Testing Furnace Pressure Switch

The steps are as follows.

Testing furnace pressure switch. Turn off the power. Set your meter to volts ac turn your furnace on so it is calling for heat. There should be either two or three wires going into your pressure switch. If you see anything clean it out.

If there is no disconnect. Ensure the draft is above the required pressure. Turn off the power to the furnace by switching off the disconnect switch located near the furnace. A multimeter will be needed to test the switch for continuity.

The pressure switch has a pressure at which it closes which is typically negative. Basically the switch needs to be tested to see if it is closing when the pressure diaphragm pulls in. How do you test the gas furnace pressure switch. The switch is being tested to check if it s closing when the diaphragm is pulled in.

Probe one lead of the pressure with one lead of your meter while touching the other lead of your meter to. The draft inducer should start. Inspect the pressure switch hose. A multimeter is used to test the pressure switch and check the continuity of the switch whether it is closed or it is opened.

Check for obstructions in the hose. Hook a manometer to the tubing and check the draft from the heat exchanger in inches w c. To test the pressure switch use a multi meter and measure the continuity of the switch as it opens and closes.