It's not unusual 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 turn off, here are a couple steps you can take to get a correctly working furnace again.
Examine the Air Filter
A dirty air filter creates problems for many homeowners and their HVAC system. Here's why. It restricts airflow, forcing your furnace to work harder and run longer to satisfy your ideal temperature.
This increases usage on your furnace, as well as the odds of a malfunction and early failure.
It can also make your furnace overheat and shut off 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 more quickly, it can increase your heating bill and make your home feel uncomfortable.
We encourage 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, 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, replacing it with a new filter should fix this common issue when your heat won't turn off. If not, we suggest checking your thermostat settings next.
Check the Thermostat
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.
Make Sure 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 operate when the furnace does.
“On” means the furnace blower will operate continuously. 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 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.
Check Your Temperature Setting
If your thermostat won't turn off heat, check the temperature setting to the room temperature. If it's higher than the room air temp, your furnace will keep operating until it hits your desired temp.
Keep in mind that if it's extremely 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 check, you can try reducing the setting to correspond with the room. Then, wait a couple of minutes. This should make the furnace shut off in a few minutes.
Replace the Batteries
If you use a programmable thermostat, it's probably 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 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 spots you can cut the power to your heating unit: at the breaker box and at its specific power switch.
- Head to your breaker box and find the breaker labeled "furnace." Move the breaker switch to the right to shut off power.
- Next, look for the dedicated 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 (713) 352-7887 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 replacing your air filter or adjusting thermostat settings. In other situations, 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 seem 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 speak through a blinking 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. Often 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 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 simple to save energy, since they create an energy-efficient heating and cooling schedule based on your preferences. Additionally, you'll be able to adjust and monitor your thermostat from just about anywhere 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 constantly since the ductwork is leaking hot air in the attic.
Diagnosing this leaky ductwork and other airflow problems can be difficult to troubleshoot on your own, since it's concealed behind walls and ceilings. Our Experts can help with identifying and handling any air duct repair service that you require.
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 rely 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.* Call us at (713) 352-7887 to book your appointment today.