How Often Should a Furnace Cycle? Homeowner’s Guide

You may hear it kicking on and off every now and then, but did you ever wonder if your furnace was cycling on and off too often?

Every now and then we will get phone calls from homeowners wondering if their furnace is operating normally. It’s normal for furnaces to make noises, so it’s not always a problem. Every now and then, it was the sign of a bigger issue though. Luckily for folks looking for furnace repair in Havertown, PA John Cipollone, Inc. is here to help!

At John Cipollone, Inc., we have been installing furnaces and heating systems for years, and know the ins and outs of how they operate. In my experience, I’ve seen some furnaces making lots of noise that needed a simple repair, some that needed a replacement, and then others that simply needed a bit of service.

The answer to this particular question is best explained by understanding how your furnace works and the signs of problems to watch for.

Furnace Cycling Explained

Furnace cycling is the process of your furnace thermostat recognizing that the temperature in the house is now below the thermostat’s set temperature. The thermostat calls for heat from the furnace until your home reaches the “set” or desired temperature on the thermostat.

Short-Cycling

Depending on the condition of your furnace, the outdoor temperature, and other variables your furnace should cycle on between 3 and 8 times per hour. If you notice that your furnace cycles significantly more than that or you notice it running for only a minute or two before shutting off, you could be experiencing a problem with your furnace. 

How Long Should A Furnace Run?

A furnace cycle typically operates for about 15 minutes at a time. How often a furnace should run also depends on the size of your space and the weather. The cycle time can run longer if the outside temperature is unusually cold or the indoor temperature needs to reach a significantly warmer temperature.

How Often Should Your Furnace Kick On?

Your furnace should kick on about 3 to 8 times per hour. Much depends on the temperature outside and how hard your furnace needs to work to heat your home

Common Causes for Furnace Short-Cycling

I have put together a few of the common causes of short cycling that you can check before calling a service technician.

Clogged Filter

One of the most common causes of short cycling is a dirty or clogged air filter. A dirty air filter doesn’t allow warm air to freely flow making your furnace work harder to achieve the desired temperature.

Electrical Problems

Occasionally we find that a damaged or malfunctioning hot surface igniter, or the pilot light will randomly shut off. We frequently see this on older model furnaces. Your furnace will automatically shut down to avoid the build-up of toxic gasses.

Faulty Thermostat

The easiest thing to check is your thermostat. Sometimes the homeowner will forget to switch over to the heat function between seasons, leaving you wondering where the heat is. 

First, make certain that the heat setting is activated on your thermostat. If that doesn’t solve the problem, check to see if the thermostat is registering the temperature that has been called for. 

Oversized Furnace

Believe it or not – bigger is not always better. An incorrectly sized furnace will short cycle in an effort to maintain even heat throughout the home. Larger furnaces generate excess heat leaving much of it to escape through faulty seals. With excess heat loss your furnace will short cycle in an attempt to keep a constant temperature.

If you are in need of heater repairs in Havertown, PA, give us a call at (610) 446-7877, or click here to contact us online!

How Often Should a Furnace Cycle? More FAQs

A properly operating furnace should cycle between 3 to 8 times per hour.

How do I stop my furnace from short-cycling?

Check for clogged air filters or obstructions and check your thermostat. If all else fails call your trusted service technician.

Is it bad for a furnace to run nonstop?

A constantly running furnace puts strain on the system and potentially shortens its lifespan.

Is it normal for a furnace to cycle every five minutes?

No – a furnace that runs for short periods is short cycling and needs a service call.