Lennox HVAC Unit ML193UH070XE36B

Electrical shock, fire, or explosion hazard warning

Disconnect all electrical power to furnace before servicing

Label all wires prior to disconnecting

Reconnect wires correctly after servicing

Verify proper operation after servicing

Exhaust and Air Intake Pipes Inspection

Check exhaust and air intake pipes for tightness

Ensure there is no blockage in the exhaust and air intake pipes

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.

Use copper wire only. Do not use aluminum wire.

Size wiring and circuit breaker(s) per Product Specifications bulletin (EHB) and unit rating plate.

WARNING! ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.

Disconnect all electrical power to furnace before servicing.

Label all wires prior to disconnecting controls.

Ensure wires are reconnected correctly after servicing.

Check the blower wheel for debris.

Clean the blower wheel if necessary.

Turn off electrical and gas supplies to the furnace

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

Remove four burner assembly screws at the vestibule panel and remove gas valve/manifold and burner box as a single unit

Disconnect all electrical power to furnace

Label all wires prior to disconnecting

Reconnect wires correctly after servicing

Filter Inspection and Maintenance

Clean or replace filters if necessary

Check filter specifications against Lennox Product Specifications bulletin

High-Efficiency Filter Considerations