What to do if your Furnace Fan limit switch is not working?
If the Fan Limit switch worked normally continue as follows: 1 Turn off electrical power to the heating system 2 Reconnect the fan motor where you previously disconnected it 3 Turn on electrical power to the heating system 4 Call for heat: Set the building thermostat to call for heat
What is the function of a furnace limit switch?
The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home.
What is the definition of a fan limit switch?
Definition of a Fan Limit Switch. A fan limit switch is a component of a furnace system that determines when the furnace blower assembly for hot air turns on and off. Essentially, this means that it determines when the hot air should be blown through your ventilation system.
How do I Turn Off the fan on my furnace?
Turn off the circuit breaker at the main electrical panel that supplies power to the furnace. Tag or otherwise mark the breaker to alert others that the power is to remain off. Remove the furnace controls access panel. Refer to the furnace manual for the location of the panel. Most access panels can be removed without tools.
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.
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,…
Why is the limit switch on my furnace open?
The limit switch shuts off the burner when the temperature exceeds a preset temperature. When the temperature reduces to normal, the burner will come back on. The most common reason for limits to open is a plugged filter or a dirty blower wheel. On the left are some high temperature limits used in furnaces.
