It’s not unheard of for heating systems to have a glitch every now and then. It could be as straightforward as a bad thermostat or an electrical issue. If your gas furnace won’t shut off, here are a few steps you can take to get a properly working furnace again.
A dirty air filter creates issues 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 multiplies wear and tear on your furnace, as well as the likelihood of a breakdown and early failure.
It can also make your furnace overheat and shut down for a time to cool down. Then it will keep repeating this process when your furnace turns on. This is known as short cycling. In addition to wearing out your furnace faster, it can drive up your heating bill and make your home feel uncomfortable.
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, remove it and hold it up to the light. If you can’t detect light through your filter, it’s too dirty and you should replace it.
If the matter was connected to a clogged air filter, putting in a fresh filter should fix this common issue when your heat won’t turn off. If not, we suggest checking your thermostat settings next.
Your thermostat controls your furnace and basically tells 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 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 run when the furnace does.
“On” means the furnace blower will operate constantly. This constant air flow can help with heat circulation but will also increase your power bill and lead to wear and tear on your furnace.
If your thermostat is set to “on,” it will sound like your furnace is not shutting 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, check the temperature setting to the room temperature. If it’s higher than the room air temp, your furnace will keep operating until it reaches your desired temp.
Remember that if it’s extremely cold outside, your furnace will have to run much longer than usual to keep your home cozy. This is due to a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try decreasing the temperature to correspond with the room. Then, wait a couple of minutes. This should make the furnace turn off in a few minutes.
If you have a programmable thermostat, it’s likely battery powered. You can try replacing the batteries to see if that resolves the issue. If it doesn’t or if there’s wiring to your electrical system, switch it to “off.”
If your furnace won’t shut 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 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, contact us at for professional service, as you may need furnace repair.
Occasionally fixing this problem can be as easy as replacing your air filter or changing thermostat settings. In other situations, you might need a professional when your heater won’t turn off.
The furnace fan limit switch regulates your furnace’s blower motor. If the switch goes out, it might sound like your furnace running continuously, even though just the blower is running.
You might see a furnace error code if there’s a problem with the limit switch. Your furnace will speak via a flashing red light on the front of your heating system.
Our Experts can identify and correct 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 break down as time passes and need to be replaced. If you’re due for a new one, ask us about getting 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 anyplace with your phone.
Your furnace relies on 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 because the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow issues can be challenging 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 require.
Troubleshooting furnace issues can be annoying, particularly when it impacts your comfort, energy efficiency and heating bill. When it involves furnaces, there’s a reason why we say we’re Experts in our field. You can count on our ACE-certified technicians to resolve 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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