It’s not unheard of for heating systems to have a glitch once in a while. It could be as straightforward as a bad 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 causes problems for many homeowners and their HVAC system. Here’s why. It limits airflow, forcing your furnace to work harder and run longer to satisfy your desired temperature.
This increases wear and tear on your furnace, as well as the likelihood of a breakdown and premature failure.
It can also make your furnace overheat and shut off for a time to cool down. Then it will keep duplicating this process when your furnace switches on. This is known as short cycling. In addition to wearing out your furnace more quickly, 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 dusty and you should replace it.
If the matter was linked to a clogged air filter, replacing it with a clean 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 usually 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 has two settings, “auto” and “on,” that manage your heating system’s blower motor.
“Auto” indicates 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 distribution 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 hearing. Switching 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 running until it hits your desired temp.
Remember that if it’s extremely cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a check, you can try lowering the temperature to match the room. Then, wait a couple of minutes. This should make the furnace turn off in a few minutes.
If you use a programmable thermostat, it’s likely battery powered. You can try replacing the 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 turn off after you switch it to “off,” you will need to cut the power.
Thermostat seems 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 switch off your system at the breaker, contact us at for professional service, as you may require furnace repair.
Occasionally fixing this problem can be as simple as changing your air filter or adjusting thermostat settings. In other instances, you might need a professional when your heater won’t shut off.
The furnace fan limit switch regulates your furnace’s blower motor. If the switch goes bad, it might sound like your furnace running nonstop, even though just the blower is running.
You might see a furnace error code if there’s an issue with the limit switch. Your furnace will speak through a flashing 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. Sometimes 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 wear out over time and need to be replaced. If you’re due for a new one, ask us about getting a smart thermostat.
These thermostats make it easy to save energy, because they develop an energy-efficient heating and cooling schedule according to your preferences. 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 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.
Identifying this leaky ductwork and other airflow problems can be difficult to resolve on your own, since it’s hidden behind walls and ceilings. Our Experts can help with diagnosing and taking care of any air duct repair service that you need.
Troubleshooting furnace issues 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 industry. You can count on our ACE-certified technicians to resolve your problem quickly and affordably. And what’s even better, we stand behind our HVAC system repairs with a 100% satisfaction guarantee for one year.* Contact us at to schedule 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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