It’s not unusual for heating systems to have a problem every now and then. It could be as straightforward as a broken thermostat or an electrical problem. If your gas furnace won’t turn off, here are a few steps you can take to get a properly working furnace again.
A dirty air filter creates problems for many homeowners and their HVAC system. Here’s why. It limits airflow, making your furnace work harder and run longer to satisfy your desired temperature.
This increases usage on your furnace, as well as the likelihood of a malfunction and early failure.
It can also make your furnace overheat and shut down for a time to cool down. Then it will keep duplicating this process when your furnace turns on. This is called short cycling. In addition to wearing out your furnace faster, it can increase your heating bill and make your home feel uncomfortable.
We recommend replacing flat filters each month and pleated filters every three months. If you can’t remember the last time you replaced your furnace filter, pull it out and hold it up to the light. If you can’t detect light through your filter, it’s too dusty and you should get a new one.
If the matter was connected to a clogged air filter, replacing it with a new filter should solve this common issue when your heat won’t turn off. If not, we suggest checking your thermostat settings next.
Your thermostat runs your furnace and basically tells the unit when to turn on and off. It’s often to blame when your furnace won’t stop running.
Sometimes having the heat turn off is as simple as changing a wrong thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat includes two settings, “auto” and “on,” that control your heating system’s blower motor.
“Auto” means the furnace blower will only run when the furnace does.
“On” indicates the furnace blower will run continuously. This constant air flow can help with heat circulation but will also drive up your power bill and increase wear and tear on your furnace.
If your thermostat is switched to “on,” it will seem like your furnace is not shutting off, but it’s really just the furnace blower you’re hearing. Switching it to “auto” should resolve the problem. It will also help you spend less money on your energy costs.
If your thermostat won’t turn off heat, check the temperature setting to the room temperature. If it’s greater than the room air temp, your furnace will keep running until it hits your desired temp.
Remember that if it’s very cold outside, your furnace will have to run much longer than normal to keep your home warm. This is due to a large temperature difference between the cold air outside and the warm indoors.
As a test, you can try lowering the setting to correspond with the room. Then, wait a couple of minutes. This should make the furnace turn off momentarily.
If you use a programmable thermostat, it’s probably battery powered. You can test putting in new batteries to see if that solves the issue. If it doesn’t or if there’s wiring to your electrical system, shift it to “off.”
If your furnace won’t shut off after you set it to “off,” you will need to turn off the power.
Thermostat seems to be working fine but your furnace still won’t shut off? There are two places you can cut the power to your heating unit: at the breaker box and at its specific power switch.
If you had to turn off your system at the breaker, call us at for professional service, as you may require furnace repair.
Sometimes fixing this problem can be as simple as changing your air filter or changing thermostat settings. In other instances, you might need a professional when your heater won’t turn off.
The furnace fan limit switch controls your furnace’s blower motor. If the switch goes bad, it might sound like your furnace running nonstop, even though just the blower is going.
You might see a furnace error code if there’s a problem with the limit switch. Your furnace will speak via a blinking red light on the front of your heating system.
Our Experts can identify and fix any problems you’re having with your furnace blower motor. Often this can involve replacement parts, like the control board, faulty wiring or the fan switch itself.
Like anything else in your home, your thermostat can wear out over time and need to be replaced. If you’re due for a new one, ask us about installing a smart thermostat.
These thermostats make it simple to save energy, because they create an energy-efficient heating and cooling schedule according to your needs. Plus, you’ll be able to set and keep tabs on your thermostat from just about anywhere with your phone.
Your furnace relies on ductwork to distribute hot air to vents across your home. If your home or ductwork is older, your furnace might be operating constantly since the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow issues can be challenging to troubleshoot on your own, since it’s concealed behind walls and ceilings. Our Experts can help with diagnosing and taking care of any air duct repair service that you need.
Troubleshooting furnace problems can be annoying, particularly when it affects your comfort, energy efficiency and heating bill. When it comes to furnaces, there’s a reason why we say we’re Experts in our field. You can depend on our ACE-certified technicians to solve your problem quickly and affordably. And what’s even better, we back our HVAC system repairs with a 100% satisfaction guarantee for one year.* Contact us at to schedule your appointment now.
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There’s no reason to skip your seasonal maintenance that saves energy and helps ensure your air conditioner and heater will work reliably all season long.
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