Fan Limit Control Switch Troubleshooting

Fan control limit 90 and 130 degrees fahrenheit.

Fan limit control switch troubleshooting.

The switch s sensor becomes dirty and stops working correctly. And the limit switch should be pulled out. When it hits the ceiling temperature i set the fan turns on. When the burners turn off and the exchange cools down the switch is obviously contracting but doesnt seem to rotate.

Find the fan limit switch see that article and return to this page if you don t know what the fan limit control switch looks like and if your control sports a metal cover remove that too. The blower motor stops working and overheats. All of the sudden it snaps about 20 degress very quickly below. If the fan limit switch worked normally continue as follows.

When the exchanger is heating up the control expands and rotates appropriately. Whatever the case may be it is important to contact a trained ac company in gresham such as the clean air act inc. Set the building thermostat to call for heat. If you are using a remote or wall control to reverse the ceiling fan confirm the dip switches on the control and receiver are set to the same frequency.

So my fan limit control switch seems to be acting up. If your ceiling fan is brand new contact the manufacturer for a replacement fan. Take care not to touch wires or any switches as you could get shocked. Fan limit switches can be bought at an hvac supply stores or online.

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. However the typical temperature settings are as follows. 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.

Problems that commonly occur with fan limit switches include. High limit 200 degrees fahrenheit. In this case replace the reverse switch. 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 you have an older ceiling fan the switch may be worn out.