Fan Limit Switch Troubleshooting

Push the white button in to force the fan to on or manual or always running mode.

Fan limit switch troubleshooting.

Problems that commonly occur with fan limit switches include. 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. The switch s sensor becomes dirty and stops working correctly.

Set the building thermostat to call for heat. Fan limit switches can be bought at an hvac supply stores or online. This opens the safety circuit and prevents the furnace from heating. However the typical temperature settings are as follows.

Step 1 remove the top access panel on the front of the rheem furnace. 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. To test a limit switch you ll want to check continuity to determine what state the switch is in. And the limit switch should be pulled out.

High limit 200 degrees fahrenheit. Pull the white button out to put the fan back into auto mode turning on and off under control of the switch and. Where can you buy a fan limit switch. Fan control limit 90 and 130 degrees fahrenheit.

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. If there is a serviceman switch turn it off. Fan limit switch troubleshooting list before you get started check the air filters in the system. If both the blower motor and limit switch test good than other possible problems may be the contactors circuit board or gas valve and possibly the thermostat.

If not shut the power off at the breaker panel. Dirty clogged air filters can cause high limit switches to open. Some control guides call this summer. Finding the limit switch in a rheem furnace takes just seconds.