When your furnace is shutting off more often than usual, it’s short-cycling.

Normal heating systems don’t run constantly, but instead, cycle on and off several times an hour. This type of furnace problem is known as, “short-cycling.”

Dirty Air Filter

If your air filter clogs with dirt, it restricts airflow to the heat exchanger and the component overheats. This, then, triggers the high limit switch, which is a safety shut-off to prevent damage to your system or the home.

To solve this problem, turn off the furnace and change the filter, if you have the disposable type. If it’s reusable, carefully wash the filter. When the new/rejuvenated filter is replaced, turn on the furnace and wait 5 minutes for the furnace to turn on.

Faulty Thermostat

Check your thermostat to determine if it is on. Make sure you switch it to heat and it’s set at the correct temperature. Ensure it isn’t too high because, as you may remember from science class, hot air rises. If the thermostat registers extreme temperatures, a shorter furnace cycle may result.

Another possible problem could be that the thermostat is malfunctioning and not sending a signal to your furnace. Slowly raise the thermostat setting, go to your furnace, wait for 5 minutes, and listen for noise from the furnace. Lack of any sound indicates that you may need an HVAC expert to diagnose the problem.

Dirty Flame Sensor

The gas furnace’s flame sensor is a safety device, which cuts off the supply of natural gas when it doesn’t detect a flame. If your flame sensor clogs from soot or corrosion, it can’t function properly and will keep turning off the furnace.

If you suspect that you have this problem, get expert furnace repair as soon as possible. Call A&T Heating and Air Conditioning in Mohnton, Berks County, PA at (484) 516-1017 or use our online form so we can perform the necessary HVAC inspections and service to ensure your system is functioning properly and safely.

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