Furnace Self Diagnosis

Make sure the thermostat is set in the heat mode and the temperature is set higher than the room temperature. If the thermostat is digital, check the batteries in the thermostat as well.

Check to see if the power switch to the furnace is in the on position. Typically, the switch will look like a normal light switch and is mounted near the furnace. Also, check the main breaker panel to make sure that the breaker has not tripped.

A dirty filter can cause the furnace to overheat and slowdown airflow in the home. DO NOT OPERATE the furnace without a filter as this will cause damage to the furnace.

Check the gas shutoff valve to make sure that it is in the ON position.

Older furnaces may be vented into a chimney, if this is the case, you need to check for blockages such as bird nests.

Newer furnacess have a drain line and should be checked to make sure that they are not clogged and are draining properly.

With the blower running make sure that the registers are open and the air is flowing out of the register.

High efficient furnaces, typically vent through a side wall and should be checked to insure those vents are not blocked.