Thermo Pride CHB1-50N User manual

MG-1006
ECN4488-MA
CONDENSING GAS FURNACE
INSTALLATION AND OPERATION MANUAL
MODELS:
CHB1-50N CDB1-50N
CHB1-75N CDB1-75N
CHB1-100N CDB1-100N
CHB1-125N CDB1-125N
: 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: [phone]
MADE IN USA

i
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.
ii
This and the previous 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.
iii
The following safety information should be read, understood, and followed by the installer.
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 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 CHB1/CDB1 furnace has been designed to be installed as a direct vent system and must have
its combustion air brought in from outside the conditioned space. 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.

All installations and services must be performed by qualified service personnel.
iv
: The CHB1/CDB1 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.

All installations and services must be performed by qualified service personnel.
v
INDEX
SECTION BEGINNINGPAGE
I. SAFETY INFORMATION i
II. FURNACE SPECIFICATIONS 1
III. GENERAL INSTALLATION 5
A. CODES AND CLEARANCES 5
B.FURNACELOCATION 6
B1.CDB1 HORIZONTAL APPLICATION 6
C. REPLACING EXISTING FURNACE FROM A COMMON VENT 8
D. GENERAL REQUIREMENTS FOR VENTING CHB1/CDB1 9
E. SIDEWALL VENTING 11
E1. SINGLE PIPE (SIDEWALL) VENTING OPTION 13
F. INSTALLATION OF OUTSIDE VENT/AIR INTAKE TERMS. 14
G. CONNECTING FURNACE TO VENT/AIR INTAKE TERMS. 16
H. CONNECTING FURNACE TO ROOF VENT/AIR TERMS. 21
I. CONDENSATE DRAIN LINE & TRAP ASSY. 22
J. GENERAL GAS PIPING 25
K.FILTERS 26
L.WIRING 29
IV. NATURAL/PROPANE GAS CONVERSION 32
V. STARTING THE UNIT 35
A. SEQUENCE OF OPERATIONS 35
B.INITIALSTART-UP 37
C. ADJUSTMENT OF BTU INPUT RATE 37
D.BURNERADJUSTMENT 38
E. FURNACE CHECKOUT PROCEDURE 39
VI. INSTALLER’S INSTRUCTIONS TO USER 40
VII. TROUBLESHOOTING 41
APPENDIX – A REPLACEMENT PARTS LIST 47
APPENDIX – B WIRING DIAGRAMS 51

All installations and services must be performed by qualified service personnel.
1
II. FURNACE SPECIFICATIONS
CHB1 SERIES
MODEL NO. CHB1-50 CHB1-75 CHB1-100 CHB1-125
BTU/HR INPUT 50,000 75,000 100,000 125,000
BTU/HR OUTPUT 46,650 68,550 92,500 115,375
HT. OF CASING 44-1/4” 44-1/4” 44-1/4” 44-1/4”
WIDTH OF CASING 17” 17” 21” 24”
DEPTH OF CASING 27-1/2” 27-1/2” 27-1/2” 27-1/2”
WARM AIR OUTLET 15 x 18 15 x 18 19 x 18 22 x 18
RETURN AIR INLET 25 x 16 25 x 16 25 x 16 25 x 16
DIA. OF FLUE 2” 2” 3” 3”
DIA. OF COMBUSTION
AIR INTAKE 2” 2” 3” 3”
CFM @ .2” & .5” w.c.
EXTERNAL STATIC PRESSURE .2” .5” .2” .5” .2” .5” .2” .5”
@HI SPEED 1100 860 1600 1380 1940 1700 2770 2060
@MH SPEED 1000 720 1250 1150 1720 1540 1800 1700
@ML SPEED -- -- 1030 930 1530 1380 1730 1600
@LO SPEED 610 420 820 700 1340 1220 1670 1550
TEMPERATURE RISE 70 70 70 70
BLOWER MOTOR HP .20 .41 .50 .75
NO. OF SPEEDS 3 4 4 4
RUN CAPACITOR 10 mfd 10 mfd 10 mfd 10 mfd
LARGEST RECOMMEDED
AIR CONDITIONER 2 Ton 3.5 Ton 4 Ton 5 Ton
SIZE OF FILTERS 24-3/4” x 15-3/4” 24-3/4” x 15-3/4” 24-3/4” x 15-3/4” 24-3/4” x 19-3/4”
NOTES:
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.

All installations and services must be performed by qualified service personnel.
2
CDB1 SERIES
MODEL NO. CDB1-50 CDB1-75 CDB1-100 CDB1-125
BTU/HR INPUT 50,000 75,000 100,000 125,000
BTU/HR OUTPUT 45,700 67,725 90,700 113,250
HT. OF CASING 46-1/4” 46-1/4” 46-1/4” 46-1/4”
WIDTH OF CASING 17” 17” 21” 24”
DEPTH OF CASING 27-1/2” 27-1/2” 27-1/2” 27-1/2”
WARM AIR OUTLET 15 x 18 15 x 18 19 x 18 22 x 18
RETURN AIR INLET 15 x 22 15 x 22 19 x 22 22 x 22
DIA. OF FLUE 2” 2” 3” 3”
DIA. OF COMBUSTION
AIR INTAKE 2” 2” 3” 3”
CFM @ .2” & .5” w.c.
EXTERNAL STATIC PRESSURE .2” .5” .2” .5” .2” .5” .2” .5”
@HI SPEED 1120 930 1530 1340 1830 1590 2280 2010
@MH SPEED 1000 750 1270 1110 1660 1460 1830 1650
@ML SPEED -- -- 1050 930 1520 1340 1750 1570
@LO SPEED 616 420 850 720 1370 1230 1660 1530
TEMPERATURE RISE 70 70 70 70
BLOWER MOTOR HP .20 .41 .50 .75
NO. OF SPEEDS 3 4 4 4
RUN CAPACITOR 10 mfd 10 mfd 10 mfd 15 mfd
LARGEST RECOMMEDED
AIR CONDITIONER 2 Ton 3.5 Ton 4 Ton 5 Ton
SIZE OF FILTERS 21-3/4” x 14”(2) 21-3/4” x 14”(2) 21-3/4” x 14”(2) 21-3/4” x 14”(2)
NOTES:
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.

All installations and services must be performed by qualified service personnel.
3
INSTALLATION PARTS PACKAGES - CHB1-50/75
PARTS PACKAGE
#S00S4405/4406 DESCRIPTION PART # QUANTITY
2-3/8” ID radiator hose 410017 1
Thermostat lead bushing 350750 1
PVC trap assembly 320816 1
#8 x ¾ coated TEK screws for
mounting trap & inlet/outlet collars 300283 4
11/16” OD x 1/2” ID vinyl tubing 410060 24”
2 x 4 electrical J-box 350024 1
2 x 4 electrical J-box cover 350020 1
#8 x ½ TEK screws for
mounting 2 x 4 J-box 300208 2
#10-32 x ½ green ground screw 300109 1
#10-32 hex nut 300110 1
3/16” dia. star washer 300270 1
Grounding instructions MG-966 1
Wire nut 300132 2
3” stainless steel hose clamp 300276 2
J-box wire bushing 350016 1
Drain hose grommet 350446 1
Spring clamp, 11/16” 300299 3
Installation notice MG-987 1
PVC tee assembly, 2” dia. 320818 1
Orifice, Propane 380039 2/3
Conversion Kit, Propane 380605 1
INSTALLATION PARTS PACKAGES - CHB1-100/125
PARTS PACKAGE
#S00S4407/4408 DESCRIPTION PART # QUANTITY
2-3/8” ID radiator hose 410017 1
Thermostat lead bushing 350750 1
PVC trap assembly 320816 1
#8 x ¾ coated TEK screws for
mounting trap & inlet/outlet collars 300283 4
11/16” OD x 1/2” ID vinyl tubing 410060 24”
2 x 4 electrical J-box 350024 1
2 x 4 electrical J-box cover 350020 1
#8 x ½ TEK screws for
mounting 2 x 4 J-box 300208 2
#10-32 x ½ green ground screw 300109 1
#10-32 hex nut 300110 1
3/16” dia. star washer 300270 1
Grounding instructions MG-966 1
Wire nut 300132 2
3” stainless steel hose clamp 300276 2
J-box wire bushing 350016 1
Drain hose grommet 350446 1
Spring clamp, 11/16” 300299 3

All installations and services must be performed by qualified service personnel.
4
Installation notice MG-987 1
PVC tee assembly, 2 x 3” dia. 320817 1
Orifice, Propane 380039 4/5
Conversion Kit, Propane 380605 1
INSTALLATION PARTS PACKAGES - CDB1-50/75
PARTS PACKAGE
#S00S4409/4410 DESCRIPTION PART # QUANTITY
2-3/8” ID radiator hose 410017 1
Thermostat lead bushing 350750 1
PVC trap assembly 320816 1
#8 x ¾ coated TEK screws for
mounting trap & inlet/outlet collars 300283 6
11/16” OD x 1/2” ID vinyl tubing 410060 24”
2 x 4 electrical J-box 350024 1
2 x 4 electrical J-box cover 350020 1
#8 x ½ TEK screws for
mounting 2 x 4 J-box 300208 2
#10-32 x ½ green ground screw 300109 1
#10-32 hex nut 300110 1
3/16” dia. star washer 300270 1
Grounding instructions MG-966 1
Wire nut 300132 2
3” stainless steel hose clamp 300276 2
J-box wire bushing 350016 1
Drain hose grommet 350446 1
Spring clamp, 11/16” 300299 3
Installation notice MG-987 1
PVC tee assembly, 2” dia. 320819 1
Pipe 2” dia. PVC 15” 14401 1
Bracket 14406 1
Orifice, Propane 380039 2/3
Conversion Kit, Propane 380605 1
INSTALLATION PARTS PACKAGES - CDB1-100/125
PARTS PACKAGE
#S00S4411/4412 DESCRIPTION PART # QUANTITY
2-3/8” ID radiator hose 410017 1
Thermostat lead bushing 350750 1
PVC trap assembly 320816 1
#8 x ¾ coated TEK screws for
mounting trap & inlet/outlet collars 300283 4
11/16” OD x 1/2” ID vinyl tubing 410060 24”
2 x 4 electrical J-box 350024 1
2 x 4 electrical J-box cover 350020 1
#8 x ½ TEK screws for
mounting 2 x 4 J-box 300208 2

All installations and services must be performed by qualified service personnel.
5
#10-32 x ½ green ground screw 300109 1
#10-32 hex nut 300110 1
3/16” dia. star washer 300270 1
Grounding instructions MG-966 1
Wire nut 300132 2
3” stainless steel hose clamp 300276 2
J-box wire bushing 350016 1
Drain hose grommet 350446 1
Spring clamp, 11/16” 300299 3
Installation notice MG-987 1
PVC tee assembly, 2 x 3” dia. 320817 1
PVC tee assembly, 2” dia. 320819 1
Pipe 2” dia. PVC 15” 14401 1
Bracket 14406 1
Reducer 2” x 3” PVC 320067 1
Orifice, Propane 380039 4/5
Conversion Kit, Propane 380605 1
III. GENERAL INSTALLATION
This furnace is equipped with orifices size for operation with natural gas. For conversion to Propane Gas see
instruction in Gas Conversion Section of this manual.
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.
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
MODEL NO. FROM SIDES OF
FURNACE & REAR FRONT TOP OF PLENUM
FROM THE
FLUE OR VENT
SIDE OF
PLENUM
CHB1-50 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.

All installations and services must be performed by qualified service personnel.
6
CHB1-75 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CHB1-100 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CHB1-125 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CDB1-50 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CDB1-75 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CDB1-100 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
CDB1-125 0 IN. 6 IN. 0 IN. 0 IN. 1 IN.
The CHB1-50, 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 CDB1-50, 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 CDB1- (50,75) model no. 100 CA base for the model no. CDB1-100 and
model no. 125 CA base for CDB1-125 are available for the counterflow furnaces to allow their installations on
combustible flooring.
These furnaces may be installed in an alcove or in a closet if the minimum clearances to combustible construction
(listed previously) are met. The CDB1 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. CDB1 HORIZONTAL APPLICATION
The CDB1-50, 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).

All installations and services must be performed by qualified service personnel.
7
For left or right horizontal applications of the CDB1 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 CDB1 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 CDB1 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.
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 CDB1 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 CDB1 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).

All installations and services must be performed by qualified service personnel.
8
Figure 1
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.

All installations and services must be performed by qualified service personnel.
9
D. General Requirements For Venting Models CHB1 / CDB1
The CHB1 / CDB1 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 Z223.1-1999, 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 pipefittings sourced to complete the exhaust vent and air intake
systems shall be constructed of PVC (polyvinyl chloride) thermoplastic. All components
shall have a wall thickness equivalent to schedule 40 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 Design Standard
Cellular Core ASTM-F891
DWV (Drain-Waste-Vent) ASTM-D2665
Schedule 40 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, schedule 40, PVC thermoplastic pipe, for models CHB1–50 / –75
& CDB1–50 / –75, or
• nominal 3-inch diameter, schedule 40, PVC thermoplastic pipe, for models CHB1–100 / –
125 & CDB1–100 / –125.
4. The furnace model series CHB1 / CDB1 shall not be common vented with any other appliance,
including those burning solid fuels.
5. All horizontal runs of exhaust vent pipe shall slope upward at least ¼ inch per foot from the outlet
of the furnace (for the model series CHB1), or the outlet of the drain tee (for the model series
CDB1) 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.

All installations and services must be performed by qualified service personnel.
10
8. The maximum quantity of schedule 40, 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
pipefittings, 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 3 in. Diameter
Furnace Model
Exhaust or
Intake
Straight
Pipe
Length (ft.)
Maximum
Qty. of
Exhaust
Elbows 1,2
Maximu
m
Qty. of
Intake
Elbows 2
Exhaust or
Intake
Straight
Pipe
Length (ft.)
Maximum
Qty. of
Exhaust
Elbows 1, 2
Maximu
m
Qty. of
Intake
Elbows 2
CHB1 / CDB1-50
CHB1 / CDB1-75
35 8 7 - - -
CHB1 / CDB1-100
CHB1 / CDB1-125
Not Permitted
35 8 7
Notes:
1 The drain tee supplied with CHB1 / CDB1 furnace model series is considered equivalent to
one (1), 90° elbow.
2 Two (2), 45° elbows can be substituted for one (1), 90° elbow.
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, DWV type elbows, couplings, and fittings. Clean all pipe surfaces
at connections using a fine abrasive material or approved PVC cleaner (primer). Secure 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.
Piping joints inside the furnace vestibule should be sealed with 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.

All installations and services must be performed by qualified service personnel.
11
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 furnace model series CHB1 / CDB1 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 H,
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)
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.

All installations and services must be performed by qualified service personnel.
12
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 clearances.
b. The vent terminal shall be at least 1-foot below, 1-foot horizontally from, or 1-foot 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. In addition, avoid
locations where wetting could be detrimental to the operation of regulators, relief valves, or
any other equipment.
d. A minimum horizontal clearance of 4-feet shall be maintained from the vent terminal to
electric meters, gas meters, regulators and relief equipment.
e. 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.

All installations and services must be performed by qualified service personnel.
13
Figure 4: Minimum Clearances Between the Vent Terminal and Various Objects or Features
4. Vent Terminal Location Guidelines
: 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
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
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.
NOTICE: When possible, we recommend all furnace of the model series CHB1 / CDB1 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.

All installations and services must be performed by qualified service personnel.
14
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.
NOTICE: Heat exchanger failure accelerated by contaminated combustion air will void the furnace
heat exchanger limited lifetime warranty.
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),
• 2-3/8 inch diameter, for furnace models CHB1 / CDB1-50 and CHB1 / CDB1-75, or
• 3-1/2 inch diameter, for the furnace models CHB1 / CDB1-100 and CHB1 / CDB1-125.
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 Construction Details of Sidewall Vent and Air Intake Terminations