508034-02
Issue 2135
Page 42 of 49
Maintenance
ELECTRICAL SHOCK, FIRE, OR EXPLOSION
HAZARD.
Failure to follow safety warnings exactly could result in
dangerous operation, serious injury, death or property
damage.
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
disconnecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas fumes,
which could contain carbon monoxide, can be drawn
into living space resulting in personal injury or death.
WARNING
Annual Furnace Maintenance
At the beginning of each heating season, and to comply
with the Allied Air Limited Warranty, your system should be
checked as follows:
1. Check wiring for loose connections, voltage at indoor
unit and amperage of indoor motor.
2. Check the condition of the belt and shaft bearings if
applicable.
3. Inspect all gas pipe and connections for leaks.
4.
Check the cleanliness of filters and change if necessary
(monthly).
5. Check the cleanliness of blower assembly and
clean the housing, blower wheel and blower motor if
necessary.
6. Inspect the condensate drain and trap for leaks and
cracks. The drain and trap must also be cleaned and
the trap must be primed with water. Inspect the rubber
hoses connected to the pressure switches for cracks
or loose connections, replace as necessary. Remove
the rubber hoses from the cold end header box and
inspect for any blockage, clean as needed. If strainers
are installed in the hoses remember to remove and
clean before reinstalling the hoses.
7. Evaluate the heat exchanger integrity by inspecting
the heat exchanger per the AHRI heat exchanger
inspection procedure. This procedure can be viewed
at www.ahrinet.org.
8.
Ensure sufficient combustion air is available to the
furnace. Fresh air grilles and louvers (on the unit and
in the room where the furnace is installed) must be
properly sized, open and unobstructed to provide
combustion air.
9. On condensing furnaces, inspect the furnace intake
and exhaust pipes to make sure they are in place,
structurally sound, without holes, blockage or leakage
and the exhaust pipe is sloped toward the furnace.
Inspect terminations to ensure they are free of
obstructions and are structurally sound. Inspect the
furnace return air duct connection to ensure the duct
is sealed to the furnace. Check for air leaks on supply
and return ducts and seal where necessary.
10. Inspect the furnace return air duct connection to
ensure the duct is sealed to the furnace. Check for
air leaks on supply and return ducts and seal where
necessary.
11. Check the condition of the furnace cabinet insulation
and repair if necessary.
12. Perform a complete combustion analysis during
the furnace inspection to ensure proper combustion
and operation. Consult Service Literature for proper
combustion values.
13. Verify operation of CO detectors and replace batteries
as required.
Perform a general system test. Turn on the furnace to
check operating functions such as the start-up and shut-off
operation.
1. Check the operation of the ignition system, inspect
and clean flame sensor. Check microamps before and
after. Check controls and safety devices (gas valve,
flame sensor, temperature limits). Consult Service
Manual for proper operating range. Thermal Limits
should be checked by restricting airflow and not
disconnecting the indoor blower. For additional details,
please see Service and Application Note H049.
2.
Verify that system total static pressure and airflow
settings are within specific operating parameters.
3. Clock gas meter to ensure that the unit is operating
at the specified firing rate for each stage of operation.
Check supply, manifold and signal pressures at
35, 70 and 100% capacity as outlined in the unit
Service Literature. If manifold pressure adjustment
is necessary, consult the Service Literature for unit
specific information on adjusting gas pressure. Not all
gas valves are adjustable. Verify correct temperature
rise.
NOTE:
After any heavy snow, ice or frozen fog event the
furnace vent pipes may become restricted. Always check
the vent system and remove any snow or ice that may be
obstructing the plastic intake or exhaust pipes.
