Gas Furnace Pressure Switch Stuck Open

The source of pressure switch problems can sometimes be a pain to track down.

Gas furnace pressure switch stuck open.

Pressure switch stuck open replaced pressure switch still getting 3 flashes wich means pressure switch stuck open. If the pressure switch is stuck it does not send enough power to the inducer and therefore the ignition sequence does not begin. If the inducer comes on the pressure switch is stuck closed. How to test pressure switch on a furnace.

In this video i show 3 ways how to check a pressure switch. This is not a repair. 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. The first method is to measure continuity and resistanc.

Furnace pressure switch troubleshooting. This is fixed in my prior video. The furnace was loud and caused by the draft inducer. If the switch is open the inducer starts and the resulting pressure change closes the switch.

Which is why i made this video that go. I need your help with furnace pressure switch stuck open error messages. I was getting 3 red blinks now which was pressure switch stuck open. Came home to no heat.

The pressure switch must be replaced. Only oem pressure switches should be used. Also noticed the control board was blinking red. 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.

A gas furnace pressure switch closes to allow current to pass through and start the ignition of the furnace. Tapping lightly on the pressure switch body may open the switch and the unit may start.