It's not uncommon for heating systems to have a problem every now and then. 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.
Check the Air Filter
A dirty air filter causes problems for numerous homeowners and their HVAC system. Here's why. It limits airflow, making your furnace work harder and run longer to meet your ideal temperature.
This multiplies wear and tear on your furnace, as well as the likelihood of a breakdown and early failure.
It can also make your furnace overheat and shut off for a time to cool off. Then it will keep duplicating this process when your furnace turns on. This is called short cycling. In addition to wearing out your furnace more quickly, it can drive up 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, remove it and hold it up to the light. If you can't see 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 the Thermostat
Your thermostat controls your furnace and simply informs the unit when to turn on and off. It's usually to blame when your furnace won't stop running.
Sometimes having the heat turn off is as easy as changing an incorrect thermostat setting.
Make Sure Your Thermostat is Set to “Auto”
Your thermostat has 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” indicates the furnace blower will operate constantly. This constant air flow can help with heat circulation 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 turning off, but it's really just the furnace blower you're noticing. 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 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 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 temperature to correspond with the room. Then, wait a few minutes. This should make the furnace turn off momentarily.
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 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 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 turn off? There are two spots you can shut off the power to your heating unit: at the breaker box and at its dedicated power switch.
- Head to your breaker box and locate the breaker marked "furnace." Push the breaker switch to the right to cut power.
- Next, look for the dedicated power switch to your heating system. It looks like 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 switch off your system at the breaker, call us at 330-269-7235 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 situations, you might need a professional when your heater won't turn off.
Fan Limit Switch Needs Replacing
The furnace fan limit switch controls your furnace's blower motor. If the switch goes bad, it might seem like your furnace running nonstop, even though just the blower is going.
You might see a furnace error code if there's an issue with the limit switch. Your furnace will communicate using a blinking 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. Often this can involve replacement parts, like the control board, faulty wiring or the fan switch itself.
Like other things in your home, your thermostat can break down 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 easy to save energy, because they create an energy-efficient heating and cooling schedule based on 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 circulate hot air to vents across your home. If your home or ductwork is older, your furnace might be running all the time because the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow issues can be difficult to resolve on your own, since it's concealed behind walls and ceilings. Our Experts can help with identifying and taking care of 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 industry. You can count 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.* Call us at 330-269-7235 to book your appointment now.