035-14371-000 REV D (900)
Unitary Products Group
3
9. Replace control access panel.
10.Turn on all electrical power to the
appliance.
11.Set thermostat to the desired set-
ting.
12.The unit will go through a 17-second
igniter warm-up period. Then if the
unit does not light within 7 seconds,
the unit will go through two additional
cycles before locking out.
13.If the furnace will not operate, follow
the instructions "To Turn OFF Gas
To Furnace" and call your service
technician or gas supplier.
SHUTDOWN INSTRUCTIONS
To Turn OFF Gas To Furnace
1. Set thermostat to the lowest setting.
2. Turn off all electrical power to the
furnace if service is to be performed.
3. Remove the control access panel.
4. Turn gas control switch to “OFF”. If
gas valve is equipped with a control
knob, turn knob clockwise to “OFF”
position.
5. Replace the control access panel.
YOUR FURNACE'S FILTER - WHAT
IT DOES
The filter in your furnace takes the lint and
dust out of the air that passes through it.
This keeps dirt particles from getting into the
moving parts of the furnace, where they
could cause serious damage. It also keeps
the dirt from circulating through your home.
As the filter continues to collect these parti-
cles, it becomes clogged and no longer
allows enough air to circulate through the
furnace. If this happens, the heat exchang-
ers and blower motor could overheat; a
potentially dangerous situation. It is very
important to keep the air filter clean! Never
operate your furnace without a suitable air
filter.
FREQUENCY OF CHECKING
FILTERS
Clean your furnace's filter at least every
three months. If you need to replace a filter,
check the filter chart to be sure you install
the right size and type of filter for your fur-
nace.
If your home is new, you should check the
filter every week for the first four weeks after
you begin to use the furnace, and then at
least every three weeks after that, especially
if the system runs constantly.
NOTE:
Some installations may have more
than one filter.
LOCATING / REMOVING FILTERS
Upflow Furnaces
Most upflow furnaces have their filters
located on the side or bottom of the furnace
in a filter frame.
If your furnace has this type return filter
frame, remove the door by pulling on it.
Slide the filter out of its channel. To replace
after cleaning, slide filter into place and
snap the door on the end of the filter rack.
Some installations may have filters located
in the blower compartment. Check with the
installer for your filter location.
To check filters located in the blower com-
partment, remove the upper furnace door by
lifting up. Pull out bottom of door and lower
from furnace. Remove the blower compart-
ment panel by lifting up.
NOTE:
The spring-loaded safety cutoff
switch, mounted under the blower deck will
automatically cut off the electrical power
supply to the furnace when the blower panel
is removed
.
To remove bottom mounted filter(s) on all
furnaces, push the looped end of the filter
retainer to the side and then lift up. Reverse
the procedure to reinstall filters.
Downflow Furnaces
The filters in your downflow furnace are
located in the plenum or ductwork above the
furnace.To check the filters, turn off the elec-
trical supply to the furnace.
Remove the access cover in the return air
duct above furnace and slide the filter(s) out
of the filter channel. You may need to tilt the
filter in order to clear the vent pipe.
NOTE:
The spring-loaded safety cutoff
switch, mounted to the blower deck will
automatically cut off the electrical supply to
the furnace when the blower access door is
removed.
Horizontal Furnaces
Most horizontal furnaces have their filters
located in a filter grille(s) so that it may be
easily changed without gaining access to
the attic or crawl space.
Some installations may have a filter rack
near the furnace. With this type of acces-
sory, unsnap the filter rack door and pull.
The filter is attached to the door and will
slide out. If you are unsure where the fur-
nace filter is installed, check with the
installer.
Should overheating occur, or the gas sup-
ply fail to shut off, shut off the main man-
ual gas valve to the furnace before
shutting off the electrical supply.
Typical Gas Piping
GAS VALVE
DROP LEG
GROUND JOINT UNION
MAY BE INSTALLED
INSIDE OR OUTSIDE UNIT
TO GAS
SUPPLY
TO GAS
SUPPLY
EXTERNAL MANUAL
SHUTOFF VALVE
When replacing filters DO NOT use a type
with excessively high pressure drop.
Some high efficiency filters available will
cause the furnace to operate improperly
and could result in a safety hazard.
Gas Valves -
White-Rodgers 36F52-204 (top)
Honeywell VR8205 (bottom)
(approved for field replacement)
Upflow Furnace Internal Filter
Applications
