Testing Furnace Pressure Switch

The steps are as follows.

Testing furnace pressure switch.

Check for obstructions in the hose. Hook a manometer to the tubing and check the draft from the heat exchanger in inches w c. Probe one lead of the pressure with one lead of your meter while touching the other lead of your meter to. Inspect the pressure switch hose.

The pressure switch has a pressure at which it closes which is typically negative. A multimeter is used to test the pressure switch and check the continuity of the switch whether it is closed or it is opened. How do you test the gas furnace pressure switch. A multimeter will be needed to test the switch for continuity.

If there is no disconnect. If you see anything clean it out. Basically the switch needs to be tested to see if it is closing when the pressure diaphragm pulls in. Turn off the power.

Turn off the power to the furnace by switching off the disconnect switch located near the furnace. To do this the pressure switch wires are removed and the furnace turned on. Set your meter to volts ac turn your furnace on so it is calling for heat. The switch is being tested to check if it s closing when the diaphragm is pulled in.

The draft inducer should start. Ensure the draft is above the required pressure. To test the pressure switch use a multi meter and measure the continuity of the switch as it opens and closes.