It's not unusual for heating systems to have a problem once in a while. It could be as simple as a bad thermostat or an electrical issue. If your gas furnace won't turn off, here are a few steps you can take to get a properly working furnace again.
Examine the Air Filter
A dirty air filter creates issues for numerous homeowners and their HVAC system. Here's why. It limits airflow, forcing your furnace to 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 down for a time to cool off. Then it will keep duplicating this process when your furnace switches on. This is known as short cycling. In addition to wearing out your furnace more quickly, it can increase your heating bill and make your home feel uncomfortable.
We recommend replacing flat filters each month and pleated filters every three months. If you can't remember the last time you replaced your furnace filter, pull it out 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 solve this common issue 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 simply informs 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.
Ensure Your Thermostat is Set to “Auto”
Your thermostat has two settings, “auto” and “on,” that control 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 constantly. This constant air flow can help with heat circulation but will also increase your power bill and lead to 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 hearing. Switching it to "auto" should resolve the problem. It will also help you spend less money on your energy costs.
Check Your Temperature Setting
If your thermostat won't turn off heat, compare the temperature setting to the room temperature. If it's greater than the room air temp, your furnace will keep running until it hits your desired temp.
Keep in mind that if it's extremely cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is due to a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try decreasing 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 New Batteries
If you have a programmable thermostat, it's probably battery powered. You can test putting in new batteries to see if that solves the problem. 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 move it to "off," you will need to turn off 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 cut 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 labeled "furnace." Move the breaker switch to the right to cut power.
- Next, look for the specific power switch to your heating system. It's similar to a light switch and can be found on or near your furnace. Push 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 502-785-8230 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Sometimes fixing 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 shut off.
Fan Limit Switch Needs Replacing
The furnace fan limit switch controls your furnace's blower motor. If the switch goes out, it might seem like your furnace running continuously, 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 through a flashing red light on the front of your heating system.
Our Experts can identify 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 break down as time passes and need to be replaced. If it's time for a new one, ask us about getting a smart thermostat.
These thermostats make it easy to save energy, because they create an energy-efficient heating and cooling schedule according to your preferences. Additionally, 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 circulate hot air to vents throughout your home. If your home or ductwork is older, your furnace might be running constantly because the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow problems can be challenging 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 need.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace problems can be inconvenient, 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 industry. You can count 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 502-785-8230 to book your appointment today.