Pressure too high?

Russell H.

I am a new homeowner with a one-pipe steam system. My boiler seems to be putting out too much pressure. The steam cutover is about .5 psi, which heats all of the radiators nicely. However, it continues to fire until the pressure gauge reads about 3.5 psi before shutting off (once the pressure is down to .5 again it fires up). Based on other posts, this sounds like typical "short cycle." The problem is that the higher pressure seems to be blowing the joints on one of my radiators (the joint that looks like a plumbing union that hooks to the valve). I've tried tightening the joint, but it doesn't help. Is there a way to lower the pressure and/or a better way of sealing that joint?

Hitzkup

differential pressuretrol

i'm a not a pro but i'l try to help you out since i have a similar size boiler & i had a similar problem.
what model pressuretrol do you have? you describe it as a differential pressuretrol
try to open the cover look for a dial. set it to 1 psi, this will give you a cut in of 1/2 psi & a cut out of 1-1/2 psi (the cut in plus the differential).
if you have more questions find your make & model # & check the manufecturers website for more information.

mark s

jeff_51

dittos to mark

Mark is totaly right. If your union still leaks you will have to back off the nut, and use pipe thread compound. Either pipe dope or teflon tape. Not always easy but give it a shot

Steamhead

Turn off the power

before you open the cover on the pressuretrol- there are exposed terminals in there.

If you have the usual Honeywell pressuretrol (small gray box) the differential is a small white wheel towards the bottom. As Mark says, set it to 1.

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Russell H.

Thanks for the info. It is a Honeywell pressuretrol, but diff was already set to 1. It seems like the spring on the cut-in setting is too tight. When the cut-in is at the lowest setting (stopped by the metal gauge marker), the cut-out pressure is too high (about 4). If I disengage the cut-in completely, the cut in and out seem about normal - cut out at about 2, cut in around .5 (gauge doesn't go that low). Would it mess it up if I stretched the spring?