My Furnace Is Not Working Right

There are a number of reasons a furnace may not work properly.

If your furnace isn't working properly, there are a number of steps you can take to troubleshoot the problem yourself and possibly avoid a costly service call from a repair technician. The problem may be with the furnace itself, or could be caused by an electrical problem, improper thermostat setting or restricted airflow in the system. Pay careful attention to what your furnace is or is not doing to correctly pinpoint the issue.

Instructions

1. Check to make sure the thermostat is on the "heat" setting and the desired temperature is set to at least 3 degrees warmer than the room temperature. If it is and the furnace is not turning on, switch the thermostat to the "fan" setting and wait a minute to see if the fan turns on. If the fan does not turn on, check the breaker or fuse box in your home to make sure a breaker has not been tripped or a fuse has not been blown. Reset the breaker or replace the fuse if necessary.

2. Inspect the air filter to make sure it is not excessively dirty or clogged, especially if your furnace is constantly running but is not adequately warming the home. A clogged air filter can restrict airflow and significantly reduce the heating capacity of your furnace.

3. Remove the front of the furnace cover and check to see that the pilot is lit, if your furnace does not have an electronic ignition but instead has a pilot flame that is always lit. If the pilot is out, reset it according to the furnace manufacturer's instructions, which can usually be found on the inside of the furnace cover.

4. Verify that the burners ignite when the furnace turns on. Blue flames will be clearly visible inside the furnace when the front cover is removed. If the burners to not ignite, the gas valve leading to the furnace may be faulty.

5. Listen to see if the furnace's blower motor turns on, which it should do within three minutes of the burners igniting. If the motor does not turn on, the motor most likely needs to be replaced.

Tips & Warnings

• A properly maintained furnace has a normal lifespan of 20 to 25 years. Goodman Air Conditioning and Heating recommends having a furnace inspected and cleaned annually.

• Furnace air filters should be changed on a monthly basis.

References

• HVAC-For-Beginners.com: Furnace Troubleshooting, Before You Call The Repairman
• Goodman Air Conditioning and Heating: Preventative Maintenance