It's not uncommon for heating systems to have a problem once in a while. It could be as straightforward as a bad thermostat or an electrical problem. If your gas furnace won't turn off, here are a few steps you can take to get a properly working furnace again.
Check the Air Filter
A dirty air filter causes problems for many 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 increases usage on your furnace, as well as the odds of a breakdown 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 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 encourage 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 detect light through your filter, it's too dirty and you should get a new one.
If the matter was connected to a clogged air filter, replacing it with a fresh 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 runs your furnace and basically tells the unit when to turn on and off. It's often to blame when your furnace won't stop running.
At times having the heat turn off is as easy as changing a wrong thermostat setting.
Make Sure Your Thermostat is Set to “Auto”
Your thermostat includes two settings, “auto” and “on,” that manage your heating system's blower motor.
“Auto” indicates the furnace blower will only operate when the furnace does.
“On” means the furnace blower will run constantly. This constant air flow can help with heat circulation but will also drive up 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. 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, compare the temperature setting to the area temperature. If it's higher than the room air temp, your furnace will keep running until it reaches your desired temp.
Keep in mind that if it's extremely cold outside, your furnace will have to run much longer than normal to keep your home warm. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a check, you can try reducing the setting to correspond with the room. Then, wait a few minutes. This should make the furnace turn off momentarily.
Replace the Batteries
If you have a programmable thermostat, it's likely battery powered. You can try 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 shut 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.
- Head to your breaker box and locate the breaker marked "furnace." Move the breaker switch to the right to shut off power.
- Next, search for the dedicated 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 switch off your system at the breaker, contact us at 908-448-2154 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 adjusting 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 regulates your furnace's blower motor. If the switch goes bad, it might sound 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 via a flashing red light on the front of your heating system.
Our Experts can diagnose and correct any issues 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 it's time for a new one, ask us about installing a smart thermostat.
These thermostats make it easy to save energy, since they create an energy-efficient heating and cooling schedule based on your needs. Plus, you'll be able to set and monitor your thermostat from just about anyplace with your phone.
Air Ducts Are Leaking
Your furnace relies on ductwork to distribute hot air to vents throughout your home. If your home or ductwork is older, your furnace might be operating 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 hidden behind walls and ceilings. Our Experts can help with diagnosing and handling any air duct repair service that you need.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace issues can be inconvenient, particularly 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 field. You can depend 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 908-448-2154 to schedule your appointment now.