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 issue. If your gas furnace won’t turn off, here are a couple steps you can take to get a correctly working furnace again. 

Check the Air Filter 

A dirty air filter causes issues for many homeowners and their HVAC system. Here’s why. It restricts airflow, making your furnace work harder and run longer to satisfy your ideal temperature. 

This increases usage on your furnace, as well as the odds of a malfunction and premature 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 switches on. This is known as short cycling. In addition to wearing out your furnace faster, it can drive up your heating bill and make your home feel unpleasant. 

We encourage replacing flat filters monthly and pleated filters every three months. If you can’t remember the last time you replaced your 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 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 suggest checking your thermostat settings next. 

Check the Thermostat 

Your thermostat controls your furnace and simply 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 an incorrect thermostat setting. 

Ensure Your Thermostat is Set to “Auto”.

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

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

“On” indicates the furnace blower will run continuously. This constant air flow can help with heat circulation 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 seem like your furnace is not shutting off, but it’s really just the furnace blower you’re hearing. 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 reaches 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 cozy. This is due to a big temperature difference between the cold air outside and the warm indoors. 

As a test, you can try reducing the thermostat to correspond with the room. Then, wait a couple of minutes. This should make the furnace shut off momentarily. 

Put in Fresh Batteries 

If you use a programmable thermostat, it’s likely battery powered. You can try 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 shut off after you set it to “off,” you will need to cut the power. 

Turn Off the Power 

Thermostat appears 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 locate the breaker labeled “furnace.” Push the breaker switch to the right to shut off power. 
  1. Next, search for the specific power switch to your heating system. It looks like 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 turned off now. 

If you had to switch off your system at the breaker, call us at 866-397-3787 for professional service, as you may need furnace repair

What Causes a Furnace to Keep Running? 

Occasionally correcting this problem can be as easy 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 bad, 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 communicate 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. 

Defective Thermostat 

Like other things in your home, your thermostat can break down over time 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 create an energy-efficient heating and cooling schedule according to your needs. Plus, you’ll be able to adjust and monitor 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 since the ductwork is leaking hot air in the attic. 

Identifying this leaky ductwork and other airflow problems can be challenging 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. 

Depend on Our Experts for All Your Furnace Repair Needs 

Troubleshooting furnace issues 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 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 book your appointment now. 

  • Zoning Systems: Customized Comfort in Every Room

    Central heating and air systems have revolutionized home comfort and made it possible to stay perfectly comfy in any season or climate. However, while centralized systems are a handy way to manage the temperature, they in some cases fall short when it comes to evenly distributing heated or cooled... Continue reading

  • Eight Popular Heating Myths Debunked

    There are plenty of myths out there about home heating that cause confusion and inefficient furnace operation. It’s time to get the facts out there. Here, the heating authorities at Service Experts Heating, Air Conditioning & Plumbing get to the bottom of the eight most common myths to keep... Continue reading

  • Eight Ways to Upgrade Your HVAC System

    During the chilly days and nights in the U.S., there’s no better way to improve your home’s comfort than with a few effective upgrades. It’s not just about keeping the house toasty warm as the snow begins to fall—it’s about enhancing efficiency and improving the very air you breathe.... Continue reading