Lennox Rooftop Unit LGH180

Remove the combustion air inducer assembly as described in the Combustion Air Inducer subsection.

Clean the flue box with a wire brush as required.

Clean the tubes with a wire brush.

Replace gaskets during reassembly

Filter Inspection and Replacement

Check the following filter conditions

Is the filter in need of replacement?

Replace the filter if necessary

Ensure air flow direction marking on filter frame is correct when reinstalling

Replace factory-installed filters within 30 days of initial unit start-up

Replace temporary filters before building is occupied

Refer to local codes or appropriate jurisdiction for approved filters

Inspect the following components for corrosion, deterioration, or debris deposits

Remove any obstructions or blockages found during inspection

Refer to Figure 5, Figure 6, or Figure 7 for detailed diagrams

Turn off the electrical power to the unit

Turn off the gas supply to the unit

Remove the burner compartment access panel

Remove screws securing burners to burner support

Lift the entire burner assembly from the orifices

Ensure all motors are lubricated at the factory

Verify that no further lubrication is required for factory-lubricated motors

Blower Shaft Bearings Lubrication

Check that blower shaft bearings are prelubricated

Is it time for the 2-year relubrication?

Select the grease to be used for relubrication

Use a hand grease gun for relubrication

Add grease until a bead appears at the seal lip contacts