Service manual

129099-UUM-F-0507
Unitary Products Group 5
To Turn Off the Appliance:
1. Set the thermostat to lowest setting.
2. Turn off all electric power to the appliance if service is to be per-
formed.
3. Remove burner access panel.
4. Move gas control switch to the “OFF” position. See Figure 4.
5. Replace burner access panel.
FURNACE USER MAINTENANCE
Every time the filters are changed the following items should be visually
inspected:
• Check roof jack assembly for blockage or leakage.
• Check all components to be sure they are in good condition and
that there are no obvious signs of deterioration.
• Check the evaporator coil drain lines to make sure there are no
cracks or leaks.
• Check for dirt or lint on any surfaces or on components. Do not try
to clean any of the surfaces or components. Cleaning of the fur-
nace and its components must be done by a qualified service pro-
fessional.
If, during the inspection of your furnace, you find any of the following
conditions:
• Excessive amounts of dust and lint on components.
• Damaged or deteriorated components or surfaces.
• Leaks or blockage in the vent pipe passages.
• Water on any surface inside or outside of the furnace.
Do not operate the furnace, and call a certified dealer / servicing con-
tractor to check and / or clean your furnace, or for more information if
you have questions about the operation of your furnace.
If all components appear to be in good operating condition, replace the
front panels. Follow the operating instructions to place the furnace in
operation.
Air Filters
Dirty filters greatly restrict the flow of air and may cause damage to the
moving parts of the furnace. If the filters become clogged the heat
exchangers and blower motor could overheat resulting in a potentially
dangerous situation.
The filters should be checked every 3 months (DO NOT USE PLEATED
FILTER in this furnace). On new construction, check the filters every
week for the first four weeks and every three weeks after that, espe-
cially if the indoor fan is running continuously. When replacing the fil-
ter(s) you must use filters that are the same size and type as those in
the furnace (2 - 16 x 20 x1).
Removing Filters
Internally Mounted Air Filters
The air filter is in a rack that is attached to the door of the furnace.
To remove the filter you must do the following:
1. Before proceeding, be sure the area is well ventilated. Follow
instruction “To turn off the appliance”. Check all metal parts and
surfaces to be sure they have cooled to room temperature before
you begin.
2. Remove the filter door.
3. Remove the air filter by sliding it down the track. The air filter will
slide out of the rack.
4. Replace throw away filter(s)) with the same size new filter(s).
Throw away filter(s)) may be replaced with cleanable filter(s) at
this time. Cleanable filter(s) may be cleaned as described in the
manufacturer instructions or as described in these instructions.
To replace the filter after cleaning you must do the following:
1. Slide filter into place. If the filter has been cleaned, make sure it is
dry before re-installing it.
2. Replace the door or cover panel.
3. Make sure the door snaps into the retaining clips.
4. Follow the Operating Instructions to place the furnace back in
operation.
Blower Care
Even with good filters properly in place, blower wheels and motors will
become dust laden after long months of operation. The entire blower
assembly should be inspected annually. If the motor and wheel are
heavily coated with dust, they can be brushed and cleaned with a vac-
uum cleaner. If the blower cannot be properly cleaned without removing
it from the furnace, then call a qualified service agency. Only a qualified
service agency can perform this service.
Should overheating occur, or the gas valve fail to shut off,
turn the external manual gas valve in the gas supply line to
the furnace to the “off” position and let the furnace cool off
before shutting off the electrical power supply. Refer to
Figure 5.
FIGURE 4: Gas Valve
FIGURE 5: Gas Piping
Before proceeding, be sure the area is well ventilated. Turn
the thermostat OFF. If the blower is running, wait until it
stops automatically. Turn OFF the gas and electrical power
supplies to the furnace. Check all metal parts and surfaces
to be sure they have cooled to room temperature before
you begin.
O
F
F
ON
INLET
WRENCH
BOSS
ON/OFF SWITCH
(shown in OFF position)
MAIN REGULATOR
ADJUSTMENT
OUTLET
SUPPLY
PRESSURE TAP
OUTLET
(MANIFOLD)
PRESSURE TAP
ELECTRICAL
CONNECTIONS
MANUAL
SHUT-OFF
VALVE
GAS
PIPE
GAS
PIPE
MANUAL
SHUT-OFF
VALVE
GAS
VALVE
GAS
BURNER
DRIP
LEG
DRIP
LEG