Lennox MERIT Series Installation Instructions Manual page 44

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.
Annual Furnace Maintenance
At the beginning of each heating season, and to comply
with the Lennox 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 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
necessary.
7- 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.
8- 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
9- 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.
10- 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.
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
furnace inspection to ensure proper combustion
and operation. 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 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. Check the supply pressure
and the manifold pressure. 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.
Winterizing and Condensate Trap Care
1 - Turn off power to the furnace.
2 - Have a shallow pan ready to empty condensate
water.
3 - Remove the clean out cap from the condensate trap
and empty water. Inspect the trap then reinstall the
drain plug.
Cleaning the Burner Assembly
1 - Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.
2 - Disconnect the 2-pin plug from the gas valve.
3 - Remove the burner box cover.
4 - Disconnect the gas supply line from the gas valve.
Remove gas valve/manifold assembly.
5 - Mark and disconnect sensor wire from the sensor.
Disconnect 2-pin plug from the ignitor at the burner
box.
6 - Remove four screws which secure burner box
assembly to vest panel. Remove burner box from
the unit.
7 - Use the soft brush attachment on a vacuum cleaner
to gently clean the face of the burners. Visually
inspect the inside of the burners and crossovers for
any blockage caused by foreign matter. Remove any
blockage.
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