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

It’s not uncommon 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 turn off, here are a couple steps you can take to get a properly working furnace again. 

Check the Air Filter 

A dirty air filter creates problems for many homeowners and their HVAC system. Here’s why. It restricts airflow, forcing your furnace to work harder and run longer to meet your ideal 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 duplicating this process when your furnace switches on. This is known as short cycling. In addition to wearing out your furnace faster, it can increase your heating bill and make your home feel unpleasant. 

We encourage replacing flat filters each month and pleated filters every three months. If you can’t remember the last time you replaced your 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 get a new one. 

If the matter was connected to a clogged air filter, replacing it with a clean 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 controls 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 simple 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 run when the furnace does. 

“On” indicates the furnace blower will run constantly. This constant air flow can help with heat circulation but will also increase your power bill and lead to wear and tear on your furnace. 

If your thermostat is set to “on,” it will seem like your furnace is not turning off, but it’s really just the furnace blower you’re hearing. Switching it to “auto” should resolve the problem. It will also help you spend less money on your energy costs. 

Confirm Your Temperature Setting 

If your thermostat won’t turn off heat, check the temperature setting to the room temperature. If it’s greater than the room air temp, your furnace will keep operating until it hits 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 cozy. This is due to a large temperature difference between the cold air outside and the warm indoors. 

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

Put in New Batteries 

If you have a programmable thermostat, it’s likely battery powered. You can test replacing the batteries to see if that solves the problem. 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 cut the power. 

Cut the Power 

Thermostat seems to be working fine but your furnace still won’t shut off? There are two places you can cut 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.” Move the breaker switch to the right to cut power. 

2. Next, search for the specific power switch to your heating system. It’s similar to a light switch and can be found on or near your furnace. Move the switch down to shut off 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 need furnace repair. 

What Causes a Furnace to Keep Running? 

Sometimes correcting this problem can be as easy as changing your air filter or changing thermostat settings. In other instances, you might need a professional when your heater won’t turn 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 running. 

You might notice 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 diagnose 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. 

Defective 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 installing 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 monitor your thermostat from just about anywhere with your phone. 

Air Ducts Are Leaking 

Your furnace uses ductwork to circulate hot air to vents throughout 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 issues can be tricky 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 need. 

Rely on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace issues can be annoying, especially 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 stand behind our HVAC system repairs with a 100% satisfaction guarantee for one year.* Call us at 954-736-4314 to schedule your appointment today.