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

It’s not unheard of for heating systems to have a problem every now and then. It could be as straightforward as a broken 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, making your furnace work harder and run longer to meet your desired temperature. 

This increases wear and tear on your furnace, as well as the odds of a breakdown and early failure. 

It can also make your furnace get too hot and shut off for a time to cool down. 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 more quickly, it can increase your heating bill and make your home feel uncomfortable. 

We encourage replacing flat filters monthly 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 detect light through your filter, it’s too dirty and you should replace it. 

If the matter was linked to a clogged air filter, replacing it with a new filter should solve this common problem when your heat won’t turn off. If not, we recommend checking your thermostat settings next. 

Check the Thermostat 

Your thermostat runs your furnace and basically informs the unit when to turn on and off. It’s often to blame when your furnace won’t stop running. 

Sometimes having the heat turn off is as simple as adjusting 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” means the furnace blower will only run when the furnace does. 

“On” indicates the furnace blower will operate constantly. This constant air flow can help with heat distribution but will also drive up 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 resolve the problem. It will also help you save money on your energy costs. 

Check 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 hits your desired temp. 

Keep in mind that if it’s extremely cold outside, your furnace will have to run much longer than normal to keep your home cozy. This is because of a large temperature difference between the cold air outside and the warm indoors. 

As a test, you can try reducing the thermostat to correspond with the room. Then, wait a couple of minutes. This should make the furnace shut off momentarily. 

Replace the Batteries 

If you have a programmable thermostat, it’s probably 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, switch it to “off.” 

If your furnace won’t turn off after you move it to “off,” you will need to turn off the power. 

Turn Off the Power 

Thermostat appears to be working fine but your furnace still won’t turn off? There are two places 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 shut off power. 
  1. Next, look for the dedicated power switch to your heating system. It’s similar to a light switch and can be found on or near your furnace. Push the switch down to cut power. 
  1. Your furnace should be turned off now. 

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

What Causes a Furnace to Keep Running? 

Sometimes correcting this problem can be as easy as replacing your air filter or adjusting thermostat settings. In other situations, you might need a professional when your heater won’t turn off. 

Fan Limit Switch Needs to Be Replaced 

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 going. 

You might notice a furnace error code if there’s a problem with the limit switch. Your furnace will communicate through a blinking red light on the front of your heating system. 

Our Experts can identify and correct 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. 

Defective Thermostat 

Like other things in your home, your thermostat can break down 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, because 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 anyplace with your phone. 

Air Ducts Are Leaking 

Your furnace uses ductwork to circulate hot air to vents across your home. If your home or ductwork is older, your furnace might be running constantly because the ductwork is leaking hot air in the attic. 

Identifying this leaky ductwork and other airflow problems can be tricky to troubleshoot on your own, since it’s concealed behind walls and ceilings. Our Experts can help with diagnosing and handling any air duct repair service that you require. 

Depend on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace problems 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 field. You can rely 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.* Call us at 866-397-3787 to book your appointment now. 

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