It's not unheard of for heating systems to have a glitch every now and then. It could be as simple as a bad thermostat or an electrical issue. If your gas furnace won't shut off, here are a few steps you can take to get a correctly 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, forcing your furnace to work harder and run longer to satisfy your desired temperature.
This multiplies usage 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 off for a time to cool off. 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 increase your heating bill and make your home feel uncomfortable.
We recommend replacing flat filters monthly 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 get a new one.
If the matter was connected to a clogged air filter, replacing it with a clean 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 runs your furnace and basically tells 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 easy as adjusting an incorrect 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” means the furnace blower will only operate when the furnace does.
“On” indicates the furnace blower will operate constantly. This constant air flow can help with heat circulation but will also increase your power bill and increase wear and tear on your furnace.
If your thermostat is switched 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 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 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 run much longer than normal to keep your home warm. This is due to a big 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 turn off in a few minutes.
Put in New Batteries
If you use 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 turn off after you set it to "off," you will need to turn off the power.
Turn Off the Power
Thermostat appears to be working fine but your furnace still won't shut off? There are two places you can shut off the power to your heating unit: at the breaker box and at its specific power switch.
- Go to your breaker box and find the breaker marked "furnace." Move the breaker switch to the right to cut power.
- Next, search for the specific power switch to your heating system. It's similar to a light switch and can be found on or close to your furnace. Push the switch down to cut power.
- Your furnace should be turned off now.
If you had to turn off your system at the breaker, call us at 386-310-2061 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Sometimes correcting this problem can be as simple 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 to Be Replaced
The furnace fan limit switch controls your furnace's blower motor. If the switch goes bad, it might sound like your furnace running continuously, 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 using a blinking red light on the front of your heating system.
Our Experts can identify and fix 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 anything else 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 getting a smart thermostat.
These thermostats make it simple to save energy, because they create an energy-efficient heating and cooling schedule based on your needs. Additionally, you'll be able to adjust and monitor your thermostat from just about anywhere with your phone.
Leaky Air Ducts
Your furnace uses 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.
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 diagnosing 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, especially when it impacts 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 count 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 386-310-2061 to schedule your appointment now.