How the Gas Furnace Pressure Switch Works & Testing!

This HVAC Furnace Video is on How to Test a Pressure Switch Accurately and How the Pressure Switch Works! I use an SDMN6 to show you how to individually test a pressure switch by isolating it from the furnace. This will leave no doubt if the pressure switch is good or bad. I go over the purpose of a pressure switch in a gas furnace and the troubleshooting of the 24-volt electrical connections on the micro-switch located on the pressure switch. I go over where the pressure tubes are connected to the furnace and why some furnaces have two ports. I go over the difference in the + and - ports. I take a pressure switch apart so that you can see the internal parts in order to understand its operation. I give you reasons why the pressure switch could fail as well as why the pressure switch could trip, signaling a problem.