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Radiant in floor psi question

Thank you in advance! I just found out my hearing pro retired with no successor or recomendation. I have a small 1300 sq ranch built in 1954, copper lines in cement slab, replaced the origanal boiler in 2000 with a Utica Boilers unit. I'll give a little history of my last few days: I had a contractor come to renovate a bathroom...water was shut of at the main...bathroom replaced...water turned back on. A 30psi pressure valve that was in line between the cold water feed to the expansion tank began dripping. In speaking with a local security supply it was decided this was an old valve from my original furnace and no longer necessary as the boiler had its own. This was removed and capped. After looking at the gauge today...it's reading 30psi . Just to he sure the boilers pressure valve was in fact hooked up and working I used the top valve and got a good old dirty spray of hot water. My question is: my memory tells me the fomer heating pro had the furnace running at 20 psi. ..I coukd be completely wrong though. Does this sound like an acceptable psi for my system? I'll be searching for a new pro but I'm concerned in the meantime. Thank you so much!

Comments

  • ChrisYates
    ChrisYates Member Posts: 11
    Psi gauge while running.
  • ChrisYates
    ChrisYates Member Posts: 11
    Service tag
  • Jamie Hall
    Jamie Hall Member Posts: 18,972
    first off -- check and double check that the boiler does, in fact, have a pressure relief valve. You have to have that -- it is quite unsafe without it!

    OK -- having done that, how tall is your house? I doubt that you need more than 15 to 20 psi for your heating system, unless it is a very tall house. So then, the question is, what did your plumber do to change the pressure? Was this valve which dripped actually a pressure relief valve? or a pressure reducing valve? Or a backflow preventer (which you also should definitely have -- again a safety item).
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Steve MinnichGordy
  • ChrisYates
    ChrisYates Member Posts: 11
    Thank you Jamie...ceilings are 8 foot... attic is 6 foot at peak...I'll attach the pics of the entire system and the part that was removed...it looks like I can only do one at a time. I do not know how the psI is/was adjusted
  • ChrisYates
    ChrisYates Member Posts: 11
    This is the valve on the side of the boiler... that I was told is a pressure valave...it says 30 psi on it
  • ChrisYates
    ChrisYates Member Posts: 11
    Cold water feed... at the top of this is a 90 bend ...then the valave removed and then expansion tank...
  • ChrisYates
    ChrisYates Member Posts: 11
    Valve removed is in center... with down spout pipe
  • ChrisYates
    ChrisYates Member Posts: 11
    Close up of valve
  • ChrisYates
    ChrisYates Member Posts: 11
    Side view of removed valve
  • ChrisYates
    ChrisYates Member Posts: 11
    Larger shot of system...if that helps
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,839
    You need 1/2 PSI (plus 5PSI, 12 PSI minimum) per foot of vertical system elevation above the boiler.

    12 PSI is a typical minimum, back it down to 12 and call it good.

    Keep an eye on the pressure though, because your expansion tank may be water logged and that is the reason for the high residual pressure. Or your pressure reducing valve may be in need of replacement.

    You are covered for pressure relief valves, but should put down comer pipes on the relief to keep someone from getting scalded should the valve actuate in a dangerous situation.

    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Jamie Hall
    Jamie Hall Member Posts: 18,972
    OK. That valve on the side of the boiler is a pressure relief valve, so you are OK there. Not piped quite as I would like to see it, but... that's life. And the one removed was also a pressure relief valve. That it was dripping indicates that either it had gotten tired -- or that the system had gotten excess pressure somehow, and it was just doing its job.

    Now from your elevation, you don't need -- or want -- more than 20 psi in that system when it is hot. I would be very much inclined to get a heating man -- maybe your plumber -- in there to check that the expansion tank has the correct air charge in it, and that the water feed to the system is set to feed at no more than 15 psi...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Gordy
    Gordy Member Posts: 9,514
    edited October 2015
    Agree with Mark. That pressure relief needs a 90 then straight to 6" above floor. Like he said don't want to be sprayed with 180* water if relief valves pops off, and someone is in close proximity to it.
  • ChrisYates
    ChrisYates Member Posts: 11
    Thanks guys...much appreciated! Is this something that can wait till Monday or do I need to make an emergency call? Im having no luck finding referal for good local guys since my guy has retired
  • hot_rod
    hot_rod Member Posts: 16,332
    rap that hanging tank with your knuckles, it should have air in the top 1/2 or so. If not it may be waterlogged.

    If it is waterlogged the pressure in the system will rise quickly as the boiler heats up.

    You should also check to see if that relief valve on the boiler actually works, they often stick closed. Might be safer to just replace it. A new diaphram type expansion tank would be another upgrade.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream