Is your furnace running improperly? One of the most common furnace problems is when the burners won’t stay lit. This causes the furnace to fire up, heat for a few minutes, and turn back off before it has had time to reach the target temperature. Below are a few possibilities why your furnace doesn’t stay on and what to do about it.
4 Possible Reasons Your Furnace Isn’t Staying On
Malfunctioning thermostat: The thermostat may not be calibrated correctly, meaning the furnace thinks it has reached the desired temperature after running for only a few minutes. To find out, replace the thermostat with a cheap model. If the problem stops, you have pinpointed the problem. If not, return the new thermostat and continue troubleshooting.
Bad thermocouple: This heat sensor installed next to the pilot light serves the important purpose of closing the gas valve if the pilot light goes out so gas doesn’t fill your home. However, a malfunctioning thermocouple may lose the ability to sense heat from the pilot light, causing it to close the gas valve at random. If your furnace doesn’t stay on, check the pilot light. If the pilot light won’t stay lit, a bad thermocouple could be to blame. You may need a professional to come take a look and replace the malfunctioning part.
Full condensate pan: Newer condensing furnaces generate condensate, which drips into a pan and drains away. If the drain line becomes clogged, the pan may begin to fill up. Once the rising liquid hits a sensor, the furnace will automatically shut off to prevent the condensate from spilling over the edge. Check the condensate pan for this problem. If the drain is clogged, insert a straightened wire hanger to clear it out. Sending a bleach mixture or algaecide treatment down the drain may help prevent future clogs.
Blower motor not running: When the furnace runs, place your hand over a supply register. If you feel hot air exiting the vent, this means the motor is running like normal. If not, the motor has lost power for some reason and the furnace is switching itself off to prevent the heat exchanger from overheating. The fan relay might be broken or the blower motor belt might be worn out. A furnace repairman is your best bet for fixing these problems.
The information on this website is for informational purposes only; it is deemed accurate but not guaranteed. It does not constitute professional advice. All information is subject to change at any time without notice. Contact us for complete details.