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

It’s not uncommon for heating systems to have a problem once in a while. It could be as straightforward 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. 

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 satisfy your desired temperature. 

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

It can also make your furnace overheat and shut off for a time to cool off. Then it will keep duplicating 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 detect light through your filter, it’s too dirty and you should replace it. 

If the matter was connected to a clogged air filter, putting in a clean 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 simply tells the unit when to turn on and off. It’s usually the problem when your furnace won’t stop running. 

At times having the heat turn off is as easy as adjusting 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” indicates the furnace blower will only operate when the furnace does. 

“On” indicates the furnace blower will operate constantly. 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 seem like your furnace is not shutting off, but it’s really just the furnace blower you’re hearing. Changing it to “auto” should resolve the problem. It will also help you save money on your energy costs. 

Confirm Your Temperature Setting 

If your thermostat won’t turn off heat, check the temperature setting to the area temperature. If it’s higher 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 lowering the thermostat to correspond with the room. Then, wait a few minutes. This should make the furnace shut off momentarily. 

Put in Fresh Batteries 

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

Cut the Power 

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

  1. Head to your breaker box and locate 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’s similar to a light switch and is located 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 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 fixing this problem can be as simple as replacing your air filter or adjusting 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 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 notice a furnace error code if there’s an issue with the limit switch. Your furnace will communicate using 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, such as the control board, faulty wiring or the fan switch itself. 

Faulty Thermostat 

Like anything else 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 getting a smart thermostat

These thermostats make it simple to save energy, because they create an energy-efficient heating and cooling schedule based on your preferences. Additionally, you’ll be able to set and keep tabs on your thermostat from just about anyplace with your phone. 

Leaky Air Ducts 

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 constantly since the ductwork is leaking hot air in the attic. 

Identifying this leaky ductwork and other airflow problems can be difficult to troubleshoot 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 need. 

Depend on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace issues can be inconvenient, particularly 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.* Contact us at 866-397-3787 to book your appointment today. 

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