How do you trouble shoot a furnace pressure switch? lennox gas furnace
lennox gas furnace
Answers: you switch it "on" then switch it "off"
You can put a meter on the two terminal and set it to read resistance, most should be normally instigate so your meter will not zero out afterwards suck on the hose and the meter should zero out. When you suck you will hear a click inside the switch recounting you it closed. If you don't hear this click try blowing instead (some switches are for different things).