How Often Should My Furnace Cycle in an Indiana Winter?

Indianapolis winter months puts your furnace to the test. After months of being dormant, the system suddenly finds itself working overtime. While it should cycle throughout the day, clicking on too frequently may indicate a problem.

Homeowners often find themselves wondering, “How often should my furnace cycle?” The answer falls into a grey area. On average, the normal winter furnace function should cycle every 15 to 20 minutes…so about 4 to 5 an hour. In extreme cold, like we are about to have, it will cycle more trying to keep up with dropping temperatures. 

Is the Furnace Cycling On and Off Normal?

The number of times your furnace runs per hour depends on several variables. Your home’s insulation, characteristics of the house, outdoor air temperatures, and even the age of your furnace may all play a role. And yes, in some instances, frequent cycling may indicate an issue with the system.

Why is My Furnace Cycling On and Off?

If you notice that your furnace is cycling frequently, it may be because:

The Furnace Is the Wrong Size

A bigger furnace isn’t always better. Furnace short cycling is often the direct result of an oversized system. But wouldn’t a larger furnace heat a home faster and better? Surprisingly, the answer is no.

While an oversized heater will heat a smaller home quickly, it won’t evenly distribute the air. The system will short cycle to keep temperatures equal throughout the house. Which size is best? The BTU we recommend in Indiana is 40,000 BTU to 50,000 BTU per 1000 Sq Ft, in general. 

The Furnace is Overheating

When it’s freezing outside, your furnace could be burning up on the inside. Overheating is a leading cause of furnace short cycling. What causes overheating? In many instances, restricted airflow is the culprit. A blockage in the ducts or a clogged filter can stop air from flowing out of the system.

The Furnace is Past Its Prime

How old is your furnace? As the system gets older, you may notice the furnace cycling on and off more frequently. On average, furnaces last for about 15 to 20 years. As it reaches the end of its lifespan, it may not run as efficiently as before. Short cycling is a common indicator that it is time to buy a newer model.

A Malfunctioning Thermostat

The thermostat tells the furnace when to cycle. If the thermostat malfunctions or breaks, your furnace will not know when to stop running. Where you place the thermostat also plays a role. To keep your furnace from cycling too often, make sure the thermostat isn’t too close to a heat source or in direct sunlight.

A Dirty Flame Sensor

Does your furnace only cycle for a few seconds at a time? A dirty flame sensor may be the reason. Cleaning the sensor will help regulate cycles and prevent harmful gas leaks in your home.

Extremely Cold Weather or Short Cycling?

Icy temperatures mean your furnace will kick on more frequently. It will do everything possible to keep up with the outside temperatures—even if that means cycling more often. However, your system shouldn’t turn on and cut off every few minutes just because there’s a layer of snow on the ground. Furnace cycles should last until the house reaches the desired temperature.

A few factors come into play when determining whether constant cycles are due to extremely cold weather or not. How well insulated is your home? Losing too much heat through the roof, windows, or doorways will cause your furnace to run more often. High ceilings and single-pane windows are common culprits.

If your furnace only turns on for a few minutes at a time, but your home never warms up, it’s probably short cycling. Colder temperatures will make the system work harder, but it’s time to have the furnace inspected if the cycles just keep getting shorter. 

The proactive steps a homeowner can do if they notice their unit short cycling is to check the filter and make sure the thermostat batteries aren’t running low (if your thermostat has batteries.)  Everything else they should call a professional to diagnose.

If you’re experiencing some of these problems, we would be happy to take a look at your unit.