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 simple as a broken thermostat or an electrical issue. If your gas furnace won’t shut off, here are a few steps you can take to get a properly working furnace again. 

Examine the Air Filter 

A dirty air filter causes problems for many homeowners and their HVAC system. Here’s why. It limits airflow, making your furnace work harder and run longer to meet your ideal temperature. 

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

It can also make your furnace get too hot and shut down for a time to cool off. Then it will keep repeating this process when your furnace switches on. This is called 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 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 see 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 fresh filter should fix 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 basically tells the unit when to turn on and off. It’s often to blame when your furnace won’t stop running. 

At times having the heat turn off is as easy as changing a wrong 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 operate when the furnace does. 

“On” indicates the furnace blower will operate continuously. This constant air flow can help with heat circulation but will also drive up your power bill and lead to wear and tear on your furnace. 

If your thermostat is switched to “on,” it will sound like your furnace is not shutting 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. 

Check Your Temperature Setting 

If your thermostat won’t turn off heat, check the temperature setting to the room temperature. If it’s greater than the room air temp, your furnace will keep operating until it hits 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 decreasing the temperature to correspond with the room. Then, wait a couple of minutes. This should make the furnace turn off momentarily. 

Replace the Batteries 

If you use a programmable thermostat, it’s likely 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, switch it to “off.” 

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

Cut the Power 

Thermostat seems 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. Go to your breaker box and find the breaker labeled “furnace.” Move the breaker switch to the right to shut off power. 
  1. Next, search 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. Push 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? 

Occasionally correcting this problem can be as simple as replacing your air filter or changing thermostat settings. In other situations, you might want a professional when your heater won’t shut 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 seem like your furnace running nonstop, even though just the blower is running. 

You might notice a furnace error code if there’s a problem with the limit switch. Your furnace will communicate via a blinking 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, like the control board, faulty wiring or the fan switch itself. 

Bad Thermostat 

Like anything else in your home, your thermostat can break down as time passes 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 create an energy-efficient heating and cooling schedule according to your needs. Plus, you’ll be able to adjust and monitor your thermostat from just about anyplace with your phone. 

Leaky Air Ducts 

Your furnace uses ductwork to distribute hot air to vents throughout 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 issues can be challenging to resolve on your own, since it’s hidden behind walls and ceilings. Our Experts can help with identifying 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 industry. You can rely on our ACE-certified technicians to solve 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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