In winter, you probably enjoy a toasty house and firing up your furnace. When spring comes around though, what do you do if your heat won’t turn off when you flick the switch? Here are some reasons your heater won’t turn off.

Getting Your Heater to Turn Off

Below you’ll find the most common at-home tips for getting the heater to turn off. These are simple things that you can start with before you call a professional.

1. Check the Air Filter

You should change your air filter at least every six months. Check your air filter for dirt. When the filter gets dirty, it restricts airflow into your heater or furnace. That causes the furnace to run non-stop. The air filter blocks dust and debris from entering the system and blowing into your home. This helps to prevent allergens from entering your house. After a few months, however, the filter becomes so dirty that it blocks the air from entering. This makes it work harder and run for a longer time to heat the home. When you change your dirty air filter for a clean one, you should find that the system stops running after a few minutes.

2. Double Check Your Thermostat Settings

Sometimes, your thermostat provides a quick solution. Check the settings. The setting for “Fan” should read “Auto” rather than “On.” A setting to “On” means your system runs continuously without any way to shut itself off. Switching to “Auto” lets the heater control its cycles. This is also the place to try to turn the thermostat off and see if the heater also shuts off.

Check its batteries. Many of these units accept AA or AAA batteries. They go bad and the thermostat stops working, which affects the entire system.


If you replace the batteries and still experience a problem, check your owners’ manual to learn if the batteries just provide a backup for the electrical connection to the thermostat. Some systems hardwire the thermostat to the electrical system. Turn off the thermostat. For thermostats with no off switch, turn the temperature down to a few degrees below room temperature.

3. Cut the Power to the System

If, after three to five minutes, your heater hasn’t turned off, you can choose to cut the power to the entire system. This means going to your breaker box and killing the switch that controls the HVAC system. Typically, these switches get labeled as heater or furnace.

Why Isn’t Your Heater Turning Off?

Since many of the issues that cause a heater to run continuously do require professional assistance, it’s important to follow up with them before turning your heating unit back on. They will advise you whether to keep the unit shut off until a repair is made or whether you can run it in the interim.

To determine exactly why your particular heating system malfunctioned and won’t turn off, a professional will have to examine it. Here are some reasons why most systems experience this problem.

1. Faulty Thermostat

One of the most common problems – a fault in the thermostat – is easily repaired. The typical issues with a thermostat include a broken switch, wiring faults, and/or a broken heating sensor. Something more serious than this can cause you to need a thermostat. Replacing a thermostat can offer you exciting new technology. We can install a smart thermostat that provides you with many alternatives to manually controlling the temperature in your home.

2. Primary Controller Damage

Sometimes, the problem lies within the heating unit. We first examine the primary controller, an easily replaced part. The primary controller turns the burner on and off, based upon the settings you or your installer made. The burner heats the water to run the boiler. If the primary controller works but causes a mechanical problem within the system, we locate it and repair it.

3. Failing Ductwork

Your heater may be running continuously because your home is never getting to your desired temperature. If your ductwork is leaking, the heated air may be warming your crawl space or attic instead of the rooms that you’re targeting.

Contact Us

Call Fire 'n' Ice Heating & Cooling, Inc. for these or other heating issues. We offer heating and cooling maintenance, repair and installation services for both residential and commercial clients in Downers Grove, IL, and the surrounding areas.

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