It's not unusual for heating systems to have a problem every now and then. It could be as simple 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.
Examine the Air Filter
A dirty air filter creates issues 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 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 repeating this process when your furnace turns on. This is known as 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 get a new one.
If the matter was connected to a clogged air filter, putting in a fresh filter should solve this common problem when your heat won't turn off. If not, we recommend checking your thermostat settings next.
Check Out the Thermostat
Your thermostat controls your furnace and basically 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 easy as changing an incorrect thermostat setting.
Make Sure 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 run when the furnace does.
“On” indicates the furnace blower will operate constantly. 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 turning off, but it's really just the furnace blower you're hearing. Changing it to "auto" should solve 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 greater than the room air temp, your furnace will keep operating until it hits your desired temp.
Keep in mind that if it's extremely cold outside, your furnace will have to run 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 check, you can try lowering the thermostat to correspond with the room. Then, wait a few minutes. This should make the furnace turn off in a few minutes.
Replace the Batteries
If you have a programmable thermostat, it's likely battery powered. You can try replacing the batteries to see if that resolves the problem. 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 shut off? There are two spots you can shut off the power to your heating unit: at the breaker box and at its specific power switch.
- Go 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 looks like a light switch and is located on or near your furnace. Move 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, contact us at 817-668-6689 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Sometimes correcting this problem can be as easy as replacing your air filter or changing thermostat settings. In other instances, 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 out, it might sound like your furnace running nonstop, 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 communicate via a flashing 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. Sometimes this can involve replacement parts, like the control board, faulty wiring or the fan switch itself.
Faulty Thermostat
Like anything else 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 according to your preferences. Additionally, you'll be able to adjust and monitor your thermostat from just about anyplace 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.
Identifying this leaky ductwork and other airflow problems can be difficult to troubleshoot 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.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace problems can be inconvenient, 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 rely on our ACE-certified technicians to resolve 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 817-668-6689 to schedule your appointment now.