What Causes Heating Systems To Shut Off Frequently?

December 29, 2020

On. Off. On. Off. The heater clicking on and off is not only annoying – it may be cause for concern! So, what exactly could be the cause for a heating system to shut off repeatedly? To answer this question, it is important to understand the typical operation of a heating system. 

Heating System Cycle for Los Angeles Homes

The average on/off cycle for a heating system is three to six times an hour.

Most homes in Los Angeles have a central heating system, like a furnace. The furnace turns on and off based on signals from your thermostat. When your thermostat senses that it is too cold, your heater turns on. And once it’s warm enough, your heater turns off. It’s normal for this cycle to happen several times an hour. 

If a unit is going through its cycles more often, we call that short-cycling. Short-cycling is just what it sounds like: the cycling on and off is happening faster than we expect. A furnace that is short-cycling definitely needs repair. Besides it being irritating to hear, short-cycling causes extra wear and tear on your system, leading to a shorter system life. It’s also the cause for higher than normal energy bills. 

Why Your Heating System Is Shutting Off All The Time

Instead of immediately calling for a furnace repair, there’s a chance you can determine and resolve the root cause of the short cycling. Here are a few things to check: 

Thermostat Causing Mixed Signals

Since your thermostat is signaling the furnace, it’s a good place to start troubleshooting. First, check the thermostat and make sure you have set it to operate in heat and at the right temperature. Next, see if the thermostat might be sensing extra heat. For example, is your thermostat in direct sunlight? Or, is it possible there’s another heat source nearby that might cause funky readings? Space heaters and even hair dryers used near the controls or the thermostat might make it sense that the home has reached the set temperature and cause short-cycling.

Clogged Air Filters

You should replace air filters every three months at a minimum, but if you have many people or pets in your home, check them monthly. A clogged filter is one of the most common causes for short cycling. Without proper air flow through the system, warm air cannot circulate through the home as it should and a cold house is the result. The unit works harder than it should without providing the desired comfort, and that can lead to mechanical problems.

Other Reasons for Your Heating System Shutting Off Repeatedly

Why else could your heating system shut off? Heaters are complex mechanical systems, and there are hundreds of components that could be the cause. Some other causes for short-cycling in a heating system are:

  • Undersized ductwork or equipment
  • Corroded flame sensor
  • Objects lodged in air vents or chimney
  • Dislodged air ducts
  • Low refrigerant in a heat pump 

Call in The Experts at Brody Pennell

Our expert team at Brody Pennell will quickly diagnose the cause for your unit short-cycling. Sometimes, the only cure for short-cycling is a new heating system. This could definitely be the case if your heater is not sized correctly for your home and lifestyle. Our comfort consultants at Brody Pennell can say for sure. We offer many affordable options and special financing to ensure you can get the comfort you need. Call us today to learn more about efficient heating options and rebates for Los Angeles homeowners. Book an appointment online with one of our professionals to get your heat pump or furnace fixed right away!


About The Author

Brody Pennell

Since 1945, Brody Pennell Heating & Air Conditioning is the committed to helping homeowners in the greater Los Angeles area experience total home comfort. In 2021, the readers of the Los Angeles Times voted Brody Pennell the Best HVAC Company in the area.

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