Dettson C45-1-D Assembly instructions

INSTALLATION INSTRUCTIONS AND HOMEOWNER’S MANUAL:
GAS FIRED FURNACE SINGLE STAGE PSC, 2-STAGE PSC, SINGLE STAGE ECM
GAS FURNACE
MULTIPOSITION
Models:
C45-1-X/C45-1-D*/C45-2-D*/
C60-1-X*/C60-1-D*/C60-2-D*
C75-1-X*/C75-1-D*/C75-2-D*
C105-1-X*/C105-1-D*/C105-2-D*
C120-1-X*/C120-1-D*/C120-2-D*
Models marqued with an * are only sold in Quebec
Models in bold can be sold in US and Canada.
INSTALLER / SERVICE TECHNICIAN:
Use the information in this manual for the installation/servicing of the furnace and keep the document near the unit for future
reference.
HOMEOWNER: Please keep this manual near the furnace for future reference.
Manufactured by: Dettson Industries Inc. Sherbrooke, Qc, Canada www.dettson.com
Gas furnace manufactured on or after May 1, 2017 are not permitted to be used in Canada for heating of buildings or structures under construction
Printed in Canada on
100% recycled paper
2022-06 X40223 rev.T

Table of content
1 SAFETY 3
1.1 SAFETY LABELING AND WARNING SIGNS . . . . . . . . 3
1.2 IMPORTANT INFORMATION . . . . . . . . . . . . . . . . . . . 3
1.3 SAFETY CONSIDERATION . . . . . . . . . . . . . . . . . . . . 3
1.4 DETECTIONSYSTEMS ....................... 5
1.5 DANGER OF FREEZING . . . . . . . . . . . . . . . . . . . . . . 5
2 INTRODUCTION 6
2.1 CODES AND STANDARDS . . . . . . . . . . . . . . . . . . . . . 6
2.2 ELECTROSTATIC DISCHARGE . . . . . . . . . . . . . . . . . 7
2.3 LOCATION................................. 7
2.3.1 Clearance and accessibility . . . . . . . . . 7
2.3.2 Location relative to cooling equipement . . . 7
3 INSTALLATION 8
3.1 UPFLOW .................................. 8
3.1.1 Right side condensate drain trap connection 8
3.1.2 Left side condensate drain trap connection . 8
3.2 DOWNFLOW ............................... 9
3.2.1 Downflow condensate drain trap connection 9
3.2.2 Downflow multiposition pressure switch
connection . . . . . . . . . . . . . . . . . . 10
3.3 HORIZONTALRIGHT......................... 10
3.3.1 Horizontal right condensate drain trap
connection . . . . . . . . . . . . . . . . . . 10
3.3.2 Horizontal right multiposition pressure switch
connection . . . . . . . . . . . . . . . . . . 11
3.4 HORIZONTALLEFT .......................... 11
3.4.1 Horizontal left condensate drain trap
connection . . . . . . . . . . . . . . . . . . 12
3.4.2 Alternate drain trap location in horizontal left
position . . . . . . . . . . . . . . . . . . . . 12
3.4.3 Horizontal left multiposition pressure switch
connection . . . . . . . . . . . . . . . . . . 12
3.5 MULTIPOSITION VENTING DRAINAGE. . . . . . . . . . . . 13
4 DUCT INSTALLATION 13
4.1 GENERAL REQUIREMENTS . . . . . . . . . . . . . . . . . . . 13
4.2 DUCT EXTERNAL STATIC PRESSURE . . . . . . . . . . . . 13
4.3 RETURN AIR CONNECTIONS . . . . . . . . . . . . . . . . . . 13
4.3.1 Bottom return . . . . . . . . . . . . . . . . 13
4.3.2 Side return . . . . . . . . . . . . . . . . . . 14
4.4 SUPPLYAIRDUCTS ......................... 14
4.4.1 Ductwork acoutiscal treatment . . . . . . . . 14
5 GAS SUPPLY AND PIPING 14
5.1 GENERAL ................................. 14
5.2 PROPANE CONVERSION . . . . . . . . . . . . . . . . . . . . . 14
5.3 GASPIPEGROMMET ........................ 14
5.4 SETTING GAS OUTLET PRESSURE . . . . . . . . . . . . . 14
5.4.1 Adjusting 2 stage gas valve . . . . . . . . . 15
5.4.2 Adjusting single stage gas valve . . . . . . . 15
6 ELECTRICAL CONNECTIONS 17
6.1 120VWIRING .............................. 17
6.2 24VWIRING ............................... 17
6.3 FUSE .................................... 17
6.4 THERMOSTATS............................. 17
6.5 ELECTRIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . 17
6.6 ALTERNATE POWER SUPPLY . . . . . . . . . . . . . . . . . . 17
7 VENTING AND COMBUSTION AIR PIPING 17
7.1 GENERAL ................................. 18
7.2 DIRECTVENT .............................. 18
7.3 NONDIRECTVENT.......................... 18
7.4 SPECIAL VENTING REQUIREMENTS FOR
INSTALLATION IN CANADA . . . . . . . . . . . . . . . . . . . . 19
7.5 MATERIAL................................. 19
7.6 SIZE THE VENT AND COMBUSTION AIR PIPES . . . . 19
7.7 EXHAUST PIPE CONNECTION TO FURNACE . . . . . . 20
7.8 COMBUSTION AIR PIPE CONNECTION . . . . . . . . . . 20
7.9 VENTTERMINATION......................... 21
7.9.1 Concentric vent . . . . . . . . . . . . . . . . 21
7.9.2 Two pipe termination . . . . . . . . . . . . . 22
8 START UP, ADJUSTMENT AND SAFETY CHECK 26
8.1 Startingthefurnace .......................... 26
9 SINGLE STAGE X13 MOTOR ECM 26
9.1 Selecting blower speed . . . . . . . . . . . . . . . . . . . . . . . . 26
9.2 Dipswitchoptions ............................ 27
9.3 Coolmode ................................. 27
9.4 ManualFanONmode......................... 27
9.5 TwinningInterface............................ 27
9.6 Errorcodes ................................ 27
10 SINGLE STAGE PSC MOTOR 28
10.1 Selecting the blower speed on PSC motor . . . . . . . . . . 28
10.2Dipswitchoptions ............................ 29
10.3Coolmode ................................. 29
10.4ManualfanONmode ......................... 29
10.5TwinningInterface............................ 29
10.6Errorcodes ................................ 29
11 2 STAGE PSC MOTOR 29
11.1 Selecting the blower speed . . . . . . . . . . . . . . . . . . . . . 29
11.2Dipswitchoptions ............................ 29
11.3Coolmode ................................. 29
11.4ManualfanONmode ......................... 29
11.5Errorcodes ................................ 30
12 SAFETY CHECK 30
12.1Primedraintrap ............................. 30
12.2 Furnace operating conditions . . . . . . . . . . . . . . . . . . . 30
12.3Checklist .................................. 30
13 OPERATING YOUR FURNACE 30
13.1 WHAT TO DO IF YOU SMELL GAS . . . . . . . . . . . . . . . 30
13.2 SHUTTING DOWN THE FURNACE . . . . . . . . . . . . . . 30
13.2.1 To turn off gas to furnace . . . . . . . . . . . 30
14 MAINTENANCE OF YOUR FURNACE 30
1

14.1 CLEANING/REPLACING THE FILTER . . . . . . . . . . . . . 31
14.2 CONDENSATE COLLECTION AND DISPOSAL
SYSTEM .................................. 31
14.3ROLLOUTSWITCH .......................... 31
14.4 SAFETY INTERLOCK SWITCH . . . . . . . . . . . . . . . . . 31
15 FURNACE INFO 36
List of figures
Figure 1: Right side connection . . . . . . . . . . . . 8
Figure 2: Left side connection . . . . . . . . . . . . . 8
Figure 3: Downflow position . . . . . . . . . . . . . . 9
Figure 4: Downflow position pressure switch assembly 10
Figure 5: Connecting pressure switch in downflow
position . . . . . . . . . . . . . . . . . . . . 10
Figure 6: Horizontal right position . . . . . . . . . . . 10
Figure 7: Horizontal right slope . . . . . . . . . . . . . 10
Figure 8: Horizontal right pressure switch connection . 11
Figure 9: Horizontal right pressure switch tubing . . . 11
Figure 10: Horizontal left position . . . . . . . . . . . . 11
Figure 11: Drain trap alternate position . . . . . . . . . 12
Figure 12: Horizontal left pressure switch connection . 12
Figure 13: Single stage gas valve . . . . . . . . . . . . 15
Figure 14: Two stage gas valve . . . . . . . . . . . . . 16
Figure 15: Adjustment screw . . . . . . . . . . . . . . 16
Figure 16: Typical gas pipe arrangement . . . . . . . . 16
Figure 17: Combustion air moisture trap . . . . . . . . 21
Figure 18: Top panel combustion air . . . . . . . . . . 21
Figure 19: side panel combustion air . . . . . . . . . . 21
Figure 20: Roof concentric termination . . . . . . . . . 22
Figure 21: Sidewall concentric termination . . . . . . . 22
Figure 22: Roof termination . . . . . . . . . . . . . . . 22
Figure 23: Standard horizontal termination . . . . . . . 22
Figure 24: Alternate horizontal termination A . . . . . . 22
Figure 25: Alternate horizontal termination B . . . . . . 22
Figure 26: Alternate horizontal termination C . . . . . . 23
Figure 27: Venting gasket . . . . . . . . . . . . . . . . 23
Figure 28: Direct vent clearance . . . . . . . . . . . . . 24
Figure 29: Other than Direct vent clearance . . . . . . 25
Figure 30: X13 motor connections . . . . . . . . . . . . 27
Figure 31: PSC motor connections . . . . . . . . . . . 28
Figure 32: Single Stage PSC Wiring diagram . . . . . . 33
Figure 33: Two Stage PSC Wiring diagram . . . . . . . 34
Figure 34: Single Stage ECM Wiring diagram . . . . . 35
Figure 35: Dimensions . . . . . . . . . . . . . . . . . . 38
Figure 36: Exploded view CXX-1-X part 1 . . . . . . . 39
Figure 37: Exploded view CXX-1-X part 2 . . . . . . . 40
Figure 38: Exploded view Cxx-1-D part 1 . . . . . . . . 42
Figure 39: Exploded view Cxx-1-D part 2 . . . . . . . . 43
Figure 40: Exploded view Cxx-2-D part 1 . . . . . . . . 45
Figure 41: Exploded view Cxx-2-D part 2 . . . . . . . . 46
List of tables
Table 1: Codes and Standards . . . . . . . . . . . . . 6
Table 2: Minimum clearance . . . . . . . . . . . . . . 7
Table 3: Suggested Filter size . . . . . . . . . . . . . 14
Table 4: Inlet gas pressure . . . . . . . . . . . . . . . 16
Table 5: Outlet gas pressure . . . . . . . . . . . . . . 16
Table 6: Maximum capacity of pipe Cu.ft./Hr for pipe
length ft (m) . . . . . . . . . . . . . . . . . . 16
Table 7: Approved Vent and Combustion air pipe
material USA installation . . . . . . . . . . . 19
Table 8: Maximum equivalent vent length (ft) for 2-
stage unit and altitude up to 4500 ft . . . . . 20
Table 9: Deduction for fittings . . . . . . . . . . . . . 20
Table 10: CFM C45-1-X . . . . . . . . . . . . . . . . . 27
Table 11: CFM C60-1-X . . . . . . . . . . . . . . . . . 27
Table 12: CFM C75-1-X . . . . . . . . . . . . . . . . . 27
Table 13: CFM C105-1-X . . . . . . . . . . . . . . . . 27
Table 14: CFM C120-1-X . . . . . . . . . . . . . . . . 27
Table 15: Option dipswitch position single stage . . . . 27
Table 16: Option switch single stage delay to fan off
heating .................... 27
Table 17: Error codes single stage . . . . . . . . . . . 28
Table 18: Suggested heating fan speed on single stage
furnace .................... 28
Table 19: CFM C45-1-D/C45-2-D . . . . . . . . . . . . 28
Table 20: CFM C60-1-D/C60-2-D . . . . . . . . . . . . 28
Table 21: CFM C75-1-D/C75-2-D . . . . . . . . . . . . 28
Table 22: CFM C105-1-D/C105-2-D . . . . . . . . . . . 28
Table 23: CFM C120-1-D/C120-2-D . . . . . . . . . . . 29
Table 24: Suggested heating fan speed on 2 stage
furnace .................... 29
Table 25: Heat delay-to-fan-off . . . . . . . . . . . . . 29
Table 26: 2nd stage delay for single stage thermostat . 29
Table 27: Electrical data . . . . . . . . . . . . . . . . . 32
Table 28: Error Codes 2 Stage PSC furnace . . . . . . 37
Table 29: Part list single stage ECM (x13) . . . . . . . 41
Table 30: Part list single stage PSC . . . . . . . . . . 44
Table 31: Part list two stage PSC . . . . . . . . . . . . 47
2

1 SAFETY
1.1 SAFETY LABELING AND
WARNING SIGNS
The words DANGER, WARNING and CAUTION
are used to identify the levels of seriousness
of certain hazards. It is important that
you understand their meaning. You will
notice these words in the manual as follows:
DANGER
Immediate hazards which WILL result in death or
serious bodily and/or material damage.
WARNING
Hazards or unsafe practices which CAN result in
death or serious bodily and /or material damage.
CAUTION
Hazards or unsafe practices which CAN result in
minor bodily and /or material damage.
1.2 IMPORTANT INFORMATION
WARNING
Non-observance of the safety regulations
outlined in this manual will potentially lead to
consequences resulting in death, serious bodily
injury and/or property damage.
WARNING
Installation and repairs performed by unqualified
persons can result in hazards to them and to
others. Installations must conform to local codes
or, in the absence of such codes, to codes of the
country having jurisdiction.
The information contained in this manual is
intended for use by a qualified technician, familiar
with safety procedures and who is equipped with
the proper tools and test instruments.
Failure to carefully read and follow all instructions
in this manual can result in death, bodily injury
and/or property damage.
1. It is the homeowner’s responsibility to engage
a qualified technician for the installation and
subsequent servicing of this furnace;
2. Do not use this furnace if any part of it was
under water. Call a qualified service technician
immediately to assess the damage and to replace
all critical parts that were in contact with water;
3. Do not store gasoline or any other flammable
substances, such as paper or carton, near the
furnace;
4. Do not stack items or boxing within the required
clearances to combustible materials specified in
Table 2;
5. Never block or otherwise obstruct the filter and/or
return air openings;
6. Ask the technician installing your furnace to show
and explain to you the following items:
• The main disconnect switch or circuit breaker;
• The gas shut off valve;
• The air filter and how to change it (at least
twice a year);
7. Before calling for service, be sure to have the
information of section 15 of your manual close by in
order to be able to provide the contractor with the
required information, such as the model and serial
numbers of the furnace.
WARNING
Failure to follow this warning could result in
dangerous operation, personal injury, death,
or property dammage. Improper installation,
adjustement, servicing or repair can cause carbon
monoxide poisoning, explosion, fire, electrical
shock, or other conditions which may cause
personal injury or property damage. Consult a
qualified service agency, local gas supplier, or
your distributor for information or assistance. The
qualified service agency must use only factory
authorized and listed kits or accessories when
modifying this product.
WARNING
INJURY HAZARD
Ignoring this warning could result in personal
injury.
Sheet metal parts may have sharp edges or burrs.
Use care and wear appropriate protective clothing,
safety glasses and gloves when handling parts,
and servicing furnaces
1.3 SAFETY CONSIDERATION
Untrained personnel can perform basic maintenance
functions such as cleaning and replacing air filters. All
3

other operations must be performed by trained service
personnel. When working on heating equipement,
observe precautions in literature, on tags, and on labels
attached to or shipped with the furnace. Other safety
precautions may apply.
These instructions cover minimum requirements and
conform to existing national standards and safety codes.
In some instances, these instructions exceed certain
local codes and ordinances, especially those that may
not have kept up with changing residential construction
practices. We require these instructions as a minimum
for a safe installation.
Follow all safety codes. Wear safety glasses, protective
clothing and work gloves. Have a fire extinguisher
available. Read these instructions thoroughly and follow
all warnings or cautions included in the literature and
attached to the unit.
1. Use only with type of gas approved for this furnace.
Refer to the furnace rating plate and section 5 :
GAS SUPPLY AND PIPING.
2. Install this furnace only in a location and position as
specified in section 3 : INSTALLATION.
3. Provide adequate combustion and ventilation air to
the furnace as specified in section 7 : VENTING
AND COMBUSTION AIR PIPING.
4. Combustion products must be discharged
outdoors. Connect this furnace to an approved vent
system only, as specified in section 7 : VENTING
AND COMBUSTION AIR PIPING.
5. Never test for gas leaks with an open flame.
Use a commercially available soap solution made
specifically for the detection of leaks to check
all connections, as specified in section 5 : GAS
SUPPLY AND PIPING.
6. Always install furnace to operate within the
furnace’s intended temperature-rise range with a
duct system which has an external static pressure
within the allowable range, as specified in section
4 : DUCT INSTALLATION of these instructions.
See furnace rating plate.
7. When a furnace is installed so that supply ducts
carry air circulated by the furnace to areas outside
the space containing the furnace, the return air
shall also be handled by duct(s) sealed to the
furnace casing and terminating outside the space
containing the furnace. See section 4 : DUCT
INSTALLATION.
This furnace may be installed, with a two pipe
sealed combustion configuration, in a space
utilized as part of the return air supply. A filter
must be installed at the return opening of the
furnace and a grill should be installed in the
space to allow proper circulation of air.
8. Gas furnace manufactured on or after May 1, 2017
are not permitted to be used in Canada for heating
of buildings or structures under construction.
9. A gas-fired furnace for installation in a residential
garage must be installed as specified in the
WARNING box below:
WARNING
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in
personal injury, death and/or property damage.
When the furnace is installed in a residential
garage, the burners and ignitions sources must be
located at least 18 in. (457 mm) above the floor.
The furnace must be located or protected to avoid
damage by vehicles. When the furnace is installed
in a public garage, airplane hangar, or other
building having a hazardous atmosphere, the
furnace must be installed in accordance with the
NFPA 54/ANSI Z223.1-2009 or CAN/CSA B149.2-
2010.
Do not install the furnace on its back or
hang furnace with control compartment facing
downward. Safety control operation will be
adversely affected. Never connect return air duct
to the back of the furnace.
WARNING
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Improper servicing could result in dangerous
operation, serious injury, death or property
damage.
-Before servicing, disconnect all electrical power
to furnace.
-When servicing controls, label all wires prior to
disconneting. Reconnect wires correctly.
-Verify proper operation after servicing.
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in
personal injury or death. The operation of
exhaust fans, kitchen ventilation fans, clothes
dryers, attic exhaust fans or fireplaces could
create a NEGATIVE PRESSURE CONDITION at the
furnace. Make-up air MUST be provided for the
ventilation devices, in addition to that required by
the furnace.
4

WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for
each appliance connected to the venting system
being placed into operation could result in carbon
monoxide poisoning or death. The following steps
shall be followed for each appliance connected to
the venting system being placed into operation,
while all other appliances connected to the
venting system are not in operation:
1. Seal any unused openings in venting
system;
2. Inspect the venting system for proper
size and horizontal pitch, as required
in the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 or the Natural Gas and
Propane Installation Code, CSA B149.1 and
these instructions. Determine that there
is no blockage or restriction, leakage,
corrosion and other deficiencies which could
cause an unsafe condition;
3. As far as practical, close all building doors
and windows and all doors between the
space in which the appliance(s) connected
to the venting system are located and other
spaces of the building;
4. Close fireplace dampers;
5. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on
any exhaust fans, such as range hoods and
bathroom exhausts, so they are operating at
maximum speed. Do not operate a summer
exhaust fan;
6. Follow the lighting instructions. Place the
appliance being inspected into operation.
Adjust the thermostat so appliance is
operating continuously;
7. Test for spillage from draft hood equipped
appliances at the draft hood relief opening
after 5 minutes of main burner operation.
Use the flame of a match or candle;
8. If improper venting is observed during any
of the above tests, the venting system must
be corrected in accordance with the National
Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or
Natural Gas and Propane Installation code,
CSA B149.1;
9. After it has been determined that each
appliance connected to the venting system
properly vents when tested as outlined
above, return doors, windows, exhaust
fans, fireplace dampers and any other gas-
fired burning appliance to their previous
conditions of use;
1.4 DETECTION SYSTEMS
It is recommended that carbon monoxide detectors be
installed wherever oil or gas fired heaters are used.
Carbon monoxide can cause bodily harm or death.
For this reason, agency approved carbon monoxide
detectors should be installed in your residence and
properly maintained to warn of dangerously high carbon
monoxide levels.
Also, the house should be equipped with approved and
properly maintained fire extinguishers.
Your unit is equipped with safety devices that can prevent
it from functioning when anomalies are detected such as
a blocked venting system.
1.5 DANGER OF FREEZING
CAUTION
FROZEN AND BURST WATER PIPE HAZARD
Failure to protect against the risk of freezing may
result in property damage. Special precautions
MUST be made if installing furnace in an area
which may drop below freezing. This can cause
improper operation or damage to equipment. If
furnace environment has the potential of freezing,
the drain trap and drain line must be protected.
CAUTION
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in
burst water pipes and/or property damage. If
a condensate pump is installed, a clogged
condensate drain or a failed pump may cause
the furnace to shut down. Do not leave the
home unattended during freezing weather without
turning off water supply and draining water pipes
or otherwise protecting against the risk of frozen
pipes.
Ensure all condensate drain connections are
secured and liquid tight. Use the furnished tube
clamps and verify tightness
5

2 INTRODUCTION
This multiposition Category IV condensing furnace is
CSA design certified direct vent (2 pipes) or non-direct
vent (1 pipe). The furnace is factory shipped for use
with natural gas. The furnace can be converted in the
field for use with propane gas when a factory supplied
conversion kit is used. Refer to the furnace rating plate
for conversion kit information and part list table
This furnace is designed for minimum continuous return
air temperature of 60 °F (16 °C) or intermittent operation
down to 55 °F (13 °C) such as when used with a
night setback thermostat. Return air temperature must
not exceed 80 °F (27 °C). Failure to follow these
return air temperature limits may affect reliability of heat
exchangers, motors, and controls.
The furnace should be sized to provide at least 100
% of the design heating load requirement. Heating
load estimates can be made using approved methods
available from Air Conditioning Contractors of America
(Manual J); American Society of Heating, Refrigerating,
and Air Conditioning Engineers; or other approved
engineering methods. Excessive over sizing of the
furnace could cause the furnace and/or vent to fail
prematurely.
2.1 CODES AND STANDARDS
Follow all national and local codes and standards in
addition to these instructions. The installation must
comply with regulations of the serving gas supplier, local
building, heating, plumbing, and other codes. In absence
of local codes, the installation must comply with the
national codes listed below and all authorities having
jurisdiction. In the United States and Canada, follow all
codes and standards for the following:
Table 1 – Codes and Standards
TOPIC USA CANADA
Safety National Fuel Gas Code
(NFGC) NFPA 54-
2009/ANSI Z223.1 and
the Installation Standards,
Warm Air Heating and
Air Conditioning Systems
ANSI/NFPA 90B
National Standard of
Canada, Natural Gas and
Propane Installation Code
(NSCNGPIC) CAN/CSA
B149.1
General
installation
NFGC and the NFPA 90B.
For copies, contact the
National Fire Protection
Association Inc., Battery
march Park, Quincy, MA
02269; or for only the NFGC
contact the American Gas
Association, 400 N. Capitol,
N.W.,Washington DC 20001
NSCNGPIC. For a copy,
contact Standard Sales,
CSA International, 178
Rexdale Boulevard,
Etobicoke (Toronto),
Ontario, M9W 1R3, Canada
Combustion and
and air ventilation
Section 9.3 of the
NFPA54/ANSI Z223.1
Air for Combustion and
Ventilation
Part 8 of the CAN/CSA
B149.1, Venting Systems
and Air Supply for
Appliances
Duct systems Air Conditioning Contractors Association (ACCA) (Manual
D), Sheet Metal and Air Conditioning Contractors National
Association (SMACNA), or American Society of Heating,
Refrigeration, and Air Conditioning Engineers (ASHRAE).
Acoustical lining
and fibrous glass
duct
current edition of SMACNA, NFPA 90B as tested by UL Standard
181 for Class I Rigid Air Ducts.
Gas piping and
pipe pressure
testing
NFPA 54/ANSI Z223.1
NFGC; Chapters 5, 6, 7,
and 8 and national plumbing
codes.
CAN/CSA-B149.1, Part 6
Manufactured
Mobile housing
Manufactured Home
Construction and Safety
Standard, Title 24 CFR,
Part 3280 or The Standard
for Manufactured Home
Installations ANSI/NCS
A225.1
Canadian Standard for
Series M92 Mobile Homes,
CAN/CSA Z240MH
Electrical
connections
National Electrical Code
(NEC) ANSI/NFPA 70
Canadian Electrical Code
CSA C22.1
Venting Part 7, Venting of
equipment, latest edition of
the National Fuel Gas Code
NPFA 54, 90A and 90B
ANSI Z223.1-
CAN/CSA-B149.1-05 latest
edition
IN THE STATE OF MASSACHUSETTS:
• This product must be installed by a
licensed plumber of gas fitter;
• When flexible connectors are used, the
maximum length shall not exceed 36 in.
(914 mm);
• When lever type gas shutoffs are used
they shall be ”T” handle type;
• The use of copper tubing for gas
piping is not approved by the state of
Massachusetts;
6

2.2 ELECTROSTATIC DISCHARGE
CAUTION
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in unit
component damage. Electrostatic discharge can
affect electronic components. Take precautions
during furnace installation and servicing to
protect the furnace electronic control. These
precautions will help to avoid exposing the control
to electrostatic discharge by putting the furnace,
the controls, and the technician at the same
electrostatic potential.
1. Disconnect all power to the furnace. Multiple
disconnects may be required. DO NOT TOUCH
THE CONTROL OR ANY WIRE CONNECTED
TO THE CONTROL PRIOR TO DISCHARGING
YOUR BODY’S ELECTROSTATIC CHARGE TO
GROUND.
2. Firmly touch the clean, unpainted, metal surface of
the furnace chassis which is close to the control.
Tools held in a person’s hand during grounding will
be satisfactorily discharged.
3. After touching the chassis, you may proceed to
service the control or connecting wires as long as
you do nothing to recharge your body with static
electricity (for example; DO NOT move or shuffle
your feet, do not touch ungrounded objects, etc.).
4. If you touch ungrounded objects (and recharge your
body with static electricity), firmly touch a clean,
unpainted metal surface of the furnace again before
touching control or wires.
5. Use this procedure for installed and uninstalled
(ungrounded) furnaces.
6. Before removing a new control from its container,
discharge your body’s electrostatic charge to
ground to protect the control from damage. If the
control is to be installed in a furnace, follow items
1 through 4 before bringing the control or yourself
in contact with the furnace. Put down all used and
new controls before touching ungrounded objects.
7. An ESD service kit (available from commercial
sources) may also be used to prevent ESD
damage.
2.3 LOCATION
This furnace must :
• Be installed so the electrical components are
protected from water;
• Not be installed directly on any combustible
material other than wood flooring;
• Be located close to the chimney or vent and
attached to an air distribution system. Refer to
section 7
Place the unit so that proper venting can be achieved,
with a minimum number of elbows, in accordance with
the instructions in this manual. The furnace should be
located as close to the chimney (vertical venting) or to
the outside vent wall (horizontal venting) as possible.
When installing the furnace, provisions must be made
to ensure the supply of adequate combustion and
ventilation air in accordance with the “air for combustion
and ventilation” section of the National Fuel Gas Code,
NFPA 5/ANSI Z223. c1 or applicable provisions of the
local building code.
2.3.1 Clearance and accessibility
Installations must provide ample space for servicing and
cleaning. Always comply with minimum fire protection
clearances shown in table 2 or on the furnace rating label.
Clearances must also accomodate an installation’s gas,
electrical, drain trap and venting/combustion air piping. If
the combustion air is installed to the side of the furnace,
additionnal clearance must be provided.
2.3.2 Location relative to cooling
equipement
The cooling coil can either be installed in the supply air
duct or in the return air duct. If the coil is installed in
the supply air duct, it must be at a minimum of 6" over
the furnace’s primary heat exchanger. This will avoid
potential error codes due to heated refrigerant when the
gas furnace is on. It also allows for a more laminar airflow
through the coil. The cooling coil base can be purchased
through your local distributor. See part list tables for the
appropriate item number.
Table 2 – Minimum clearance
Position Clearance in (mm)
Rear 0
Front124 (610)
All sides of supply plenum 21 (25)
Sides30
Vent 0
Top of furnace 1 (25)
1- For servicing or cleaning, a 24" front clearance is
required.
2- For at least the first 3 ft of plenum from furnace
3-Unit connections (electrical, drain trap and combustion
air) may necessitate greater clearances than the
minimum clearances listed above.
7

3 INSTALLATION
To ensure proper drainage of the condensate when
installed in position other than upflow, the furnace
MUST be tilted. Refer to figures corresponding to the
position of the furnace in the following sections.
CAUTION
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in water
spillage and/or property damage.
For any position other than upflow, the
multiposition pressure switch must be connected
pneumatically to the condensate box and
electrically to the control to allow the furnace
to stop in the event of drain blockage.
3.1 UPFLOW
The furnace is factory built for upflow position. In this
position, the drain trap can be installed on the right or left
side depending on air return duct. When installing the
furnace in the upflow position, make sure it is leveled or
tilted foward.
In the upflow orientation, the drain trap can be installed
to the right or to the left of the furnace. The location of
the drain trap is dependent of the return duct connection.
The furnace must be perfectly leveled or slightly leaned
forward to help drain condensate.
3.1.1 Right side condensate drain trap
connection
Figure 1 – Right side connection
See figure 1 and read the following instructions:
1. Remove the oblong knock-out from the right side of
the casing.
2. Place the drain trap gasket on drain trap.
3. Install the drain trap on the right side. See figure 1.
4. Screw in place the drain trap with two head tapping
screws on the right side of the furnace.
5. Connect the three stubs to the condensate tubings
already in place in the furnace.
6. Connect the outlet drain from the drain trap to an
additional condensate tubing using a ½” tee for an
adequate drainage of the condensate. DO NOT
vent using the remaining 3 outlet stubs.
7. Prime the drain trap with water. This will ensure
proper furnace drainage at startup and will avoid
any recirculation of flue gas.
8. On the remaining 3 outlet stub, connect caps
(1x5/8” and 2x1/2”). Those caps are furnished in
the parts bag.
9. If a condensate pump needs to be use, make sure
it is suited for acidic condensate.
3.1.2 Left side condensate drain trap
connection
See figure 2 and read the following instructions:
Figure 2 – Left side connection
1. Remove the oblong knock-out from the left side of
the casing.
8

2. Place the drain trap gasket on the drain trap.
3. Install the drain trap on the left side, the three outlet
stub of the drain trap toward the interior of the
furnace.
4. Connect each condensate tubing to a stub. Use the
furnished ½” and 5/8” tubing to cut the appropriate
length to reach the drain trap. The condensate
tubing from the condensate box is 5/8” and it must
be connected to the 5/8” stub of the drain trap. The
condensate tubing from the ID blower and the vent
flange are ½” and are connected to the ½” stubs of
the drain trap.
5. Ensure the tubings are adequately connected to the
stubs and are correctly sloped to the drain trap.
Left side connection requires special attention to
the slope of condensate tubing through the furnace.
6. Screw the drain trap in place with two head tapping
screws on the furnace side.
7. Connect the outlet drain from the drain trap to an
additional condensate tubing using a ½” tee for an
adequate drainage of the condensate. DO NOT
vent using the remaining three outlet stubs. If a
condensate pump is used, make sure it is approved
for acidic condensate.
8. Prime the drain trap with water. This will ensure
proper furnace drainage at startup and will avoid
any recirculation of flue gas.
9. On the remaining 3 outlet stub, connect caps
(1x5/8” and 2x1/2”). These caps are provided in
the parts bag.
3.2 DOWNFLOW
SEE FIGURE 3 FOR INSTALLATION DETAILS
CAUTION
It is STRONGLY RECOMMENDED to use the
optional downflow base to ensure the 1” clearance
around the supply duct going through the floor
and the proper slope of the furnace for condensate
drainage. Also, the base allows sufficient spacing
for the venting and the drain trap.
When installing the furnace in downflow position, make
sure the furnace is tilted foward to make it drain properly.
Plan your installation to have at least 1.0 ft. of clearance
under the installed furnace to put the exhaust pipe
drainage and drain trap.
Figure 3 – Downflow position
3.2.1 Downflow condensate drain trap
connection
1. Remove all condensate tubing from the inducer
blower, condensate box and vent collector. Block
the openings with the provided 5/8” and 1/2” black
caps. In the downflow position, the only connection
to the drain trap comes from the condensate box.
The inducer blower will be drained through the
exhaust pipe.
2. Remove the downflow drain trap knock-out.
3. Place the drain trap gasket on the drain trap.
4. Install the drain trap.
5. Screw the drain trap in place with two head tapping
screws on the side of the furnace.
6. Install two 1/2” black plastic caps on the unused
1/2” inlets of the drain trap inside the furnace.
7. Cut the required length of 5/8” tubing and connect
one end on the downflow port of the condensate
box. See figure 3 for port location.
8. Connect the other end to the 5/8” inlet of the drain
trap and secure the tubing on the gas manifold with
a tie wrap.
9. Connect the outlet of the drain trap to the
condensate drain piping with a tee. DO NOT vent
using the remaining 3 inlet of the drain trap. If a
condensate pump is used, make sure it is approved
for acidic condensate.
10. Make sure the 5 unused inlets of the drain trap are
plugged with provided plastic caps.
9

11. Si une pompe a condensat doit être utilisée,
assurez-vous qu’elle soit compatible avec le
condensat acide.
3.2.2 Downflow multiposition pressure
switch connection
The 3/16" stub just beside the drain of the condensate
box must be drilled or cut open. Use the supplied black
squared PVC tubing to connect the pressure switch (-0.2
in. w.c.) to this stub. (see figure 5)
The pressure switch must also be electrically connected
in series with the low fire pressure switch (top) using the
brown jumper provided in the parts bag. Refer to figure 4
for more details.
Figure 4 – Downflow position pressure switch
assembly
Figure 5 – Connecting pressure switch in downflow
position
3.3 HORIZONTAL RIGHT
Figure 6 – Horizontal right position
Figure 7 – Horizontal right slope
When installing the furnace in horizontal right position,
make sure the furnace is tilted foward to make it drain
properly. Refer to figure 7.
Plan your installation and make sure you have sufficient
space for the drain trap and exhaust pipe drainage. Drain
trap will add approximately 6.50" to the furnace width.
Refer to figure 6.
3.3.1 Horizontal right condensate drain
trap connection
REFER TO FIGURE 6 FOR INSTALLATION DETAILS
1. Remove all condensate tubings from the inducer
blower and vent collector. Block the openings with
provided 5/8" and 1/2" black caps.
2. Remove the horizontal right drain trap knock-out.
10

3. Place the gasket on the drain trap.
4. Screw the drain trap in place with 2 self-tapping
screws to the side of the furnace.
5. Install two 1/2” black caps on the unused inlets of
the drain trap inside the furnace.
6. Connect a small length of 5/8" condensate tubing
to the condensate box and route with an elbow to
the drain trap. Make sure it can drain properly.
7. Connect the outlet of the drain trap to the
condensate drain piping with a tee. DO NOT
vent using the remaining 3 inlets. If a condensate
pump is used, make sure it is approved for acidic
condensate.
8. Prime the drain trap with water. This will ensure
proper furnace drainage at startup and will avoid
any recirculation of flue gas.
9. On the remaining 5 inlets, connect black caps
(1x5/8" and 2x1/2"). These caps are provided in
the parts bag.
3.3.2 Horizontal right multiposition
pressure switch connection
Figure 8 – Horizontal right pressure switch
connection
Figure 9 – Horizontal right pressure switch tubing
The 3/16" stub just beside the drain of the condensate
box must be drilled or cut open. The black squared PVC
tubing must connect the pressure switch (-0.2 in w.c.)
to this stub. This tubing is provided with the furnace.
Refer to figure 6 to see which port is associated to the
horizontal right position.
The pressure switch must also be electrically connected
in series with the low fire pressure switch (top) using
the brown jumper provided in the parts bag. Refer to
figure8 (Horizontal right pressure switch connection) for
more details.
3.4 HORIZONTAL LEFT
Figure 10 – Horizontal left position
11

3.4.1 Horizontal left condensate drain trap
connection
REFER TO FIGURE 10 FOR INSTALLATION DETAILS.
1. Remove all tubing from the ID blower, condensate
box and vent collector and block the stub openings
with furnished 5/8” and 1/2” black caps.
2. Remove the oblong knock-out from the bottom
middle side of the casing. (An alternate knock-
out is available on the furnace top panel if space
is constraint)
3. Place gasket on the drain trap.
4. Screw in place the drain trap with 2 self-tapping
screws to the side of the furnace. The drain trap
must be vertical.
5. Drill open the new bottom stub of the ID blower (if
not already open). Be sure to remove all debris.
6. Reroute the ID blower drain tube from the bottom
of the ID blower casing to one of the 1/2” stub of
the drain trap. Cut the provided 1/2" tubing at the
appropriate length to reach the drain trap.
7. Reroute the condensate box drain tubing from the
bottom of the condensate box to the 5/8” stub of
the drain trap. Cut the provided 5/8" tubing at
appropriate length to reach the drain trap.
8. Reroute the vent collector drain tube to one of the
1/2” stubs of the drain trap. Cut the provided 1/2"
tubing at the appropriate length to reach the drain
trap.
9. Connect the outlet from the drain trap to the
condensate drain piping using a ½” PVC tee. If a
condensate pump is used, make sure it is approved
for acidic condensate.
10. Prime the drain trap with water. This will ensure
proper furnace drainage at startup and will avoid
any recirculation of flue gas.
11. On the remaining 3 outlet stub, connect caps
(1x5/8” and 2x1/2”). These caps are provided in
the parts bag.
3.4.2 Alternate drain trap location in
horizontal left position
Figure 11 – Drain trap alternate position
3.4.3 Horizontal left multiposition
pressure switch connection
Figure 12 – Horizontal left pressure switch
connection
The 3/16" stub just beside the drain of the condensate
box must be drilled or cut open. Use the supplied black
squared PVC tubing to connect the pressure switch (-0.2
in. w.c.) to this stub. (see figure 10)
The pressure switch must also be electrically connected
12

in series with the low fire pressure switch (top) using the
brown jumper furnished in the parts bag. Refer to figure
12 for more details.
3.5 MULTIPOSITION VENTING
DRAINAGE
All furnaces with horizontal exhaust vent piping must
have drain tee assembly and trap installed in the exhaust
pipe as close to the furnace as possible. See Figures 3,
6 and 10.
4 DUCT INSTALLATION
4.1 GENERAL REQUIREMENTS
The duct system should be designed and sized according
to accepted national standards such as those published
by: Air Conditioning Contractors Association (ACCA),
Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) or American Society of Heating,
Refrigerating and Air Conditioning Engineers (ASHRAE).
Consult The Air Systems Design Guidelines reference
tables available at your local distributor.
The duct system should be sized to handle the required
system design aiflow at the design external static
pressure. When a furnace is installed so that the supply
ducts carry air circulated by the furnace to areas outside
the space containing the furnace, the return air shall also
be handled by duct(s) sealed to the furnace casing and
terminating outside the space containing the furnace.
This furnace may be installed, with a two pipe sealed
combustion configuration (direct vent), in a space utilized
as part of the return air supply. A filter must be installed
in the return opening of the furnace and a grill should be
installed in the space to allow proper circulation of air.
Secure ductwork with proper fasteners for type of
ductwork used. Seal supply and return duct connections
to the furnace with code approved tape or duct sealer.
Ductwork passing through an unconditioned space
should be insulated to enhance system performance.
When air conditioning is used, a vapour barrier is
recommended.
Maintain a 1 in. (25 mm) clearance from combustible
materials to supply air ductwork for a distance of 36 in.
(914 mm) horizontally from the furnace. See NFPA 90B
or local code for further requirements.
Flexible connections can be used between ductwork and
furnace to prevent transmission of vibration.
Many states, provinces and localities are considering
or have implemented standards and/or restrictions on
duct sizing practices, ductwork leakage, and/or ductwork
thermal, airflow and electrical efficiencies. CONSULT
LOCAL CODE OFFICIALS for ductwork design and
performance requirement in your area.
4.2 DUCT EXTERNAL STATIC
PRESSURE
Higher than prescripted static pressure will decrease the
air flow, causing excessive temperature rise, opening of
the thermodisk, failure of the heat exchanger and / or
poor performance of the heat pump / air conditioning.
To measure total external static pressure, proceed as
follow:
1. Run the furnace at the system maximum airflow
2. Return duct : Make sure the furnace filter is clean
and measure the static pressure between the filter
and the inlet of the furnace (negative pressure
reading)
3. Supply duct : Measure the static pressure between
the furnace and the cooling coil (positive static
pressure). Tape up the hole when test is complete.
4. Substract the inlet pressure from the supply
pressure. For exemple, if you measured 0.3"w.c.
in the supply and -0.2" in the return:
0.3"w.c. - (-0.2"w.c.) = 0.5"w.c.
If the total external static pressure exceeds the maximum
listed on the furnace rating plate, check for closed
dampers, register, unproperly size duct work or incorrect
dipswitch settings. Make sure the temperature rise is
coherent with the furnace rating plate.
4.3 RETURN AIR CONNECTIONS
The return air duct must be connected to the bottom, left
side or right side. If necessary (depending on your filter
restriction), provision should be made for a double return.
In downflow configuration, side return air is not permitted,
it must be connected to bottom.
Connection to the back of the furnace is prohibited.
Static pressure in the return air duct should be -0.2"w.c.
at system maximum airflow.
To avoid high noise level from the return side of the unit,
return duct shall have at least two 90° elbows and 10 ft
of straight duct.
4.3.1 Bottom return
Cut a rectangular opening on the bottom plate of the
furnace using the knock-outs.
In Upflow orientation when using the bottom inlet, return
air base can be used. This base allows the connection
of the duct on the side with a bottom inlet. See tables
29, 30 and 31 for the part number corresponding to your
furnace.
13

4.3.2 Side return
Remove 4 knock-outs on the side of the furnace of the
8 knock-outs available. Use table 3 for suggested return
size. Install the return air inlet as per local codes.
Table 3 – Suggested Filter size
Model Filter size
15kBTU 16.00 x 20.00"
30kBTU 16.00 x 20.00"
45kBTU 16.00 x 20.00"
60kBTU 16.00 x 25.00"
75 kBTU 16.00 x 25.00"
105 kBTU 16.00 x 25.00"
120 kBTU 16.00 x 25.00"
4.4 SUPPLY AIR DUCTS
The supply air duct must be connected to the furnace
supply outlet air duct flanges. DO NOT cut furnace
casing to attach supply air duct, humidifier, or other
accessories. All accessories must be connected to the
supply or return ductwork, external to furnace’s casing.
It is recommend that the outlet duct be provided with
a removable access panel. This opening shall be
accessible when the furnace is installed and shall be
sized to allow the heat exchanger to be viewed or a probe
to be inserted for sampling the air stream. The cover
attachement should prevent leaks.
4.4.1 Ductwork acoutiscal treatment
Metal duct systems that do not have a 90 degree elbow
and 10 ft. (3 M) of main duct to the first branch
take-off may require internal acoustical lining. As an
alternative, fibrous ductwork may be used if constructed
and installed in accordance with the latest edition of
SMACNA construction standard on fibrous glass ducts.
Both acoustical lining and fibrous ductwork shall comply
with NFPA 90B as tested by UL Standard 181 for Class 1
Rigid air ducts.
5 GAS SUPPLY AND PIPING
5.1 GENERAL
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnigns exactly could
result in serious injury, death or property damage.
Never test for gas leaks with an open flame.
Use a commercially available soap solution made
specifically for the detection of leaks to check
all connections. A fire or explosion may result
causing property damage, personal injury or loss
of life.
Gas piping must be installed in accordance with national
and local codes. Refer to current edition of NFGC in the
U.S.A.
Refer to current edition of CAN/CSA B149.1 in Canada.
Installations must be made in accordance with all
authorities having jurisdiction.
Use a back-up wrench on the inlet of the gas valve when
connecting the gas line to the gas valve.
Report to Table 6 for recommended gas pipe sizing.
Support all gas piping with appropriate straps and
hangers. Use a minimum of 1 hanger every 6 ft (1.8 m).
Joint compound (pipe dope) should be applied sparingly
and only to male threads of joints. Pipe dope must be
resistant to the action of propane gas.
An accessible manual equipment shut off valve MUST
be installed external to furnace casing.
Install a sediment trap in riser leading to furnace as
shown in Figure 16 Typical gas pipe arrangement.
Connect a capped nipple into lower end of tee. Capped
nipple should extend below level of furnace gas controls.
Install a union between the manual shut off gas and the
gas valve in order to remove it easily.
Piping should be pressure and leak tested in accordance
with the current edition of the NFGC in the United States,
local, and national plumbing and gas codes before the
furnace has been connected. Refer to current edition of
NSCNGPIC in Canada.
The gas supply pressure shall be within the maximum
and minimum inlet supply pressures marked on the rating
plate and in Table 4.
The furnace gas valve inlet pressure tap connection is
suitable to use as test gauge connexion providing test
pressure.
5.2 PROPANE CONVERSION
To convert from natural to L.P. gas, installer should use
the appropriate conversion kit. Please refer to parts lists
in this manual.
Make sure the inlet gas pressure is as indicated in table
4.
The conversion kit consist of orifices, spring and stickers
to clearly identify conversion on the gas valve.
5.3 GAS PIPE GROMMET
For direct vent applications, the hole for the gas pipe on
the cabinet must be sealed to prevent air leakage. Install
the grommet in the hole, then insert the gas pipe.
5.4 SETTING GAS OUTLET
PRESSURE
NOTE : These furnace are high altitude certified,
elevations under 4500 ft doesn’t require orifice
change.
14

5.4.1 Adjusting 2 stage gas valve
To make sure the furnace operates to the correct input
refer to furnace rating plate or to table 5, follow those
steps to properly adjust the outlet gas pressure:
1. Turn off all electrical power to the system.
2. Back outlet pressure test screw out one turn
counterclockwise. (See outlet pressure boss on
figure 14)
3. Attach a hose and manometer to the oulet pressure
boss of the valve.
4. Turn on system power and make a call for first stage
heat on the thermostat.
5. Remove both regulator cover screw and adjust
low fire regulator (see figure 14 and figure 15).
Adjust screw clockwise to increase pressure or
counterclockwise to decrease pressure. Always
adjust regulator to provide the correct pressure, as
mentionned on rating plate (approx. 1.55 in w.c.).
6. Turn on system power and make a call for second
stage heat on the thermostat.
7. Turn high fire regulator adjust screw (see figure 14)
clockwise to increase pressure or counterclockwise
to decrease pressure. Always adjust regulator to
provide the correct pressure, as mentionned on
rating plate (approx. 3.0 in w.c.).
8. Replace regulators cover screws and tighten
securely.
9. Turn off all electrical power to the system.
10. Remove manometer hose from outlet pressure
boss.
11. Turn outlet pressure test screw in to seal pressure
port (clockwise, 7in-lb minimum)
12. Turn on electrical power to the system.
13. Make a call for heat on the thermostat.
14. Using a leak detection solution or soap suds, check
for leaks at the pressure boss screw. If a leak is
detected, SHUT OFF GAS AND FIX ALL LEAKS
IMMEDIATELY.
5.4.2 Adjusting single stage gas valve
To make sure the furnace operates to the correct input,
follow those steps to properly adjust the outlet gas
pressure:
1. Turn off all electrical power to the system.
2. Back outlet pressure test screw out one turn
counterclockwise.(See outlet pressure boss on
figure 13)
3. Attach a hose and manometer to the oulet pressure
boss of the valve.
4. Turn on system power and make a call for heat on
the thermostat.
5. Remove regulator cover screw and turn regulator
adjust screw clockwise to increase pressure or
counterclockwise to decrease pressure. (see figure
13 and figure 15) Always adjust regulator to provide
the correct pressure, as mentionned on rating plate
(approx. 3.0 in w.c.).
6. Replace regulator cover screw and tighten
securely.
7. Turn off all electrical power to the system.
8. Remove manometer hose from outlet pressure
boss.
9. Turn outlet pressure test screw in to seal pressure
port (clockwise, 7in-lb minimum)
10. Turn on electrical power to the system.
11. Turn on system power and make a call for heat on
the thermostat.
12. Using a leak detection solution or soap suds, check
for leaks at the pressure boss screw. If a leak is
detected, SHUT OFF GAS AND FIX ALL LEAKS
IMMEDIATELY.
Figure 13 – Single stage gas valve
15

Figure 14 – Two stage gas valve
Figure 15 – Adjustment screw
Table 4 – Inlet gas pressure
Gas Pressure in w.c. (psig) Natural gas Propane
Maximum 10.5 (0.38) 13.0 (0.47)
Minimum 4.5 (0.16) 11.0 (0.40)
Table 5 – Outlet gas pressure
Gas Pressure in w.c. Natural Gas Propane
High fire (100%) 3.0 8.6
Low fire (70%) 1.55 5.0
Figure 16 – Typical gas pipe arrangement
Table 6 – Maximum capacity of pipe Cu.ft./Hr for pipe length ft (m)
Nominal Iron pipe size in. (mm) Internal dia. in. (mm) 10 (3.0) 20 (6.0) 30 (9.1) 40 (12.1) 50 (15.2)
1/2 (13) 0.622 (158) 175 120 97 82 73
3/4(19) 0.824 (20.9) 360 250 200 170 151
1 (25) 1.049 (26.6) 680 465 375 320 285
1-1/4 (32) 1.380 (35.0) 1400 950 770 660 580
1-1/2 (39) 1.610 (40.9) 2100 1460 1180 990 900
16

6 ELECTRICAL CONNECTIONS
WARNING
FIRE HAZARD
Failure to follow this warning could result in
personal injury, death, or property damage.
Do not connect aluminium wire between
disconnect switch and furnace. Use only copper
wire.
Check all factory and field electrical connections for
tightness.
Supplied field wiring shall conform to the limitations of
63°F (33°C) rise.
6.1 120V WIRING
Furnace must have a 120 V power supply properly
connected and grounded.
NOTE: Proper polarity must be maintained for 120 V
wiring. If polarity is incorrect, control LED status indicator
light will flash rapidly and furnace will NOT operate.
Verify that the voltage, frequency, and phase correspond
to that specified on unit rating plate. Also, check to be
sure that service provided by utility is sufficient to handle
load imposed by this equipment. Refer to rating plate or
Table 27 for equipment electrical specifications.
U.S.A. Installations:
Make all electrical connections in accordance with the
current edition of the National Electrical Code (NEC)
ANSI/NFPA 70 and any local codes or ordinances that
might apply.
Canada Installations:
Make all electrical connections in accordance with the
current edition of the Canadian Electrical Code CSA
C22.1 and any local codes or ordinances that might
apply.
Use a separate, fused branch electrical circuit with a
properly sized fuse or circuit breaker for this furnace.
See Table 27 for fuse specifications. A readily accessible
means of electrical disconnect must be located within
sight of the furnace.
6.2 24V WIRING
Make field 24 V connections at the 24 V terminal strip.
Connect terminal Y/Y2 for proper cooling operation. Use
only AWG No. 18, color-coded, copper thermostat wire.
Use AWG No. 18 color coded copper thermostat wire for
lengths up to 100ft. (30.5m). For wire lengths over 100
ft., use AWG No 16 wire.
6.3 FUSE
The 24 V circuit contains an automotive type, 3-amp
fuse located on the control. Any direct shorts during
installation, service, or maintenance could cause this
fuse to blow. If fuse replacement is required, use ONLY
a 3 amp.
6.4 THERMOSTATS
A single stage or two stage thermostat may be used
with the furnace. Consult the thermostat installation
instructions for specific information about configuring the
thermostat.
6.5 ELECTRIC DIAGRAMS
For CXX-1-D models, refer to figure 32.
For CXX-2-D models, refer to figure 33.
For CXX-1-X models, refer to figure 34.
6.6 ALTERNATE POWER SUPPLY
Dettson doesn’t recommend to operate the furnace on a
generator or other alternate power supply. If so it must
produce a smooth sinusoidal waveform for compatibility
with the furnace electronics. The alternate power supply
must generate the same voltage, phase, and frequency
(Hz) as shown on the furnace rating plate.
Power from an alternate power supply that is non-
sinusoidal may damage the furnace electronics or cause
erratic operation.
Contact the alternate power supply manufacturer for
specifications and details.
7 VENTING AND COMBUSTION
AIR PIPING
WARNING
CARBON-MONOXIDE POISONING HAZARD
Failure to follow instructions could result in severe
personal injury or death due to carbon-monoxide
poisoning, if combustion products infiltrate into
the building.
Check that all openings in the outside wall around
the vent (and air intake) pipe(s) are sealed to
prevent infiltration of combustion products into
the building.
Check that furnace vent (and air intake) terminals
are not obstructed in any way, regardeless of
outdoor conditions.
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WARNING
Corrosive or contaminated air may cause failure
of parts containing flue gas, which could leak into
the living space. Air for combustion must not
be contaminated by halogen compounds, which
include fluoride, chloride, bromide and iodide.
These elements can corrode the heat exchanger
and burner cabinet component. This conditions
would shorten the furnace life. Air contaminants
are found in aerosol sprays, detergents, bleaches,
cleaning solvents, salts, air fresheners, and other
household products. Do not install the furnace
in a corrosive or contaminated atmosphere.
Make sure all combustion and circulating air
requirements are met, in addition to all local codes
and ordinances.
7.1 GENERAL
These furnaces are certified as either direct vent (two
pipe) or non-direct vent (single pipe).
If this furnace replaces a furnace that was connected to
a vent system or chimney, the vent may need to be re-
sized.
An abandoned masonry chimney may be used as a
raceway for properly insulated and supported combustion
air (when applicable) and vent pipes. If more than
one furnace is installed, they must have their own set
of combustion air and vent pipes and be terminated
individually. Other gas appliances with their own venting
system may also use the abandoned chimney as a
raceway providing it is permitted by local code, the
current edition of the National Fuel Gas Code and the
vent or liner manufacturer’s installation instructions. Care
must be taken to prevent the exhaust gases of one
appliance from contaminating the combustion air of other
gas appliances. Do not take combustion air from inside
the chimney when using ventilated combustion air or
single pipe vent option.
For Canadian Installations, field supplied PVC venting
materials must be UL S636 listed. This requirement does
not apply to the combustion air pipe.
Below are important information that needs to be
considered when installing the venting system:
• The vent pipe and combustion air pipe must of be
the same diameter.
• Slope horizontal vent piping upward a minimum
of 1/4" per foot of run so that condensate drains
toward the furnace.
• Support horizontal vent piping at least every five
feet. No sags or dips are permitted.
• The vent pipe and combustion air pipe must
terminate on the same building side.
• Provide the space with sufficient air for proper
combustion using permanent pipe (direct-vent)
or opening(s) directly communicating with the
outdoors (non directe vent).
• Insulate all vent runs through unconditioned
spaces where below-freezing temperatures are
expected with 1" thick medium-density, foil-faced
fiberglass. (In Canada, per the vent manufacturer’s
instructions)
• For runs where condensate could accumulate and
freeze (including vent termination), wrap the vent
pipe with self-regulating 5 Watt heat tape. The heat
tape must be U.L./CSA. listed and installed per the
manufacturer’s instructions.
• The combustion air and exhaust terminations must
be at least 12” above grade/expected level of snow.
• Ensure the location of the combustion air inlet with
respect to the exhaust vent terminal complies with
Figure 28 and local codes.
7.2 DIRECT VENT
When this furnace is installed as a direct vent (2 pipes)
furnace, no special provisions for combustion air are
required.
Direct vent installations require a dedicated combustion
air and exhaust vent piping. The system is only using
outside air for combution.
The vent and combustion air pipe can terminate vertically,
through the roof or horizontaly through and outside wall.
Refer to figures for approved termination.
Penetration throught a roof requires appropriate sealing
and proper flashing.
In Canada, refer to manufacturer’s instructions for
supporting ULC S636 venting. ABS can be used for the
combustion air pipe.
7.3 NON DIRECT VENT
All air for combustion comes directly to the furnace from a
space that is well ventilated with outdoor air (such as an
attic or crawlspace). In addition, other gas appliances
installed in the space with the furnace may require
outside air for combustion. The combustion air pipe
cannot be terminated in attics or crawlspaces that uses
ventilation fans designed to operate during the heating
season. If ventilation fans are present in these areas, the
combustion pipe must terminate outdoors as a direct vent
(2 pipe) system.
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7.4 SPECIAL VENTING
REQUIREMENTS FOR
INSTALLATION IN CANADA
In Canada, S636 certified primers and cements must
be used and be of the same manufacturer of the S636
venting system. Do not mix primers and cements from
one manufacturer with a vent system from a different
manufacturer. Follow the manufacturer’s instructions for
the use of primer and cement and never use primer or
cement beyond its expiration date.
All fire stop and roof flashing used with this system must
be UL listed material.
Acceptability under Canadian standard CAN/CSA B149
requires full compliance with all installation instructions.
The authority having jurisdiction (gas inspection
authority, municipal building department, fire department,
etc.) should be consulted before installation to determine
the need to obtain a permit.
7.5 MATERIAL
USA:
Combustion air and vent pipe, fittings, primers and
solvents must conform to American National Standard
Institute (ANSI) and American Society for Testing and
Material (ASTM) and be of the same manufacturer. See
table 7
Table 7 – Approved Vent and Combustion air pipe
material USA installation
Material Standards
PVC - DWV ANSI/ASTM D2265
PVC schedule 40 ANSI/ASTM D1785
CPVC Schedule 40 ANSI/ASTM F441
SDR-21, SDR-26-26 PVC ANSI/ASTM D2241
ABS-DWV Schedule 40 ANSI/ASTM D2661
Stainless steel (SS) UL-1738
Polypropylene (PP) UL-1738 and ULC-
S636
All vent piping and combustion air piping MUST
conform to local and national codes.
Pipe cement must be PVC (ANSI/ASTM D2564) or
CPVC (ANSI/ASTM F493).
Primers must be PVC/CPVC (ANSI/ASTM F656).
CANADA:
Vent pipe installations in Canada must conform to
the requirements of CAN/CSA B149 code. PVC and
CPVC vent systems must be composed of pipe, fittings,
cements, and primers listed to ULC S636 and must be of
the same manufacturer.
Combustion air pipe can use ABS material meeting the
ASTM standard D2661 / CSA B181.1.
All vent piping and combustion air piping MUST conform
to local and national codes.
7.6 SIZE THE VENT AND
COMBUSTION AIR PIPES
Furnace combustion air and vent pipe connections are
sized for 2” pipe. Any pipe diameter change should be
made outside furnace casing in a vertical section of the
pipe. Any change in diameter to the pipe must be made
as close to the furnace as reasonably possible.
The maximum allowable vent length for the vent and
combustion air pipe (when used) is listed in table 8 and
depends on the furnace input. The maximum length
must include straight pipe and any fitting and termination.
Equivalent length of various fitting is list in table 9.
A minimum linear length of 5 ft must be respected.
To properly measure the Equivalent Vent Length :
1. Measure the linear pipe distance from the furnace
to the termination for each pipe.
2. Count the number of elbows for each pipe.
3. For each pipe, multiply the number of elbows by the
equivalent length for the type of elbow used (see
table 9). Record the equivalent length of all the
elbows for each pipe.
4. Record the equivalent length of the termination
used (see table 9 ).
5. Add the equivalent length of the elbows and
termination to the linear distance measured for
each pipe.
6. If the calculated vent length is greater than the
maximum allowed vent length (for either vent pipe
or combustion air pipe), consider modifying the
termination location or use a greater pipe diameter.
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