Which Pressure Differential Switch

[sullivanjay]

I have to replace a Pressure Differential Switch in propane direct vent heating system.
It’s an Olsen 160 BTU forced hot air unit. It’s short cycling and if I jumper out this switch it works fine. Question is what range switch do I use. I can get one with a WC of 0.20 to 1.0 or WC 1.0 to 4.0. I think it’s the 1.0 to 4.0 but not sure. No markings on the old one and can’t find the specs.

[flange]

why not hook up your digital manometer and measure the actual, then you'd know for sure.