It's not unheard of for heating systems to have a glitch every now and then. It could be as simple as a broken 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.
Examine the Air Filter
A dirty air filter creates 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 ideal temperature.
This increases usage on your furnace, as well as the likelihood of a malfunction and premature failure.
It can also make your furnace get too hot and shut off for a time to cool down. Then it will keep duplicating this process when your furnace switches on. This is called 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 linked to a clogged air filter, putting in a clean filter should fix this common problem when your heat won't turn off. If not, we recommend checking your thermostat settings next.
Check the Thermostat
Your thermostat runs 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.
At times having the heat turn off is as easy as changing an incorrect thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat has two settings, “auto” and “on,” that manage your heating system's blower motor.
“Auto” means the furnace blower will only run when the furnace does.
“On” indicates the furnace blower will run constantly. 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 turning off, but it's really just the furnace blower you're hearing. Changing 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, check 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 very cold outside, your furnace will have to run much longer than normal to keep your home cozy. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a check, you can try lowering the setting to match the room. Then, wait a couple of minutes. This should make the furnace shut off momentarily.
Put in New Batteries
If you have a programmable thermostat, it's likely battery powered. You can test replacing the batteries to see if that solves the issue. 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 switch it to "off," you will need to turn off the power.
Cut the Power
Thermostat appears to be working fine but your furnace still won't turn off? There are two spots you can shut off the power to your heating unit: at the breaker box and at its dedicated power switch.
- Head to your breaker box and find the breaker marked "furnace." Move the breaker switch to the right to shut off power.
- Next, look for the dedicated power switch to your heating system. It looks like a light switch and is located on or close to 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, call us at 321-428-7635 for professional service, as you may need furnace repair.
What Causes a Furnace to Keep Running?
Occasionally fixing this problem can be as easy 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 Replacing
The furnace fan limit switch regulates your furnace's blower motor. If the switch goes bad, it might seem 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 flashing red light on the front of your heating system.
Our Experts can identify and correct any problems 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.
Faulty Thermostat
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 develop an energy-efficient heating and cooling schedule based on your needs. Additionally, you'll be able to set and keep tabs on your thermostat from just about anywhere with your phone.
Air Ducts Are Leaking
Your furnace uses ductwork to circulate hot air to vents across your home. If your home or ductwork is older, your furnace might be running all the time since the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow issues can be tricky to resolve on your own, since it's hidden behind walls and ceilings. Our Experts can help with identifying and handling 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 field. You can count 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.* Contact us at 321-428-7635 to schedule your appointment today.