It's not unheard of 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 shut 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 problems for numerous homeowners and their HVAC system. Here's why. It restricts airflow, making your furnace work harder and run longer to satisfy your ideal temperature.
This increases usage on your furnace, as well as the odds of a breakdown and early failure.
It can also make your furnace overheat and shut off for a time to cool down. Then it will keep duplicating this process when your furnace turns on. This is known as short cycling. In addition to wearing out your furnace faster, it can drive up 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 linked 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 Out 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.
Sometimes having the heat turn off is as easy as changing a wrong thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat includes two settings, “auto” and “on,” that control your heating system's blower motor.
“Auto” indicates the furnace blower will only operate when the furnace does.
“On” indicates the furnace blower will operate continuously. 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 shutting 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 save money on your energy costs.
Check Your Temperature Setting
If your thermostat won't turn off heat, check the temperature setting to the room 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 extremely cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is because of a large temperature difference between the cold air outside and the warm indoors.
As a test, you can try reducing the thermostat to match the room. Then, wait a couple of minutes. This should make the furnace turn off in a few minutes.
Put in Fresh Batteries
If you have a programmable thermostat, it's likely battery powered. You can test replacing the 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 shut off after you set it to "off," you will need to cut the power.
Turn Off the Power
Thermostat appears 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 dedicated power switch.
- Go to your breaker box and locate the breaker marked "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 is located on or close to your furnace. Move the switch down to shut off power.
- Your furnace should be shut off now.
If you had to switch off your system at the breaker, call us at 866-397-3787 for professional service, as you may need furnace repair.
What Causes a Furnace to Keep Running?
Sometimes fixing this problem can be as easy as changing your air filter or adjusting 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 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 notice 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 problems 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 break down over time 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 develop an energy-efficient heating and cooling schedule according to your preferences. Plus, you'll be able to set and keep tabs on your thermostat from just about anyplace with your phone.
Air Ducts Are Leaking
Your furnace relies on ductwork to distribute hot air to vents across your home. If your home or ductwork is older, your furnace might be operating constantly since the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow issues can be difficult to troubleshoot on your own, since it's concealed behind walls and ceilings. Our Experts can help with diagnosing 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 annoying, particularly 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 field. 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.* Call us at 866-397-3787 to book your appointment today.