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 shut off, here are a couple steps you can take to get a properly working furnace again. 

Examine the Air Filter 

A dirty air filter creates issues for numerous homeowners and their HVAC system. Here’s why. It restricts airflow, forcing your furnace to 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 premature 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 switches on. This is called short cycling. In addition to wearing out your furnace more quickly, 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 see light through your filter, it’s too dusty and you should replace it. 

If the matter was linked to a clogged air filter, putting in a new filter should solve this common problem 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 informs the unit when to turn on and off. It’s often the problem when your furnace won’t stop running. 

Sometimes having the heat turn off is as simple 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” indicates the furnace blower will only run when the furnace does. 

“On” means the furnace blower will run constantly. This constant air flow can help with heat distribution but will also drive up your power bill and increase wear and tear on your furnace. 

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

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 running until it hits your desired temp. 

Remember that if it’s extremely cold outside, your furnace will have to operate much longer than normal to keep your home warm. This is due to a large temperature difference between the cold air outside and the warm indoors. 

As a test, you can try lowering the setting to match the room. Then, wait a couple of minutes. This should make the furnace turn off momentarily. 

Replace the Batteries 

If you have a programmable thermostat, it’s probably battery powered. You can try replacing the batteries to see if that resolves the issue. 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 appears to be working fine but your furnace still won’t turn off? There are two spots you can shut off the power to your heating unit: at the breaker box and at its specific power switch. 

  1. Go to your breaker box and locate the breaker marked “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 close to your furnace. Push the switch down to shut off power. 
  1. Your furnace should be shut 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 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 shut off. 

Fan Limit Switch Needs to Be Replaced 

The furnace fan limit switch controls your furnace’s blower motor. If the switch goes out, it might seem like your furnace running continuously, even though just the blower is going. 

You might see a furnace error code if there’s an issue with the limit switch. Your furnace will speak using 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. 

Bad Thermostat 

Like anything else in your home, your thermostat can wear out as time passes and need to be replaced. If it’s time for a new one, ask us about getting a smart thermostat

These thermostats make it easy to save energy, because they develop an energy-efficient heating and cooling schedule based on your preferences. Plus, you’ll be able to adjust and keep tabs on your thermostat from just about anywhere with your phone. 

Leaky Air Ducts 

Your furnace relies on ductwork to distribute hot air to vents throughout 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 issues can be difficult to resolve on your own, since it’s hidden behind walls and ceilings. Our Experts can help with diagnosing 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 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 field. You can count 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.* Call us at 866-397-3787 to schedule your appointment today. 

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