Why Is My Coleman Furnace Not Putting Out Hot Air?

Power and Oil Supply

• Make sure the Coleman furnace has power, and reset or replace the circuit breaker or fuse if necessary. Open the access door on the furnace, and locate the oil shut-off valve. Make sure the valve is set to "Open" or "On," and close the access door.

Air Filter

• Over time the air filter in the furnace will get clogged with lint, dirt and debris and can restrict air flow and heat. Disconnect power to the furnace, and open the access panel on the furnace. Remove the filter, and wash and dry the filter thoroughly. Re-install the filter with the arrows pointed in the direction of air flow, and close the access panel firmly.

Burner Area

• The same dirt and debris that clogs the air filter can also obstruct the burner area, reducing heating efficiency. While the furnace power is disconnected, open the access panel and use a soft brush to carefully clean the burner area and the circulating fan. Do not touch the burner itself or the wiring. If there are any signs of rust, corrosion or leaking, disconnect power to the furnace and contact Coleman for service.

Restarting the Furnace

• Sometimes the pilot light has gone out, often due to a power failure, and the furnace must be restarted to light the pilot light again. Set the thermostat at the lowest set point, and make sure all supply and return air grilles in the home are open. Disconnect power to the furnace, and open the access door. Look to make sure the oil shut-off valve is set to “On,” and close the access door firmly. Restore power, turn the thermostat to “Heat” and set it to the desired temperature. If the furnace still does not put out heat, call Coleman for service.