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 problem. 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 creates issues for many homeowners and their HVAC system. Here's why. It restricts airflow, making your furnace work harder and run longer to satisfy your ideal temperature.
This multiplies usage on your furnace, as well as the likelihood of a breakdown and premature failure.
It can also make your furnace get too hot and shut down for a time to cool off. Then it will keep duplicating this process when your furnace switches on. This is known as short cycling. In addition to wearing out your furnace more quickly, it can increase your heating bill and make your home feel uncomfortable.
We recommend replacing flat filters each month 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 dirty and you should replace it.
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 tells the unit when to turn on and off. It's usually to blame when your furnace won't stop running.
At times having the heat turn off is as simple as adjusting an incorrect 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 run when the furnace does.
“On” means the furnace blower will run 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 save 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 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 cozy. This is because of a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try reducing the setting to match the room. Then, wait a few minutes. This should make the furnace shut off in a few minutes.
Put in New Batteries
If you have a programmable thermostat, it's likely 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, switch 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 spots 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 locate the breaker labeled "furnace." Push 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 is located on or near your furnace. Move the switch down to shut off power.
- Your furnace should be turned off now.
If you had to turn off your system at the breaker, contact us at 780-800-7092 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 changing your air filter or changing thermostat settings. In other instances, you might want 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 out, it might sound 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 speak 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. Sometimes 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 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 needs. Plus, you'll be able to set and monitor 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 all the time because the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow issues can be challenging to troubleshoot on your own, since it's concealed 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 problems can be annoying, particularly 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 rely 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 780-800-7092 to schedule your appointment now.