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

It’s not unusual for heating systems to have a glitch once in a while. It could be as straightforward as a broken thermostat or an electrical problem. 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 problems for many homeowners and their HVAC system. Here’s why. It limits airflow, forcing your furnace to work harder and run longer to satisfy your desired temperature. 

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

It can also make your furnace overheat and shut down for a time to cool down. Then it will keep repeating this process when your furnace turns on. This is known as short cycling. In addition to wearing out your furnace more quickly, it can drive up your heating bill and make your home feel unpleasant. 

We recommend replacing flat filters each month and pleated filters every three months. If you can’t remember the last time you got a new furnace filter, remove it and hold it up to the light. If you can’t detect 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 fresh filter should solve this common issue 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 tells the unit when to turn on and off. It’s usually the problem when your furnace won’t stop running. 

Sometimes having the heat turn off is as easy as adjusting a wrong 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 run continuously. This constant air flow can help with heat circulation 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 shutting 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 higher than the room air temp, your furnace will keep operating until it hits your desired temp. 

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

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

Put in New 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 shut off after you move it to “off,” you will need to turn off the power. 

Turn Off the Power 

Thermostat seems to be working fine but your furnace still won’t shut 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 find the breaker marked “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 is located 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 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? 

Occasionally fixing this problem can be as simple as changing your air filter or changing thermostat settings. In other situations, you might want 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 seem like your furnace running nonstop, even though just the blower is running. 

You might notice a furnace error code if there’s an issue with the limit switch. Your furnace will speak via a blinking red light on the front of your heating system. 

Our Experts can diagnose and fix any issues 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 other things in your home, your thermostat can wear out 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, since they develop an energy-efficient heating and cooling schedule according to 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 relies on ductwork to distribute 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 challenging to resolve on your own, since it’s concealed behind walls and ceilings. Our Experts can help with identifying 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, particularly when it affects your comfort, energy efficiency and heating bill. When it involves furnaces, there’s a reason why we say we’re Experts in our field. You can depend on our ACE-certified technicians to resolve your problem quickly and affordably. And what’s even better, we back 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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