Testing Furnace Pressure Switch

Turn off the power.

Testing furnace pressure switch.

The steps are as follows. If there is no disconnect. Check for obstructions in the hose. Hook a manometer to the tubing and check the draft from the heat exchanger in inches w c.

How do you test the gas furnace pressure switch. Set your meter to volts ac turn your furnace on so it is calling for heat. A multimeter is used to test the pressure switch and check the continuity of the switch whether it is closed or it is opened. Probe one lead of the pressure with one lead of your meter while touching the other lead of your meter to.

To test the pressure switch use a multi meter and measure the continuity of the switch as it opens and closes. Inspect the pressure switch hose. Basically the switch needs to be tested to see if it is closing when the pressure diaphragm pulls in. With a manometer or magnahelic.

The switch is being tested to check if it s closing when the diaphragm is pulled in. The pressure switch has a pressure at which it closes which is typically negative. To do this the pressure switch wires are removed and the furnace turned on. If you see anything clean it out.

There should be either two or three wires going into your pressure switch. The draft inducer should start. Turn off the power to the furnace by switching off the disconnect switch located near the furnace.