3 Signs of a Bad Furnace Limit Switch in Glen Echo, MD

When your furnace turns on, it begins a controlled combustion process to heat your home. That process could become dangerous if not for your furnace’s limit switch. Here are three signs that may indicate your furnace has a malfunctioning limit switch:

Furnace Blower Won’t Turn Off

One of the functions of your furnace’s limit switch is turning your blower on at a preset internal temperature. It ensures that your furnace only blows hot rather than cold air. If your limit switch malfunctions, it may turn on your blower and not turn it off.

Furnace Shuts Down Unexpectedly

Another important role the limit switch plays is that it turns off the burner if temperatures exceed safe levels. That prevents your furnace from overheating and causing a fire in your home. If your limit switch malfunctions, it may trigger repeated shutdowns.

A malfunctioning limit switch may even cause short cycling. That’s when your furnace turns on and off in rapid succession. It can happen as your thermostat and limit switch alternate, sending on and off signals to the furnace control board.

Inadequate Heat Production

Finally, a faulty limit switch might fail to turn on your furnace blower when necessary. That would result in your furnace burning fuel for heat but not distributing it around your home. Eventually, when the furnace temperature exceeded safe limits, the switch would shut it down.

Furnace Limit Switch Repair Process

If you believe your furnace has a faulty limit switch, one of our service technicians can diagnose the problem. They’ll use a multimeter to test the switch’s continuity and determine if it’s stuck in one position or another. If so, replacing a limit switch is typically a quick process they can perform immediately.

A faulty limit switch can cause significant comfort and safety issues in your Glen Echo, MD, home. Call B.M.C. Clower Heating and Air Conditioning for an HVAC repair appointment if you suspect a problem.

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