Lennox HVAC Unit ML193UH045XE36B

Disconnect all electrical power to furnace

Label all wires prior to disconnecting

Filter Inspection and Maintenance

Is cleaning or replacement of filters necessary?

Clean or replace the filters if necessary

Read and understand all safety warnings before proceeding with the inspection.

Disconnect all electrical power to the furnace before servicing.

Label all wires prior to disconnecting them.

Reconnect wires correctly after servicing.

Verify proper operation after servicing.

Exhaust and Air Intake Pipes Inspection

Check the exhaust and air intake pipes for tightness and ensure there is no blockage.

Inspect all connections for tightness and ensure there is no blockage.

Read and understand all safety warnings before proceeding.

Disconnect all electrical power to the furnace before servicing.

Label all wires prior to disconnecting them.

Reconnect wires correctly after servicing.

Verify proper operation after servicing.

Ensure the unit is properly grounded in accordance with national and local codes.

Remove hoses from cold end header box

Remove screens by twisting and pulling

Rinse screens with tap water if needed

Turn off electrical and gas supplies to the furnace

Use papers or protective covering in front of furnace while removing heat exchanger assembly

Mark all gas valve wires and disconnect them from valve

Remove gas supply line connected to gas valve

Remove sensor wire from flame sensor and disconnect 2-pin plug from the ignitor

Disconnect wires from flame roll-out switches