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

It’s not unusual for heating systems to have a glitch every now and then. It could be as straightforward as a bad thermostat or an electrical problem. If your gas furnace won’t shut off, here are a couple steps you can take to get a properly working furnace again. 

Examine the Air Filter 

A dirty air filter causes issues for many homeowners and their HVAC system. Here’s why. It restricts airflow, forcing your furnace to work harder and run longer to satisfy your ideal temperature. 

This increases usage on your furnace, as well as the likelihood of a malfunction and premature failure. 

It can also make your furnace overheat and shut off for a time to cool off. Then it will keep repeating this process when your furnace turns on. This is called 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 encourage replacing flat filters each 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 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, replacing it with a fresh filter should fix this common problem when your heat won’t turn off. If not, we recommend checking your thermostat settings next. 

Check Out the Thermostat 

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

At times having the heat turn off is as simple as changing an incorrect 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 operate when the furnace does. 

“On” means the furnace blower will run 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 sound like your furnace is not turning off, but it’s really just the furnace blower you’re noticing. Changing 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, check the temperature setting to the area temperature. If it’s greater than the room air temp, your furnace will keep operating until it hits your desired temp. 

Keep in mind that if it’s very cold outside, your furnace will have to run much longer than usual to keep your home warm. This is due to a big temperature difference between the cold air outside and the warm indoors. 

As a test, you can try lowering the setting to correspond with the room. Then, wait a few minutes. This should make the furnace turn off in a few minutes. 

Put in Fresh Batteries 

If you have a programmable thermostat, it’s likely battery powered. You can test putting in new 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 set 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 shut off? There are two places you can cut the power to your heating unit: at the breaker box and at its specific power switch. 

  1. Head to your breaker box and find the breaker marked “furnace.” Push the breaker switch to the right to cut power. 
  1. Next, look for the specific power switch to your heating system. It’s similar to a light switch and can be found on or close to your furnace. Push the switch down to shut off power. 
  1. Your furnace should be shut off now. 

If you had to turn 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 fixing this problem can be as simple as replacing your air filter or adjusting thermostat settings. In other instances, you might want a professional when your heater won’t shut off. 

Fan Limit Switch Needs to Be Replaced 

The furnace fan limit switch controls your furnace’s blower motor. If the switch goes bad, it might seem like your furnace running continuously, even though just the blower is going. 

You might see a furnace error code if there’s a problem with the limit switch. Your furnace will speak through a blinking 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, such as the control board, faulty wiring or the fan switch itself. 

Bad Thermostat 

Like anything else in your home, your thermostat can wear out as time passes 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 needs. Plus, you’ll be able to set and monitor your thermostat from just about anyplace with your phone. 

Air Ducts Are Leaking 

Your furnace relies on ductwork to distribute hot air to vents throughout 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. 

Diagnosing this leaky ductwork and other airflow problems can be challenging to resolve on your own, since it’s concealed behind walls and ceilings. Our Experts can help with diagnosing and taking care of any air duct repair service that you require. 

Rely on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace problems can be annoying, especially 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 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.* Call us at 866-397-3787 to book your appointment now. 

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