It’s not uncommon for heating systems to have a glitch every now and then. It could be as straightforward as a bad thermostat or an electrical issue. If your gas furnace won’t shut off, here are a couple steps you can take to get a correctly working furnace again.
A dirty air filter creates issues for numerous 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 usage on your furnace, as well as the likelihood of a breakdown and premature 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 turns on. This is known as short cycling. In addition to wearing out your furnace faster, it can drive up 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 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 replace it.
If the matter was linked to a clogged air filter, putting in a fresh filter should solve this common issue when your heat won’t turn off. If not, we suggest checking your thermostat settings next.
Your thermostat controls your furnace and simply 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 simple as changing an incorrect thermostat setting.
Ensure Your Thermostat is Set to “Auto”
Your thermostat includes two settings, “auto” and “on,” that control your heating system’s blower motor.
“Auto” indicates the furnace blower will only operate when the furnace does.
“On” indicates the furnace blower will run continuously. 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 switched to “on,” it will seem like your furnace is not turning off, but it’s really just the furnace blower you’re hearing. Changing it to “auto” should solve the problem. It will also help you spend less money on your energy costs.
If your thermostat won’t turn off heat, check 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 operate much longer than usual 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 momentarily.
If you use a programmable thermostat, it’s likely battery powered. You can try replacing the 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.
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 specific power switch.
If you had to turn off your system at the breaker, contact us at for professional service, as you may require furnace repair.
Occasionally correcting this problem can be as simple as replacing your air filter or changing thermostat settings. In other situations, you might want a professional when your heater won’t shut off.
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 see a furnace error code if there’s a problem with the limit switch. Your furnace will communicate via a blinking red light on the front of your heating system.
Our Experts can diagnose and fix 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 other things in your home, your thermostat can wear out as time passes and need to be replaced. If it’s time for a new one, ask us about installing a smart thermostat.
These thermostats make it easy to save energy, since they develop an energy-efficient heating and cooling schedule according to your preferences. Additionally, you’ll be able to adjust and monitor your thermostat from just about anyplace with your phone.
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 operating all the time since the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow issues 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.
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 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 to book your appointment today.
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