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

It’s not unheard of for heating systems to have a glitch once in a while. 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 correctly working furnace again. 

Check the Air Filter 

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

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

It can also make your furnace get too hot and shut off for a time to cool down. 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 increase 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 dirty and you should get a new one. 

If the matter was linked to a clogged air filter, putting in a clean filter should fix this common problem when your heat won’t turn off. If not, we suggest checking your thermostat settings next. 

Check the Thermostat 

Your thermostat runs your furnace and simply informs 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 changing an incorrect thermostat setting. 

Ensure Your Thermostat is Set to “Auto”.

Your thermostat includes 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” means 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 set to “on,” it will sound like your furnace is not turning 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, compare 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 very cold outside, your furnace will have to run much longer than normal to keep your home cozy. This is due to a big temperature difference between the cold air outside and the warm indoors. 

As a check, you can try reducing the setting to match the room. Then, wait a few minutes. This should make the furnace shut off in a few minutes. 

Put in Fresh Batteries 

If you have a programmable thermostat, it’s probably 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 shut off after you set it to “off,” you will need to turn off the power. 

Cut the Power 

Thermostat seems 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. Head to your breaker box and locate the breaker marked “furnace.” Push the breaker switch to the right to cut power. 

2. Next, look for the dedicated power switch to your heating system. It’s similar to a light switch and is located on or close to your furnace. Move the switch down to cut power. 

3. Your furnace should be shut off now. 

If you had to switch off your system at the breaker, call us at 954-736-4314 for professional service, as you may require 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 instances, 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 continuously, even though just the blower is going. 

You might see a furnace error code if there’s a problem with the limit switch. Your furnace will speak via 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. 

Faulty Thermostat 

Like other things in your home, your thermostat can break down as time passes and need to be replaced. If you’re due for a new one, ask us about installing a smart thermostat. 

These thermostats make it simple to save energy, because they develop an energy-efficient heating and cooling schedule according to your needs. Additionally, you’ll be able to set and keep tabs on your thermostat from just about anywhere 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 all the time since the ductwork is leaking hot air in the attic. 

Diagnosing 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 diagnosing and handling 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 comes to furnaces, there’s a reason why we say we’re Experts in our field. You can rely 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.* Call us at 954-736-4314 to book your appointment now.