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VI-MAINTENANCE
Annual Furnace Maintenance
At the beginning of each heating season, and to comply
with the Lennox Limited Warranty, your system should be
checked by a licensed professional technician (or equiva
lent) as follows:
WARNING
Disconnect power before servicing unit.
CAUTION
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dan
gerous operation. Verify proper operation after ser
vicing.
WARNING
The inner blower access panel and vent pipe 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.
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 ap
plicable.
3- Inspect all gas pipe and connections for leaks
.
4- Check the cleanliness of filters and change if necessary
(monthly).
5- Check the condition and cleanliness of burners and
heat exchanger and clean if necessary.
6- Check the cleanliness of blower assembly and clean
the housing, blower wheel and blower motor if neces
sary
. The blower motors are prelubricated for extended
bearing life. No further lubrication is needed.
7- Inspect the combustion air inducer and clean if neces
sary.
8- Evaluate the heat exchanger integrity by inspecting the
heat exchanger per the AHRI heat exchanger inspec
tion procedure. This procedure can be viewed at
www.ahrinet.org
9- Ensure sufficient combustion air is available to the fur
nace. 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
.
10 Inspect the furnace venting system to make sure it is in
place, structurally sound, and without holes, corrosion,
or blockage. Vent system must be free and clear of ob
structions and must slope upward away from the fur
nace
. Vent system should be installed per the National
Fuel Gas Code
11 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
.
12 Check the condition of the furnace cabinet insulation
and repair if necessary.
13 Perform a complete combustion analysis during the fur
nace inspection to ensure proper combustion and oper
ation. Consult Service Literature for proper combustion
values.
14 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 dis
connecting the indoor blower. For additional details,
please see Service and Application Note H049.
2 - Verify that system total static pressure and airflow set
tings are within specific operating parameters.
3 - Clock gas meter to ensure that the unit is operating at
the specified firing rate. Check the supply pressure
and the manifold pressure. On two-stage gas furnaces
check the manifold pressure on high fire and low fire. If
manifold pressure adjustment is necessary, consult
the Service Literature for unit specific information on
adjusting gas pressure. Not all gas valves are ad
justable. Verify correct temperature rise.
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