It’s not unheard of for heating systems to have a problem every now and then. It could be as simple as a bad thermostat or an electrical problem. If your gas furnace won’t shut off, here are a couple steps you can take to get a properly working furnace again.
A dirty air filter creates problems for numerous homeowners and their HVAC system. Here’s why. It restricts airflow, forcing your furnace to work harder and run longer to meet your ideal temperature.
This multiplies wear and tear on your furnace, as well as the likelihood of a breakdown and early failure.
It can also make your furnace get too hot and shut down for a time to cool off. Then it will keep duplicating this process when your furnace switches on. This is called short cycling. In addition to wearing out your furnace faster, it can drive up your heating bill and make your home feel uncomfortable.
We encourage replacing flat filters once a month and pleated filters every three months. If you can’t remember the last time you got a new 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 replace it.
If the matter was connected to a clogged air filter, putting in a fresh 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.
At times having the heat turn off is as easy as adjusting a wrong thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat has two settings, “auto” and “on,” that manage your heating system’s blower motor.
“Auto” means the furnace blower will only operate when the furnace does.
“On” means the furnace blower will operate 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 sound like your furnace is not turning off, but it’s really just the furnace blower you’re hearing. Changing it to “auto” should resolve the problem. It will also help you save money on your energy costs.
If your thermostat won’t turn off heat, compare the temperature setting to the area temperature. If it’s greater than the room air temp, your furnace will keep operating until it reaches your desired temp.
Remember that if it’s very cold outside, your furnace will have to operate much longer than normal to keep your home warm. This is due to a big temperature difference between the cold air outside and the warm indoors.
As a check, you can try reducing the thermostat to match the room. Then, wait a few minutes. This should make the furnace shut off in a few minutes.
If you use a programmable thermostat, it’s likely battery powered. You can try putting in new batteries to see if that solves the problem. If it doesn’t or if there’s wiring to your electrical system, shift it to “off.”
If your furnace won’t turn off after you set it to “off,” you will need to turn off the power.
Thermostat appears to be working fine but your furnace still won’t turn off? There are two spots 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.
Occasionally fixing this problem can be as simple as replacing your air filter or changing thermostat settings. In other instances, you might want a professional when your heater won’t shut off.
The furnace fan limit switch regulates your furnace’s blower motor. If the switch goes out, it might seem like your furnace running nonstop, even though just the blower is running.
You might notice a furnace error code if there’s an issue with the limit switch. Your furnace will communicate via a blinking red light on the front of your heating system.
Our Experts can diagnose and fix any issues you’re having with your furnace blower motor. Often this can involve replacement parts, such as the control board, faulty wiring or the fan switch itself.
Like anything else in your home, your thermostat can break down over time and need to be replaced. If it’s time for a new one, ask us about getting a smart thermostat.
These thermostats make it easy to save energy, since they develop an energy-efficient heating and cooling schedule based on your needs. Plus, you’ll be able to set and monitor your thermostat from just about anywhere with your phone.
Your furnace uses ductwork to circulate hot air to vents throughout your home. If your home or ductwork is older, your furnace might be running all the time since the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow problems can be difficult to troubleshoot on your own, since it’s hidden behind walls and ceilings. Our Experts can help with diagnosing and handling any air duct repair service that you require.
Troubleshooting furnace issues can be inconvenient, especially when it impacts your comfort, energy efficiency and heating bill. When it comes to furnaces, there’s a reason why we say we’re Experts in our industry. You can count 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 book your appointment now.
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