It's not unusual for heating systems to have a problem every now and then. It could be as simple 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.
Examine 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 satisfy your desired temperature.
This multiplies wear and tear 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 repeating 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 recommend replacing flat filters monthly and pleated filters every three months. If you can't remember the last time you replaced your 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 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 recommend 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.
At times having the heat turn off is as easy as changing a wrong thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat has two settings, “auto” and “on,” that control your heating system's blower motor.
“Auto” indicates the furnace blower will only run when the furnace does.
“On” indicates the furnace blower will operate constantly. This constant air flow can help with heat distribution but will also drive up your power bill and lead to wear and tear on your furnace.
If your thermostat is switched to "on," it will seem like your furnace is not shutting 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, compare the temperature setting to the area temperature. If it's higher than the room air temp, your furnace will keep operating until it hits 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 lowering the temperature to correspond with the room. Then, wait a couple of minutes. This should make the furnace shut off momentarily.
Put in New Batteries
If you use a programmable thermostat, it's probably battery powered. You can test putting in new batteries to see if that resolves 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 move it to "off," you will need to cut 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 labeled "furnace." Push 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 can be found 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, call us at 281-407-9478 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 changing thermostat settings. In other instances, you might need a professional when your heater won't shut off.
Fan Limit Switch Needs to Be Replaced
The furnace fan limit switch controls 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 notice a furnace error code if there's a problem with the limit switch. Your furnace will communicate via 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, like the control board, faulty wiring or the fan switch itself.
Like other things 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, since they develop an energy-efficient heating and cooling schedule based on your preferences. Additionally, 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 relies on ductwork to distribute 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 difficult 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 require.
Rely on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace problems can be inconvenient, especially 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 count 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.* Call us at 281-407-9478 to book your appointment today.