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How a Furnace Limit Switch Helps Keep You Safe

Your furnace is manufactured with a number of safety mechanisms to help keep you, your home and your heating system safe. One of these safety mechanisms is the limit switch. The limit switch is part of your blower assembly, but is also part of your overall control system. This is why, should a problem develop with your limit switch, your furnace may experience operational issues. To understand more about the limit switch on your furnace in Hamilton, it’s important to learn what it is and how it works.

What Does a Limit Switch Do?

The limit switch is a device that has two functions: first, it won’t allow the fan to turn on until the air generated inside your furnace is warm enough and second, it acts as a kill switch to the burner should the air temperature around the heat exchanger become too hot. The reason the limit switch can turn off the burner is that when the temperature around the heat exchanger becomes too high, the heat exchanger can crack, allowing the toxic byproducts of combustion into your home.

Common Problems with Limit Switches

Like other components in your heating system, the limit switch can malfunction. The most common sign of a malfunctioning limit switch is the continuous operation of your furnace’s blower. Just as the limit switch won’t allow the fan to turn on until the warm air has reached the right temperature, the limit switch also shuts down when the air cools to a certain temperature. However, when a limit switch starts to go bad, it may not turn off at the end of a cycle; the result is a continuously-running blower.

A second problem is common with a limit switch is that won’t allow the furnace to operate. For example, if the air flow in your system is significantly reduced by a clogged air filter, there won’t be enough air circulating through the system; this can cause the heat exchanger to get too hot. Once the limit switch senses this, it turns off the burner.

It is very important that all the safety mechanisms on your furnace in Hamilton work correctly in order to keep you, your family and your home safe. If you suspect your limit switch may be experiencing problems, call Bartels Heating & Cooling today and schedule an appointment with one of our professional furnace repair and maintenance experts.

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