What to Do When Your Heater Won’t Turn Off!

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 issue. If your gas furnace won’t turn off, here are a few steps you can take to get a properly working furnace again. 

Check the Air Filter 

A dirty air filter causes issues for numerous homeowners and their HVAC system. Here’s why. It limits 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 odds of a breakdown and early failure. 

It can also make your furnace overheat and shut down for a time to cool off. Then it will keep repeating this process when your furnace switches 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 monthly 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 see light through your filter, it’s too dirty and you should replace it. 

If the matter was linked 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 recommend checking your thermostat settings next. 

Check the Thermostat 

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. 

Sometimes having the heat turn off is as simple as adjusting a wrong thermostat setting. 

Make Sure Your Thermostat is Set to “Auto”.

Your thermostat has 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” 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. Switching it to “auto” should solve the problem. It will also help you spend less money on your energy costs. 

Confirm Your Temperature Setting 

If your thermostat won’t turn off heat, compare the temperature setting to the room 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 warm. 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 setting to match the room. Then, wait a few minutes. This should make the furnace turn off momentarily. 

Put in Fresh Batteries 

If you use a programmable thermostat, it’s probably battery powered. You can test 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 shut off after you set it to “off,” you will need to turn off the power. 

Turn Off the Power 

Thermostat seems to be working fine but your furnace still won’t shut off? There are two spots you can shut off the power to your heating unit: at the breaker box and at its specific power switch. 

1. Head to your breaker box and locate the breaker labeled “furnace.” Push the breaker switch to the right to cut power. 

2. Next, look for the specific power switch to your heating system. It’s similar to a light switch and can be found on or near your furnace. Move the switch down to shut off power. 

3. Your furnace should be turned off now. 

If you had to turn off your system at the breaker, call us at 866-397-3787 for professional service, as you may need furnace repair. 

What Causes a Furnace to Keep Running? 

Occasionally correcting this problem can be as simple as changing your air filter or changing thermostat settings. In other situations, you might need a professional when your heater won’t shut off. 

Fan Limit Switch Needs Replacing 

The furnace fan limit switch regulates your furnace’s blower motor. If the switch goes bad, it might seem like your furnace running continuously, 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 communicate via a flashing red light on the front of your heating system. 

Our Experts can identify and fix any issues you’re having with your furnace blower motor. Sometimes this can involve replacement parts, like the control board, faulty wiring or the fan switch itself. 

Faulty Thermostat 

Like anything else in your home, your thermostat can wear out over time and need to be replaced. If it’s time for a new one, ask us about installing 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 adjust and monitor your thermostat from just about anyplace with your phone. 

Air Ducts Are Leaking 

Your furnace uses ductwork to distribute hot air to vents across your home. If your home or ductwork is older, your furnace might be operating constantly 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 concealed behind walls and ceilings. Our Experts can help with identifying and taking care of any air duct repair service that you need. 

Depend on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace issues can be annoying, 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 866-397-3787 to book your appointment now.