It's not unheard of for heating systems to have a glitch once in a while. It could be as simple as a bad thermostat or an electrical problem. If your gas furnace won't turn off, here are a couple steps you can take to get a properly working furnace again.
Examine the Air Filter
A dirty air filter creates problems for many homeowners and their HVAC system. Here's why. It limits airflow, making your furnace work harder and run longer to meet your desired temperature.
This increases usage on your furnace, as well as the likelihood of a breakdown and early failure.
It can also make your furnace overheat and shut off for a time to cool off. Then it will keep duplicating this process when your furnace turns on. This is called short cycling. In addition to wearing out your furnace faster, 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, pull it out 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, putting in a fresh filter should solve this common problem when your heat won't turn off. If not, we suggest checking your thermostat settings next.
Check the Thermostat
Your thermostat controls your furnace and basically 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 easy as changing an incorrect thermostat setting.
Make Sure 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 run when the furnace does.
“On” means the furnace blower will run continuously. This constant air flow can help with heat distribution but will also increase your power bill and increase wear and tear on your furnace.
If your thermostat is set 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 solve the problem. It will also help you save money on your energy costs.
Confirm Your Temperature Setting
If your thermostat won't turn off heat, compare the temperature setting to the room temperature. If it's higher than the room air temp, your furnace will keep running until it reaches your desired temp.
Remember that if it's extremely cold outside, your furnace will have to operate 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 test, you can try lowering the setting to correspond with the room. Then, wait a few minutes. This should make the furnace turn off in a few minutes.
Replace the Batteries
If you use a programmable thermostat, it's probably battery powered. You can test replacing the batteries to see if that resolves 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 seems to be working fine but your furnace still won't turn 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 specific power switch to your heating system. It's similar to a light switch and is located on or near your furnace. Push the switch down to shut off power.
- Your furnace should be turned off now.
If you had to switch off your system at the breaker, contact us at 518-205-3324 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Sometimes correcting this problem can be as easy as changing your air filter or adjusting thermostat settings. In other situations, 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 using 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. Sometimes 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 wear out over time and need to be replaced. If you're due for a new one, ask us about getting a smart thermostat.
These thermostats make it easy to save energy, since they create an energy-efficient heating and cooling schedule based on your preferences. 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 distribute hot air to vents across your home. If your home or ductwork is older, your furnace might be operating all the time since the ductwork is leaking hot air in the attic.
Diagnosing 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 identifying and taking care of 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 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 rely 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 518-205-3324 to schedule your appointment now.