Creeping Boiler Pressure! Too High Help!


Ok well let me start off my story by this. i went into the basement and noticed the floor was wet and the relief valve had popped off. so i initially thought it was time for a new one cause it was fairly old etc.

I decided to turn off the switch for the boiler and drain the water and let it cool for a few hours. Went to home depot and decided to replace a few things just as i didn’t know the age of them on the boiler. i picked up a new relief valve, hy-vent, and expansion tank (which i found out was from 1996 and only had about 2 psi in it). Anyway i went home replaced all 3 items on the boiler, opened the fill valve and fired up the boiler. Psi was bout at 20psi when fully hot, has been fine for a few weeks now no pop off or anything but i kept checking it and noticed that the psi keeps creeping up higher and higher. Now given my heat is off the season as i have baseboard heating but the boiler still heats my water for showers etc. Anyway it slowly creeps and now has been sitting steady between 25-28 psi which i know is not right at all. Shouldn’t it be at about 20psi full operating temp around 180 degress? Only thing left by what i was reading it could be would be faulty internal leaking water reducing valve. mine is currently a B&G.

Let me know what you guys think of my situation, also is there anyway to tell if the pressure reducing valve is leaking internally? i read one thing saying if you touch the “bell” part of it and its stone cold that water is getting through and that is leaking internally. this should be warm or hot to the touch ?

thanks guys let me get some of your opinions.

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STEPHEN DEROSA 3 years 6 Answers 889 views 0

Answers ( 6 )

  1. ok thats what i figured, ive never seen it any other way. i will go ahead and try to get this installed and report back to you

  2. The fresh water valve should always be left on. This makes sure your system always has water when needed.

  3. redid all the bleeding last night and still getting the same thing, now let me ask you this

    i have one more question for you. i got a new valve and plan on installing it today, after i get it installed and fill the boiler and bleed out all the air out and get it up to about 12-15 psi should i turn off and leave off the water shut off valve right before the B&G ? ive never heard of this before and doesn’t sound right to me. every boiler ive seen always had the shut off valve open. This is what the guy at the plumbing supply told me but does not sound like its right. Please let me know.

  4. Im not sure i did the  bleeding part correctly. can you explain to me what the correct procedure would be so i can try and redo it and see if this fixes the problem

    also you are talking about the B&G pressure reducing valve?

  5. Hi, I’m assuming you did bleed the system after replacing all that stuff. I would check the external fresh water supply regulator. When these go bad it allows the system to build up using the pressure you have as fresh water. Also try to keep the psi between 15 and 19

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