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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 for each stage of operation.
Check the supply pressure and the manifold pressure
on both low fire and high fire. If manifold pressure ad
justment is necessary, consult the Service Literature
for unit specific information on adjusting gas pressure.
Not all gas valves are adjustable. Verify correct tem
perature rise.
WARNING
Sharp edges.
Be careful when handling unit to avoid sharp edges
which may result in personal injury.
Repair Parts List
The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model
number listed on the CSA International nameplate -- Example: EL296UHV045P36B. All service must be done by a li
censed professional installer (or equivalent), a service agency, or the gas supplier.
Cabinet Parts
Upper access panel
Blower access panel
Top Cap
Control Panel Parts
Transformer
Integrated control
Door interlock switch
Blower Parts
Blower wheel
Motor
Motor mounting frame
Motor capacitor
Blower housing cutoff plate
WARNING
The State of California has determined that this prod
uct may contain or produce a chemical or chemicals,
in very low doses, which may cause serious illness
or death. It may also cause cancer, birth defects or
reproductive harm.
Heating Parts
Flame Sensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster
Main burner orifices
Pressure switch
Ignitor
Primary limit control
Flame rollout switches