Hissing of steam air valve and sometimes water

melo

Can high pressure on the boiler, I'm talking over 3 psi cause the air vents to continuously hiss and sometimes let out some water?

delcrossv

Yes. Especially if the vent is failing/has failed.

Wcurtis

Why is the boiler pressure so high, is the pressuretrol set up properly, working as intended, pigtail plugged, adequate low pressure gauge installed at the boiler….something to consider.

This was my problem when I moved into the house and found pressuretrol set to 4 pounds, then had to replace several air vents although they had water in them (could have drained and blew through them and maybe would have worked but I wanted adjustible vents for balancing so they were replaced instead)

dopey27177

Steam pressure should not exceed 2 psig..

Set differential to 1/2 psig.

You may need to replace pressure controller with a vaporstat.

vaporstat settings 1 1/2 psig with 1/2 pig diffferential,

Jake