Fan Limit Switch Troubleshooting

And the limit switch should be pulled out.

Fan limit switch troubleshooting.

The blower motor stops working and overheats. The switch s sensor becomes dirty and stops working correctly. To test a limit switch you ll want to check continuity to determine what state the switch is in. Fan control limit 90 and 130 degrees fahrenheit.

This opens the safety circuit and prevents the furnace from heating. However the typical temperature settings are as follows. Set the building thermostat to call for heat. Turn off electrical power to the heating system reconnect the fan motor where you previously disconnected it turn on electrical power to the heating system call for heat.

The furnace filter is clogged and raises the temperature within the plenum prematurely tripping the sensor. Some control guides call this summer. High limit 200 degrees fahrenheit. Push the white button in to force the fan to on or manual or always running mode.

If the fan in your furnace runs continuously or turns off and on too frequently you may need to adjust or replace the limit switch. Open the access panel and locate the high limit switch. Step 1 remove the top access panel on the front of the rheem furnace. Pull the white button out to put the fan back into auto mode turning on and off under control of the switch and.

Dirty clogged air filters can cause high limit switches to open. Where can you buy a fan limit switch. Problems that commonly occur with fan limit switches include. The instructions differ depending on whether you have a combination switch or separate high and fan control limit switches as well as on the specific model you have.

If not shut the power off at the breaker panel. If the fan limit switch worked normally continue as follows. Fan limit switch troubleshooting list before you get started check the air filters in the system. If there is a serviceman switch turn it off.