Three Reasons Your Furnace Is Short-Cycling

A furnace that is in good working order will only cycle on and off a limited number of times within an hour. However, a furnace in poor condition may repeatedly turn on and off. When you have a furnace that behaves in this fashion, there is an underlying issue to blame. The frequent on and off cycle is known as short-cycling. Short-cycling can damage a furnace, but the process can also drive up your energy cost. Learn some of the reasons why your unit might be short-cycling.


Professional furnace installation is important for a wide range of reasons. One of the more critical reasons has to do with sizing. Furnace manufacturers make their units in all sorts of sizing options because not all structures have the same heating needs. When a homeowner bypasses a professional and chooses a furnace on their own, they are more likely to select the wrong option, including a unit that is too large for their needs. 

Too large of a furnace will send a rush of warm air into your house. The thermostat then assumes that your home has reached the ideal temperature. As a result, the heat will go off. However, a few short moments later when the temperature drops again, the furnace will turn back on. The short-cycling process will just continue over and over. 

Air Filter

Many people only look at air filters in terms of their ability to keep allergens and other particles out of the air inside their home. However, air filters also play a role when it comes to airflow. When a filter is clogged, a sufficient amount of air cannot cycle through the furnace. The restricted flow of air forces the furnace to work harder, which often causes it to overheat. 

Once the furnace gets too hot, it will automatically shut itself down as a sort of safety measure. When you keep the air filter clean, you don't have to worry about the problem. Look at your filter to see if it's cleanable or removable, and follow the manufacturer's guidelines to clear the screen. For more information on how often you should change the filter in your home, it's best to contact an HVAC professional. 

If you notice a problem with your furnace, contact a furnace replacement and repair professional as soon as possible. Short-cycling will not fix itself. Instead, the problem will only get worse. A repair professional can highlight and correct the problem for you.