It's not unusual for heating systems to have a glitch every now and then. It could be as straightforward as a bad thermostat or an electrical issue. If your gas furnace won't turn off, here are a couple steps you can take to get a properly working furnace again.
Check the Air Filter
A dirty air filter causes problems for numerous homeowners and their HVAC system. Here's why. It restricts airflow, making your furnace work harder and run longer to meet your desired temperature.
This increases usage on your furnace, as well as the likelihood of a breakdown 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 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 got a new furnace filter, remove it and hold it up to the light. If you can't detect 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, replacing it with a fresh filter should fix this common problem when your heat won't turn off. If not, we suggest checking your thermostat settings next.
Check the Thermostat
Your thermostat runs your furnace and simply 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 simple as changing a wrong 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” indicates the furnace blower will only operate when the furnace does.
“On” means the furnace blower will operate constantly. This constant air flow can help with heat circulation 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 shutting off, but it's really just the furnace blower you're hearing. Switching it to "auto" should resolve the problem. It will also help you save money on your energy costs.
Check 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 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 cozy. 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 setting to correspond with the room. Then, wait a few minutes. This should make the furnace shut off momentarily.
Replace the Batteries
If you have a programmable thermostat, it's probably battery powered. You can try putting in new batteries to see if that solves 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.
Turn Off 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 dedicated power switch.
- Go to your breaker box and find the breaker marked "furnace." Move 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 shut off power.
- Your furnace should be turned off now.
If you had to turn off your system at the breaker, call us at 308-210-4398 for professional service, as you may need furnace repair.
What Causes a Furnace to Keep Running?
Occasionally correcting this problem can be as simple as replacing your air filter or changing thermostat settings. In other instances, you might need 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 notice a furnace error code if there's a problem with the limit switch. Your furnace will communicate through a blinking red light on the front of your heating system.
Our Experts can identify and correct 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 you're due for a new one, ask us about installing a smart thermostat.
These thermostats make it simple to save energy, because they develop an energy-efficient heating and cooling schedule according to your preferences. Additionally, you'll be able to adjust and keep tabs on your thermostat from just about anywhere with your phone.
Air Ducts Are Leaking
Your furnace uses ductwork to distribute hot air to vents across your home. If your home or ductwork is older, your furnace might be running constantly since the ductwork is leaking hot air in the attic.
Diagnosing 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 handling any air duct repair service that you need.
Depend 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 comes to furnaces, there's a reason why we say we're Experts in our field. You can depend on our ACE-certified technicians to resolve 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 308-210-4398 to book your appointment now.