It’s not unheard of for heating systems to have a problem every now and then. It could be as simple as a broken thermostat or an electrical problem. If your gas furnace won’t shut off, here are a couple steps you can take to get a correctly 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 ideal temperature.
This increases wear and tear on your furnace, as well as the likelihood of a malfunction and premature 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 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 unpleasant.
We recommend replacing flat filters once a 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 see light through your filter, it’s too dirty and you should get a new one.
If the matter was linked to a clogged air filter, putting in a clean filter should solve this common problem when your heat won’t turn off. If not, we recommend checking your thermostat settings next.
Your thermostat runs your furnace and basically informs the unit when to turn on and off. It’s often the problem when your furnace won’t stop running.
At times having the heat turn off is as easy as changing an incorrect 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 operate when the furnace does.
“On” means the furnace blower will run continuously. This constant air flow can help with heat circulation but will also increase your power bill and increase wear and tear on your furnace.
If your thermostat is set to “on,” it will seem like your furnace is not turning off, but it’s really just the furnace blower you’re noticing. Changing it to “auto” should solve 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 running until it reaches your desired temp.
Remember that if it’s very cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is due to a large temperature difference between the cold air outside and the warm indoors.
As a check, you can try reducing the temperature to match the room. Then, wait a few minutes. This should make the furnace turn off momentarily.
If you have a programmable thermostat, it’s likely battery powered. You can test replacing the batteries to see if that resolves 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 move it to “off,” you will need to turn off the power.
Thermostat appears to be working fine but your furnace still won’t shut off? There are two places you can shut off the power to your heating unit: at the breaker box and at its dedicated 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 easy as changing 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 controls your furnace’s blower motor. If the switch goes out, it might sound like your furnace running continuously, even though just the blower is going.
You might notice a furnace error code if there’s an issue with the limit switch. Your furnace will speak 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. Sometimes this can involve replacement parts, such as the control board, faulty wiring or the fan switch itself.
Like other things 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, since they create an energy-efficient heating and cooling schedule according to your preferences. Additionally, you’ll be able to adjust 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 running constantly since the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow problems can be tricky to resolve on your own, since it’s hidden behind walls and ceilings. Our Experts can help with identifying and handling any air duct repair service that you need.
Troubleshooting furnace problems can be inconvenient, especially 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 book your appointment today.
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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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