HVAC DIY Tips & Tricks
Learn all about furnace limit switches - what they are, how they work, and how to troubleshoot them in this informative blog post. Keep your home warm and safe all winter long!
The limit switch either shuts the gas furnace down if the heat exchanger is getting too hot or cycles the blower fan on and off based on the heat exchanger temperature.
The fan-limit switch looks like a black rectangular box with a clock-looking dial on the top portion and wires going into the bottom portion.
Both limit switches would be installed in the burner section on the front wall, and they would be above the burners in most cases.
You need a furnace limit switch to protect your home from the heat exchanger overheating and causing a fire.
As the furnace gets older, it is typical for the furnace limit switch to get dirt, grime, and other materials built up on it.
You cannot repair a furnace limit switch unless it’s a broken wire. The cost is usually around $35-$135 depending on the brand and the type of switch.