Thermo Pride GMD1-60N Manual

THERMO PRODUCTS, LLC.
POST OFFICE BOX 217
NORTH JUDSON, IN 46366
PHONE: [phone]
MG-505
ECN 5396-MA 141211 MADE IN USA
GAS-FIRED FURNACE
DOWN FLOW & DIRECT VENT (SEALED COMBUSTION)
MODELS: GMD1-60N and GMD1-80N
INSTALLATION AND SERVICE MANUAL
For installation in:
1. Manufactured Homes
2. Modular Homes/Buildings
3. Site Constructed—Residential (Single Story Dwellings)
:
FOR YOUR SAFETY
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.
• 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.
: If the information in these instructions is not followed exactly, a fire or explosion may
result causing property damage, personal injury, or loss of life.
:Improper installation, adjustment, alteration, service, or maintenance can cause
injury or property damage. Refer to this manual. For assistance or additional information, consult
a qualified installer, service agency, or fuel supplier.
: Do not use this appliance if any part has been underwater. Immediately call a
qualified service technician to inspect the appliance and to replace any part of the electrical or
control system that has been underwater.
PLEASE READ THESE INSTRUCTIONS PRIOR TO INSTALLATION, INITIAL FIRING, AND BEFORE
PERFORMING ANY SERVICE OR MAINTENANCE. THESE INSTRUCTIONS MUST BE LEFT WITH THE USER
AND SHOULD BE RETAINED FOR FUTURE REFERENCE BY QUALIFIED SERVICE PERSONNEL.

All installations and services must be performed by qualified service personnel.
1
I. SAFETY SECTION
This page and the following two pages contain various warnings and cautions
found throughout this furnace Service and Installation Manual. Please read and
comply with the statements on the cover and the statements below.
: This furnace is not to be used as a construction heater.
: When testing electrical equipment, always follow standard electrical
procedures and precautions.
:
The area around the furnace should be kept free and clear of
combustible materials, especially papers and rags.
:
This furnace uses an automatic hot surface ignition control. NEVER
try to ignite gas manually.
: If the temperature rise exceeds 85°F, the heat exchanger may fail
voiding the heat exchanger warranty resulting in property damage, personal
injury or loss of life.
: Burner adjustments must be confirmed by instrumentation. Failure to
use accurate or calibrated instrumentation to setup the burner may result in
reduced efficiency, sooting, and/or the production of hazardous carbon
monoxide gas.
: Any attempt to relocate safety controls or replace safety controls with
a control that is not approved or incompatible, may result in personal injury,
substantial property damage or death.
: If you do not follow these instructions exactly, a fire or explosion may
result causing personal injury, loss of life or property damage.
: HAZARD OF ASPHYXIATION: Negative pressure inside the closet with
closet door closed and the furnace blower operating shall be no more negative
than minus 0.05 inch water column.
: Do not obstruct any return air openings, including the return grille on
the furnace. To do so may cause the furnace to activate the high limit and shut
down or it may cause asphyxiation.
:
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.
: All gas pipe connections must be leak tested using a strong soap and
water solution (with the gas turned on). Any leaks must be repaired immediately

All installations and services must be performed by qualified service personnel.
2
after turning off the gas supply. A final test for gas leakage must be made after
purging the gas line.
:
DO NOT wet electronic components during the leak test. Wetting
electronic components may damage circuitry and cause a hazardous situation.
Dry moisture from all leads and terminals if wetting occurs. Wait at least 24
hours for the circuit to fully dry before energizing the system.
: The furnace and its gas valve must be disconnected from the gas
supply during pressure testing of the gas supply system at pressures in excess
of 1/2 PSIG or 14.0 inches W.G. The furnace can be isolated from the gas supply
by closing its manual shut off valve at test pressures equal to or less than 1/2
PSIG or 14.0 inches W.G.
:
Copper and brass tubing and fittings (except tin lined) shall not be
used if the gas contains more than a trace (0.3 grains per 100 cubic ft.) of
hydrogen sulfide gas. Check with your gas supplier.
:
If you suspect there is a problem with the furnace, the venting system
or any other related problem, immediately contact a qualified service agency. If a
service agency is not available, contact your fuel supplier.
: Personal injury, or property damage, could result from major repair or
service of this furnace by anyone other than a qualified contractor. Only the
routine maintenance described in the user section of this manual should be
performed by the user.
: Do not block or obstruct air openings on the furnace or air openings
communicating with the area in which the furnace is installed.
: Do not allow the outside air intake to be blocked or obstructed by
vegetation, ice, snow or any other materials.
: Do not use this furnace if any part has been underwater. Immediately
call a qualified service agency to inspect the furnace and to replace any part of
the electrical or control system, which has been underwater.
: Should overheating occur or the gas supply fail to shut off, shut off the
manual gas supply valve to the furnace before shutting off the electrical supply.

All installations and services must be performed by qualified service personnel.
3
This page and the following page contain reproductions of the various warning
and instruction labels placed on the Thermo Pride Gas Furnace. Please read and
comply with the contents of these labels.
WARNING: If you do not follow these instructions exactly, a
fire or explosion may result causing property damage,
personal injury or loss of life.
390540
1. Set thermostat to lowest setting, and, if equipped, set the operating
mode to "COOL" or "OFF".
2. If service is to be performed, turn off all electric power to the
appliance.
3. To turn off gas control valve, remove the burner compartment cover.
4. Move the gas control switch to the "OFF" position.
5. Replace the burner compartment cover.
1. STOP! Read the safety information above on this label.
2. Set the thermostat to the lowest setting.
3. Turn off all electric power to the appliance.
4. This appliance is equipped with a hot surface igniter that
automatically lights the burner. Do not try to light the burner by
hand.
5. Move the gas control switch to the "OFF" position.
6. Wait five (5) minutes to clear out any gas. Then smell for gas,
including near the floor or ground. If you smell gas, STOP! Follow
"B" in the safety information above on this label. If you don't smell
gas, go to the next step.
7. Move the gas control switch to the "ON" position.
8. Turn on all electric power to the appliance.
9. Set thermostat to desired setting, and, if equipped, set the operating
mode to "HEAT".
10.If appliance will not operate, follow the instructions "To Turn Off
Gas To Appliance" and call your service technician or gas supplier.
A. This appliance does not have a pilot. It is equipped with a hot
surface igniter that automatically lights the burner. Do not try to
light the burner by hand.
B. BEFORE OPERATING smell all around the appliance area for gas.
Be sure to smell next to the base of unit because some gas is
heavier than air and will settle on the floor or ground.
WHAT TO DO IF YOU SMELL GAS
? Do not try to light any appliance.
? Do not touch any electric switch; do not use any phone in your
building.
? Immediately call your gas supplier from a neighbor's phone.
Follow the gas supplier's instructions.
? If you cannot reach your gas supplier, call the fire department.
C. Use only your hand to move the gas control switch. Never use tools.
If the switch will not move by hand, don't try to repair it, call a
qualified service technician. Force or attempted repair may result in
a fire or explosion.
D. Do not use this appliance if any part has been underwater.
Immediately call a qualified service technician to inspect the
appliance and to replace any part of the control system and any gas
control which has been underwater.

All installations and services must be performed by qualified service personnel.
4

All installations and services must be performed by qualified service personnel.
5
TABLE OF CONTENTS
SECTION BEGINNING PAGE
I. SAFETY SECTION 1
II. GENERAL INSTRUCTIONS AND CLEARANCES 6
III. FURNACE SPECIFICATIONS 8
IV. INSTALLATION 10
A. ROOF JACK 10
B. STANDARD CHIMNEY 10
C. FURNACE LOCATION 10
D. BASE INSTALLATION 12
1. Combustible Floor Base Model: 70-BASE 12
2. Cottage Base Model: 01COT-BASE 13
E. ALCOVE INSTALLATION 14
F. CLOSET INSTALLATION 15
G. COMBUSTION AIR 16
H. GAS PIPING 18
I. ELECTRICAL WIRING 19
J. INITIAL START UP 21
K. ADJUSTMENT OF BTU INPUT RATE 21
L. BURNER ADJUSTMENT 23
M. SETTING TEMPERATURE RISE 24
N. FURNACE CHECKOUT PROCEDURE 25
V. INSTALLER’S INSTRUCTIONS TO USER 26
VI. STARTING THE UNIT 27
A. SEQUENCE OF OPERATIONS 27
VII. TROUBLESHOOTING 29
VIII. DEALER MAINTENANCE 35
A. ELECTRICAL 35
B. BURNERS 35
C. INDUCER BLOWER ASSEMBLY 36
D. INSPECTING THE VENTING SYSTEM 36
E. GASKETS/SEALING MATERIALS 37
F. HEAT EXCHANGER 37
G. HOUSE AIR BLOWER 37
H. EXTENDED SHUTDOWN 37
IX. USERS INFORMATION SECTION 38
A. WARNINGS & CAUTIONS 38
B. COMPONENT LOCATIONS 39
C. INSPECTION AREAS 39
D. FILTER LOCATION AND CLEANING 40
APPENDIX A – REPLACEMENT PARTS 41
APPENDIX B – WIRING DIAGRAM 43

All installations and services must be performed by qualified service personnel.
6
II. GENERAL INSTRUCTIONS AND CLEARANCES
NOTE: READ THIS SECTION BEFORE STARTING INSTALLATION
1. This furnace is equipped with orifices for operation with natural gas. For
conversion to propane gas, see instructions in Gas Conversion Section of this
manual.
2. Any reference to L.P. or Propane gas in this manual, any other labels, or
markings on this furnace is to be construed to be propane HD-5. A commercial
grade of liquefied petroleum gases composed of a minimum of 90 percent liquid
propane (C8H8).
3. The selection of a furnace heating capacity for a proposed installation should be
based on a heat loss calculation made according to the manuals provided by the
Air Conditioning Contractors of America (ACCA) or the American Society of
Heating, Refrigeration and Air Conditioning Engineers, Inc. (ASHRAE).
4. It is recommended that a commercial available CO alarm be installed in
conjunction with any fossil fuel burning appliance. The CO alarm shall be
installed according to the alarm manufacturer’s installation instructions and be
listed in accordance with the latest edition of the UL Standard for Single and
Multiple Station Carbon Monoxide Alarms, UL 2034, or the CSA International
Standard, Residential Carbon Monoxide Alarming Devises, CSA 6.19.
5. The installer shall be familiar with and comply with all codes and regulations
applicable to the installation of these heating appliances and related equipment.
In lieu of local codes, the installation shall be in accordance with the current
provisions of one or more of the following standards.
a. Federal Manufactured Home Constructions & Safety Standard (HUD Total 24,
Part 280).
b. American National Standard (ANSI-119.2/NFPA-501C), for installations of all
recreational vehicles.
c. American National Standard (ANSI-Z223.1/NFPA-54), for installation of all gas-
fired furnaces.
d. American National Standard Electric Code (ANSI-C1/NFPA-70), for installation of
all electrical field wiring.
The gas-fired furnace has been investigated under the ANSI Z 21.47-CAN/CGA 22.3-
2001 CENTRAL FURNACE test standard. This gas fired unit is listed by Intertek
Testing Services and described as, “For installation as central furnace special type for
single story dwelling.”

All installations and services must be performed by qualified service personnel.
7
: The area around the furnace must be kept free and clear of
combustible materials, especially papers and rags.
:
This furnace is not to be used as a construction heater.
6. Definitions of "combustible" and "non-combustible" materials as presented in the
1999 version of the National Fuel Gas Code, ANSI Z223.1-1999/NFPA 70-1999, are
as follows:
a. Combustible material:
“...materials made of or surfaced with wood, compressed
paper, plant fibers, or other materials that are capable of
being ignited and burned. Such material shall be
considered combustible even though flame proofed, fire-
retardant treated, or plastered.”
b. Non-combustible material:
“...material that is not capable of being ignited and
burned; such as material consisting entirely of, or a
combination of, steel, iron, brick, tiles, concrete,
slate, asbestos, glass, and plaster.”
This heating appliance must be installed with clearances to combustible material
surfaces of not less than the minimum distances given below. Also, allow ample
clearances for servicing the furnace for easy access to the air filter, blower assembly,
burner assembly, controls, and vent connections.
MODELS GMD1-60N and GMD1-80N CLOSET ALCOVE
FRONT
BACK
SIDES
ROOF JACK
VENT CONNECTOR
TOP
PLENUM SIDES
TOP AND SIDES OF DUCT
BOTTOM OF DUCT
6”
0”
0”
0”
6”
1”
1”
1”
1”
18”
0”
0”
0”
6”
1”
1”
1”
1”

All installations and services must be performed by qualified service personnel.
8
III. FURNACE SPECIFICATIONS
MODEL GMD1-60 GMD1-80
HEAT INPUT RATE (BTUH) 60,000 80,000
HEATING CAPACITY (BTUH) 49,000 65,000
BURNER ORIFICE-NAT. GAS (MM) #38 2.45
BURNER ORIFICE-PROP. GAS (DMS) #52 #53
GAS SUPPLY PRESSURE (IN.W.G.)
MINIMUM REQUIRED
PROPANE 11 11
NATURAL 5.5 5.5
MAXIMUM ALLOWED
PROPANE 14.0 14.0
NATURAL 14.0 14.0
GAS MANIFOLD PRESSURE (IN. W.G.)
PROPANE 10 + 0.3 10 + 0.3
NATURAL 3.5 + 0.3 3.5 + 0.3
VENT PIPE SIZE (INCHES) 4 4
DESIGN TEMPERATURE RISE (°F) 70 70
SEASONAL EFFICIENCY
(AFUE*, %) 82 81
*AFUE - INCLUDES STEADY STATE THERMAL EFFICIENCY AND OFF CYCLE
LOSSES.
ELECTRICAL RATINGS AND SETTINGS:
ELECTRICAL SUPPLY: 115 VAC / 60HZ / 1 PHASE
MAXIMUM TIME DELAY TYPE FUSE OR HACR BREAKER RATING: 15 AMPS
TOTAL RATED CURRENT (AMPS): 7.15 (GMD1)
NOMINAL HEAT ANTICIPATOR SETTING -- 0.8 mA (GMD1)
DIMENSIONS & WEIGHTS:
CABINET: WIDTH - 18 IN., DEPTH – 25-3/4 IN., HEIGHT - 57 IN.
NO.70 MOBILE HOME BASE: WIDTH - 18-5/16 IN., DEPTH - 24¼ IN., HEIGHT - 4 IN.
WARM AIR DUCT: WIDTH – 12 IN., DEPTH – 12 IN.
COTTAGE BASE: WIDTH – 18-3/16 IN., DEPTH - 24¼ IN., HEIGHT – 14 IN.
FILTER QUANTITY & SIZE: 1 – 18” x 24 “
APPROXIMATE SHIPPING WEIGHT: 165 LBS.
PRODUCT LISTED UNDER ETL FILE NUMBER –

All installations and services must be performed by qualified service personnel.
9
BLOWER DATA
GMD1-60
MANUFACTURER: MORRISON PRODUCTS, INC.
BLOWER MODEL: 10-7, DIRECT DRIVE
NOMINAL MOTOR POWER OUTPUT (HORSEPOWER): 1/3
TYPICAL AIRFLOW @ SPECIFIED EXTERNAL
STATIC PRESSURES (SCFM @. IN.W.G.):
ESP (IN W.C.) 0.2 0.5
LOW SPEED: 759 694
MEDIUM LOW
SPEED: 907 809
MEDIUM HIGH
SPEED: 1096 934
HIGH SPEED: 1207 1029
GMD1-80
MANUFACTURER: MORRISON PRODUCTS, INC.
BLOWER MODEL: 10-9, DIRECT DRIVE
NOMINAL MOTOR POWER OUTPUT (HORSEPOWER): 1/3
TYPICAL AIRFLOW @ SPECIFIED EXTERNAL
STATIC PRESSURES (SCFM @. IN.W.G.):
ESP (IN W.C.) 0.2 0.5
LOW SPEED: 712 640
MEDIUM LOW
SPEED: 870 760
MEDIUM HIGH
SPEED: 1100 886
HIGH SPEED: 1258 1003
ALL SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE.

All installations and services must be performed by qualified service personnel.
10
IV. INSTALLATION
A. ROOF JACK
The roof jack assembly and accessories must be listed by a nationally recognized
testing agency for the appropriate heating fuel.
The roof jack assembly must be installed according to the vent manufacturer’s
instructions prior to the furnace installation. (Refer to Figure 2 for flue location on
furnace.) Adapters for pitched roofs as well as extended barrel length roof jacks are
available from other suppliers.
All vent seams and connections must be sealed with high temperature silicone caulk.
B. STANDARD CHIMNEY
When installed as a central furnace special type for single story dwelling, venting into a
metal vent system approved by a nationally recognized testing agency for the
appropriate heating fuel type is permitted. Lined masonry chimneys are acceptable
when sized appropriately. The minimum chimney size should equivalent to the inside
free area of the 4-inch diameter vent collar exiting the furnace, or 12.5 square inches.
Maximum chimney sizes and acceptable installation practices are referenced in the
following publication. When installing the GMD1-80N, refer to Appendix G of the latest
edition of the installation standard NFPA 54, National Fuel Gas Code.
C. FURNACE LOCATION
1. For best performance, locate the furnace so that it is centralized with respect to the
duct system.
2. This furnace is only intended for installation with free air return through the furnace
door louvers. c CAUTION: DO NOT connect a ducted return air system directly to
the furnace. Improper installation may create a fire hazard and damage internal
equipment, as well as void all manufacturers’ warranties.
3. This furnace may be installed on combustible flooring when utilizing either the No. 70
counterflow floor base, for below the floor duct systems, or with the cottage base, for
floor level air distribution. See Figures 1A and 1B for depictions of the No. 70 and
the cottage bases.
4. This furnace is listed for closet, alcove, or freestanding applications. All applications
must comply with the requirements of this manual.

All installations and services must be performed by qualified service personnel.
11
Combustible Floor Base
Model: 70-BASE
Figure 1A
Cottage Base
Model: 01COT-BASE
Figure 1B
Coil Cabinet
Model: CE111S / CE211T
Figure 1C
CE111S CE211T

All installations and services must be performed by qualified service personnel.
12
D. BASE INSTALLATION
1. Combustible Floor Base Model: 70-BASE
Use the base bottom panel as a template to mark floor opening locations (see
Figure 2). Cut a square opening in the floor for the supply air connector duct. Cut the
opening 1-inch larger than the square template opening. (duct requires 1-inch
clearance to combustible floor). Cut a combustion air duct opening in the floor 1/8-
inch larger than the template opening.
Figure 2
After cutting openings in the floor, place the bottom panel in position. Mark the
square opening location on the distribution duct at the connection point of the
connector duct. Remove the bottom panel. Cut an opening in the distribution duct
slightly larger than the connector duct. (refer to Figure 2 for location of this cut.) Cut
the connector duct to length. Install the connector duct. Bend over each tab. Insure
an airtight seal by using high temperature sealant or tape on the joint. Reinstall the
bottom panel over the connector duct. Insert and secure the combustion air duct. Put
the base top assembly in place (see Figure-3).
c CAUTION: A combustion air duct must be used. If the underside of the mobile
home is skirted or enclosed (e.g. enclosed in a crawlspace), the combustion air
intake should exit through the skirting, or enclosure, if at all possible. All joints
and seams of supply ducts and combustion air ducts must be closed with a
sealing method suitable to the application conditions and temperatures (e.g. high
temperature silicone caulk and/or aluminum tape).

All installations and services must be performed by qualified service personnel.
13
If the combustion air passageway cannot terminate outside of the skirting or
enclosure, a permanent opening with a minimum of 50 square inches of
unobstructed infiltration (free area) for ventilation air must be provided for
adequate combustion. This permanent opening must be located no less than 12
inches from the bottom of the enclosure or skirting.
Figure 3
Slit the corners of connector duct down to the top of the base assembly. If metal
projects more than 1-inch above the top of the base assembly, trim the flanges down
to 1-inch. While the top of distribution duct is being pulled up with one hand, bend
down each side of the connector duct tightly to the base assembly with the other
hand. This assures a tight connection between the base assembly and the connector
duct and that the distribution duct will be full size. Use high temperature tape and/or
high temperature silicone caulking on all joints and seams to minimize air leakage.
Secure the base assembly to the floor with two screws in the front flange.
2. Cottage Base Model: O1COT-BASE
The O1COT-BASE cottage base (Figure 1B) is required for a freestanding cottage
base installation. The cottage base is designed to permit the installation of a 6-inch x
14-inch register in each of the two side panels and the front panel.

All installations and services must be performed by qualified service personnel.
14
c CAUTION: A permanent opening with a minimum of 50 square inches of
unobstructed infiltration (free area) for ventilation and combustion air must be
provided to the interior of the structure. Additional make-up air may need to be
supplied to the interior of the structure to compensate for exhaust fans,
appliances, or vents, which consume air from the interior of the structure.
Refer to the assembly installation instructions included with OM1COT-BASE cottage
base for additional information.
3. Coil Cabinet: CE111S / CE211T
The CE111S / CE211T coil cabinet (figure 1C) is for applications requiring air
conditioning. The coil cabinet is designed to have the combustion air brought in
from the bottom thru a flexible hose, supplied with the cabinet. Refer to section G
Combustion air of this manual for further instructions on the combustion air
termination and connections. For additional information refer instructions provided
with the coil cabinet.
E. ALCOVE INSTALLATION
In this application, a minimum of 18
inches of clearance must be provided
to the front of the unit. Refer to
Figure 4.
Alcove installations must use the No.
70 mobile home base.
Note – access to diagnostic view port.
Refer to section G. COMBUSTION AIR
for additional combustion air
requirements.
Figure 4

All installations and services must be performed by qualified service personnel.
15
F. CLOSET INSTALLATION
c WARNING: HAZARD OF
ASPHYXIATION: A suction
effect will occur when the
furnace is operating inside the
closet with the closet door
closed. For proper operation,
the furnace blower shall create
no more than a 0.05-inch water
column pressure differential
between the closet and the
adjoining space.
Figure 5
1. The return air opening into the closet is to have a minimum free area of 250 square
inches, (refer to Figure 5).
2. The return air opening may be located in the top, the center or (ideally) the bottom of
the closet door, or sidewall.
:
Do not obstruct any return air openings, including the return grille on
the furnace. To do so may cause the furnace to activate the high temperature
limit and shutdown, or it may cause asphyxiation.
3. The cross-sectional area of the return air grille leading into the closet (when located
in the floor or ceiling) shall not be less than 250 square inches.

All installations and services must be performed by qualified service personnel.
16
4. The total free area of openings in the floor or ceiling registers serving the return air
system must be at least 350 square inches. At least one register must be located
where it is not likely to be covered by carpeting, boxes, furniture, or any other
objects.
5. Materials located in the return air system must have a flame spread classification of
200 or less.
6. Wiring materials located in the return air duct system must conform to Article 300-22
of the latest edition of the National Electrical Code, NFPA 70.
7. Gas piping shall not be located in, or extend through, the return air duct system.
8. Refer to section G. COMBUSTION AIR for additional combustion air requirements.
G. COMBUSTION AIR
cCAUTION: Flexible, spiral, or corrugated duct is not recommended, due to the
relatively high-pressure drop associated with air movement through this type of
passageway.
The furnace requires the proper amount of combustion airflow through the combustion
air intake to combust the fuel cleanly and efficiently. An inadequate combustion air
supply can result in unsafe and erratic operation of the burner, sooting of the
combustion chamber and the heat exchanger, and possibly, offensive fuel odors. Refer
to chapter 5.3 of the National Fuel Gas Code, ANSI Z223.1 / NFPA 54-1999, or latest
edition for application specific combustion air requirements.
The preferred location of the outside combustion air intake terminal (e.g. an optional
stainless steel intake hood, part no. AOPS7402) is through the side of the structure,
skirting, or enclosure. An acceptable alternate location is under the structure in the
skirted or crawlspace area providing a minimum of 50 square inches of free area exists
around the perimeter for outside combustion air to be drawn through. The opening of
the termination must be at least 7 inches below the top of the floor.
The 70-base/coil cabinet is shipped with a combustion air duct that must be installed in
the bottom of the base enclosure, before the furnace is installed. This 2-inch by 7-inch
duct is shipped in two pieces. High temperature silicone sealant should be applied to
both vertical seams, before it is snapped together with all four flanges on the same end.
High temperature silicone must be applied to the flanges. The combustion air duct can
then be inserted through the opening in the floor base model no.70. When the
combustion air duct has been inserted completely, secure the duct to the combustion
adapter with self-tapping sheet metal screws, refer to Figure 6. Make certain that the
flanges, duct, and adapter are completely sealed to the burner enclosure base with high
temperature silicone caulk. A 3-inch round to 7-inch x 2-1/4 inch rectangular adapter

All installations and services must be performed by qualified service personnel.
17
plate is supplied with the furnace for adapting the 3-inch round flex combustion air duct
to the 2-inch x 7-inch combustion air duct.
Recommended materials for the combustion air duct are smooth, round, galvanized
steel duct or schedule 20 PVC pipe. The maximum intake duct length allowed is
equivalent to 40-feet of straight duct. Reduce this length by 6-feet for the intake hood
and each 90-degree elbow used, and by 3-feet for each 45-degree elbow used the
combustion air duct.
Optional combustion air - a 4” round duct may be used by connecting a 3 x 4 reducer
to the 3” flex duct supplied with the furnace.
Figure 6

All installations and services must be performed by qualified service personnel.
18
H. GAS PIPING
: Because of the potential of the odorant to 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.
: With the gas piping pressurized, all gas piping connections must be
leak tested using a strong soap and water solution. Any leaks must be repaired
immediately after turning off the gas supply. A final test for gas leakage must be
made after purging the gas line.
: DO NOT wet electronic components during the leak test. Wetting
electronic components may damage circuitry and cause a hazardous situation.
Dry moisture from all leads and terminals if wetting occurs. Wait at least 24
hours for the circuit to fully dry before energizing the system.
:
The furnace and its gas valve must be disconnected from the gas
supply during pressure testing of the gas supply system at pressures in excess
of 1/2 PSIG (13.9 inches W.G.). The furnace can be isolated from the gas supply
by closing the manual gas shutoff valve serving the appliance at test pressures
equal to, or less than, 1/2 PSIG or (13.9 inches W.G.).
: Copper and brass tubing and fittings (except tin lined) shall not be
used if the gas contains more than a trace (0.3 grains per 100 cubic ft.) of
hydrogen sulfide gas. Check with your gas supplier.
Sizing and installation of fuel lines must be in accordance with federal, state, and local
regulations.
A qualified installer or service person must install all gas piping and perform all required
testing.
Piping from the natural gas meter to the furnace shall be in accordance with
requirements of the local gas utility. Piping from the propane tank to the furnace must
follow the recommendations of the gas supplier. In the absence of local codes
governing gas piping selection and installation, follow the National Fuel Gas Code,
ANSI Z223.1 / NFPA 54-1999, or latest edition.
A readily accessible, manual gas shutoff valve (design-certified for the applicable gas)
with a non-displaceable rotor member shall be installed within six (6) feet of the
furnace.
A pipe union, or flanged connection, shall be provided directly up stream of the burner
to allow burner removal. Unions must be of a ground joint type or flange-jointed type
using a gasket resistant to the corrosive effects of LP gases. Pipe dope or sealant

All installations and services must be performed by qualified service personnel.
19
design-certified to be resistant to the action of the LP gases should be used on all
threaded joints.
The burner is setup to be piped to the gas supply through the left-hand side of the
furnace. For service purposes, it is recommended the gas union be located inside the
furnace.
A drip leg must be used on both propane and natural gas installations immediately
upstream of the furnace in order to trap oil, condensate, and other impurities which
might otherwise lodge in the gas valve, or plug the main burner orifice. A drip leg shall
be provided at the outlet of the gas meter when there is excessive condensation
between the gas meter and the furnace.
Failure to install drip leg(s) may void the manufacturer’s limited warranty on the furnace.
For natural gas, the maximum supply pressure is 14.0 in. W.G. and the minimum
supply pressure, for purposes of input adjustment, is 5.5 in. W.G.
For propane gas, the maximum supply pressure is 14.0 in. W.G. and the minimum
supply pressure, for purposes of input adjustment, is 11.0 in. W.G.
I. ELECTRICAL WIRING
:
When testing electrical equipment, always follow standard electrical
procedures and precautions.
All electrical wiring must be installed in strict accordance with local ordinances and
codes. In the absence of local ordinances and codes, all electrical wiring must conform
to the requirements of the National Electric Code, ANSI/NFPA 70-1999, or latest
edition.
1. Electrical Branch Supply Circuit
Route all electrical wiring to the left side of the furnace. The power supply circuit to
the furnace must be installed and grounded in accordance with the provisions of the
National Electrical Code, ANSI/NFPA-70-1999, or latest edition, and all local codes
having jurisdiction.
2. Connection Of Power Supply Wires
a. Remove the cover from junction box.
b. Insert 115 VAC wires through the strain relief bushing (or conduit connection as
applicable) on the left side of the furnace junction box.
c. Connect the “hot” wire to the black wire
.
d. Connect the “neutral” wire to the white wire.
e. Connect the “ground” wire to the green wire.