Troubleshooting: Why is my furnace turning off and on repeatedly?

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As the temperature in your home changes, the thermostat operates the furnace to bring the home to the desired room temperature, known as the furnace cycle. When your furnace operates, “on then off” for a short period, it is known as short-cycling.

Short cycling is a sign of a serious problem within your HVAC system.

Here are the primary reasons why your furnace may be short cycling:

Size Matters

A furnace that is too large for a home will kick off and on rapidly or overheat because it has nowhere to push the hot air. Therefore, it is important to have a professional HVAC Contractor install your system because they can properly match the size of the furnace to the size of your home.

If your HVAC system is too large for your home, it is likely driving up your monthly energy bills and causing more wear and tear on your fan requiring it to be serviced earlier than usual.


Many times, a furnace will short-cycle because is overheating. Frequent overheating can cause major damage to a furnaces heat exchange, so it is important to address this problem immediately.

Overheating is usually caused by restricted airflow. The most common cause of restricted air flow is a dirty furnace filter. Make sure to replace your air filter and get into the habit of changing the filter regularly.

Another area to watch for airflow restriction is air vent registers. Sometimes furniture or other home décor can be blocking the vents.

Thermostat Problems

Your furnace receives all its instructions from the thermostat. Make sure it is functioning properly.

The location of your thermostat can cause short cycling. A thermostat needs to be away from drafts, windows, and heat sources. We recommend a thermostat is placed on an inside wall in a room that is regularly occupied.

Short-cycling is a serious problem that needs to be addressed as soon as possible. It causes wear and tear on your system and decreases energy efficiency resulting in higher energy bills.

If you are experiencing short-cycling and need assistance getting the problem under control, call Burkholder’s HVAC today!