It's not uncommon for heating systems to have a problem every now and then. It could be as straightforward as a bad thermostat or an electrical issue. 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 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 odds of a malfunction and early failure.
It can also make your furnace overheat and shut down 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 more quickly, it can drive up 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 replace it.
If the matter was connected to a clogged air filter, replacing it with a clean filter should solve this common problem when your heat won't turn off. If not, we suggest checking your thermostat settings next.
Check Out the Thermostat
Your thermostat runs your furnace and simply tells the unit when to turn on and off. It's usually the problem when your furnace won't stop running.
At times having the heat turn off is as simple as changing an incorrect thermostat setting.
Make Sure Your Thermostat is Set to “Auto”
Your thermostat has 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” indicates the furnace blower will operate 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 switched to "on," it will sound like your furnace is not turning 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 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 area 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 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 thermostat to correspond with the room. Then, wait a couple of minutes. This should make the furnace turn off momentarily.
Replace the Batteries
If you use 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, 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.
Cut the Power
Thermostat appears 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 dedicated power switch.
- Go to your breaker box and find the breaker marked "furnace." Move the breaker switch to the right to cut power.
- Next, look 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 cut power.
- Your furnace should be turned off now.
If you had to switch off your system at the breaker, contact us at 817-380-5647 for professional service, as you may require furnace repair.
What Causes a Furnace to Keep Running?
Occasionally correcting this problem can be as simple 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 to Be Replaced
The furnace fan limit switch regulates your furnace's blower motor. If the switch goes out, it might sound like your furnace running nonstop, even though just the blower is going.
You might see a furnace error code if there's an issue with the limit switch. Your furnace will communicate through a blinking red light on the front of your heating system.
Our Experts can identify and fix any problems 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.
Bad Thermostat
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 getting a smart thermostat.
These thermostats make it easy to save energy, because they develop an energy-efficient heating and cooling schedule based on your needs. Plus, you'll be able to set and keep tabs on your thermostat from just about anyplace with your phone.
Air Ducts Are Leaking
Your furnace uses ductwork to distribute hot air to vents throughout 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 problems can be challenging 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 require.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace issues can be annoying, especially 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 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.* Contact us at 817-380-5647 to book your appointment now.