October 13, 2021
Heater Troubleshooting in Peoria, IL

You may have a problem with your heater if it won’t turn off. This is a common issue, and there are a few reasons why this could be happening. This article will give some reasons why your heater might be failing to turn off even when you expect it to.

A Bad Thermostat

The first thing to check is your thermostat. Your heater may constantly be working because your temperature drops even though the thermostat is set for a higher temperature. It may also be stuck in the “on” position because of ice buildup around the power button. You can solve this by turning off the breaker and removing any ice buildup from around the actual button.

Damaged Fan

Another component to check is the fan. If the fan isn’t turning on, it could mean that there’s a problem with either your thermostat or your limit switch. The fan provides a signal for when the heater needs to turn on and off, so if this doesn’t work, neither will your heater. This can be fixed by simply checking the wiring and the fan itself.

Bad Limit Switch

You may have a lousy limit switch if your heater is constantly turning on and off. This can be solved by either replacing or resetting the switch. If you turn the thermostat back down to a lower setting, it might mean that you need a new thermostat. You don’t always need to purchase a new one. Rather, you can reset it by turning off the circuit breaker for five minutes, and then hooking everything back up. If your heater turns on after doing this, you’ll want to replace your thermostat.

Damaged Primary Controller

The primary controller is like the brain of your heater. If it’s damaged, you won’t be able to control your heater using the thermostat or limit switches. There are three different primary controllers: a timer, an electromechanical one, and a digital one. The timer only controls your heater’s on/off times, but the others can also control the heat levels. If you have a faulty primary controller, it’s often easier to replace it rather than trying to diagnose what’s wrong with it.

Damaged Fuses

Another thing that could cause your heater not to turn off when expected is any blown fuses. Once again, this is a common issue, and it’s easy to fix. If you have any fuses that are blown, replace them. Be sure to check the rest of the system, too, so you don’t get stuck with this problem again.

Relay Problems

Something else you can check if your heater won’t turn off is your relay. It’s often difficult to diagnose because it’s impossible if you don’t know how your relays are hooked up. If the relay fails, the gas won’t shut off when you expect it to, which can be fixed by replacing or resetting the relay switch. You may find that there’s rust in the clock spring, but this is easily fixed by removing it and cleaning it. If none of these seems to be the problem, then you probably need a new heater.

Temperature Sensor

If your heater is constantly turning on and off because the temperature is too hot or too cold, even when you have set it at its lowest level, this could mean that your temperature sensor has failed. There are two different types of temperature sensors: one that uses a thermocouple and one that doesn’t. Unfortunately, it’s impossible to know if your heater has the first type without doing an electrical test, so you’ll have to replace your sensor. If your sensor doesn’t use a thermocouple, you can check for corrosion or dirt around the terminals before returning it. You can also reset it by turning off the breaker for five minutes, but you’ll still need to replace it.

Defective Check Valve

A defective check valve is another thing that can cause your heater to continue running. A check valve prevents water from flowing back into the tank, which stops the heater from constantly trying to heat it again. Once you fix this problem, you’ll be able to adjust your thermostat without worrying about the temperature dropping too low.

The check valve can get stuck open and cause a gas leak, but a few things could be causing it to stay stuck closed. If your tank is empty or you have little water in it, there won’t be enough weight to push the valve open. You’ll want to fill up your tank before turning on your heater again.

Turn to the Pros

If you’re still wondering why your heater won’t turn off, it’s worth contacting Bratcher Heating & Air Conditioning, Inc. for a check-up and expert advice. We offer a wide range of heating and cooling services in central Illinois and the surrounding areas, including repair, installation, and maintenance. Give us a call today to learn more.

company icon