It's not uncommon for heating systems to have a glitch once in a while. 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 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 limits airflow, forcing your furnace to work harder and run longer to satisfy your ideal temperature.
This multiplies wear and tear on your furnace, as well as the odds of a malfunction and premature failure.
It can also make your furnace get too hot and shut down for a time to cool off. Then it will keep duplicating this process when your furnace switches 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 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 detect light through your filter, it's too dusty and you should get a new one.
If the matter was linked to a clogged air filter, replacing it with a new filter should fix this common problem when your heat won't turn off. If not, we suggest checking your thermostat settings next.
Check Out the Thermostat
Your thermostat controls your furnace and simply informs the unit when to turn on and off. It's often the problem when your furnace won't stop running.
At times having the heat turn off is as easy as adjusting a wrong thermostat setting.
Ensure 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 run continuously. This constant air flow can help with heat circulation but will also drive up your power bill and lead to wear and tear on your furnace.
If your thermostat is switched to "on," it will seem 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 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 reaches your desired temp.
Keep in mind that if it's very cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try reducing the temperature to match the room. Then, wait a few minutes. This should make the furnace shut off momentarily.
Put in New Batteries
If you use a programmable thermostat, it's probably battery powered. You can test putting in new batteries to see if that solves the issue. 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 turn off the power.
Cut the Power
Thermostat seems to be working fine but your furnace still won't shut off? There are two places you can cut 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 shut off power.
- Next, look for the specific power switch to your heating system. It looks like a light switch and can be found on or near your furnace. Move the switch down to cut power.
- Your furnace should be turned off now.
If you had to switch off your system at the breaker, call us at 289-813-5566 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Sometimes fixing this problem can be as simple as replacing your air filter or changing thermostat settings. In other instances, you might want a professional when your heater won't shut 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 notice a furnace error code if there's an issue with the limit switch. Your furnace will communicate via a flashing red light on the front of your heating system.
Our Experts can identify and fix any problems 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 anything else in your home, your thermostat can break down as time passes and need to be replaced. If you're due for a new one, ask us about getting a smart thermostat.
These thermostats make it simple to save energy, since they create an energy-efficient heating and cooling schedule according to your needs. Additionally, you'll be able to adjust and keep tabs on your thermostat from just about anywhere with your phone.
Leaky Air Ducts
Your furnace relies on ductwork to circulate 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 issues can be difficult to resolve 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 require.
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 involves 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 back our HVAC system repairs with a 100% satisfaction guarantee for one year.* Contact us at 289-813-5566 to schedule your appointment today.