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

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

Check the Air Filter 

A dirty air filter causes problems for numerous homeowners and their HVAC system. Here’s why. It limits airflow, forcing your furnace to work harder and run longer to meet 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 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 increase your heating bill and make your home feel uncomfortable. 

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, pull it out 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 suggest checking your thermostat settings next. 

Check the Thermostat 

Your thermostat controls 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. 

At times having the heat turn off is as easy as adjusting a wrong thermostat setting. 

Make Sure Your Thermostat is Set to “Auto”.

Your thermostat includes two settings, “auto” and “on,” that control your heating system’s blower motor. 

“Auto” means the furnace blower will only run when the furnace does. 

“On” indicates the furnace blower will operate continuously. This constant air flow can help with heat distribution 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 turning off, but it’s really just the furnace blower you’re noticing. Changing it to “auto” should solve 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, compare the temperature setting to the area temperature. If it’s greater than the room air temp, your furnace will keep running until it reaches your desired temp. 

Remember that if it’s extremely cold outside, your furnace will have to run much longer than normal 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 decreasing the temperature to correspond with the room. Then, wait a few minutes. This should make the furnace turn off in a few minutes. 

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 resolves the issue. 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 move 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. Go to your breaker box and locate the breaker marked “furnace.” Move the breaker switch to the right to cut power. 
  1. Next, search for the specific power switch to your heating system. It’s similar to a light switch and is located on or close to your furnace. Push the switch down to cut power. 
  1. Your furnace should be shut 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 require furnace repair

What Causes a Furnace to Keep Running? 

Occasionally correcting this problem can be as simple as replacing your air filter or adjusting thermostat settings. In other situations, 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 seem like your furnace running continuously, even though just the blower is running. 

You might see a furnace error code if there’s a problem 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 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 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 preferences. Plus, you’ll be able to set and keep tabs on your thermostat from just about anywhere 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 operating constantly since the ductwork is leaking hot air in the attic. 

Diagnosing this leaky ductwork and other airflow problems can be difficult to troubleshoot on your own, since it’s hidden behind walls and ceilings. Our Experts can help with diagnosing 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, 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 field. 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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