Introducing Furnace Limit Switch and Its Important Role

As a homeowner, you should take the time to learn how your furnace works. It has many vital parts that you should get familiar with, like the furnace limit switch. This switch is essential to the furnace’s operation; without it, your furnace could be a danger to your family.

What Is a Furnace Limit Switch?

The furnace limit switch is a safety device designed to help prevent overheating. It triggers the furnace fan to stop running when the temperature rises too far and can also block the fuel supply to the furnace. The control board for the furnace will usually have its override switch that will allow you to restore power to the furnace if it has been shut down.

This critical safety device is installed in the furnace and linked to the control board. It can also be connected to the thermostat or a heat sensor if the furnace has one.

How Do I Test a Limit Switch?

Before testing your furnace limit switch, ensure your power is off to the furnace. You can set the thermostat to its highest temperature and check the limit switch by placing an ohmmeter across its terminals. 

If there is resistance between the terminals, you will know that the switch is working. If there is no resistance, the furnace limit switch is defective and must be replaced.

How Does a Furnace High Limit Switch Regulate Temperature?

The furnace limit switch works with the thermostat to maintain a specific temperature in the home. It also responds to a sensor attached to the furnace, which signals that the furnace is too high. 

If the thermostat and the sensor indicate that the temperature is too high, the limit switch will turn off the furnace.

If the furnace can’t turn off the fuel supply, it will signal the control board to shut off the furnace. The fan will continue to run until it receives the same signal to stop. The furnace limit switch is an essential safety device that helps to protect your family from overheating.

How It Helps Keep Your Home Safe

A furnace limit switch is an important safety device in your furnace. It helps keep your heating system in top condition by regulating the temperature. You might not be able to feel the difference, but turning the furnace on and off helps prolong the life of the equipment.

How to Know If Your Furnace Limit Switch Is Broken?

As a homeowner, you need to be aware of the signs of a faulty furnace limit switch to get it repaired in time. If you notice your furnace:

  • Running excessively
  • Having a high-pitched whine sound
  • Bumping

You have to have it inspected right away. Your furnace will work more when it is colder. This extra work can lead to excessive wear and tear, especially if the limit switch is broken. Replacing a faulty switch is a good option for those who want to save money on heating bills.

What to Do When Your Furnace Limit Switch Is Broken?

If your furnace limit switch is not working well, you must fix it. That is a safety issue and is usually best left to the professionals. Homeowners can replace it themselves but are advised to use caution. Investing in a brand new furnace limit switch is also an option, but it is expensive.

Acquiring a new furnace limit switch is what most homeowners do when they want to replace a defective one. If you are having trouble locating the switch, you can get help from a professional. They can help explain the process so you can order the right furnace limit switch.

For your furnace maintenance in Edmonton, Legacy Heating & Cooling is the area’s premier furnace and air-conditioning installation and repair service provider. We specialize in HVAC systems for residential new home construction (RNC) and installing and replacing furnaces, air conditioners, and more. Contact us today.

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