LEFOO LF31 Water Heater Pressure Switch Gas furnance Vent air Pressure Switch HVAC Adjustable 0.1" w.c to 34" W.C

This pressure differential switch is used to let your furnaces control panel know if it is properly venting. I had to replace this because my furnace was shutting down, the original valve stopped working. This valve detects the difference in the pressure inside the burner box and outside the burner box to make sure it is negative pressure. Negative pressure indicates the fumes are being sucked out and vented to the outdoors. I recommend this product it is a great universal fit.

Was able to use this as a substitute for a product from the original manufacturer whose part would have taken another 7-10 days to arrive. Fixed our HVAC for $15 and didn't have to call a repair person

So HVAC guy was awesome and told me what was wrong and how to set one of these things (also said it would cost $189 part only if he installed it). So even with his advice I had about an hour of meticulous tinkering to make it work with my ol’ 1991 Amana Air Command 80. I know you can use specialized equip but I figured I could do without. Anyway, I’d buy this again and your results may vary. But my furnace was very picky for the exact amount of negative pressure it needed to satisfy the correct ohms or whatever the control board is looking for. Furnace is working like new now.

This sensor/switch works just as advertised. It has both a normally open and a normally closed electrical contact (SPDT) which is a bonus for users that may appreciate such a feature. Dual ports provide sensing for both vacuum and pressure. Nicely made, too.

What do you know - it worked. Me so happy.

Pleased with price but instructions were not clear how to adjust switch

Kit comes with lots of nice hardware, springs and brackets but the pre-installed adjustment set screw is plastic and stripped out at my very first turn. (Allen head) i had to return since it couldn't adjust into range.

This dP switch was a perfect replacement for my Ducane Furnace. You need only match up the pressure ratings (this was 0.4 in w.c.) and ensure you match the normally open or normally closed wiring requirement. Mounting was not exact but it does not need to be. Hose connection was straight-forward. My furnace has not kicked out since installing it.