It's not unusual for heating systems to have a problem every now and then. It could be as straightforward as a broken thermostat or an electrical problem. If your gas furnace won't turn 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 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 premature failure.
It can also make your furnace get too hot and shut off for a time to cool off. Then it will keep repeating this process when your furnace turns 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 uncomfortable.
We recommend replacing flat filters once a 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 see light through your filter, it's too dusty and you should replace it.
If the matter was connected to a clogged air filter, putting in a fresh filter should fix 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 basically informs 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 adjusting an incorrect thermostat setting.
Make Sure 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 run when the furnace does.
“On” indicates the furnace blower will operate continuously. 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 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 operating until it reaches your desired temp.
Remember that if it's very cold outside, your furnace will have to run much longer than usual to keep your home cozy. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try lowering the thermostat to match the room. Then, wait a few minutes. This should make the furnace turn off in a few minutes.
Replace the Batteries
If you use a programmable thermostat, it's likely 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 turn off after you switch it to "off," you will need to turn off 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 dedicated power switch.
- Go to your breaker box and locate the breaker labeled "furnace." Move the breaker switch to the right to shut off power.
- Next, look 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. Push the switch down to cut power.
- Your furnace should be shut off now.
If you had to turn off your system at the breaker, call us at 587-404-0790 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Occasionally correcting this problem can be as easy as replacing 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 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 going.
You might see a furnace error code if there's a problem with the limit switch. Your furnace will speak using a flashing red light on the front of your heating system.
Our Experts can diagnose and correct any problems you're having with your furnace blower motor. Often this can involve replacement parts, like the control board, faulty wiring or the fan switch itself.
Like anything else 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, since they develop an energy-efficient heating and cooling schedule according to your preferences. Plus, you'll be able to adjust and keep tabs on your thermostat from just about anyplace with your phone.
Air Ducts Are Leaking
Your furnace uses ductwork to distribute hot air to vents throughout your home. If your home or ductwork is older, your furnace might be operating constantly because the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow problems can be tricky to resolve on your own, since it's hidden behind walls and ceilings. Our Experts can help with identifying 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 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 solve 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.* Contact us at 587-404-0790 to schedule your appointment now.