It's not unheard of for heating systems to have a glitch once in a while. It could be as simple as a broken 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 causes issues 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 early failure.
It can also make your furnace overheat and shut down 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 faster, it can increase 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 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 clean filter should fix 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 often the problem when your furnace won't stop running.
Sometimes having the heat turn off is as simple as changing an incorrect thermostat setting.
Make Sure Your Thermostat is Set to “Auto”
Your thermostat includes two settings, “auto” and “on,” that control your heating system's blower motor.
“Auto” means the furnace blower will only run when the furnace does.
“On” means the furnace blower will operate constantly. This constant air flow can help with heat distribution but will also increase your power bill and lead to wear and tear on your furnace.
If your thermostat is set to "on," it will seem like your furnace is not turning off, but it's really just the furnace blower you're noticing. Changing it to "auto" should solve 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, check the temperature setting to the room temperature. If it's higher than the room air temp, your furnace will keep running until it hits 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 warm. This is because of a large temperature difference between the cold air outside and the warm indoors.
As a check, you can try decreasing the setting to correspond with the room. Then, wait a couple of minutes. This should make the furnace shut off in a few minutes.
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, shift 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 appears 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 dedicated power switch.
- Go to your breaker box and find the breaker marked "furnace." Push the breaker switch to the right to cut power.
- Next, look for the specific power switch to your heating system. It looks like a light switch and is located on or close to 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, contact us at 440-252-1375 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Occasionally fixing this problem can be as simple as replacing your air filter or adjusting 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 controls 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 see a furnace error code if there's a problem with the limit switch. Your furnace will speak via a flashing 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.
Defective Thermostat
Like other things in your home, your thermostat can break down over time and need to be replaced. If you're due for a new one, ask us about installing a smart thermostat.
These thermostats make it easy to save energy, because they develop an energy-efficient heating and cooling schedule according to your preferences. Plus, 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 relies on ductwork to circulate hot air to vents throughout 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 problems can be difficult to resolve on your own, since it's hidden behind walls and ceilings. Our Experts can help with diagnosing and taking care of any air duct repair service that you need.
Depend on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace issues can be annoying, especially 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 solve your problem quickly and affordably. And what's even better, we back our HVAC system repairs with a 100% satisfaction guarantee for one year.* Call us at 440-252-1375 to schedule your appointment now.