Gas Furnace Pressure Switch Stuck Open

Furnace pressure switch troubleshooting.

Gas furnace pressure switch stuck open. I need your help with furnace pressure switch stuck open error messages. If the switch is open the inducer starts and the resulting pressure change closes the switch. If the inducer comes on the pressure switch is stuck closed. A pressure switch is designed to sense the negative pressure created by the draft inducer motor during the furnace startup and to shut down the furnace ignition if the air pressure is inadequate.

For many furnace brands error code three is for an open pressure switch. The pressure switch must be replaced. Tapping lightly on the pressure switch body may open the switch and the unit may start. This is not a repair.

In this video i show 3 ways how to check a pressure switch. How to test pressure switch on a furnace. Replaced circuit board white rodgers 50a50 241 inducer motor comes on then get 3 fl read more. A gas furnace pressure switch closes to allow current to pass through and start the ignition of the furnace.

The source of pressure switch problems can sometimes be a pain to track down. Only oem pressure switches should be used. Pressure switch stuck open replaced pressure switch still getting 3 flashes wich means pressure switch stuck open. This is fixed in my prior video.

After looking up online at some of other people having the same issue i measured the voltage on both wires going to the pressure switch when the furnace wasn t running and both were 24v. The pressure switch on a furnace may fail or get stuck in an open position and there are few simple checks you can complete before testing the switch. Came home to no heat. If the pressure switch is stuck it does not send enough power to the inducer and therefore the ignition sequence does not begin.

I was getting 3 red blinks now which was pressure switch stuck open. The first method is to measure continuity and resistanc.