Why Does My Furnace Keep Turning On and Off?

When your furnace keeps turning on and shutting off more than its standard three to six times in an hour, this is called short-cycling, and it could be racking up your energy bill.

Short-cycling may not seem serious at first, but it’s typically a sign that your furnace is too big, your thermostat is malfunctioning, or a blocked or dirty air filter is making your heat exchanger overheat.

What can you do to resolve the short-cycling problem? Learn more here about our short-cycling solutions at BVSM Heating & Air Conditioning in Beaver County.

What Causes Furnace Short-Cycling?

The difference between a furnace that’s operating correctly and a furnace that’s short-cycling comes down to a few small but important observations.

In a typical furnace cycle, a thermostat operates the furnace to maintain the air at the desired room temperature. Once the desired temperature is reached, it will shut off momentarily to preserve energy, and turn on again as needed, typically only two or more times per hour.

However, when a furnace turns on and off constantly, this is short-cycling, which is an inefficient way to heat your home and can be taxing on your heating system, increasing your chances of needing furnace repairs or a premature furnace replacement.

If your furnace turns off and on at an unusually high rate, contact BVSM Heating & Air Conditioning for affordable heating and cooling services in Beaver County, PA.

Restricted Airflow: A Leading Cause of Furnace Short-Cycling

If you haven’t replaced the air filter in your furnace in over two months, it may be clogged with dirt. Or, if you notice short-cycling even after replacing your furnace’s air filter, the filter could be too restrictive to allow proper airflow.

Reducing your risks of short-cycling starts with using air filters that comply with your specific model and brand of furnace, and remembering to change your air filters regularly. Ask yourself:

• Have I changed my furnace’s air filter within the past two months?
• Does my air filter match my brand and model of furnace?
• Are the air vent registers blocked by furniture, small objects, or debris?
• Do the air conditioner coils in my HVAC unit have debris blocking airflow?

Regularly replacing dirty furnace air filters is an inexpensive way to support the optimal use of your furnace and keep it running smoothly.

However, if your furnace still short-cycles even after replacing the filters, clearing around the air vent registers, and cleaning the AC coils around your HVAC system, it may be a thermostat issue.

Is Your Thermostat Malfunctioning?

A common mistake homeowners make when they notice their heater or AC isn’t working as well as it should be, is to assume they need HVAC repair before checking that their thermostat is properly adjusted.

To determine if your thermostat is causing your furnace to short-cycle, answer these questions:

• Is my thermostat turned on and displaying accurate settings?
• Is my thermostat placed too close to another heat source, such as a heat register?
• When was the last time I scheduled preventative maintenance for my HVAC system?

Thermostats are highly sensitive to changes in room temperature. When they’re too close to other heat sources (even sunlight!), they can shut off, believing the air is too warm. To ensure your thermostat and HVAC system are working properly, routine inspections are highly recommended.

Furnace problems won’t get better on their own — they only get worse. If your furnace is having issues, contact us for furnace repairs in Beaver Valley.

Additional Causes of Furnace Short-Cycling

If your furnace is still short-cycling after checking for a dirty air filter or a malfunctioning thermostat, the cause may be more difficult to determine. It could indicate one of these furnace issues:

• Your heating system is too big.
• The furnace has a corroded flame sensor.
• The chimney or air vents are clogged.

Not all furnace repair issues can be spotted right away. To guarantee a thorough HVAC inspection, contact qualified heating and cooling contractors for professional advice and repair options.

Schedule Furnace Repair or Replacement With BVSM

If your furnace is shutting off and turning on too frequently, call our HVAC contractors at BVSM Heating & Air Conditioning to inspect your furnace and resolve your short-cycling problem. Regular furnace maintenance can help prevent issues like short-cycling, ensuring your system runs efficiently year-round.

Contact us today to learn about all our heating and cooling services in Monaca and Beaver County, PA.

FAQs

Why does my furnace keep turning off and on so often?

A furnace that constantly turns off and on is usually short cycling. This often happens because of restricted airflow, thermostat problems, or a safety sensor shutting the system down to prevent damage. A professional inspection can pinpoint the exact cause.

What is short cycling and why is it bad for my furnace?

Short cycling means your furnace runs for very short periods and then shuts off before completing a full heating cycle. This can lead to higher energy bills, uneven heating, and unnecessary wear on your system.

What mechanical issues cause a furnace to cycle on and off?

Problems with the flame sensor, pressure switch, blower motor, or ignition system can cause the furnace to shut down for safety reasons. These issues need to be diagnosed by a trained HVAC technician.

Should I worry if my furnace keeps turning on and off?

Yes. Short cycling can damage your furnace over time and increase your energy costs. It can also indicate a safety issue. It is best to have the system inspected as soon as possible.