Pressuretrol cut in was set higher than the cut-out

Alix

We have one pipe steam heat. I'm getting ready for heating season and noticed the pressuretrol cut-in had somehow been set at 2 psi while the cut-out (round plastic wheel) appears to be at 1 psi (the '1' on the dial is at 6 o'clock). Looking at my Holohan guide I see the cut-in should have been set at .5 psi. I'm surprised as everything appeared to be working fine last heating season. What happens when the pressuretrol cut-in is set higher than the cut-out?

Fred

That round plasitic whell is not the "Cut-Out" it is to set the differential. So, if the cut-in is set at 2psi and the white wheel is set at 1psi, on an Additive Pressuretrol, Cut-Out will be 3psi (2 cut-in + 1 differential). In reality, the cut-in should be set at about .5 (half pound) and the Differential at 1psi so that the boiler will cut out at 1.5psi, which if properly sized you typically won't reach unless it is sub-zero outside.

Alix

Aha! Boy do I feel dumb, first for having let the cut-in be set at 2 psi, and more recently for misinterpreting the dial! I think I got it now, many thanks! I reset the cut-in to .5 and left the differential at 1 psi.