What to Do When Your Heater Wont Turn Off!

It's not unheard of for heating systems to have a problem once in a while. It could be as straightforward as a bad thermostat or an electrical problem. If your gas furnace won't turn off, here are a few steps you can take to get a correctly working furnace again.

Examine the Air Filter

A dirty air filter causes issues for numerous 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 wear and tear on your furnace, as well as the odds of a malfunction and premature failure.

It can also make your furnace get too hot and shut down for a time to cool down. Then it will keep repeating this process when your furnace turns on. This is called short cycling. In addition to wearing out your furnace faster, 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 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 replace it.

If the matter was linked to a clogged air filter, replacing it with a new filter should solve this common issue when your heat won't turn off. If not, we recommend checking your thermostat settings next.

Check Out the Thermostat

Your thermostat runs your furnace and basically 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 easy 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” means the furnace blower will only operate when the furnace does.

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

If your thermostat is switched to "on," it will sound 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 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 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 very 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 decreasing the thermostat to correspond with the room. Then, wait a couple of minutes. This should make the furnace turn off momentarily.

Put in Fresh Batteries

If you use a programmable thermostat, it's likely battery powered. You can try putting in new 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 switch 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 turn off? There are two places you can cut the power to your heating unit: at the breaker box and at its dedicated power switch.

  1. Head to your breaker box and find the breaker labeled "furnace." Move the breaker switch to the right to shut off power.
  2. Next, look 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. Move the switch down to shut off power.
  3. Your furnace should be turned off now.

If you had to turn off your system at the breaker, contact us at 289-273-2229 for professional service, as you may require furnace repair.

What Causes a Furnace to Keep Running?

Occasionally fixing 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 shut off.

Fan Limit Switch Needs Replacing

The furnace fan limit switch regulates your furnace's blower motor. If the switch goes bad, it might seem like your furnace running nonstop, 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 blinking red light on the front of your heating system.

Our Experts can identify and fix any problems 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 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 simple to save energy, since they create an energy-efficient heating and cooling schedule based on your needs. Plus, you'll be able to set and monitor your thermostat from just about anywhere with your phone.

Leaky Air Ducts

Your furnace relies on ductwork to circulate hot air to vents throughout your home. If your home or ductwork is older, your furnace might be operating all the time since the ductwork is leaking hot air in the attic.

Identifying this leaky ductwork and other airflow issues can be challenging to troubleshoot 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.

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 comes to furnaces, there's a reason why we say we're Experts in our industry. You can count 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 289-273-2229 to book your appointment today.