Unitary products group AUTOMATIC IGNITION FURNACES Guide

650.66-O2V (998)
035-15813-301
USER’S
INFORMATION
MANUAL
USE AND CARE INSTRUCTIONS
FOR ALL POSITION
AUTOMATIC IGNITION FURNACES
If not installed, operated, and maintained in ac-
cordance with the manufacturer's instructions,
this product could expose you to substances in
fuel or from fuel combustion which are known to
the State of California to cause cancer, birth
defects or other reproductive harm. Also, opera-
tion, installation and servicing of this product
could expose you to airborne particles of glass-
wool fibers known to the State of California to
cause cancer through inhalation.
If the information in this manual is not followed exactly, a
fire or explosion may result causing property damage,
personal injury or loss of life.
Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.
WHAT TO DO IF YOU SMELL GAS
•Do not try to light any appliance.
•Do not touch any electrical switch; do not use any
phone in your building.
•Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
•If you cannot reach your gas supplier, call the fire
department.
Installation and service must be performed by a
qualified installer, service agency or the gas supplier

2
Introduction
Your furnace will give you all the
comforts of complete winter air
conditioning - heating, circula-
tion, filtering - you have control
and yet the furnace is as auto-
matic as you desire it to be.
If you will observe the few oper-
ating and maintenance instruc-
tions in this booklet, this high
efficiency forced warm air fur-
nace will give you many years of
dependable service.
Failure to observe the fol-
lowing safety precautions
could cause fire, explosion,
or asphyxiation.
Safety Precautions
For your safety – Do not store
or use flammable liquids, vapors,
or materials in the immediate
area near the furnace or other
heating appliance. Do not store
brooms, mops, or equipment or
materials near the furnace in any
confined space which may be
around or in front of the furnace.
When the furnace is in-
stalled in an attic or other
insulated space, make sure
that all insulation is at least
12” away from furnace
combustion air openings.
Failure to do this could
cause asphyxiation or fire.
Adequate ventilation and
combustion air must be
provided to insure satis-
factory and safe operation
of the furnace. Air openings
in front panel and top panel
must not be obstructed.
Any openings into the fur-
nace closet or confined
room in which the furnace
is located, for the entrance
of combustion and ventila-
tion air must be kept open
and unobstructed. Failure
to observe these require-
ments could result in as-
phyxiation.
NOTICE – Do not use this
furnace if any part has
been under water. Immedi-
ately call a qualified service
technician to inspect the
furnace and to replace any
part of the control system
and any gas control which
has been under water.
Should overheating occur,
or the gas supply fail to
shut off, shut off the man-
ual gas valve to the appli-
ance before shutting off the
electrical supply.
Do not store or use halo-
gen-emitting substances in
the vicinity of this appli-
ance. Such substances in-
clude chlorine based
cleaners and swimming
pool chemicals, water sof-
tening chemicals, de-icing
salts and chemicals,
cleaning solvents such as
carbon tetrachloride or per-
chloroethylene, halogen
type refrigerants, printing
inks, paint and paint re-
movers, varnishes, hydro-
chloric acid, cements and
glues, and masonry acid
washing materials. The air
used by the burner for
combustion must be free of
halogens to avoid possible
corrosion to the heating
surfaces, which could re-
sult in asphyxiation.
Improper installations, ad-
justment, alteration, service
or maintenance can cause
property damage, personal
injury or loss of life. Instal-
lation and service must be
performed by a qualified
installer, service agency or
the gas supplier.
Never attempt to modify
this furnace. Fire, explo-
sion, or asphyxiation may
result. If malfunction oc-
curs, obtain the assistance
of a qualified service agent.

3
FIGURE 1 – DOWNFLOW POSITION
FIGURE 2 – UPFLOW POSITION

4
Description
This furnace can be installed in the
upflow, downflow, or horizontal po-
sition. Figure 1 shows a typical
model in the downflow position and
figure 2 shows a typical model in
the upflow position. The furnace
may also lie on either side in a
horizontal position. The furnace is
equipped with an induced-draft vent
blower and atmospheric burners.
Combustion air is taken from the
space or area in which the furnace
is installed and drawn into the
burners through the louvers in the
front panel. Flue gas is drawn from
the furnace by the vent blower and
discharged through the flue pipe to
the outside atmosphere.
This is a forced air furnace. The
furnace circulating air blower draws
cool air from the house, passes it
over the hot furnace heat ex-
changer and circulates the warmed
air through the ductwork to the
house.
The furnace is equipped with the
controls necessary for proper op-
eration. The various components
referred to in this manual and on
the furnace nameplate are identi-
fied in Figures 1 and 2.
Sequence of Operation
These furnaces are equipped with
an electric hot surface burner igni-
tion system. In response to a call
for heat by the room thermostat,
the burners are lighted by a hot
glowing ignitor at the beginning of
each operation cycle. The burners
will continue to operate until the
thermostat is satisfied at which time
all burner flame is extinguished.
During the off cycle no gas is con-
sumed. With the room thermostat
set below room temperature, and
with the electrical power and gas
supply to the furnace on, the nor-
mal sequence of operation is as
follows:
1. When the room temperature
falls below the setting of the
room thermostat, the thermo-
stat energizes the furnace con-
trol board.
2. When the furnace control
board is activated, the vent
blower is turned on. A circuit
is also made through the
normally open pressure
switch contacts.
3. As the vent blower in-
creases in speed, the con-
tacts of the pressure switch
will close and complete the
electrical circuit to the igni-
tor.
4. During the next 15-30 sec-
onds, the vent blower will
bring fresh air into the heat
exchanger and the ignitor
will begin to glow. At the
end of this period, the gas
valve will open and the
burners will light.
5. After the burners light, a
separate sensor acts as a
flame probe to check for the
presence of flame. As long
as flame is present, the
system will monitor it and
hold the gas valve open.
6. If the burners fail to light
within 6-8 seconds after the
gas valve opens, the gas
valve will close and the ig-
nitor will be turned off. After
a short pause, the system
will recycle and try again for
ignition. If the burners fail to
light after three tries, the ig-
nition system will lock out.
The system will remain in
lockout mode until one hour
has passed, or until the
room thermostat is cycled
off then back on. The fur-
nace will then try for ignition
again.
7. The lapsed time from the
moment the room thermo-
stat closes to when the
burner light may be 30-40
seconds. This delay is
caused by (1) the time re-
quired for the vent blower to
come to full speed, (2) the
time required for the ignitor
to heat up and (3) the time
required for fresh air to be
brought into the heat ex-
changer.
8. Thirty to forty seconds after
the burners have lighted,
the fan switch will close and
the furnace air circulation
blower will run.
9. When room thermostat is
satisfied, the circuit to the
furnace control board is
broken. The circuit to the
gas valve is broken and the
burners are extinguished.
The vent blower will con-
tinue to run for a few sec-
onds. The furnace control
board will keep the circulat-
ing blower running for a
fixed period of time to allow
additional heat to be drawn
from the heat exchanger.
Furnace Operation
Safety Information
For your safety read before op-
erating:
If you do not follow these
instructions exactly, a fire
or explosion may result
causing property damage,
personal injury or loss of
life.
1. This appliance does not
have a pilot. It is equipped
with an ignition device
which automatically lights
the burners. DO NOT try to
light the burners by hand.
2. Before operating, smell all
around the appliance area
for gas. Be sure to smell
next to the floor because
some gas is heavier than air
and will settle on the floor.
What to do if you smell gas:
•Do not try to light any
appliance.
•Do not touch any 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.

5
3. Use only your hand to turn the
gas control lever or switch.
Never use tools. If the lever or
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.
4. Do not use this appliance if any
part has been under water.
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 under water.
Operating Instructions
1. STOP! Read the safety infor-
mation listed above.
2. Set the thermostat to the low-
est setting, or OFF.
3. Turn off all electric power to the
furnace.
4. This appliance does not have a
pilot. It is equipped with an ig-
nition device which automati-
cally lights the burners. Do not
try to light the burners by hand.
5. Remove front door panel.
6. Move gas valve control lever or
switch to "OFF". See Figure 3.
FIRGURE 3 – WHITE-RODGERS GAS
VALVE
7. Wait five (5) minutes to clear
out any gas. Then smell for
gas, including near the floor. If
you smell gas, STOP! Follow
#2 in the Safety Information. If
you don't smell gas, go to the
next step.
8. Move gas control lever or
switch to "ON".
9. Replace front door panel.
10. Turn on all electric power to the
furnace.
11. Set thermostat to desired set-
ting.
Gas Shutoff
This furnace is equipped with a
gas shutoff lever or switch on
the gas valve, which can be
used to prevent gas from flow-
ing to the furnace. Figure 3
shows the location of the shutoff
lever or switch. To turn off gas
to the furnace, move the lever or
switch to the "OFF" position.
The furnace installation should
also have a manual shutoff
valve in the gas piping to the
furnace, similar to what is
shown in Figure 4. To turn off
the gas to the furnace, use a
wrench and turn the knob or
lever so that it is pointing 90
degrees from the gas pipe, as
shown in Figure 4.
FIGURE 4 – MANUAL GAS
SHUTOFF VALVE
Thermostat
Set the room thermostat at the
desired room temperature.
Greatest comfort will be
achieved when the setting is not
changed frequently.
For energy conservation and
economy - It is recommended
that the thermostat be set at 68°
for heating and 80°for cooling.
For Heating with Air Condi-
tioning Applications - Set
HEAT/COOL switch to HEAT
position and set FAN switch to
AUTO position.
Energy Saver Thermostat - An
energy saver thermostat or set-
back thermostat will provide
even greater fuel economy. This
type of thermostat may be set to
control the temperature at a
"HIGH" setting during the day-
time hours and a "LOW" setting
during night-time hours. Follow
the instructions supplied with
the thermostat by the thermostat
manufacturer. If these are not
available, check with the in-
stalling dealer or contractor for
proper setting and operation of
your specific thermostat.
If Furnace Fails to Operate
Properly:
1. Check setting of thermostat,
and position of HEAT/COOL
switch if air conditioning is
installed. If a setback type
thermostat is employed, be
sure that the thermostat is
in the correct operating
mode.
2. Check to see that electrical
power is ON.
3. Check to see that the lever
or switch on the gas control
valve is in the full ON posi-
tion.
4. Make sure filters are clean,
return grilles are not ob-
structed, and supply regis-
ters are open.
5. Be sure that furnace flue
piping is open and unob-
structed.
6. This furnace is equipped
with a BLOWER DOOR
SAFETY SWITCH. It is lo-
cated behind the blower
door. See Figures 1 or 2 .
The switch controls the
electrical power to the fur-
nace and prevents the fur-
nace from operating if the
blower door is not in place
or is improperly installed.
7. This furnace is equipped
with three rollout switches,
which are designed to shut
down the furnace in the
event that excessive rollout
occurs. These switches are
located near the burners as
shown in Figures 1 or 2. If
any of these switches shuts
down the furnace, do not
attempt to restart it. Call a
service technician to correct
the problem

6
If the cause for the failure to
operate is not obvious, do not
attempt to service the furnace
yourself. Call a qualified serv-
ice agency or your gas sup-
plier.
Filters
It is very important that filters in
your furnace or air conditioning
system be cleaned frequently or
replaced when necessary. Clean
filters not only provide added com-
fort and a more healthful environ-
ment, but also allow the system to
operate more efficiently. Check
filters every two or three weeks.
Your furnace may be equipped with
a permanent type filter, which need
not be replaced provided it is
cleaned frequently. A permanent
filter may be washed in a mild solu-
tion of detergent and water and
then rinsed thoroughly with clear
water. If the pores of the filter me-
dia become clogged with dirt or lint,
which cannot be washed out, or
if the filter becomes damaged, it
must be replaced. A replace-
ment filter should be of the
same type and the same size as
the old filter.
Filter Replacement –
Downflow
In your installation the filter may
be located in the return air duct
above the furnace as shown in
Figure 5, or it may be located
behind a return air grille.
If the filter is located in the re-
turn air duct above the furnace,
replace the filters as shown in
Figure 5, with the bottom of the
filter resting in the filter rack and
the top edges of the filters
leaning against the inside of the
duct. If the filter is not located in
the return air duct above the
furnace or if the method of re-
moval and replacement is not
obvious, then contact the in-
stalling contractor of the furnace
for assistance.
Filter Replacement –
Horizontal
The filter may be located in a
filter rack near the furnace, or it
may be located behind a return
air grille. If you cannot find the
filter, or if the method of removal
and replacement is not obvious,
then contact the installing con-
tractor of the furnace for assis-
tance.
Filter Replacement –
Upflow
The filter may be located in a
filter rack attached to the side of
the furnace or it may be located
in a filter rack beneath the fur-
nace. See Figure 6. If the filter is
not located in one of these
places, or if the method of re-
moval and replacement is not
obvious, then contact the in-
stalling contractor of the furnace
for assistance.
FIGURE 5 – DOWNFLOW FILTERS FIGURE 6 – UPFLOW FILTERS

7
Periodic Inspection and
Maintenance
It is recommended that the
homeowner or user make an
inspection of the furnace at least
every 90 days or more often if
desired. It is also recommended
that a qualified service agency
inspect the furnace before each
operating season the furnace is
used, both heating and air condi-
tioning, and at any time that
there is an indication of malfunc-
tion. The owner/user should not
attempt to disassemble the fur-
nace unless experienced and
qualified to do so.
FOR SAFETY – Turn off
electrical power to furnace
before performing any
service.
The furnace installation should
be examined to determine that:
1. All flue product carrying
areas external to the furnace
(chimney, vent connector,
etc.) are clear and free of
obstructions,
2. The vent connector is in
place, slopes upward, and is
physically sound without
holes or excessive corrosion,
3. The return air connection is
physically sound, is sealed to
the furnace casing, and ter-
minates outside the space
containing the furnace,
4. The physical support of the
furnace is sound without
sagging and the furnace is
level, and
5. There are no obvious signs
of deterioration of the fur-
nace.
Flue Piping
Inspect the flue piping connec-
tion at the furnace and the con-
nection of the individual sections
to ensure that pipe joints have
not become disengaged and that
there are no openings, which
could allow leakage of products
of combustion. Inspect the termi-
nation of the flue outside the
structure and look for any indi-
cation of carbon or soot streaks.
The presence of any soot would
indicate a malfunction and the
cause must be determined and
corrected.
Motor Lubrication
The circulating air blower motor
and vent blower are perma-
nently lubricated and do not re-
quire periodic lubrication.
This equipment must be
serviced only by qualified
individuals specially trained
and experienced in servic-
ing of this type equipment
and related system com-
ponents, such as duct
systems, air conditioning,
etc. Installation and service
personnel are required to
be licensed in some areas.
Persons not qualified
should not attempt to serv-
ice this equipment.
Your Service Technician
Your furnace's best friend is
your qualified service techni-
cian. If the unit gives any indica-
tion of improper operation, call
your service technician. If the
service technician is allowed to
perform the normal routine care
of your furnace, he/she can
many times detect potential dif-
ficulties and make corrections
before trouble develops. Pre-
ventative maintenance of this
type will allow you to operate
the unit with a minimum of con-
cern, and at the same time will
pay for itself in added years of
comfort.
When You Call For Service
Assistance
Very often time can be saved if
you will give the service com-
pany the MODEL and SERIAL
NUMBER of your furnace. This
will enable the company to de-
termine the specific components
used, and perhaps to better
identify the possible problem
and be better prepared if a
service call is required.
To Contact Your Service
Technician
For immediate reference, fill in
the following blanks and keep
this booklet in a safe and easily
accessible place.
COMPANY: ____________
ADDRESS: ____________
TELEPHONE: ____________
Trips and Vacations
The furnace is equipped with
controls which are designed to
shut off the furnace burners
should malfunction occur. How-
ever, it is best never to assume
that the furnace will operate un-
attended for long periods of
time, especially if there is a pos-
sibility of damage to your prop-
erty because of freezing. If you
plan to be away for an extended
period, it is suggested that ar-
rangements be made for some-
one to check the house and fur-
nace operation frequently.

Subject to change without notice. Printed in U.S.A.
Copyright by Unitary Product Group 1998. All rights reserved 035-15813-301 (998)
Unitary 5005 Norman
Products York OK
Group Drive 73069