHX3-125  
125,000 /  
87,500  
71,000 / 49,000  
95,000 / 66,000  
115,000 /  
82,000  
BTU/HR OUTPUT (High fire/ Low fire)  
44-1/4”  
17”  
27-1/2”  
15 x 18  
25 x 16  
44-1/4”  
21”  
27-1/2”  
19 x 18  
25 x 16  
44-1/4”  
24”  
27-1/2”  
22 x 18  
25 x 16  
HEIGHT OF CASING  
WIDTH OF CASING  
DEPTH OF CASING  
WARM AIR OUTLET  
RETURN AIR INLET  
2”  
2”  
3”  
3”  
3”  
3”  
DIA. OF FLUE  
DIA. OF COMBUSTION  
AIR INTAKE  
CFM from .2” & .5” w.c.  
EXTERNAL STATIC PRESSURE  
@COOLING TAP A  
COOLING  
COOLING  
COOLING  
1000  
800  
1200  
1400  
1200  
1000  
1400  
1600  
1400  
1200  
1600  
2000  
@COOLING TAP B  
@COOLING TAP C  
@COOLING TAP D  
HEATING  
931 / 760  
HEATING  
1243 / 1015  
HEATING  
1556 / 1270  
@HEATING TAP A (High fire/Low fire)  
70 / 60  
.5  
70 / 60  
.75  
70 / 60  
1
TEMPERATURE RISE  
BLOWER MOTOR HP  
-
2.65 Mh  
4 Ton  
2.1 Mh  
5 Ton  
POWER CHOKES  
LARGEST RECOMMEDED  
AIR CONDITIONER  
SIZE OF FILTERS  
NOTES:  
3.5 Ton  
24-3/4” x 15-3/4” 24-3/4” x 15-3/4” 24-3/4” x 19-3/4”  
1. BTU output based on annual fuel utilization efficiency rated by manufacturer.  
2. On all outlet and inlet dimensions, the first dimension is width.  
3. To permit largest recommended air conditioning (at .5 static pressure), selection of the highest motor speed is  
required.  
1
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CDX3 SERIES  
MODEL NO.  
BTU/HR INPUT (High fire / Low fire)  
CDX3-75  
75,000 / 56,250  
CDX3-100  
100,000 /  
75,000  
CDX3-125  
125,000 /  
93,750  
71,000 / 52,000 94,000 / 69,000  
116,000 /  
87,000  
BTU/HR OUTPUT (High fire / Low fire)  
46-1/4”  
17”  
27-1/2”  
15 x 18  
15 x 22  
46-1/4”  
21”  
27-1/2”  
19 x 18  
19 x 22  
46-1/4”  
24”  
27-1/2”  
22 x 18  
22 x 22  
HEIGHT OF CASING  
WIDTH OF CASING  
DEPTH OF CASING  
WARM AIR OUTLET  
RETURN AIR INLET  
2”  
2”  
3”  
3”  
3”  
3”  
DIA. OF FLUE  
DIA. OF COMBUSTION  
AIR INTAKE  
CFM from .2” & .5” w.c.  
EXTERNAL STATIC PRESSURE  
COOLING  
COOLING  
COOLING  
1000  
800  
1200  
1400  
1200  
1000  
1400  
1600  
1400  
1200  
1600  
2000  
@COOLING TAP A  
@COOLING TAP B  
@COOLING TAP C  
@COOLING TAP D  
HEATING  
1012 / 826  
HEATING  
1340 / 1094  
HEATING  
1673 / 1366  
@HEATING TAP C (High fire / Low  
fire)  
65 / 60  
.5  
65 / 60  
.75  
65 / 60  
1
TEMPERATURE RISE  
BLOWER MOTOR HP  
-
2.65Mh  
4 Ton  
2.1Mh  
5 Ton  
POWER CHOKES  
LARGEST RECOMMEDED  
AIR CONDITIONER  
SIZE OF FILTERS  
NOTES:  
3.5 Ton  
21-3/4” x 14”(2) 21-3/4” x 14”(2)  
21-3/4” x 14”(2)  
1. BTU output based on annual fuel utilization efficiency rated by manufacturer.  
2. On all outlet and inlet dimensions, the first dimension is width.  
3. To permit largest recommended air conditioning (at .5 static pressure), selection of the highest motor  
speed is required.  
4. Electrical characteristics at 115 volts, 60 Hz., 1 phase (less than 15 amps. for all models).  
5. All specifications are subject to change without notice.  
2
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INSTALLATION PARTS PACKAGES – CHX3-75  
PARTS PACKAGE  
DESCRIPTION  
PART #  
QUANTITY  
#S00S4413  
2-3/8” ID radiator hose  
Thermostat lead bushing  
PVC trap assembly  
410017  
350750  
320816  
1
1
1
#8 x ¾ coated TEK screws for  
mounting trap & inlet/outlet collars  
11/16” OD x 1/2” ID vinyl tubing  
2 x 4 electrical J-box  
2 x 4 electrical J-box cover  
#8 x ½ TEK screws for  
mounting 2 x 4 J-box  
#10-32 x ½ green ground screw  
#10-32 hex nut  
3/16” dia. star washer  
Grounding instructions  
Wire nut  
3” stainless steel hose clamp  
J-box wire bushing  
Drain hose grommet  
Spring clamp, 11/16”  
Installation notice  
PVC tee assembly, 2” dia.  
CPVC XPVC adapter  
Gas Conversion Kit  
300283  
4
410060  
350024  
350020  
24”  
1
1
300208  
2
300109  
300110  
300270  
MG-966  
300132  
300276  
350016  
350446  
300299  
MG-987  
320818  
320833  
AOPS7682  
1
1
1
1
2
2
1
1
3
1
1
1
1
INSTALLATION PARTS PACKAGES – CHX3-100-125  
PARTS PACKAGE  
DESCRIPTION  
PART #  
QUANTITY  
#S00S4414/4415  
2-3/8” ID radiator hose  
Thermostat lead bushing  
PVC trap assembly  
410017  
350750  
320816  
1
1
1
#8 x ¾ coated TEK screws for  
mounting trap & inlet/outlet collars  
11/16” OD x ½” ID vinyl tubing  
2 x 4 electrical J-box  
2 x 4 electrical J-box cover  
#8 x ½ TEK screws for  
mounting 2 x 4 J-box  
#10-32 x ½ green ground screw  
#10-32 hex nut  
3/16” dia. star washer  
Grounding instructions  
Wire nut  
3” stainless steel hose clamp  
J-box wire bushing  
300283  
4
410060  
350024  
350020  
24”  
1
1
300208  
2
300109  
300110  
300270  
MG-966  
300132  
300276  
350016  
350446  
300299  
MG-987  
1
1
1
1
2
2
1
1
3
1
Drain hose grommet  
Spring clamp, 11/16”  
Installation notice  
3
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PVC tee assembly, 2 x 3” dia.  
CPVC XPVC adapter  
Gas Conversion Kit  
320817  
320833  
AOPS7683/7419  
1
1
1
INSTALLATION PARTS PACKAGES – CDX3-75  
PARTS PACKAGE  
DESCRIPTION  
#S00S4416  
PART #  
QUANTITY  
2-3/8” ID radiator hose  
Thermostat lead bushing  
PVC trap assembly  
410017  
350750  
320816  
1
1
1
#8 x ¾ coated TEK screws for  
mounting trap & inlet/outlet collars  
11/16” OD x ½” ID vinyl tubing  
2 x 4 electrical J-box  
2 x 4 electrical J-box cover  
#8 x ½ TEK screws for  
mounting 2 x 4 J-box  
#10-32 x ½ green ground screw  
#10-32 hex nut  
3/16” dia. star washer  
Grounding instructions  
Wire nut  
3” stainless steel hose clamp  
J-box wire bushing  
Drain hose grommet  
Spring clamp, 11/16”  
Installation notice  
PVC tee assembly, 2” dia.  
Pipe 2” dia. PVC 15”  
Bracket  
300283  
6
410060  
350024  
350020  
24”  
1
1
300208  
2
300109  
300110  
300270  
MG-966  
300132  
300276  
350016  
350446  
300299  
MG-987  
320819  
14401  
1
1
1
1
2
2
1
1
3
1
1
1
1
1
1
14406  
320833  
AOPS7682  
CPVC XPVC adapter  
Gas Conversion Kit  
INSTALLATION PARTS PACKAGES – CDX3-100-125  
PARTS PACKAGE  
DESCRIPTION  
#S00S4381  
PART #  
QUANTITY  
2-3/8” ID radiator hose  
Thermostat lead bushing  
PVC trap assembly  
410017  
350750  
320816  
1
1
1
#8 x ¾ coated TEK screws for  
mounting trap & inlet/outlet collars  
11/16” OD x 1/2” ID vinyl tubing  
2 x 4 electrical J-box  
2 x 4 electrical J-box cover  
#8 x ½ TEK screws for  
mounting 2 x 4 J-box  
300283  
4
410060  
350024  
350020  
24”  
1
1
300208  
2
#10-32 x ½ green ground screw  
#10-32 hex nut  
3/16” dia. star washer  
300109  
300110  
300270  
1
1
1
4
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Grounding instructions  
Wire nut  
MG-966  
300132  
300276  
350016  
350446  
300299  
MG-987  
320817  
320819  
14401  
1
2
2
1
1
3
1
1
1
1
1
1
1
1
3” stainless steel hose clamp  
J-box wire bushing  
Drain hose grommet  
Spring clamp, 11/16”  
Installation notice  
PVC tee assembly, 2 x 3” dia.  
PVC tee assembly, 2” dia.  
Pipe 2” dia. PVC 15”  
Bracket  
14406  
320067  
320833  
Reducer 2” x 3” PVC  
CPVC XPVC adapter  
Gas Conversion Kit  
AOPS7683/7419  
5
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III. GENERAL INSTALLATION  
These Category Type IV furnaces are shipped completely assembled and wired (internally). See the  
Dealer Receiving and Freight Claim Procedure Section of the price guide for parts shortage or damage.  
The furnace and duct system must be adjusted to obtain a temperature rise of 55°F to 85°F through the  
furnace after installation. (See rating label located on side panel inside the furnace vestibule). The  
installation must conform with local codes, or in the absence of local codes, with the National Fuel Gas  
Codes (ANSI Z223.1 or latest edition) and with these instructions.  
: This furnace is not to be used for temporary heating of buildings or structures under  
construction.  
Many of the chemicals used during construction, when burned, form acid bearing condensate that can  
substantially reduce the life of the heat exchanger.  
It is recommended that a commercially available CO alarm be installed in conjunction with any fossil fuel  
burning appliance. The CO alarm shall be installed according to the alarm manufacturer’s installation  
instructions and be listed in accordance with latest edition of the UL Standard for Single and Multiple  
Station Carbon Monoxide Alarms, UL 2034, or the CSA International Standard, Residential Carbon  
Monoxide Alarming Devices, CSA 6.19.  
A. CODES AND CLEARANCES  
The following items must be considered when choosing the size and location of the furnace.  
1. All local codes and/or regulations take precedence over the instructions in this manual and should be  
followed accordingly. In the absence of local codes, installation must conform with these instructions,  
regulations of the National Fire Protection Association, provisions of National Electrical Code  
(ANSI/NFPA70 or latest edition), and the National Fuel Gas Code (ANSI Z223.1 or latest edition).  
2. The BTU output capacity of the furnace proposed for installation should be based on a heat loss  
calculation made according to the manuals provided by the Air Conditioning Contractors of America  
(ACCA) or ASHRAE.  
3. MINIMUM CLEARANCES TO COMBUSTIBLE MATERIALS  
TABLE 1  
FROM SIDES OF  
FURNACE & REAR  
TOP OF  
PLENUM  
0 IN.  
FROM THE  
FLUE OR VENT  
0 IN.  
SIDE OF  
PLENUM  
1 IN.  
MODEL NO.  
FRONT  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
6 IN.  
6 IN.  
6 IN.  
6 IN.  
6 IN.  
6 IN.  
CHX3-75  
CHX3-100  
CHX3-125  
CDX3-75  
CDX3-100  
CDX3-125  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
0 IN.  
1 IN.  
1 IN.  
1 IN.  
1 IN.  
0 IN.  
0 IN.  
1 IN.  
The CHX3-75, 100 and 125 furnaces may be installed on combustible flooring. The furnace shall not be  
installed directly on carpeting, tile or other combustible material other than wood flooring.  
The CDX3-75, 100 and 125 furnaces are to be installed on non-combustible flooring only. The non-  
combustible floor bases model no. 50 DA base for CDX3-75 model no. 100 CA base for the model no.  
CDX3-100 and model no. 125 CA base for CDX3-125 are available for the counterflow furnaces to allow  
their installations on combustible flooring.  
6
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All installations and services must be performed by qualified service personnel.  
These furnaces may be installed in an alcove or in a closet if the minimum clearances to combustible  
construction (listed previously) are met. The CDX3 series furnaces may be installed in an attic or crawl  
space. Refer to section III, B1 of this installation manual.  
The minimum clearances are listed for fire protection. Clearance for servicing the front of the furnaces  
and to all points on the furnace requiring access must be 24”*.  
*For horizontal furnace installation, refer to section III, B1 of this installation manual.  
Equipment must be installed in accordance with regulations of the National Board of Fire  
Underwriters. Authorities having jurisdiction should be consulted before installations are made.  
B. FURNACE LOCATION  
: These high efficiency condensing furnaces are not certified for and shall not be  
vented into a standard or any type of chimney.  
The following shall be considered for locating the furnace:  
1. For best performance locate the furnace so that it is centralized with respect to the duct system and  
as near as possible to a floor drain since condensate drainage must be provided.  
2. Place the unit so that proper venting can be achieved, with a minimum number of elbows, in accord  
with the instructions in this manual.  
3. The furnace must be located on a level, dry surface. The furnace must be installed so that the  
electrical components are protected from water. If the area becomes wet or damp at times, the  
furnace should be raised above the floor using a concrete base, bricks, patio blocks, etc.  
NOTICE: Ensure furnace is level after installation to ensure proper drainage and operation.  
4. This furnace must be connected to a drain in accordance with these instructions. If it is not practical  
to connect the unit to a drain, a condensate pump must be used and can be ordered as an  
accessory, part number 350225. If an acid neutralizer kit is required by local code or the customer, it  
is available under part number 320095.  
B1. CDX3 HORIZONTAL APPLICATION  
The CDX3-75, 100, and 125 furnaces may be installed in a horizontal position by placing the furnace on  
the left or right side (as viewed from the front in the upright position).  
For left or right horizontal applications of the CDX3 series units, the rollout switch located on the burner  
box must be moved to the pre-punched mounting holes on the side of the burner box. Screws are  
provided in pre-punched holes at the required limit location. Remove these screws and use them to  
mount the limit to new location. Utilize previously removed limit mounting screws to fill voided holes at  
previous limit location (See Figure 1).  
For a right side horizontal application of the CDX3 series units, the hose from the single tap pressure  
switch (top switch) is already connected correctly (See Figure 1).  
For a left side horizontal application of the CDX3 series units, the hose from the single tap pressure  
switch (bottom switch) must be moved to the lower front tap on the face of the collector box. Use the  
black cap removed from this tap to plug the original pressure switch tap.  
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NOTE: The hose, when moved, must be shortened (cut) to ensure that no excess hose exists to cause a  
sag, loop, or "water trap".  
For a right side horizontal application of the CDX3 series units, the auxiliary limit switch located on the  
right side of the house air blower must be moved to the bracket on the opposite (left) side of the blower  
(See Figure 1).  
NOTE: When the CDX3 is installed as horizontal unit, it is imperative that the auxiliary limit switch and  
bracket be located on the upper side of the house air blower; the burner rollout switch located on the  
burner box be relocated to the side of the burner box; and that the hose from the single tap pressure  
switch be connected to the lower tap on the front of the collector box (See Figure 1).  
Figure 1  
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All installations and services must be performed by qualified service personnel.  
The horizontal furnace installation should be on a service platform large enough to allow for proper  
clearances on all sides and service access to the front of the furnace (See Table 1). If the furnace is  
suspended, it must be supported at both ends and in the middle with clearance allowed for removal of  
both access doors. Gas supply line contact is only permissible between lines formed by the intersection  
of the top and two sides of the furnaces casing and the building joists, studs, or framing (See Figure 1).  
Equipment must be installed in accordance with regulations of the National Board of Fire  
Underwriters and the National Fuel Gas Code. Authorities having jurisdiction should be consulted  
before installations are made.  
C. Replacing An Existing Furnace From A Common Vent  
: These furnaces may NOT be common vented with any other appliance.  
D. General Requirements For Venting Models CHX3 / CDX3  
The CHX3 / CDX3 furnace venting system must be installed by a qualified service person in  
accordance with local installation codes and these instructions. In the absence of applicable local  
codes, conform to the National Fuel Gas Code, NFPA 54 /ANSI Z223.1-2002, or latest edition  
thereof.  
Installation shall, at least, conform to the following requirements.  
1. The exhaust vent / combustion air intake terminations specified by Thermo Products, in this  
manual, shall be used.  
2. All plastic pipe and pipe fittings sourced to complete the exhaust vent and air intake  
systems shall be constructed of rigid PVC (polyvinyl chloride) thermoplastic. All  
components shall have a wall thickness equivalent to Schedule 40 series materials.  
In addition, all sourced PVC components shall be listed by a nationally recognized testing agency  
(e.g. NSF, UL, etc.) as conforming to one (1) or more of the following design standards.  
PVC Pipe Designation  
Cellular Core  
Design Standard  
ASTM-F891  
DWV (Drain-Waste-Vent)  
Schedule 40  
ASTM-D2665  
ASTM-D1785  
3. The exhaust vent pipe and combustion air pipe shall be at least as large as the exhaust vent / air  
intake pipe specified by Thermo Products. Size reduction is never permissible. The required  
exhaust vent / air intake pipe sizes are:  
nominal 2-inch diameter IPS, Schedule 40 series, PVC thermoplastic pipe, for models  
CHX3-75 & CDX3-75, or  
nominal 3-inch diameter IPS, Schedule 40 series, PVC thermoplastic pipe, for models  
CHX3-100 / -125 & CDX3-100 / -125.  
4. The furnace model series CHX3 / CDX3 shall not be common vented with any other appliance,  
including those burning solid fuels.  
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5. All horizontal runs of exhaust vent pipe shall slope upward at least ¼ inch per foot from the outlet  
of the furnace (for model CHX3), or the outlet of the drain tee (for the model CDX3), to the vent  
termination, beyond the outside wall. This slope will permit proper drainage of the condensate.  
Horizontal runs of air intake pipe shall slope downward at least ¼ inch per foot from the outlet of  
the last elbow or last horizontal run, before exiting the wall, to the intake termination beyond the  
outside wall. This slope will permit proper drainage of any precipitation that enters the intake  
pipe.  
6. The exhaust vent pipe shall be supported at every joint (no more than 4-feet between supports)  
to prevent pipe blockage due to condensate trapped at a local low point, or sag, in the vent  
system.  
7. The maximum permissible length of piping (consisting of a combination of straight pipe and a  
corresponding number of elbows) permitted is:  
75 equivalent feet, for the exhaust vent system, and  
70 equivalent feet, for the combustion air intake system.  
8. The maximum quantity of Schedule 40 series, type DWV thermoplastic pipe elbows allowed in  
each system is listed in Table 2. When counting pipe elbows, all elbows used in the exhaust vent  
or combustion air intake systems must be considered. This includes all elbows, or equivalent  
pipe fittings, used inside the furnace jacket in addition to those used to construct the termination.  
Furthermore, a credit of 5-feet of straight pipe may be taken for each elbow, up to maximum of  
three (3) elbows, which is dropped from the maximum permissible number for each system.  
Table 2: Maximum Permissible Exhaust Vent and Combustion Air Intake Lengths When Using the  
Maximum Quantity of Elbows  
Thermoplastic  
Pipe Vent Size  
(Nominal)  
2 in. Diameter IPS  
3 in. Diameter IPS  
Exhaust or  
Intake  
Straight  
Pipe Length  
(ft.)  
Maximum Qty. Maximum  
Exhaust or  
Intake  
Maximum Qty. Maximum  
Furnace Model  
of Exhaust  
Qty. of Intake  
of Exhaust  
Qty. of Intake  
Elbows 1, 2  
Elbows 2  
Straight Pipe Elbows 1, 2  
Length (ft.)  
Elbows 2  
CHX3 / CDX3-75  
CHX3 / CDX3-100  
CHX3 / CDX3-125  
35  
8
7
-
35  
-
8
-
7
Not Permitted  
Superscripts:  
1
The drain tee supplied with the model series CHX3 / CDX3 furnaces is considered  
equivalent to one (1), 90° elbow.  
Two (2) 45° elbows can be substituted for one (1), 90° elbow.  
2
Care should be taken to design the shortest possible intake and exhaust systems. Each system  
should contain as few elbows as possible to insure the satisfactory operation of the furnace.  
However, system length should never be less than 8 ft of pipe with two (2), 90 deg. elbows.  
For best overall operation of the combustion system, we recommend the actual equivalent  
lengths for both the constructed intake and the exhaust systems have approximately the same  
value.  
9. Use a saw designed to cut thermoplastic pipe. All cuts should be made at right angles to the pipe  
wall. Smooth jagged edges and remove all burrs and strings. All pipe joints must utilize  
standard PVC Schedule 40 series, DWV type elbows, couplings, and fittings. Clean all pipe  
surfaces at connections using a fine abrasive material or approved PVC cleaner (primer). Secure  
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All installations and services must be performed by qualified service personnel.  
all pipe joints using suitable permanent PVC pipe solvent cement. Joints are NOT to be made by  
simply gluing raw edges of butted together vent pipe.  
The piping joints inside the furnace vestibule should be sealed with a silicone caulk, rather than  
pipe cement, to allow for disassembly and removal of piping, if necessary, during maintenance.  
NOTICE: DO NOT use silicone caulk to seal the pipe sleeve or coupling to the metal air  
intake collar on the burner box. Securing the sleeve or coupling to the collar using a screw  
is sufficient.  
10. Vent connections shall be checked for leakage with the furnace induced draft blower running and  
with the vent termination blocked. Use a mild soap and water solution to check for leaks.  
11. Vent pipe passing through an unheated space shall be insulated with 1-inch thick, foil-faced  
fiberglass insulation, or equivalent, to prevent freezing of condensate within the pipe.  
12. No clearance is required from the outer surface of the thermoplastic piping to combustible  
materials for fire hazard prevention.  
13. Thermo Products does not require screens be installed in the exhaust vent and air intake piping.  
However, optional stainless steel screens are available from Thermo Products, should the  
homeowner request them.  
NOTICE: The CHX3 / CDX3 furnace models may be vented either through the sidewall or the roof.  
For sidewall instructions, continue to the following section. For roof venting, refer to Section III G, of  
this manual.  
E. Direct Venting Through a Sidewall  
1. Vent and combustion air pipes may pass through a maximum wall thickness of 18 inches. The  
minimum wall thickness is 2 inches. Referring to Figure 2, the maximum distance from the outer  
wall to the center of the elbow is 12 inches.  
Figure 2: Proper Direct Vent Terminations (RH & LH views) and Vent Termination Only w/o  
Outside Combustion Air Intake (RH view).  
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All installations and services must be performed by qualified service personnel.  
NOTICE: If exterior sidewall building materials are subject to degradation from contact with flue gases or  
moisture, a minimum 24-inch diameter shield shall be fabricated from stainless steel or UV-resistant  
plastic sheet. The protective shield shall be installed around the vent pipe on the outside wall.  
2. The exhaust vent termination elbow shall be installed in accordance with these instructions and  
any applicable local codes. Refer to Figures 2 and 3 for typical examples of proper terminations.  
a. The exhaust vent termination must be installed in the same atmospheric pressure zone (i.e.  
on the same wall) as the air intake termination.  
b. The bottom edge of the vent termination elbow must be installed at least 12-inches above the  
outlet of intake termination elbow.  
c. The horizontal distance between the inlet and exhaust terminations should be minimized,  
when possible, and should never exceed 24-inches.  
d. The vent and intake systems should utilize the same numbers of elbows and approximately  
the same length of straight pipe to reach the outside termination.  
Figure 3: Typical Relative Locations of Direct Vent Terminations When Sidewall Venting.  
3. Exhaust Vent Terminal Location Clearance Requirements  
a. The vent terminal shall be located at least 3-feet above any forced air inlet located within 10-  
feet. Refer to Figure 4 for a depiction of the required minimum clearances between vent  
terminations and building features according to the National Fuel Gas Code (NFGC).  
b. The vent terminal shall be at least 12-inches below, 12-inches horizontally from, or 12-inches  
above, any door, window, or gravity air inlet into a building. The bottom of the vent terminal  
shall be located at least 12-inches above grade.  
c. The vent terminal shall not be located:  
over public walkways or over an area where wetting of surfaces by condensate, or water  
vapor, could create a nuisance or hazard,  
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All installations and services must be performed by qualified service personnel.  
near soffit vents, crawl space vents, or other areas where condensate or water vapor  
could create a nuisance, hazard, or cause property damage, and  
where wetting of components by condensate, or water vapor, could be detrimental to the  
operation of pressure regulators, relief valves, or any other equipment.  
d. The vent terminal shall be installed a minimum of 14-inches from any obstruction and 3-feet  
from an inside corner of an L-shaped structure.  
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Figure 4: NFGC Minimum Clearances Between the Vent Terminal and Various Building Features  
Vent Terminal Location Guidelines  
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: Bushes, shrubs, or any vegetation that may restrict the flow of flue products  
must be kept away from vent and air intake terminations. Terminations must also be kept  
clear of any leaves, weeds, combustible materials, snow, and ice build-up. Avoid locating  
the vent terminal over areas where dripping of condensate, or small pools of acidic  
condensate, could create a problem.  
In addition to following any local code requirements, when possible, utilize the guidelines below in  
locating the vent terminal to help insure trouble-free operation of a sidewall vented furnace:  
Avoid locating the vent terminal on a wall facing prevailing winds and wide-open areas. When  
impractical, choose a location that protects the vent from strong winds, such as behind a  
fence or hedge.  
In geographical areas with considerable snowfall, it is advisable to locate the vent terminal  
much higher than the minimum 12-inches above ground to prevent blockage by snow  
accumulation or drifting.  
The vent and combustion air terminations shall be checked periodically, at least at the start of  
each heating season, for restriction or blockage from foreign material in the exhaust vent or  
in the air intake piping. Clean the air intake and vent terminations when necessary.  
E1. Single-Pipe (Sidewall) Venting Option  
NOTICE: When possible, we recommend all model series CHX3 / CDX3 furnaces be installed  
to utilize outside combustion air. The use of outside combustion air usually results in the  
most energy efficient, nuisance free, and long-lived operation of the furnace.  
NOTICE: Heat exchanger failure accelerated by contaminated combustion air will void the  
furnace heat exchanger limited lifetime warranty.  
This furnace may be horizontally, i.e. sidewall, vented using an exhaust vent pipe alone without  
drawing in outside combustion air. When single-pipe, sidewall venting a furnace, combustion air is  
drawn from the indoor space. This type of installation is not classified as a direct vent installation.  
However, the same exhaust venting guidelines apply as for a direct vent installation, except the  
exhaust termination will be similar to the air intake of the "two- pipe", direct vent installation. Refer to  
depictions of proper intake terminal installations in Figures 2 and 3. Referring to the left-hand (LH)  
sketch in Figure 2, vent termination will consist of one (1), 90° elbow, opening downward.  
When indoor air is used for combustion, measures should be taken to prevent drawing in corrosive  
chemicals vapors or gases with the combustion air supply. Such chemicals include, but are not  
limited to, chlorinated and/or fluorinated hydrocarbons such as found in refrigerants, aerosol  
propellants, dry cleaning fluids, degreasers and removers. Other harmful compounds may come from  
bleaches, air fresheners or mastics. Vapors from such products can form reactive acid producing  
chemical species when burned in a gas flame. The life of the furnace could be reduced should acidic  
compounds form within the furnace.  
F. Installation Of Outside Exhaust / Intake Terminations  
1. After determining appropriate installation locations (suitable locations must observe all  
clearances specified in this manual), mark and cut two (2) holes in the outside wall of the  
following sizes for the outdoor terminal(s),  
a. 2-3/8 inch diameter, for furnace models CHX3 / CDX3-75, or  
b. 3-1/2 inch diameter, for the furnace models CHX3 / CDX3-100 and CHX3 / CDX3-125.  
15  
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2. Measure and cut two (2), 2-inch diameter thermoplastic pipes 1-1/2 inches longer than the depth  
of the wall. Cutting the pipe longer leaves a ¾ inch connection allowance at both ends of the  
pipe. (For 3-inch diameter PVC pipe, leave a 3-inch allowance for end connections). Using PVC  
pipe cement, glue a PVC elbow or coupling fitting to one (1) end of each pipe.  
Before inserting the pipe through the wall, mark the other end of the pipe so the elbow orientation  
can be determined. Also, if a protective shield (refer to Section E., passage 1. of this manual) will  
be used on the exterior surface of the wall, it should be installed at this time. From the inside,  
glue a coupling fitting to each pipe, using PVC pipe cement, while being careful to maintain the  
proper orientation of the termination elbow(s). Complete the assembly of the outlet and inlet as  
shown in Figure 5, making sure that the spacing between the inlet and outlet complies with that  
noted in Figure 3.  
Figure 5: Typical Sidewall Vent and Air Intake Termination Construction Details  
3. Finish the vent installation by caulking the annulus to seal around the two (2) holes where the  
thermoplastic pipes pass through the wall.  
4. To prevent foreign material, insects, or small animals from entering the pipes, an optional vent or  
intake terminal (stainless steel) screen is available from Thermo Products, 3”-part no. 320226, 2”-  
part# 320219.  
5. Optional Direct Vent Terminations  
Three optional vent kits are available for direct vent terminations, refer to Figure 6.  
The concentric vent kits (Thermo Products p/n AOPS7488 & AOPS7489) provide a means  
for the vent and intake to be installed through a single opening in the roof or exterior wall. Kit  
p/n AOPS7488 requires a 4” inch diameter hole and is used on furnace models CHX3/CDX3-  
75. Kit p/n AOPS7489 requires a 5” inch diameter hole and is used on furnace models  
CHX3/CDX3-100 &125.  
The sidewall vent cap (Thermo Products part no. 370191) is a cover installed over the  
exhaust vent and air intake pipes on the exterior of the building. For horizontal sidewall vent  
applications only. This kit may be used on any size furnace in the CHX3/CDX3 family.  
16  
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All installations and services must be performed by qualified service personnel.  
Install these optional kits according to the instructions provided with each kit. The location and  
clearance requirements are identical to those of the standard vent terminations described in this  
manual.  
370191  
SIDE WALL VENT KIT  
AOPS7488 / AOPS7489  
CONENTRIC VENT KIT  
VERTICAL  
HORIZONTAL  
Figure 6: Optional Direct Vent Kits for the CHX3 / CDX3 Model Series of Furnaces  
G. Connecting The Furnace To Roof Exhaust / Intake Terminations  
If it is not desirable, or feasible, to vent the furnace through a sidewall, it may be vertically vented  
through the roof. Installation shall conform to the following guidelines, which are illustrated in  
Figure 6A, below.  
1. The outlet of the exhaust vent and the inlet of the combustion air intake, i.e. the terminations,  
shall be a minimum of 12-inches above highest anticipated snow level.  
2. The exhaust vent outlet must be installed a minimum of 12-inches above the air intake inlet.  
3. Where exposed to prevailing winds, the combustion air intake shall be installed upwind of the  
vent outlet.  
4. The exhaust vent and combustion air intake can be a minimum of 3-inches and a maximum  
of 24 inches apart.  
NOTICE: When the vent termination is installed correctly, a draft should NOT be present in  
the system during the furnace off-cycle.  
Figure 6A: Typical Rooftop Vent and Air Intake Termination Construction Details  
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H. Exhaust / Intake Piping And Condensate Drain Connections At Furnace  
1. Figures 6B, 7, and 8 follow depicting typical exhaust vent and air intake connections for the  
furnace model series CHX3 and the CDX3, respectively, as well as a list of required parts to  
correctly install each system.  
Figure 6B: Required Exhaust Vent and Air Intake Piping for CHX3 Furnace  
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Figure 7: Required Exhaust Vent and Air Intake Piping for CDX3 Furnace in Downflow  
Applications  
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Figure 8: Required Exhaust Vent and Air Intake Piping for CDX3 Furnace in Horizontal  
Applications.  
2. Connecting The Exhaust Vent To The Inducer  
a. Slip the end of the 2-inch diameter PVC elbow (for the model CDX3 in horizontal  
applications, the 2-inch diameter PVC tee assembly) over the outlet of the inducer blower  
assembly. Measure the length of 2-inch diameter thermoplastic pipe needed to clear the  
furnace side casing, while allowing for installation of a 2-3/8 inch length of reinforced rubber  
hose, used as a coupling, within the casing of the furnace. Cut the measured lengths of 2-  
inch diameter PVC pipe being sure to allow a sufficient length of pipe for connections. Refer  
to Figures 9, 10 and 11 for assembly details.  
NOTICE: For the model CDX3-75, a length of 2-inch diameter PVC pipe and a 2-inch  
diameter PVC tee assembly are supplied with each furnace. For the models CDX3-100 and  
CDX3-125, a 3-inch x 2-inch diameter PVC reducer is also supplied.  
NOTICE: For models CDX3-100 and CDX3-125 used in horizontal applications,  
immediately transition from 2-inch to 3-inch diameter pipe by installing the 3-inch x 2-inch  
diameter PVC reducer just outside the furnace casing. The remainder of the venting system  
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leading away from the furnace must be composed of 3-inch diameter PVC pipe and pipe  
fittings only. Refer to item E in Figure 8.  
b. After preparation of the internal 2-inch diameter PVC pipe sections, put a thin bead of a  
silicone rubber type sealant around the outlet flange of the inducer. Slip the 2-inch diameter  
PVC elbow (for the model series CDX3 in horizontal applications, a 2-inch diameter PVC tee)  
over the inducer outlet flange. Drive one (1) #8 x 3/4 inch sheet metal screw with black  
protective coating (supplied with furnace) through the elbow and into the outlet flange of the  
inducer to secure the elbow in place.  
Figure 9: Typical Internal Vent Piping Arrangement for the Furnace Model Series CHX3.  
Figure 10: Typical Internal Vent  
Piping Arrangement for the  
Furnace Model Series CDX3-100 / -  
125.  
Figure 11: Typical Internal Vent  
Piping Arrangement for the  
Furnace Model Series CDX3-100 / -  
125 in RH Horizontal Applications.  
c. Using PVC cement, glue the pre-cut 2-inch diameter thermoplastic pipe, from step (a) above,  
to the 2-inch diameter PVC elbow (for the model series CDX3 in horizontal applications, the  
2-inch diameter PVC tee). Couple the drain tee assembly to the pre-cut 2-inch diameter PVC  
pipe using the reinforced rubber hose and the two (2) band clamps supplied.  
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All installations and services must be performed by qualified service personnel.  
NOTICE: All PVC thermoplastic pipe must be supported beginning directly over the  
exhaust vent tee assembly, then every 4-feet thereafter, and at every joint. Trial fit the  
entire exhaust vent and air intake piping systems, making sure the slope and length of the  
piping are correct, before permanently assembling the pipe components.  
If the vent piping is run through an unconditioned space, it must be insulated with 1-inch  
thick, foil-faced fiberglass insulation, or an equivalent product.  
3. Connecting The Combustion Air Intake Piping  
: Outside combustion air must NOT be drawn from an area directly adjacent to  
a pool, hot tub or spa. Measures should be taken to prevent the entry of corrosive  
chemicals or vapors into the combustion air supply. Such chemicals include, but are not  
limited to, chlorinated and/or fluorinated hydrocarbons such as found in refrigerants,  
aerosol propellants, dry cleaning fluids, degreasers and removers. Other harmful  
compounds may come from bleaches, air fresheners or mastics. Vapors from such  
products can form reactive acid producing chemical species when burned in a gas flame.  
Should acidic compounds form in the furnace they may significantly reduce the useful life  
of the furnace.  
a. For the models CHX3 / CDX3-75, install a 2-inch PVC elbow with sleeve and coupling (for  
models CHX3 / CDX3-100 & -125, a 3-inch PVC elbow with sleeve) on the inlet of the burner  
box. Measure the length of pipe needed to clear the casing. Be sure to allow sufficient length  
to account for insertion of the pipe into the elbow at the burner box and the elbow, or coupling  
fitting, on the end. Cut the pipe to length.  
b. After preparation of the thermoplastic pipe, drive one (1) #8 x 3/4 inch sheet metal screw with  
black protective coating (supplied with furnace) through the PVC coupling, or sleeve, into the  
metal collar of the burner box to secure the piping in place.  
NOTICE: DO NOT apply silicone rubber type sealant or PVC cement to the joint at the  
thermoplastic piping connection to the metal burner box collar. Attach the PVC elbow  
to the sleeve and then to the coupling where required, using silicone rubber type  
sealant, refer to Figure 12.  
c. Insert the precut 2-inch (or 3-inch) thermoplastic pipe into the elbow at the burner box and to  
the elbow, or coupler, just outside the furnace using a silicone rubber type sealant. To  
properly make these seals, run a thin bead of silicone type sealant around the circumference  
of the PVC pipe, about 3/8 inch from either end. Insert the straight pipe section into the  
appropriate couplings and elbows and rotate 1/4 turn. Silicone rubber type sealants remain  
pliable after the initial setup period has passed allowing for relatively easy disconnection of  
the air intake system, should the burner assembly require removal at a later date, refer to  
Figure 12.  
NOTICE: When applying silicone sealants, ensure that no excess sealant is pushed  
into the inside opening of the pipe. This may cause flow restriction within the piping. If  
possible, always apply the sealant to the male component of the piping joint.  
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DO NOT! SILICONE OR SEAL  
THIS CONNECTION IN  
ANYWAY. MUST BE LOOSE  
FIT WITH LEAKAGE BETWEEN  
PVC AND METAL COLLAR.  
Figure 12: Typical Internal Air Intake Piping Arrangement for All Furnace Models  
d. After trial fitting the entire combustion air intake system, use a PVC cement to glue all  
connections in place, except the length of pipe between the combustion air fitting on the  
burner box and the first fitting.  
e. If the combustion air piping is installed in a warm, humid place, such as a laundry room or above a  
suspended ceiling, it must be insulated with a 1-inch thick, foil-faced fiberglass insulation, or an  
equivalent product, to help prevent the outside surface of the pipe from sweating.  
I. CONDENSATE DRAIN LINE AND TRAP ASSEMBLY  
1. The following diagrams show the typical drain and trap connection for a CHX3 and CDX3 furnace.  
Figure 14. TRAP ASSEMBLY MOUNTED ON CHX3  
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Figure 15. TRAP ASSEMBLY MOUNTED ON CDX3  
Figure 16. TRAP ASSEMBLY MOUNTED ON CDX3 RIGHT SIDE HORIZONTAL INSTALLATION  
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2. Determine on which side of furnace the condensate disposal line is to be run (NOTICE: On  
CHX3/CDX3’s this must be the same side as the flue outlet or bottom of unit). Attach the condensate  
trap to the furnace casing using the #8x3/4” sheet metal screws provided in the parts package. Pilot  
holes are provided on both sides of the casing for mounting.  
NOTE: When the CDX3 series unit is used in a horizontal application, the drain hose from the  
collector box will require a location change from it's factory shipped connection. A knockout has  
been provided in the unit side casing for the drain hose to exit. The connection change can be  
accomplished as follows: Refer to Figure 16.  
a) Locate and disconnect the drain hose at the collector box from its factory shipped connection  
location.  
b) Locate and uncap the drain at the bottom (as it is oriented) of the collector box.  
c) Connect the drain hose from step a to the uncapped bottom drain from step b.  
d) Cap the previous drain connection from step a with the existing cap removed in step b.  
3. Attach the drain hose (11/16” diameter clear tubing) from the front (CHX3) or bottom (CDX3) of the  
condensing coil cover plate to one side of the PVC tee provided in the trap assembly. Secure the  
drain hose (11/16” o.d. tubing) with the silver clamp provided in the parts package. Be careful to route  
the tubing through the proper hole in the furnace casing using the Heyco bushing provided. While  
making all connections with the clear tubing, be careful to route the tubing in a manner to prevent  
kinking or abrasion of the tubing.  
4. Measure the drain hose (11/16” o.d. clear tubing) provided and remove any extra length, making sure  
that the hose has sufficient length not to kink or otherwise be restricted once installed. Attach the  
drain hose (11/16” o.d. clear tubing) to the other side of the condensate trap tee. On CHX3/CDX3’s,  
this hose is shipped in the parts package and it will be necessary to attach the other end to the PVC  
drain tee assembly (see Figure 15). Use the silver clamp(s) provided in the parts package to secure  
all connections.  
5. Install field supplied 1/2” CPVC drain pipe and elbows using CPVC cement to reach a nearby drain. A  
minimum 1/4” per foot downward slope toward the drain must be maintained. The drain line must be  
water tight, supported and secured so that it can’t be moved. The length of the drain must be kept as  
short as possible.  
IMPORTANT: If an air conditioning condensate drain line is combined with the furnace condensate drain  
line, it must have a separate trap ahead of the joint connection.  
6. If a drain is not readily available or is above the trap outlet level on the furnace or the drain line  
cannot be sloped downward its full length to the drain, then a condensate pump (part #350225) can  
be ordered from the factory. Follow the pump manufacturers installation instructions.  
7. The furnace condensate is slightly acidic with a pH of 3.5. Cola drinks with a pH of 3.1 are actually  
more acidic. If local codes require a neutralizing kit, the kit may be ordered using part no. 320095.  
Instructions included with the neutralizing kit must be followed for its proper installation.  
8. The condensate piping in the furnace and the drain system must be flushed out at the start of every  
heating season. This will assure trouble free operation and will keep the acidity level well above 3.4  
pH.  
To flush the condensate drain system, turn off power to the furnace at the electrical disconnect switch  
and turn the thermostat to the lowest setting.  
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Remove the 11/16” diameter clear tubing from the coil drain nipple and run tap water into the open end of  
the tubing. This should keep the drain system clean. Replace the tubing by pushing it firmly onto the  
nipple. Make sure the spring clamp is returned to the original position to prevent leaks. If any of the  
electrical controls are exposed to water, dry with a soft cloth and wait 24 hours before operating the  
furnace. Set the room thermostat to the desired temperature and restore electrical power to the furnace.  
J. GENERAL GAS PIPING  
: Because of the potential of odorant fade, a gas leak may not be detected by smell. If  
this furnace is installed below grade, contact your gas supplier for a gas detector.  
1. Left and right gas supply piping - These furnaces are set-up to be gas piped through either the left or  
right side by using a street elbow and a straight pipe. For the purposes of service, it is recommended  
that the gas union be located inside the furnace, when possible.  
Figure 18  
2. A drip leg must be used on both LP and natural gas installations prior to the furnace in order to trap  
oil, condensate and other impurities which might otherwise lodge in the gas valve or plug the burner  
orifice. A drip leg shall be provided at the outlet of the gas meter when there is excessive  
condensation between the gas meter and the furnace. Failure to install a drip leg may void the limited  
warranty on the furnace.  
: All gas piping must be leak tested using a soap and water solution (when the gas is  
turned on) following the procedure outlined in Section III, J, of this manual. A final test for gas  
leakage must be made after purging the gas line (refer to Section IV, B, of this manual). This test  
must be conducted with the unit operating and should include the furnace piping and gas valve.  
Never use an open flame to check for a gas leak.  
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: Care must be taken not to wet electronic components during leak test. Wetting the  
primary ignition module may damage its circuitry and cause a hazardous situation. Dry moisture  
from all leads and terminals if wetting occurs. Wait at least 24 hours for the circuit to fully dry  
before energizing the burner circuit.  
J1. REQUIREMENTS AND SIZING OF DUCT WORK  
The duct system must be sized and installed by a qualified installer or service person, following the  
design standards of the Air Conditioning Contractors of America (ACCA) or ASHRAE.  
1. When it is located in the same room as the furnace, a return air register must be installed a minimum of  
20 feet away from the furnace.  
2. The return air duct shall also be sealed to the furnace and also terminate outside of the furnace space,  
if supply ducts carry circulated air to areas outside the space containing the furnace.  
3. The return air duct system must equal the supply air duct system in its capabilities. Use a supplier's  
catalog for proper sizing of outlet and return air registers and grills to ensure that they meet the CFM  
requirements of the run to which they are connected.  
4. If the furnace is used in connection with an air conditioning evaporator coil, the furnace must be  
installed parallel with or on the upstream side of the coil, to prevent condensation in the heat exchanger.  
If the evaporator coil is installed with a parallel flow arrangement, dampers or other means to control flow  
of air should be installed to prevent chilled air from entering the furnace. If such a device is manually  
operated, it must be equipped with a means to prevent operation of either the furnace or air conditioner  
unless it is in the full heat or cool position.  
We recommend that the outlet duct be equipped with a removable access panel to allow for visual  
inspection of the heat exchanger to check for leakage or to allow for insertion of a probe sampler in the  
air stream. This removable access cover should be attached to ensure there is no air leakage.  
5. The duct system shall be sized for the maximum CFM requirement of the installation whether it is for  
heating or cooling. Two common rules for heating and cooling follow:  
A. 400 CFM (1200 BTU's) per ton of cooling is required.  
B. 14 CFM of heating per 1000 BTU's of furnace output based on its steady state efficiency and a 55° to  
85° temperature rise.  
EXAMPLE: Heating output of a furnace is 100,000 BTU/HR  
100,000 BTU x 14 cfm  
1000 BTU  
=
1400 CFM  
Air conditioning installed is 4 tons x 400 CFM = 1600 CFM or 48,000 BTU’s. NOTE: The duct system  
must be sized for the larger CFM requirement for cooling. If only 3 tons 36,000 BTUs of cooling x 400  
CFM = 1200 CFM was installed, the duct would have to be sized for the 1400 Cfm heating requirement.  
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Figure 18A  
All trunk lines, take-offs, registers and grill-free areas must be figured when determining the air handling  
capacity of a duct system. One can obtain the necessary duct system size by utilizing the chart below.  
(For example, see Figure 18A.) Use a supplier’s catalog for proper sizing of outlet and return air registers  
to insure that the register will meet the CFM requirements of the run to which it is connected.  
The main trunk lines, take offs, registers and grills of the supply return air duct system must have an  
adequate square inch area to move the desired CFM in order to achieve proper movement. The following  
chart shows the CFM air handling capability based on a 0.1” SP loss in the supply duct system. The total  
external static pressure should not exceed .2 inches water column.  
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DUCT SIZES FOR HOMES, QUIET OFFICES, OR SIMILAR INSTALLATIONS  
TABLE 2A  
Each of the system components (trunk lines, take offs, runs and register and grill-free areas) must be  
properly sized and matched together to ensure the necessary air handling capacity of a duct system. A  
12" x 8" duct with a 400 CFM capacity for example will not flow 400 CFM if the register(s) to which it  
connects only flow a total of 200 CFM.  
The speed of the blower motor may have to be changed to obtain the proper 55°F to 85°F temperature  
rise for heating when an air conditioning coil is installed. This depends on the static resistance of an  
individual duct system and the size of the air conditioner.  
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K. FILTERS  
1. CHX3 MODELS: HIGHBOYS  
It is necessary to cut the return air opening in the bottom or side casing depending upon the needs of the  
specific installation.  
NOTICE: If your CHX3 will require air delivery above 1800 CFM, it is advisable that both sides, a  
combination of 1 side and the bottom, or the bottom only be used for return air. (If a return is cut in the  
bottom, it should be as large as the return opening in the equivalent CDX3 model. (See specification  
sheet in beginning of this manual).  
This CHX3 furnace has been factory supplied with a high quality re-usable filter rated for air velocities up  
to 600 ft/min. An optional Thermo Products filter rack assembly (part no. AOPS7547 for CHX3-75 thru  
100 and AOPS7375 for CHX3-125) is available which is sized for the filter provided.  
If an optional Thermo Pride filter rack AOPS7547 (figure 19) is used with the furnace, it will serve as a  
template to scribe a mark for the return air opening on the casing. Place the filter rack on the casing one  
inch up from the bottom of the furnace and centered from side to side. Place the securing flange against  
the casing for locating the return air opening.  
Figure 19  
PLEASE NOTE: While scribing the return air opening, the filter rack can be held into position by tape or  
similar means.  
Position the open end of the filter rack so that it is accessible for filter replacement. Once the filter rack is  
positioned correctly, scribe a line along the inside of the securing flange of the filter rack on three of the  
sides. To scribe a line on the fourth side, on the open end, use the open end support for a guide.  
Remove the filter rack and cut the return air opening in the casing. Now the filter rack can be permanently  
attached to the furnace with screws or pop-rivets along the securing flange.  
Connect the return plenum to the filter rack and slide the filter into place.  
2. CDX3 MODELS: COUNTERFLOWS  
This CDX3 furnace has been factory supplied with two high quality reusable filters rated at 600 ft/min.  
These filters are designed to be mounted on the return air plenum opening on the top of the furnace in  
the double “vee” style rack provided (see Figure 20). If feasible, it is recommended that slits be cut in the  
return front to allow for easier access of the filters.  
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Figure 20  
3. USE OF NON-THERMO PRIDE FILTER RETENTION MEANS  
If a method other than the Thermo Pride filter rack is selected for retention of the filter and/or use of a  
different filter type is desired, see Table 3 for minimum size guidelines for selecting a filter system for the  
CHX3 or CDX3 furnaces.  
MINIMUM FILTER AREA REQUIRED (LENGTH X WIDTH, SQ. IN.)  
TABLE 3  
FILTER TYPE  
MAXIMUM  
RATE  
Required CFM / (Filter Velocity Rating x 144) = min. filter  
(in2)  
AIR VELOCITY  
FURNACE MODEL  
CHX3,CDX3-75  
CHX3,CDX3-100  
CHX3,CDX3-125  
*THERMO  
600 FT./MIN.  
254 IN.2*  
328 IN.2*  
402 IN.2*  
PRODUCTS  
SUPPLIED  
PERMANENT FILTER  
STANDARD  
PERMANENT FILTER  
DISPOSABLE TYPE  
FILTER  
500 FT./MIN.  
300 FT./MIN.  
304 IN.2  
506 IN.2  
394 IN.2  
656 IN.2  
484 IN.2  
804 IN.2  
* The Thermo Products supplied filter can be cut to size to fit other filter retention systems as long as the  
minimum size requirement is met. NOTICE: Any internal stiffeners used in the filter must not be removed,  
although they can be cut to size as needed.  
NOTICE: The filter areas in table 3 are the minimum areas required based on the CFM generated by  
the furnace for standard heating speeds only. The following formula can be used to determine the  
minimum filter area required for cooling if the unit is equipped with cooling. This value should then be  
compared to the value shown in table 3 and the larger of the two should then be used for determining the  
minimum filter area required for that installation.  
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FORMULA:  
(tons of cooling) x (400 CFM per ton) (144 square inches per foot)  
(max. air velocity of filter from table 3 for the filter type)  
= filter area sq.inches  
= length x width of  
filter in inches  
EXAMPLE: If you had a CHX3-100 furnace and 4 tons of cooling and a standard permanent filter.  
4 tons x 400 CFM x 144 = 460 square inches for cooling  
500  
For heating a CHX3-100 needs 394 square inches of filter. The filter system must be designed for the  
larger CFM requirement determined for cooling of 460 square inches. A filter would have to be sized so  
that the area (length X width) was at least 460 sq. in.  
L. WIRING  
All wiring shall be performed by a qualified electrician or service person. The wiring must comply with  
local codes, the instructions in this manual, and in the absence of codes with the National Electrical Code  
(ANSI/NFPA-70 or latest edition).  
1. The following items are guidelines to complete the wiring portion of the installations.  
a. A separate power supply circuit with over current protection and a disconnect switch must be  
provided. The minimum fuse or circuit breaker size is 20 amp.  
b. All CHX3 and CDX3 Series furnaces are supplied with a fuse disconnect switch box to be mounted  
on the outside surface of the right or left side casing so a fuse disconnect can be mounted on the  
furnace. Make the 115 volt supply connection in this junction box. A green screw and a strain relief  
are provided in order to connect the power supply ground wire and provide strain relief for the 115  
volt power leads from the furnace in the fuse disconnect box. A disconnect switch can be field  
mounted on the 2x4 box provided. If not, the disconnect switch must be located reasonably close to  
and within sight of the furnace.  
NOTICE: The hot surface igniter and operation of this furnace depends on correct polarity. The hot leg of  
the supply circuit must be connected to the black line lead and the common leg to the white line lead in  
the field mounted junction box. The hot leg must pass through the disconnect switch in all cases to  
prevent the hazard of electrical shock when servicing.  
IMPORTANT: The furnace must be grounded in accordance with local codes and with the National  
Electrical Code (ANSI/NFPA NO. 70 or latest edition) when an external electrical source is utilized.  
2. ELECTRONIC AIR CLEANER (EAC) AND HUMIDIFIER INSTALLATION  
The ignition module on this furnace has designated terminals to control the operation of an electronic air  
cleaner and/or humidifier. These terminals provide line voltage (110-20VAC) for the control of these  
accessories. (See Figure 21). NOTICE: It is important to confirm that the operating voltage of the  
humidifier or EAC being installed matches the output of this control. If not, a field supplied relay or  
transformer may be necessary to provide the proper control and supply voltage for the accessory being  
installed. See the manufacturers instructions for the humidifier or EAC for additional instructions.  
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3. THERMOSTAT CONNECTIONS AND ANTICIPATOR SETTING  
NOTICE: For two-stage thermostat wire connectors see wire diagram page 59.  
For single-stage thermostat with two-stage operation connect W from thermostat to W1 on control. W2  
on control board is not used. Thermostat dip switches S7-1 & S7-2 on control board (Fig. 21) will need to  
set at the desired setting per (Table 4B). In this configuration the furnace will light and burn on low fire. If  
thermostat has not been satisfied in set delay time for second stage the control will step up to high fire  
until thermostat is satisfied. The auto setting will allow the control to calculate the delay for second stage  
based on demand. The average calculated duty cycle chart below (Table 4A) shows how the control  
calculates staging based on demand.  
Table 4A  
Average  
Calculated  
Duty Cycle % or is less Low to High  
Equals  
0
38  
than  
38  
50  
Stage Delay  
12 Min  
10 Min  
7 Min  
Demand  
Light  
Light to Average  
Average  
50  
62  
62  
75  
88  
75  
88  
100  
5 Min  
3 Min  
1 Min  
Average to Heavy  
Heavy Light  
Heavy  
Proper control of the indoor temperature can only be achieved if the thermostat is calibrated to the  
heating and/or cooling cycle. A vital consideration of this calibration is related to the thermostat heat  
anticipator.  
The proper thermostat heat anticipator setting is 0.4 AMPS for furnace operation only. To increase length  
of cycle, increase setting of heat scale; to decrease length of cycle, decrease setting of heat scale.  
Anticipators for the cooling operation are generally pre-set by the thermostat manufacturer and require no  
adjustment.  
Anticipators for the heating operation are of two types, pre-set and adjustable. Those that are pre-set will  
not have an adjustment scale and are generally marked accordingly.  
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4. BLOWER AND CONTROL PANEL WIRING  
Figure 21  
: TURN OFF THE ELECTRICAL POWER to the furnace before attempting to  
disconnect blower wiring.  
Table 4B  
S7 DIP Switch  
Switch Settings  
Options  
Time  
Off *  
10 Min  
Auto  
20 Min  
Time  
90 Sec  
120 Sec *  
150 Sec  
180 Sec  
S7-1  
Off  
On  
Off  
On  
S7-2  
Thermostat  
Type and  
W2 Delay  
Off  
Off  
On  
On  
S7-3  
Off  
Off  
On  
On  
S7-4  
Off  
On  
Off  
On  
Heat Fan  
Off Delay  
* Factory Setting / 2 Stage Thermostat setting  
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Modifications to ECM blower speed settings are done using the S3 and S4 dip switch controls. Thermo  
Pride two-stage furnaces are factory shipped at the CFM settings listed below in Table 4C.  
2-Stage Blower Settings (from factory)  
Table 4C  
Control Board  
Dip Switch  
Settings  
Heating  
CFM  
(low fire)  
Heating  
CFM  
(high fire)  
Constant Fan  
CFM  
Cooling  
CFM  
Unit  
SW3 1-4 Off  
SW4 1-3 Off  
SW4 4 On  
CDX3-75  
CHX3-75  
CDX3-100  
CHX3-100  
CDX3-125  
CHX3-125  
885  
760  
1012  
931  
500  
500  
600  
600  
700  
700  
1000  
1000  
1200  
1200  
1400  
1400  
SW3 1-4 Off  
SW4 1-4 Off  
SW3 1-4 Off  
SW4 1-3 Off  
SW4 4 On  
1094  
1015  
1366  
1270  
1340  
1243  
1673  
1556  
SW3 1-4 Off  
SW4 1-4 Off  
SW3 1-4 Off  
SW4 1-3 Off  
SW4 4 On  
SW3 1-4 Off  
SW4 1-4 Off  
For adjustments to the Cooling CFM settings, as well as all additional CFM changes, please reference  
the dip switch tables listed in the ECM operation manual. (Included with every furnace.)  
5. DE-HUMIDIFICATION  
The ECM motor in conjunction with the W/R 50V51-843 has a feature to enhance de-humidification in the  
cooling mode. In the dehumidify mode the indoor blower motor (ECM) reduces CFM. By reducing airflow  
the indoor coil runs colder and thus extracts more moisture from the air.  
The W/R 50V51-843 is shipped from the factory with dipswitch S5-2 set to on for system that do not have  
a dehumidification connection from the thermostat. For systems using a thermostat that provides  
dehumidification option move dip switch S5-2 to “OFF”. With the S5-2 switch in the “OFF” position the air  
conditioning fan speed will be reduced 30% from the normal CFM setting when the humidity in the home  
is higher than the set point of the dehumidistat.  
6. FIELD WIRING AND REPLACING WIRING  
Field wiring between the furnace and devices not attached to the furnace shall conform with the  
temperature limitation for Type T wire[63°F rise (35°C)] when installed in accordance with the  
manufacturer’s instructions. If any of the original factory supplied furnace wiring is replaced or a separate  
device other than the thermostat is wired internal to the unit 105°C thermoplastic or equivalent wire must  
be used.  
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IV. STARTING THE UNIT  
A. SEQUENCE OF OPERATIONS  
AT ANY TIME THE  
GAS VALVE IS  
NOT ENERGIZED  
CONTINUOUS SAFE OPERATION CHECK  
IF FLAME SIMULATION CONDITION PRESENT OR ROLL-OUT SWITCH  
OPENS, SYSTEM ENERGIZES INDUCER FAN FOR 15 SECONDS AND  
CIRCULATOR BLOWER AT HEATING SPEED UNTIL SITUATION CORRECTION  
THERMOSTAT CALLS FOR  
HEAT W1 OR W1 & W2,  
CONTACTS CLOSE  
50V51-843 CONTROL  
ENERGIZED, INDUCER  
ENERGIZED ON HIGH SPEED  
LOW FIRE PRESSURE  
SWITCHES SENSES ADEQUATE  
DIFFERENTIAL PRESSURE,  
CONTACTS CLOSE  
PREPURGE IGNITION DELAY,  
INDUCER RUNS FOR 15 SECONDS  
INDUCER REDUCES  
TO LOW SPEED  
LOW PRESSURE SWITCH  
SENSES ADEQUATE  
PRESSURE DIFFERENTIAL,  
CONTACTS STAY CLOSED  
POWER IS APPLIED TO  
THE WHITE RODGERS  
SILICON NITRIDE IGNITOR.  
IGNITOR WARM-UP IS  
17 SECONDS  
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AFTER IGNITOR WARM-UP,  
THE 36J54 GAS VALVE IS  
ENERGIZED TO OPEN ON  
LOW FIRE SETTING  
FLAME MUST BE DETECTED  
WITHIN 4 SECONDS IF  
FLAME IS DETECTED, THE  
DELAY-TO-FAN-ON TIME  
BEGINS (45 SECONDS)  
IF FLAME IS NOT DETECTED, THE  
GAS VALVE IS DE-ENERGIZED,  
THE IGNITOR IS TURNED OFF AND  
THE 50V51-843 CONTROL GOES  
INTO "RETRY" SEQUENCE  
IF NOT  
THE RETRY SEQUENCE  
PROVIDES A 60 SECOND  
WAIT BEFORE IGNITION  
RETRY. RETRY IS  
ATTEMPTED WITH A  
DIFFERENT VOLTAGE  
SETTING.  
IF IGNITION ATTEMPT IS  
UNSUCCESSFUL, ONE MORE  
RETRY WILL BE MADE  
IF SO  
BEFORE THE 50V51-843  
GOES INTO SYSTEM LOCKOUT  
IF FLAME IS DETECTED, THEN LOST,  
THE 50V51-843 WILL REPEAT THE  
INITIAL IGNITION SEQUENCE FOR A  
TOTAL OF TEN RECYCLES. AFTER  
TEN UNSUCCESSFUL RECYCLE  
ATTEMPTS, THE CONTROL WILL  
GO INTO SYSTEM LOCKOUT.  
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IF SYSTEM IS IN LOCKOUT,  
THE MODULE WILL RESET  
ITSELF AFTER 60 MINUTES  
IF THERMOSTAT  
OR MAY BE MANUALLY  
W2 CONTACTS  
RESET BY INTERRUPTING  
ARE CLOSED  
THE POWER TO THE FURNACE  
AT THE DISCONNECT OR  
INTERRUPTING THE CALL FOR  
HEAT AT THE THERMOSTAT.  
IF THIS DOES NOT RESTART  
OTHERWISE  
THE SYSTEM, REFER TO THE  
TROUBLESHOOTING SECTION  
OF THIS MANUAL.  
AFTER DELAY-TO-FAN-ON PERIOD  
ENDS (45 SECONDS), CIRCULATING  
AIR FAN IS ENERGIZED AT LOW  
FIRE HEATING SPEED OR HIGH  
FIRE IF W2 IS ENERGIZED. THE  
(OPTIONAL) ELECTRONIC AIR  
CLEANER AND HUMIDIFIER  
THERMOSTAT CLOSES W2  
CALLING FOR HIGH FIRE  
HEATING.  
CALL  
FOR  
HIGH  
FIRE  
ARE ENERGIZED.  
GAS VALVE, INDUCER AND  
AIR FAN ARE ENERGIZED  
TO HIGH FIRE SETTINGS  
NO CALL  
FOR  
HIGH FIRE  
WHEN THERMOSTAT HAS  
SATISFIED W2, CONTACTS  
OPEN AND THE GAS VALVE  
AND AIR FAN HIGH FIRE  
SETTINGS ARE DE-ENERGIZED  
AFTER 30 SECOND DELAY.  
WHEN THERMOSTAT W1 IS SATISFIED,  
CONTACTS OPEN AND THE GAS  
VALVE IS DE-ENERGIZED. AFTER  
PROOF OF FLAME LOSS, INDUCER  
STARTS 5 SECOND POST PURGE  
AND (OPTIONAL) HUMIDIFIER IS  
DE-ENERGIZED. THE DELAY-TO-  
FAN-OFF PERIOD BEGINS (120 SECONDS)  
AFTER THE DELAY-TO-FAN-OFF  
PERIOD ENDS, THE CIRCULATING  
AIR FAN AND (OPTIONAL) ELECTRONIC  
AIR CLEANER ARE DE-ENERGIZED.  
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B. INITIAL START UP:  
This furnace does not have a pilot. It is equipped with a hot surface igniter, which automatically lights the  
burner. Do not attempt to light the burner by hand. Check the following items before the initial start-up.  
1. Check all wiring for loose connections and proper hook up.  
2. Leak test gas piping connections.  
3. Check all tubing to the pressure switch and drains to make sure they are connected firmly at all their  
connection points.  
4. Check flue pipe, combustion air inlet and all PVC connections for tightness and to make sure there is  
no blockage.  
5. Make sure air filter is in place.  
6. Make sure the outside vent and air intakes are installed according to instructions and that they are  
free from blockage.  
7. Make sure that the drain trap is properly connected to the furnace and to the buildings drain system.  
OPERATING INSTRUCTIONS:  
: Turn off power to furnace before it is placed into service. The gas piping system  
must have been leak tested by a qualified heating contractor. (See Section III, J, of these  
instructions on the installation of gas piping).  
: It may be necessary to purge the air out of the gas line for initial start-up of the  
furnace after installation. This should be done by a qualified heating contractor. If excessive gas  
escapes when purging the gas supply at the union, allow the area to ventilate for at least 15  
minutes before attempting to start the furnace. LP gas is especially dangerous because the  
specific gravity of LP gas allows it to accumulate at floor level at a dangerous concentration. For  
remainder of operating instructions, reference Users Information Manual.  
: Heat exchanger oil will burn off on initial firing creating an unpleasant odor. To  
prevent this odor from occurring more than once, it is suggested that:  
1. A window(s) be opened.  
2. The thermostat be set at highest setting.  
3. The furnace remain running at conditions 1&2 for 30 minutes or until odor has dissipated.  
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C. Measuring And Adjusting Heat Input Rate  
DO NOT exceed input rating stamped on furnace nameplate or manufacturer's  
recommended burner manifold pressure for orifice size used.  
Observe the following precautions when measuring:  
A. Burner manifold pressure with a pressure gauge.  
1. Close the gas valve (turn the gas control knob to the OFF position) BEFORE removing the:  
a. burner manifold pressure tap plug to connect the manometer (or calibrated pressure  
gauge)  
b. manometer, or gauge, and replacing the pressure tap plug.  
2. Shut off the gas supply at the appliance service (manual gas shutoff) valve (or for LP  
gases, shut off the gas at the storage tank service valve) BEFORE removing the:  
a. gas valve inlet pressure tap plug  
b. manometer, or gauge and replacing the inlet pressure tap plug.  
3. Perform a gas leakage test at the gas valve inlet and burner manifold pressure tap plugs.  
B. Gas flowrate by clocking gas meter.  
1. To determine the amount of flow, through the gas meter, due to the operation of the  
furnace.  
a. Turn off all other appliances and extinguish their pilot flames, if equipped, or  
b. Deduct the gas consumption of all other operating appliances from the total meter  
reading.  
2. Convert the gas flowrate to the heat input rate (in BTUH) as described in step 10 (in the  
following section) and compare the value to the heat input rating on the furnace  
nameplate.  
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NOTICE: A U-tube manometer, measuring pressure in inches of water column, is recommended  
for all gas pressure measurements. However, an aneroid pressure gauge, in good working  
condition, capable of reading pressure changes of 0.05 in. W.G., or less, that was recently  
calibrated (within the last year), is a satisfactory alternate. These two (2) devices will be  
considered as equivalent and interchangeable. Either device is referred to below as a “pressure  
gauge”  
NOTICE: This 2-stage gas valve has two separate gas pressure regulators. Checks and  
adjustments must be made at both high fire (high adjustment) and low fire (low adjustment).  
1. Shut off the gas at the automatic gas control valve (turn gas control switch to the OFF position).  
2. Remove the outlet pressure tap plug from gas burner manifold and connect a pressure gauge.  
Refer to Figure 22, below.  
Figure 22: Exploded View of CDX/CHX Gas Control System  
3. Turn on the gas at the automatic gas control valve (turn gas control switch to the ON position).  
4. Adjust the room thermostat so the furnace will operate on low fire only.  
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5. To obtain an accurate manifold gas pressure reading, the main burner must be cycled on and off  
several times to stabilize the gas control valve pressure regulator diaphragm.  
6. Allow the burner to operate for at least 3 minutes before taking gas pressure readings.  
7. Using a pressure gauge, measure the burner manifold gas pressure.  
8. If checking the input rate by measuring burner manifold pressure, skip to step 12. If  
measuring the input rate using a gas meter, proceed to step 9.  
9. Using a clock (or watch) capable of measuring time in seconds, carefully clock the gas meter to  
determine the time for one (1) complete revolution of the gas meter dial or reel. At least one (1)  
cubic foot of gas flow should be measured. Use Table 6 to determine the main burner gas flow  
rate in cubic feet per hour (CFH).  
NOTICE: Some gas meters will require more than one (1) cubic foot of gas pass through the  
meter for reasons of accuracy. When more than one (1) cubic foot of gas is consumed, divide  
the total time by the number of cubic feet for comparison to the figures in Table 6.  
10. Compare actual heat input rate with our recommended input (printed on the furnace rating label).  
To convert the rating label input rate (given in BTUH) to the equivalent gas flowrate (in CFH), use  
the following formula:  
Heat input rate (in BTUH) =  
BTU  
ft3  
Fuel gas higher heating value in  
× Fuel gas flowrate  
(
in CFH  
)
or,  
Heat input rate (in BTUH)  
Fuel gas flowrate  
(
in CFH  
)
=
BTU  
ft3  
Fuel gas higher heating value in  
11. If the measured input rate is above, or below, the rating label value by more than 2%, adjust the  
manifold gas pressure using the gas control valve pressure regulator to obtain the input rating  
within a ± 2% range. Refer to steps 12(a) through 12(d).  
12. If the gas pressure is not within the specified low fire manifold pressure range (refer to  
Table 5), use the following procedure to adjust the low fire, gas pressure regulator to match the  
specified low fire manifold pressure.  
a. Remove the regulator cover screw from the gas valve. Refer to Figure 23.  
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Figure 23:  
b. Turn the inner plastic adjustment screw clockwise to increase, or counterclockwise to  
decrease, the gas pressure (and gas flow) to the main burner.  
c. Replace the regulator cover screw and tighten it firmly to prevent gas leakage.  
d. Referring to Table 5, measure the gas pressure and to confirm it has been adjusted to within  
the allowable range. Repeat adjustments (a) through (c), as required.  
Table 5 Design Gas Pressures for each Furnace Model Series,  
Operating Mode, and Type of Fuel.  
Fuel Gas Type  
Propane  
Natural  
Operating Mode and  
Model Series  
CHX Low CDX Low  
CHX Low CDX Low  
High Fire  
High Fire  
Fire  
Fire  
Fire  
Fire  
Normal Manifold  
Pressure (in. W.G.)  
10.0 ± 0.3 4.8 ± 0.3 5.6 ± 0.3 3.5 ± 0.3 1.8 ± 0.3 2.0 ± 0.3  
Maximum Gas Supply  
Pressure (in. W.G.)  
14.0  
11.0  
14.0  
4.5  
Minimum Gas Supply  
Pressure (in. W.G.)  
13. Adjust the room thermostat so the burner will operate on high fire only.  
14. To obtain an accurate manifold gas pressure reading, the main burner must be cycled on and off  
several times to stabilize the gas control valve pressure regulator diaphragm.  
15. Allow the burner to operate for at least 3 minutes before taking gas pressure readings.  
16. Using a pressure gauge, measure the burner manifold gas pressure.  
17. If checking the input rate by measuring burner manifold pressure, proceed to step 18. If  
measuring the input rate by clocking the gas meter, repeat steps 9 through 11, above.  
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18. If the gas pressure is not within the specified high fire manifold pressure range (refer to  
Table 5), repeat steps 12(a) through 12(d), above, adjusting the high fire gas pressure regulator.  
If the manifold pressure remains low and it cannot be adjusted into the proper range, the supply  
pressure may be too low. Follow these steps.  
a. Turn off the gas at the manual gas shutoff valve.  
b. Remove the automatic gas control valve inlet pressure tap and attach another pressure  
gauge to the inlet tap.  
c. Turn on the gas and repeat steps 14 and 15, above.  
d. Adjust the upstream (inlet) gas pressure to 14.0 in. W.G., or as close as possible.  
e. Using a pressure gauge, measure and adjust the burner manifold gas pressure.  
If it is still not possible increase the manifold gas pressure to within the required range, there  
is too little gas supply to operate the furnace at full (high fire) input rate under present  
conditions. If necessary, consult your gas supplier or qualified heating contractor for  
recommendations to alleviate the problem.  
19. Turn off the gas at the manual gas shutoff valve (turn handle to the OFF position).  
20. Remove all pressure gauges and replace all pressure tap plugs.  
21. Go to Checkout Procedure below.  
Adjusting Burner Input For Altitudes Above 2000 Feet  
Ratings of gas utilization equipment are based on sea level operation and shall not be changed for  
operation at elevations up to 2,000 feet (600 m.). For operation at elevations above 2,000 feet  
(600 m), equipment ratings shall be reduced at the rate of 4 percent for each 1,000 feet (300 m)  
above sea level.  
For additional information, refer to the latest edition of the National Fuel Gas Code.  
Checking The Burner Flame  
c CAUTION: The furnace model series CDX3 and CHX3 are sealed combustion designs that do  
not require an air shutter adjustment (air shutters are not used) for proper flame characteristics. The  
burner box access cover must always be secured with all screws in place and tightened before  
operating furnace.  
Once the input rate has been confirmed correct for a specific application, the burner flames should be  
checked for proper adjustment.  
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This furnace is designed not to require any burner adjustment. Burner aeration is fixed in this design.  
Burner flames can be seen by looking through the sight glass located on the burner box. Burner  
flames should be well-defined, light to medium blue in color, and almost transparent. (refer to Figure  
24).  
Figure 24: Sketch of Typical Main Burner Flames During Operation  
NOTICE: When operating on propane gas, it is not unusual for flames to have yellow or orange  
colored tips.  
If combustion problems are evident, it may indicate problems with either the furnace air supply or the  
vent system. Refer to the installation and maintenance sections of this manual, or contact Thermo  
Products at (574) 896-2133.  
Checkout Procedure  
1. Confirm the furnace exhaust vent and combustion air intake are constructed as outlined in the  
installation and service manual. They must not be blocked or otherwise obstructed.  
2. Place system in operation and observe at least one (1) complete cycle to ensure all controls are  
operating properly. The main burner must light reliably under all conditions.  
3. Perform gas leakage test on all gas pipe connections and pressure tap plugs.  
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TIME (sec.)  
FLOW (cfh)  
TABLE 6 - CONVERTING GAS FLOW RATE  
40  
41  
42  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
62  
64  
66  
68  
70  
72  
74  
76  
78  
80  
84  
88  
92  
90  
88  
86  
82  
80  
78  
77  
75  
73  
72  
71  
69  
68  
67  
65  
64  
63  
62  
61  
60  
58  
56  
54  
53  
51  
50  
49  
47  
46  
45  
43  
41  
39  
38  
36  
34  
33  
31  
30  
29  
28  
27  
26  
24  
23  
21  
20  
* For one cubic foot per revolution gas meter dials,  
use Table directly.  
* For 1/2 cubic foot per revolution gas meter dials:  
1. Determine time for two dial revolutions  
2. Use Table directly  
* For two cubic foot per revolution gas meter dials:  
1. Determine time for one complete dial revolutions  
2. Divide time by two  
3. Use Table directly  
96  
100  
105  
110  
115  
120  
125  
130  
135  
140  
150  
160  
170  
180  
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D. FURNACE CHECKOUT PROCEDURE  
Before any system of gas piping is finally put into service, it shall be carefully tested to assure that it is  
gas tight as indicated in the manual.  
NOTICE: All controls on the unit should be checked for proper functioning prior to the qualified service  
personnel leaving the job site. Specifically the following should be checked:  
With furnace in normal heating operation, check to make certain blower will start and stop automatically  
under control of integrated fan control.  
1. Check safety limit control as follows:  
a. Shut off incoming power.  
b. Disconnect blower motor leads.  
c. Restore power to furnace.  
d. Set thermostat above room temperature calling for heat.  
e. When temperatures are reached in furnace at limit control setting with blower out of  
operation, burner should shut off.  
f. Shut off electrical power.  
IMPORTANT: Remove blockage or reconnect blower motor and restore power.  
2. Make certain thermostat will automatically start and stop furnace.  
3. Block the flue pipe gradually with a flat piece of metal, until the pressure switch functions shutting off  
the main burners. Note: If the burner was initially operating in high fire, the burner will first reduce  
rate to the low fire setting. As the flue becomes more blocked, the pressure switch will function and  
completely shut off the main burners.  
4. Block the PVC pipe inlet gradually with a flat piece of metal until pressure switch functions shutting off  
the main burners. Note: If the burner was initially operating in high fire, the burner will first reduce  
rate to the low fire setting. As the flue becomes more blocked, the pressure switch will function and  
completely shut off the main burners.  
IMPORTANT: Remove flue air inlet blockage when done.  
5. Remove the blower compartment access door with the furnace operating. The door interrupt switch is  
in the 120 volt circuit and will shut down the entire system. Replace the blower door and the furnace  
start-up cycle will begin.  
V. INSTALLER'S INSTRUCTIONS TO USER:  
After completing the installation, the installer shall inform and/or demonstrate to the homeowner:  
1. The location of all the instructions in the furnace and that these instructions and the users information  
manual must be kept along with instructions for any accessories in the plastic pouch on the inside of  
the furnace.  
2. The location and use of the manual gas shut off valve and furnace electrical disconnect switch.  
Instruct user to always shut off gas before shutting off electric power.  
3. The sequence of operation of the furnace.  
4. The correct operation and maintenance of the appliance as outlined in the users information manual.  
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5. That failure to maintain and operate this furnace in accordance with these instructions could result in  
hazardous conditions, bodily injury, property damage and may void the limited warranty on the  
furnace.  
6. Review with and encourage the user to read the label reproductions and all warnings and instructions  
outlined on the front cover and in sections I, II and III of this manual and in the Users Information  
Manual.  
7. Recommend that the user have a qualified heating contractor inspect the furnace at the start of each  
heating season. Inform the user of the frequency of inspection required for reach item in Section III of  
the Users Manual.  
Figure 25  
VI. TROUBLESHOOTING  
NOTICE: BEFORE TROUBLESHOOTING, FAMILIARIZE YOURSELF WITH THE START UP AND  
CHECKOUT PROCEDURE.  
ALL INSTALLATION AND SERVICES MUST BE PERFORMED BY QUALIFIED HEATING  
CONTRACTORS.  
To assist you in troubleshooting this furnace, it is equipped with an integrated ignition control with  
diagnostics. These diagnostics evaluate what control system has experienced a failure and will activate a  
flashing light on the control in different sequences to help pinpoint the failure which has occurred.  
For your convenience, Thermo Products has installed a sight glass in the blower door of this furnace. The  
number of flashes in groups should be observed through this sight glass and recorded before turning off  
power to the furnace. Turning off power to the furnace or removing the blower door which is equipped  
with a door interlock switch will reset the control. Should this occur, use the fault code retrieval process as  
described below.  
To retrieve fault codes, push and release the “LAST ERROR” button for more than 1/5 second and less  
than 5 seconds. (Control will indicate this period by solid GREEN for 1/5 second to 5 seconds.) The LED  
will flash up to five stored fault codes, beginning with the most recent. If there are no fault codes in  
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memory, the LED will flash two green flashes. The control will flash the most recent error first and the  
oldest error last (last in first out). There will be 2 seconds between codes. Solid LED error codes will not  
be displayed.  
DIAGNOSTIC FEATURES  
The 50V51 control used on this furnace continuously monitors its operation and the operation of the  
system.  
If the sensed failure is in the system (external to the control), the red LED will flash in the following flash-  
pause sequences to indicate failure status (each flash will last approximately 0.25 seconds, and each  
pause will last approximately 2 seconds):  
Red LED Flash (DS1)  
1 - flame sensed when no flame should be present  
2 - pressure switch stuck closed / inducer error  
3 - 1st stage pressure switch stuck open / inducer error  
4 - open limit switch  
5 - open rollout / aux limit  
6 - pressure switch cycle lockout  
7 - external lockout (retries)  
8 - external lockout (recycles)  
9 - grounding or reversed polarity  
10 - gas flow with no call for heat  
11 - limit switch open – blower failure  
12 - ignitor failure  
Solid - internal GV error, micro, and frequency check  
3 double - 2nd stage pressure switch stuck open / inducer error  
The LED will also flash once at power-up.  
Amber LED Flash (DS1)  
1 – normal call for first stage heat  
2 – normal call for second stage heat  
3 – W2 present with no W1  
4 – Y present with no G call  
Rapid – low flame sense current  
Green LED indicator (DS2) is present to obtain an estimate of the air flow rate (in CFM) produced by the  
house air blower. This LED cycles regularly by providing a constant light, followed by a sequence of  
flashes. Each flash can be translated to programmed CFM by using the following:  
1 flash per 100(programmed) CFM  
: Power must be disconnected before servicing.  
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TROUBLESHOOTING GUIDE  
THE SYSTEM IS STARTED BY SETTING THE THERMOSTAT TO CALL FOR  
HEAT. THE FOLLOWING SHOULD HELP ESTABLISH THE TYPE OF  
MALFUNCTION OR DEVIATION FROM THE NORMAL OPERATION.  
NOTE: REFER TO PAGE 48 FOR DEFINITION OF DIAGNOSTIC LEDS.  
TO USE THIS DIAGRAM, YOU JUST NEED TO FOLLOW THE INSTRUCTIONS IN THE BOXES.  
SET THERMOSTAT TO CALL FOR HEAT  
(MAKE CERTAIN ROOM TEMPERATURE IS BELOW THERMOSTAT SETTING)  
IS THERE 120 VOLTS  
CHECK INPUT POWER,  
ACROSS "L1" AND  
"NEUTRAL" AT THE  
50V51-843 CONTROL  
MODULE?  
IS THE INDUCER  
BLOWER OPERATING?  
NO  
NO  
DOOR INTERLOCK,  
SERVICE SWITCH  
AND FUSES  
YES  
IS THERE 24 VOLTS  
ACROSS "TH" & "TR"  
AT THE INTEGRATED  
CONTROL MODEL  
50V51-843?  
CHECK 115 VOLT  
CONNECTIONS. IF OK,  
REPLACE TRANSFORMER  
NO  
YES  
YES  
IS THERE 24V  
ACROSS R AND B/C  
NO  
CHECK FUSE ON  
W/R 50V51-843  
YES  
CHECK WIRING TO  
THERMOSTAT. IF OK,  
REPLACE THERMOSTAT.  
IS THERE 24 VOLTS  
ACROSS "R" AND "W1"?  
YES  
NO  
IS THERE LINE VOLTAGE  
ACROSS INDUCER POWER  
TERMINALS "IND HI" TO  
"IND N" OR "IND LO" TO  
"IND N" AT THE 50V51-843  
CONTROL?  
NO  
REPLACE THE  
50V51-843 CONTROL.  
YES  
CHECK WIRING TO INDUCER  
AND IF OK, REPLACE  
INDUCER ASSEMBLY.  
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CHECK CONTACTS ON LOW  
FIRE PRESSURE SWITCH  
AND FOR BLOCKAGE IN FLUE.  
IF OK, REPLACE DUAL  
PRESSURE SWITCH.  
IS INDUCER RUNNING  
ON LOW SPEED?  
NO  
NO  
REPLACE THE  
50V51-843 CONTROL.  
YES  
YES  
IS THERE VOLTAGE ACROSS  
HOT SURFACE IGNITOR  
TERMINALS "IGN" & "IGN N"  
AT THE 50V51-843 CONTROL  
AFTER 17 SECOND PREPURGE?  
IS THE HIGH LIMIT,  
ROLL-OUT LIMIT, AND  
AUX LIMIT ON  
DOES THE HOT  
SURFACE IGNITOR  
ENERGIZE AND GLOW?  
NO  
(CDX MODELS)  
SWITCHES CLOSED?  
YES  
NO  
CHECK WIRING TO HOT  
SURFACE IGNITOR AND  
IF OK, REPLACE HOT  
SURFACE IGNITOR  
ASSEMBLY  
IF HIGH LIMIT OR  
AUX LIMIT OPEN CHECK  
FOR RESTRICTED  
FILTERS OR DUCT WORK  
IF ROLL-OUT SWITCH  
OPEN INSPECT FLUE FOR  
RESTRICTIONS.  
YES  
CHECK ACROSS "MVL" AND  
"MV COM" TERMINALS ON  
50V51-843 CONTROL FOR 24  
VOLTS DURING THE 4 SECOND  
FLAME PROVING PERIOD  
AFTER IGNITOR WARM-UP.  
IS THERE 24 VOLTS?  
AFTER HOT SURFACE  
IGNITOR WARM-UP,  
DOES GAS VALVE OPEN?  
NO  
NO  
REPLACE THE  
50V51-843 CONTROL.  
YES  
CHECK DRAIN FOR  
BLOCKAGE WATER  
TRAPPED IN HOSE,  
REPLACE SWITCH.  
IS COLLECTOR BOX  
PRESSURE SWITCH CLOSED?  
NO  
YES  
YES  
CHECK WIRING TO GAS  
VALVE AND IF OK,  
REPLACE GAS VALVE.  
CHECK FOR PROPER LINE  
AND MANIFOLD PRESSURE.  
REFERENCE GAS PRESSURE  
CHART PAGE 31.  
AFTER GAS VALVE  
OPENS, DO THE  
BURNERS IGNITE?  
NO  
YES  
OK  
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IS IGNITOR  
NO  
REPOSITION TO  
POSITIONED CORRECTLY?  
CORRECT LOCATION  
YES  
CHECK AND CLEAN BURNERS  
CHECK FOR PROPER LINE  
AND MANIFOLD PRESSURE  
REFERENCE GAS  
DO BURNERS STAY  
LIT PAST PROOF OF  
FLAME CHECK?  
NO  
PRESSURE CHART PAGE 31.  
OK  
CHECK FLAME PROB2  
AND WIRE AND CHECK  
POLARITY ON INCOMING  
POWER AND GROUND  
YES  
IS THERE LINE  
VOLTAGE ACROSS  
INDUCER POWER  
TERMINALS "IND HI"  
TO "IND N"?  
DOES INDUCER  
GO TO  
HIGH SPEED?  
REPLACE  
NO  
YES  
NO  
IS W2 ENERGIZED?  
THE 50V61-143  
CONTROL.  
YES  
CHECK CONNECTIONS  
TO INDUCER. IF OK,  
REPLACE INDUCER.  
YES  
NO  
CHECK  
CONTACTS  
IN HIGH  
FIRE SWITCH  
IS THE HIGH FIRE  
PRESSURE SWITCH  
CLOSED?  
DOES BURNER  
NO  
NO  
AND FOR  
BLOCKAGE IN  
FLUE. IF OK,  
REPLACE DUAL  
PRESSURE  
SWITCH.  
STEP TO HIGH FIRE?  
YES  
YES  
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IS THERE 24 VOLTS  
ACROSS "MVH" AND  
"MV COM" ON  
NO  
REPLACE THE  
50V51-843 CONTROL.  
50V51-843 CONTROL?  
YES  
CHECK CONNECTIONS  
TO GAS VALVE. IF OK,  
REPLACE GAS VALVE.  
CONFIRM IF EITHER  
BLOWER WHEEL  
IS RUBBING AGAINST  
HOUSING OR MOTOR  
SHAFT IS SPINNING  
FREELY AND REPAIR  
OR REPLACE AS  
IS THE VARIABLE  
SPEED AIR FAN  
OPERATING?  
NO  
DOES BLOWER  
SPIN FREELY?  
NO  
YES  
NECESSARY  
REFERENCE ECM  
OPERATION MANUAL  
YES  
DOES SYSTEM RUN  
UNTIL THERMOSTAT  
IS SATISFIED?  
IS LED LIGHT  
ON 50V51-843  
CONTROL FLASHING?  
NO  
NO  
CHECK ALL WIRING FOR  
LOOSE CONNECTIONS.  
YES  
REFERENCE LED  
CHART ON PG. 48  
OF THIS MANUAL.  
YES  
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DOES BURNER SHUT OFF  
WHEN THERMOSTAT IS  
SATISFIED?  
NO  
CHECK FOR 24 VOLTS  
AT GAS VALVE.  
NO  
REPLACE GAS VALVE  
YES  
YES  
CHECK FOR SHORT IN WIRE TO  
THERMOSTAT AND CORRECT  
IF NECESSARY.  
DOES THE CIRCULATING  
AIR BLOWER TURN OFF  
AFTER THERMOSTAT IS  
SATISFIED WITHIN  
NO  
REFERENCE ECM  
OPERATION MANUAL  
120 SECONDS?  
YES  
TROUBLE SHOOTING COMPLETE  
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Appendix –A Replacement Parts List  
1. Replacement parts list for CHX3-75, CHX3-100 and CHX3-125.  
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2. Replacement parts list for CDX3-75, CDX3-100 and CDX3-125.  
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58  
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All installations and services must be performed by qualified service personnel.  
Appendix – B Wiring Diagrams  
59  
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All installations and services must be performed by qualified service personnel.  
60  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Download from Www.Somanuals.com. All Manuals Search And Download.  

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