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 issue. If your gas furnace won't shut off, here are a couple steps you can take to get a properly working furnace again.
Examine the Air Filter
A dirty air filter causes problems for numerous homeowners and their HVAC system. Here's why. It restricts airflow, making your furnace work harder and run longer to meet your ideal temperature.
This increases wear and tear on your furnace, as well as the odds of a breakdown and early failure.
It can also make your furnace overheat and shut down for a time to cool off. Then it will keep repeating 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 unpleasant.
We recommend replacing flat filters once a month and pleated filters every three months. If you can't remember the last time you replaced your 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, putting in 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 controls 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.
Sometimes having the heat turn off is as simple as changing a wrong 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” means the furnace blower will only operate when the furnace does.
“On” means the furnace blower will operate constantly. This constant air flow can help with heat circulation but will also drive up your power bill and lead to wear and tear on your furnace.
If your thermostat is set to "on," it will sound like your furnace is not shutting off, but it's really just the furnace blower you're hearing. Switching it to "auto" should resolve 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 running until it reaches your desired temp.
Remember that if it's extremely cold outside, your furnace will have to operate much longer than usual to keep your home cozy. This is due to a big temperature difference between the cold air outside and the warm indoors.
As a test, you can try decreasing the thermostat to correspond with the room. Then, wait a few minutes. This should make the furnace turn off momentarily.
Put in New 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, shift it to "off."
If your furnace won't turn off after you switch 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 shut off the power to your heating unit: at the breaker box and at its specific power switch.
- Go to your breaker box and locate the breaker marked "furnace." Push 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 can be found on or near your furnace. Move the switch down to shut off power.
- Your furnace should be shut off now.
If you had to switch off your system at the breaker, contact us at 305-440-1505 for professional service, as you may need furnace repair.
What Causes a Furnace to Keep Running?
Sometimes fixing this problem can be as simple as changing your air filter or adjusting thermostat settings. In other instances, 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 nonstop, even though just the blower is running.
You might see a furnace error code if there's a problem with the limit switch. Your furnace will speak using a flashing red light on the front of your heating system.
Our Experts can identify and fix 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 wear out as time passes and need to be replaced. If it's time for a new one, ask us about getting a smart thermostat.
These thermostats make it easy to save energy, because they create an energy-efficient heating and cooling schedule according to your preferences. Additionally, you'll be able to set and monitor 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 operating constantly since the ductwork is leaking hot air in the attic.
Identifying this leaky ductwork and other airflow problems can be tricky to troubleshoot on your own, since it's hidden behind walls and ceilings. Our Experts can help with diagnosing and taking care of any air duct repair service that you need.
Depend on Our Experts for All Your Furnace Repair Needs
Troubleshooting furnace problems can be annoying, particularly when it affects your comfort, energy efficiency and heating bill. When it involves 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 back our HVAC system repairs with a 100% satisfaction guarantee for one year.* Contact us at 305-440-1505 to schedule your appointment now.