How do I reset my HVAC limit switch?

How do I reset my HVAC limit switch?

How to Reset a Furnace Limit Switch

1. Locate your furnace’s heating duct.
2. Locate the white limit switch.
3. Look at each arm to identify the settings.
4. Identify the component (setting) located in between the two arms.
5. Set the temperature on the middle component to approximately 105 to 115 degrees Fahrenheit.

Can you bypass limit switch?

1 Answer. Yes, you can bypass the high limit switch for testing. It’s as trivial to do as it sounds.

What causes a high limit switch to trip?

If the supply air is too hot, the interior of the furnace overheats, which can cause damage to components. The limit switch trips when temperatures are too hot, effectively shutting down the system and locking furnace operation until the unit cools.

Why is my furnace going off on high limit?

In a gas furnace, a high-limit, switch turns the unit off if air doesn’t ventilate from the exhaust flue properly. A high-limit switch will turn a furnace off if it becomes too hot or is obstructed. Changing the furnace’s air filter and cleaning the blower motor may help the switch perform better.

Is there a limit switch on a furnace?

One is the furnace limit switch, also known as a furnace high limit switch and furnace fan limit switch, and without this essential part, your furnace could put your family in harm’s way. Do you know what this small part does? Keep reading to find out.

When does the high limit switch turn off?

The energy used to heat that air isn’t wasted. Sometimes the temperature of the supply air inside the furnace drops below a certain temperature. This is when the high limit switch signals the blower motor to turn off. The high limit switch is also an extremely important safety device inside your furnace.

How does a high temperature limit switch work?

How a Limit Switch Works. When the air in the plenum reaches the high limit setting on the limit switch, the switch turns on and activates the blower fan, circulating air through the heat exchanger on its way to the house while simultaneously pulling cool air from the house through the air returns and into the furnace.

How does the high limit switch work on a blower fan?

So the high limit switch detects the temperature of the supply air. When that air reaches a warm enough temperature, the switch tells the blower fan to come on. Ever notice there’s a two to three minute delay between when your thermostat switches the heat on and when the warm air actually comes out of the vents?

How do you reset the limit switch on a furnace?

Press and hold the red “Reset” button in the center of the rollout limit switch component. Hold the button for one to two seconds before releasing it.

How does the limit switch work in a furnace?

The limit switch is a safety control switch located on the furnace just below the plenum. If the plenum gets too hot, the limit switch shuts off the burner. It also shuts off the blower when the temperature drops to a certain level after the burner has shut off.

What is a limit switch?

Limit switch. In electrical engineering a limit switch is a switch operated by the motion of a machine part or presence of an object.

How do you test a furnace limit switch?

To test your limit switch, first shut OFF the power to your furnace. Then remove the wires from the limit switch. Put your meter on the two terminals. If the meter beeps or the needle jumps to the other end, that tells you the switch is closed (which is what you want). If the meter doesn’t beep or the needle doesn’t move,…