Why Does My Furnace Keep Running

Jan 27, 2020

With unpredictable winter weather on the way, there is certainly cause for concern if your furnace isn’t working as it should be. Please don’t ignore your furnace until a problem rears its ugly head. Preventive maintenance is essential to the performance and longevity of your HVAC system. Each year, before the cold-weather season arrives, give New Albany Heating & Cooling a call to schedule a comprehensive inspection and thorough cleaning of your HVAC system by one of our HVAC technicians. You will start off the winter season right, knowing your system is ready to take on the cold weather ahead, and that your home and your family will be warm and comfortable. The term “short-cycling” means your furnace is running for only a few minutes, shutting off, and coming back on repeatedly. It means that your furnace is not completing a full, proper operating cycle. There are a number of reasons this may be happening. Some of these you can troubleshoot yourself, but others will require the help of one of our expert technicians.


Possible Causes Of Your Nonstop Running Thermostat 


Someone Has Turned Up the Thermostat 

This is such a simple explanation that it may not even occur to you, but it is the most common reason for your furnace running more frequently than usual. If the temperature on your thermostat has been turned up, the furnace will, of course, run more than usual. When you realize this is happening, check your thermostat’s setting first. Something this simple is, of course, preferable to a more serious issue. Adjust your thermostat back to a lower temperature setting. If it continues to short-cycle, another problem exists. 


The Air Filter Needs to Be Replaced 

When your furnace’s air filter gets clogged with dust, dirt, and debris, air can’t flow freely through it anymore. Your furnace will struggle to work and keep your home warm. The blocked airflow stops the furnace’s heat exchanger from receiving the air it needs, and the heat exchanger becomes overheated. This will cause the furnace’s fan to run continuously, as cold air is required to cool off the heat exchanger. This can be fixed – and prevented altogether – very easily by checking and changing the air filter before winter arrives. Making sure there is always a clean air filter in your furnace is very important to keep your HVAC system functioning properly. Make a note on your calendar to remind yourself to check the air filter once a month throughout the cold-weather season and replace it at least once during the winter months. 


The Fan Switch is Set To ‘On’ 

The fan switch on your thermostat has two settings: ‘Auto’ and ‘On.’ This switch operates the fan in your furnace. When it is in the ‘On’ position, the furnace’s blower will remain on and running continuously, wasting energy as well as causing your HVAC system to work needlessly. The continuous activity can cause your furnace to become overworked and overheated, and that could potentially damage your HVAC system. Change the fan setting to ‘Auto.’ The fan will run only when it needs to blow warm air into your home. 


Problems with The Fan Limit Switch 

If the fan limit switch in your furnace becomes damaged or worn out, your furnace will begin to short cycle. The switch can be found under the hood of the furnace. It controls the furnace’s blower. The fan limit switch features a probe-like device that turns the fan on in the event the burner assembly becomes overheated. After it cools down, the probe turns the fan off. If the limit switch or the probe gets damaged or becomes stuck in the ‘On’ position, the blower won’t be shut off and will run continuously. If you think this may be happening, give us a call and let one of our skilled HVAC specialists assess the problem and make any necessary repairs. 


The Pilot Flame Needs to Be Re-Lit 

Cold air being blown into your home along with short-cycling may be an indication that the furnace’s pilot light has gone out. When this occurs, the furnace will run continuously as it tries to heat your home. You can re-light the pilot light yourself if you feel comfortable doing so; or, if you would prefer to have a professional do it, call us, and we will send one of our HVAC technicians to re-light it for you. 


Still Have Questions About Your Furnace?

If your furnace is running more than usual, short-cycling, or if there is any other type of indication of a problem with your system, call New Albany Heating & Cooling at 614-636-5002 or visit our webpage at https://newalbanyheatingcooling.comschedule-now/ and let us set up an appointment for you with one of our HVAC technicians who will find the issue and repair it immediately. We are available 24 hours a day, seven days a week, 365 days a year for your convenience to assist you with all your HVAC needs and to answer any questions you may have.