Thermo Pride CDB1-125 Guide

GAS FURNACE
HIGHBOY AND COUNTERFLOW
USERS INFORMATION MANUAL
MODELS
FOR USE WITH NATURAL GAS OR LP GAS (PROPANE)
CHB1-50 CDB1-50 MHA1-50 MDA1-50
CHX1-75 CHB1-75 CDX 1-75 CDB1-75 MHA1-75 MDA1-75
CHX1-100 CHB1-100 CDX1-100 CDB1-100 MHA1-100 MDA1-100
CHX1-125 CHB1-125 CDX1-125 CDB1-125 MHA1-125 MDA1-125
: 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 INITIAL FIRING, OPERATING THE FURNACE, AND
BEFORE PERFORMING ANY MAINTENANCE. THESE INSTRUCTIONS MUST BE LEFT WITH THE
HOMEOWNER AND SHOULD BE RETAINED FOR FUTURE REFERENCE BY THE HOMEOWNER/USER.
THERMO PRODUCTS, LLC.
BOX 217
MG-1012 NORTH JUDSON, IN 46366
ECN 4456-MA PHONE: [phone] MADE IN USA

INDEX
SECTION BEGINNINGPAGE
I.SAFETYINFORMATION 1
II. GENERAL INSTRUCTIONS 5
III. FURNACE OPERATION 10
A. WARNINGS BEFORE OPERATING 10
B. OPERATING INSTRUCTIONS 10
C. SHUTDOWN PROCEDURE 11
IV. HOMEOWNER/USER MAINTENANCE INSTRUCTIONS 11
(ROUTINE MAINTENANCE)
A. ANNUAL INSPECTION 11
B. FILTER MAINTENANCE PROCEDURE 12
C. VISUAL INSPECTION PROCEDURE 14

All installations and services must be performed by qualified service personnel.
1
I. SAFETY INFORMATION
This and the following page contain reproductions of the various warning and instruction labels
placed on the Thermo Pride Condensing Gas Furnaces. Please read and comply with the contents
of these labels.

All installations and services must be performed by qualified service personnel.
2
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.

All installations and services must be performed by qualified service personnel.
3

All installations and services must be performed by qualified service personnel.
4
This page contains various warnings and cautions found throughout this manual. Please
read and comply with the statements below.
: 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.
: Property damage, personal injury, or loss of life could result from repair or service of
this furnace by anyone other than a qualified heating contractor. Only the routine maintenance
described in this manual may be performed by the user.
: To avoid injury from moving parts, shut off the power to the furnace before
removing blower compartment door.
: Keep furnace free and clear of combustible materials, gasoline, and other flammable
liquids and vapors.
:Do not use this furnace if any part has been under water. Immediately call a qualified
heating contractor to inspect the furnace and to replace any part of the control system and any gas
control which has been under water.
: If you suspect there is a problem with the furnace, its venting system or any other
related problem, immediately contact a qualified service agency.
: In the event your furnace fails to operate, do not attempt to put the furnace into
operation. Contact a qualified heating contractor to service the furnace.
: A fire or explosion may result causing property damage, personal injury or loss of
life if you do not follow these instructions exactly.
: Homeowners attempting maintenance other than that covered as homeowner/user
maintenance may cause conditions which could result in personal injury or property damage.
: Shut off the power to the furnace before removing blower compartment door to avoid
injury from moving parts.
: This furnace is not to be used for temporary heating of buildings or structures under
construction.
: Call a qualified heating contractor to report suspected deficiencies (Do not attempt to
make repairs yourself!)

All installations and services must be performed by qualified service personnel.
5
II. GENERAL INSTRUCTIONS
1. : Property damage, personal injury, or loss of life could result from repair or
service of this furnace by anyone other than a qualified heating contractor. Only the routine
maintenance described in this manual may be performed by the user.
2. The following diagrams show typical furnace installations and the typical position of the
components referenced in these instructions.
Figure 1

All installations and services must be performed by qualified service personnel.
6
Figure 2

All installations and services must be performed by qualified service personnel.
7
Figure 3

All installations and services must be performed by qualified service personnel.
8
3. : To avoid injury from moving parts, shut off the power to the furnace before
removing blower compartment door.
4. : Keep furnace free and clear of combustible materials, gasoline, and other
flammable liquids and vapors.
5. The furnace needs air for combustion and ventilation for safe and proper operation.
IMPORTANT: Do not block or obstruct air openings on the furnace, air openings
communicating with the area in which the furnace is installed, or the spacings around the
furnace.
Figure 1A.
IMPORTANT: Do not allow the outside vent terminal or air intake to be blocked or obstructed
by vegetation, ice, snow or any other materials.
6. This furnace is equipped with a safety feature which will not allow the furnace to be
operated if either the inlet or outlet vent to the appliance is blocked.
7. No attempt should be made to restart the unit in the event that gas to the main burner has
been shut off. Contact a qualified heating contractor before restarting the furnace.

All installations and services must be performed by qualified service personnel.
9
8. The furnace should be inspected annually by a qualified heating contractor.
9. :Do not use this furnace if any part has been under water. Immediately call a
qualified heating contractor to inspect the furnace and to replace any part of the control
system and any gas control which has been under water.
10. Should overheating occur or the gas supply fail to shut off, shut off the manual gas valve to
the furnace before shutting off the electrical supply.
: If you suspect there is a problem with the furnace, its venting system or any other
related problem, immediately contact a qualified service agency.
11. Your furnace should be described by the model number and serial number when contacting a
qualified heating contractor. This important information is located on the rating plate behind
the front door.
12. Should this unit be installed in an attic or other insulated area or if the area is insulated after
the furnace is installed, the furnace must be kept free and clear of the insulating material and
any fibers that may have come loose. Remember some insulating materials are combustible.
: In the event your furnace fails to operate, do not attempt to put the furnace into
operation. Contact a qualified heating contractor to service the furnace.

All installations and services must be performed by qualified service personnel.
10
III. FURNACE OPERATION
A. WARNINGS BEFORE OPERATING
FOR YOUR SAFETY, READ BEFORE OPERATING
: A fire or explosion may result causing property damage, personal injury or loss of
life if you do not follow these instructions exactly.
A. This appliance does not have a pilot. It is equipped with an ignition device which
automatically lights the burner. Do not try to light the burner by hand.
B. BEFORE OPERATING - Smell all around the appliance area for gas. Be sure to smell next to
the floor because some gases are heavier than air and will settle on the floor.
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.
* Leave the building immediately.
* Immediately call your gas supplier from your neighbor’s phone.
* Follow the gas suppliers instructions.
* If you cannot reach your gas supplier, call the fire department.
C. Use only your hand to push in or turn the gas control knob. Never use tools. If the knob will
not push in or turn by hand, don’t try to repair it, call a qualified heating contractor. Force or
attempted repair may result in a fire or explosion.
B. OPERATING INSTRUCTIONS
TO START THE FURNACE:
1. Please read the safety information in this book before operating furnace.
2. Set the thermostat to the lowest setting.
3. Turn off all electric power to the appliance.
4. Remove the louvered door.

All installations and services must be performed by qualified service personnel.
11
5. Turn gas control knob clockwise to “OFF” position. (For gas valves with a switch, move the
switch to the “OFF” position).
6. Wait five (5) minutes to clear out any gas. If you then smell gas, STOP! Follow Step B in the
previous safety information. Go to the next step if you don’t smell gas.
7. Turn gas control knob counterclockwise to “ON” position. (For gas valves with a switch,
move the switch to the “ON” position).
8. Replace front door.
9. Turn on electric power to the appliance.
10. Set thermostat to desired setting.
11. Follow the instructions “To Turn Off Gas To Appliance” and call a qualified heating
contractor or gas supplier if the appliance will not operate.
C. SHUTDOWN PROCEDURE
TO TURN OFF GAS TO FURNACE:
1. Set the thermostat to lowest setting.
2. Turn off the electric power to the appliance if service is to be performed.
3. Remove front door.
4. Turn the knob on the combination valve to the full OFF position.
5. Replace front door.
IV. HOMEOWNER/USER MAINTENANCE INSTRUCTIONS
(ROUTINE MAINTENANCE)
The following maintenance procedures should be performed by the homeowner/user during the
heating season.
: Homeowners attempting maintenance other than that covered as homeowner/user
maintenance may cause conditions which could result in personal injury or property damage.
: Shut off the power to the furnace before removing blower compartment door to avoid
injury from moving parts.
A. ANNUAL INSPECTION
The homeowner must have this furnace professionally inspected at the beginning of each heating
season by a qualified heating contractor to ensure proper operation.

All installations and services must be performed by qualified service personnel.
12
NOTICE: This furnace has been shipped from the factory with a permanently lubricated
circulating air blower motor. Any maintenance to this blower motor is to be performed only by a
qualified heating contractor.
B. FILTER MAINTENANCE PROCEDURE
1. The return air filter provided with this unit is a re-useable type filter. This filter should be
inspected monthly. When dirty, the filter must be cleaned or replaced, if necessary, to assure
proper furnace operation. Follow the cleaning, removal and replacement procedure below.
NOTICE: If the furnace is installed in a home or structure being remodeled, dust levels may be
much higher than normal The filter must be inspected daily and cleaned as needed until dusty
conditions have been eliminated. Any replacement motors not obtained through Thermo
Products should be lubricated according to the motor name plate.
: This furnace is not to be used for temporary heating of buildings or structures under
construction.
UPFLOW FURNACE (CHX1/CHB1/MHA1)
The filter rack or drop chute will be located between the return air plenum and the return air
opening of the furnace (See Figure 3). Slide dirty filter out of the filter rack. Clean the filter by
vacuuming, rinsing with tap water, hosing or dipping in an ordinary detergent solution. Replace
the completely dry filter in the rack. The mesh side of the filter must be installed towards the
furnace after cleaning.
COUNTERFLOW FURNACE (CDX1/CDB1/MDA1)
TURN OFF POWER TO FURNACE. The filter rack will be located on top of the furnace
inside the return air duct using either a V-rack or a drop chute similar to one shown for the CHX1
in Figure 3. To change filter with a front load type drop chute, follow the instructions for an
upflow furnace. To change filters using the V-rack, remove the furnace front door and remove
the filters through the blower opening (or in the event access slots are provided in the plenum,
pull the filters directly out through these slots). Clean filters by vacuuming, tap water rinsing,
hosing or dipping in an ordinary detergent solution. After cleaning, replace completely dry filter,
mesh side down on the filter rack on the top of the furnace. Replace front door. Turn on power to
furnace.

All installations and services must be performed by qualified service personnel.
13
Figure 4.
FILTER REPLACEMENT
See Table 1 for minimum heating filter areas required for the different types of filters available
should the filter used require replacement.
If the unit is equipped with cooling, contact your installer or a qualified service person to
determine the minimum filter area required for the different filter types and your cooling system.

All installations and services must be performed by qualified service personnel.
14
MINIMUM FILTER AREA REQUIRED (LENGTH X WIDTH, SQ. IN.)
TABLE 1
FILTER TYPE MAXIMUM
RATE AIR
VELOCITY FURNACE MODEL
CDB1, CHB1-50
MDA1, MHA1-50
CHX1, CDX1-75
CDB1, CHB1-75
MDA1, MHA1-75
CHX1, CDX1-100
CDB1, CHB1-100
MDA1, MHA1-100
CHX1, CDX1-125
CDB1, CDB1-125
MDA1, MHA1-125
*THERMO PRODUCTS
SUPPLIED
PERMANENT FILTER
600 FT./MIN. 172 IN.2254 IN.2328 IN.2402 IN.2
STANDARD
PERMANENT FILTER
500 FT./MIN. 208 IN.2304 IN.2394 IN.2484 IN.2
DISPOSABLE TYPE
FILTER
300 FT./MIN. 344 IN.2506 IN.2656 IN.2804 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 the length required.
C. VISUAL INSPECTION PROCEDURE
It is recommended that the homeowner/user conduct the following periodic visual inspection of
the furnace at the start of the heating season and monthly during the heating season.
: Call a qualified heating contractor to report suspected deficiencies (Do not attempt to
make repairs yourself!)
1. Turn off power to furnace.
2. Vent pipe, air intake pipe, and condensate system (CDB1/CHB1, CDX1/CHX1): Visually
check the vent and intake pipe as well as condensate lines both inside and outside the furnace
to make sure that vent intake joints and the condensate system are sealed. There should be no
sign of water leakage at any vent intake or condensate joints or anywhere inside the furnace.
Make sure that horizontal runs of vent pipe slope upward towards the outside. The inlet pipe
should slope slightly downward to prevent condensate build up. Any signs of damage,
leakage, deterioration, or possible blockage should be immediately reported to your dealer or
the local gas company.
It is recommended that the condensate removal system be cleaned annually by a qualified service
agency to insure its proper and continued operation.
Outside vent and outside combustion air termination: the outside vent terminations should be
inspected to insure that they are clear and free of obstruction by ice, snow, debris, of vegetation.
Any obstruction of the terminal should be carefully removed without damaging the vent terminal.
If ice has formed on the outside terminals themselves, it should be removed.

All installations and services must be performed by qualified service personnel.
15
3. Flue Pipe Connection & Chimney for MDA1/MHA1: Visually check flue pipe and chimney
for tightness, blockage and corrosion. If fittings are loose or if blockage or corrosion is suspected
to be a problem, contact a qualified heating contractor. Make sure horizontal runs of the flue
have an upward slope away from furnace of 1/4" per foot minimum and are physically sound
without holes, cracks or signs of corrosion. There should be no sign of moisture or vent gas
leakage at any vent connection.
ADDITIONAL REQUIREMENTS OF FURNACES VENTED THROUGH THE SIDE OF
THE HOUSE WITH NO CHIMNEY.
a. Such horizontally vented furnaces should also be inspected to make sure that all vent joints
are sealed and that the outside vent terminal is clear and free of obstruction by ice, snow or
debris. Any obstruction of the terminal should be carefully removed without damaging the vent
terminal. If ice has formed on the terminal itself, it should be removed using a blow dryer.
b. The sidewall venting kit (SWGII Power Venter) manufacturer’s instructions to be supplied by
Field Controls. Use information must be supplied by the installer then read and understood by
the user.
4. If a CDB1/CHB1 or CDX1/CHX1 furnace is equipped with a Thermo Products, LLC.
condensate neutralizer kit, (See Figure 5) it should be inspected at the start of every heating
season. Remove the 2” PVC cap from the neutralizer kit and replace dissolved filter material
with #9 limestone. Keep instructions for neutralizer kit in plastic pouch on the inside of the
furnace blower door.
Figure 5.
5. Return Air Duct Connection: Check to see if it is (1) physically sound; (2) sealed to the
furnace casing; and (3) terminates outside the space containing the furnace.
6. Make sure the furnace is sealed to the base (if applicable) without sagging, cracks or gaps.
Make sure there are no signs of deterioration of the furnace or base.
7. Examine the entire furnace, including removing the vestibule door and inspect the control
compartment and the furnace for signs of damaged or unusually worn wiring, condensation,
sooting or other damage or deterioration.
8. Restore power to the furnace. Follow the operating instructions to light furnace.

All installations and services must be performed by qualified service personnel.
16
9. Make sure the burner flames are in good adjustment (See Figure 6). Burner flames should not
impinge or fire against the side of the tube opening.
NOTICE: It is not unusual to have orangish flames visible in the tube for LP gas.
Figure 6.
: Call a qualified heating contractor to report suspected deficiencies (do not attempt to
make repairs yourself!)