It's not uncommon for heating systems to have a glitch once in a while. It could be as simple as a bad thermostat or an electrical problem. 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 creates problems for many homeowners and their HVAC system. Here's why. It limits airflow, making your furnace work harder and run longer to meet your desired temperature.
This multiplies usage 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 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 faster, it can increase your heating bill and make your home feel unpleasant.
We recommend replacing flat filters monthly and pleated filters every three months. If you can't remember the last time you got a new furnace filter, pull it out 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 linked to a clogged air filter, putting in a clean 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 simply informs the unit when to turn on and off. It's often to blame 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” indicates the furnace blower will only operate when the furnace does.
“On” means the furnace blower will run 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 seem like your furnace is not turning off, but it's really just the furnace blower you're hearing. Switching it to "auto" should solve 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 reaches your desired temp.
Remember that if it's very cold outside, your furnace will have to operate much longer than usual to keep your home warm. This is due to a big temperature difference between the cold air outside and the warm indoors.
As a check, you can try lowering the setting to match the room. Then, wait a couple of minutes. This should make the furnace shut off in a few minutes.
Replace the Batteries
If you have a programmable thermostat, it's likely battery powered. You can try putting in new batteries to see if that solves 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 set it to "off," you will need to cut the power.
Turn Off the Power
Thermostat seems to be working fine but your furnace still won't turn off? There are two places you can shut off the power to your heating unit: at the breaker box and at its specific power switch.
- Head to your breaker box and find the breaker marked "furnace." Move the breaker switch to the right to shut off power.
- Next, search for the dedicated power switch to your heating system. It's similar to a light switch and is located on or close to your furnace. Push the switch down to shut off power.
- Your furnace should be turned off now.
If you had to switch off your system at the breaker, call us at 330-305-2799 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 replacing your air filter or adjusting 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 out, 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 using a blinking red light on the front of your heating system.
Our Experts can diagnose and correct any issues you're having with your furnace blower motor. Often this can involve replacement parts, such as the control board, faulty wiring or the fan switch itself.
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 installing a smart thermostat.
These thermostats make it simple to save energy, because they create an energy-efficient heating and cooling schedule based on your needs. Additionally, you'll be able to set and monitor your thermostat from just about anywhere with your phone.
Leaky Air Ducts
Your furnace uses ductwork to distribute hot air to vents throughout 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 tricky to troubleshoot 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 need.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace problems can be inconvenient, 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 rely 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.* Contact us at 330-305-2799 to schedule your appointment now.