Are you a professional? Customize your experience.

Furnace Maintenance

Before proceeding, be sure the area is well ventilated. Turn the thermostat OFF. If the blower is running, wait until it stops automatically. Turn OFF and electrical power supplies to the furnace. Check all metal parts and surfaces to be sure they have cooled to room temperature before you begin.



Filters used with this furnace must be installed external to the furnace casing. DO NOT attempt to install filters inside the furnace cabinet. Some installations may have the air filter in a rack attached to the casing of the furnace or placed in the return air duct. If the filter location or replacement process is not obvious, contact your installer or service technician for assistance.

Every time the external air filters are changed, the following items should be visually inspected:

  • Check combustion air and vent pipe for blockage or leakage;
  • Check all components to be sure they are in good condition and that there are no obvious signs of deterioration;
  • Check the drain lines to make sure there are no cracks or leaks;
  • Check for dirt or lint on any surfaces or on components.

Do not try to clean any of the surfaces or components. Cleaning of the furnace and its components must be done by a qualified service professional.

If during the inspection of your furnace, you find any of the following conditions:

  • Excessive amounts of dust and lint on components;
  • Damaged or deteriorated components or surfaces;
  • Leaks or blockage in the vent pipe passages;
  • Water on any surface inside or outside of the furnace.

Do not operate the furnace, call a certified dealer or servicing contractor to check or clean your furnace, or for more information if you have questions about the operation of your furnace. If all components appear to be in good operating condition, replace the furnace access panels/doors. Turn ON the gas and electrical power supplies to the furnace, and set thermostat to the desired temperature.


High-velocity filters may be cleaned with a vacuum cleaner or washed with a garden hose. Be sure to shake off excess water and allow filter to completely dry before re-installing the filter.

Replace throw-away filter(s) with the same size new filter(s). Throw-away filter(s) may be replaced with cleanable filter(s) at this time.


Even with good filters properly in place, blower wheels and motors will become dust laden after months of operation. The entire blower assembly should be inspected annually. This service must be performed by a qualified service agency.

NOTE: The spring-loaded safety cut-off switch, mounted at the blower deck will automatically cut off the electrical power supply to the furnace when the furnace blower access panel/door is removed. As a safety precaution, all electrical power and the gas supply to the furnace should be turned off before servicing.


The motors in these furnaces are permanently lubricated, and do not require periodic oiling.


If your furnace is not operating correctly, the following visual checks should be made before contacting your local contractor, dealer, or service provider.

  1. Check that electrical power to the furnace is turned on.
  2. Check that the manual gas shut-off valve in the gas piping supply is turned to the ON position.
  3. Check that the ON/OFF switch on the gas valve is turned to the ON position.
  4. Check that the furnace blower access panel/door is correctly positioned. The electrical power supply will be cut off if this door is removed.


The furnace should be cleaned and adjusted by a certified dealer or qualified service contractor once a year or before the start of every heating season. The following items must be cleaned and serviced or replaced if there are signs of deterioration.

  1. The vent terminal.
  2. The furnace vent and combustion air intake passageways. Should it be necessary to service the vent/air intake system, the manufacturer recommends this service be conducted by a qualified service agency. The operation of this appliance requires the reassembly and resealing of the vent/air intake system.
  3. The furnace burners, ignitor and flame sensor.
  4. The condensate collection and disposal system. If any disassembly of components containing flue or vent gases is required, a qualified service agency must perform the service.
  5. Heat exchanger assembly.
  6. Induced draft motor assembly.