The tester should read 0 or close to 0 indicating no resistance. The switch wires have to be removed first.
Using your meter you can trace the 24 volts coming from the control board through the safeties and on to the pressure switch.
How to test furnace pressure switch. A multimeter is used to test the pressure switch and check the continuity of the switch whether it is closed or it is opened. The source of pressure switch problems can sometimes be a pain to track down. How to test a furnace pressure switch.
To test the pressure switch use a multi meter and measure the continuity of the switch as it opens and closes. However many people are more comfortable calling an hvac specialist to ensure the job is done right. Test the switch for resistance.
Place the other on the incoming terminal of the switch. Set your meter to volts ac turn your furnace on so it is calling for heat. Touch each tester probe to one of the switch terminals.
Set a multimeter to test for resistance ohms. The second method is to check voltage on the pressure switch while the furnace is running and the third method is to put a manometer in series with the pressure switch to see what vacuum pressure the inducer motor is pulling and if it matches exceeds the rating of the pressure switch. Place one lead on ground or a solid piece of metal attached to the furnace.
A multi meter will be needed to test the switch for continuity. Which is why i made this video that go. Basically the switch needs to be tested to see if it is closing when the pressure diaphragm pulls in.
Disconnect the wires connected to the pressure switch by pulling the wire connectors off of the switch terminals. Furnace pressure switch troubleshooting. To do this the pressure switch wires are removed and the furnace turned on.
The steps are as follows. The switch is being tested to check if it s closing when the diaphragm is pulled in. For some testing a furnace pressure switch is an easy do it yourself job.
There are multiple steps involved in testing a furnace pressure switch and if any of these steps is missed or done incorrectly. The draft inducer should start. Using a meter test if the switch closes.
How can i test to see if a pressure switch is operating properly. There should be either two or three wires going into your pressure switch.