Pressuretrol Setting

wanttolearn

Hi-

I am an avid reader of this forum, and have learnt a lot of helpful things about my steam system. 

Today, I set about to check the pressuretrol settings on my boiler.  I have two separate pressuretrols.  One of them has a cut-in set at 2.5 and a differential setting of 1, which means the cutout is set at 3.5.  The second pressuretrol seems to only have a cut-out at 12 psi, with no cut in (I assume this is only a safety device of sorts?)

I have read many postings recommending that the cut-in should be no more than 0.5 and the cut-out no more than 2.  This means that my setting is wrong.

Before I go about changing it, I want to make sure that a lower setting is always better than a higher setting.  Are there exceptions to the rule?  The plumber that installed my boiler last year seemed quite knowedgeable, so I am reluctant to second guess the settings he put on.

I should also mention the fact that in addition to my steam pipes, there are two hot water baseboards connected to the boiler.  Could the pressuretrol setting have something to do with these hot water zones?

Lastly, if I do want to lower the setting, do I just take a screwdriver and turn the screw at the top of the pressuretrol, or is the process something more complicated?

Your help is greatly appreciated!

Jamie Hall

sort of last to first

yes, the way to reset a pressuretrol is with a screwdriver and the little screw on the top.  I would suggest setting it down to about 1.0 and giving that a try.



Leave the one set to 12 alone -- it is a safety device (manual reset), and is only there if the one you are adjusting fails closed.



Are there exceptions to the lower is better rule?  Of course.  There are exceptions to everything!  However, it would be a very rare residential steam heating system indeed that needed more than 2 psi.