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 simple as a bad thermostat or an electrical problem. If your gas furnace won’t turn off, here are a couple steps you can take to get a correctly working furnace again. 

Check the Air Filter 

A dirty air filter creates problems for numerous homeowners and their HVAC system. Here’s why. It restricts airflow, forcing your furnace to work harder and run longer to meet your desired temperature. 

This increases usage on your furnace, as well as the likelihood of a malfunction and early 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 increase 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 replaced your furnace filter, pull it out and hold it up to the light. If you can’t see light through your filter, it’s too dusty and you should get a new one. 

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

Check Out the Thermostat 

Your thermostat runs your furnace and simply tells 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 easy as changing an incorrect thermostat setting. 

Ensure Your Thermostat is Set to “Auto”.

Your thermostat includes 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 operate constantly. 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 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 area 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 very cold outside, your furnace will have to run 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 test, you can try lowering the temperature to match 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 probably battery powered. You can test replacing the 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 cut 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 dedicated power switch. 

  1. Head to your breaker box and find the breaker labeled “furnace.” Push the breaker switch to the right to cut power. 
  1. Next, look for the dedicated power switch to your heating system. It looks like a light switch and can be found on or near your furnace. Move the switch down to shut off power. 
  1. 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? 

Sometimes correcting this problem can be as simple as replacing your air filter or adjusting thermostat settings. In other instances, 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 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 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 correct 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 other things 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 easy to save energy, because they create an energy-efficient heating and cooling schedule according to your preferences. Additionally, you’ll be able to set 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 running all the time because the ductwork is leaking hot air in the attic. 

Diagnosing this leaky ductwork and other airflow problems can be difficult to resolve on your own, since it’s concealed behind walls and ceilings. Our Experts can help with identifying and handling 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 rely 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.* Call us at 866-397-3787 to schedule your appointment now. 

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