How Do You Know If The Limit Switch On Your Furnace Is Bad?

One of the best characteristics of modern furnaces is the built-in safety devices that protect them against most things that can go wrong with them. One such safety device is the limit switch, which is responsible for keeping your furnace’s internal temperature in check. Let’s look at how a limit switch works and how you can identify a bad limit switch.

How It Works

Typically, your furnace burners require a little bit of time to heat up and reach the preset temperature. Once the furnace reaches the temperature you have set, the limit switch signals it is safe to distribute the warm air.

Additionally, the limit switch monitors the temperature to ensure it stays at a comfortable level. If the temperature becomes too high, the switch shuts down the burners and activates the blower to cool down the furnace.

Identifying a Bad Limit Switch

A limit switch, unfortunately, does not last forever and can develop problems over time. These problems occur due to:

  • Airflow issues in the furnace
  • A dirty filter and temperature sensor
  • A defective limit switch

Improper airflow can cause the furnace to overheat repeatedly, causing your limit switch to undergo excessive wear and tear, eventually causing it to malfunction. A faulty limit switch may also fail to signal the blower to start or stop at the right time, which leads to the furnace overheating without shutting down, putting you in danger.

Contrarily, a defective limit switch may turn off the burner gas even when there is no danger of overheating, stopping the furnace from producing any heat. Therefore, getting timely maintenance from an Everett heating contractor is essential for your furnace to run smoothly.

If you observe the following signs, your furnace limit switch may be faulty, and you may need to schedule a gas furnace repair in Everett, WA, to fix the furnace:

  • Your furnace blower won’t turn off
  • The furnace distributes cool air
  • The furnace keeps switching on and off in short intervals

What You Can Do For Your Furnace

When necessary, make sure you clean the temperature sensor on your furnace’s limit switch, along with the furnace filters. Replacing your furnace filter when required is also a great way to ensure a smooth airflow within the furnace.

If your limit switches trips repeatedly, it can enter a lockdown mode. That is, it shuts down completely. You can try resetting the furnace limit switch yourself if you have a newer model by turning off the furnace for 30 seconds and then turning it back on. However, if this does not work or the furnace repeatedly shuts down, calling heating experts to reverse or reset the limit switch is a good idea.

If the above methods do not work successfully, you may need to replace the entire furnace. Get in touch with Climate Pro, one of the best Everett heating contractors. Contact us at (425) 787-5804 to clear up questions you may have about the limit switches or if you require any service related to heating systems.