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boiler pressure

john_181
john_181 Member Posts: 93
in THE MAIN WALL
I went to get a friends boiler running for him and after cleaning it out (lots of rust) it fired up. It is probaly a 1996 model from sears 150,000 BTU. My question is, my home boiler runs from 12 - 18 psi. his was at 25 cold and reached 35 when hot. i also noticed he did not have a in line regulator for the boiler. should his read about 12psi cold and should it have a reg in line?

Tnks

Comments

  • Timco
    Timco Member Posts: 3,040


    It should be 12 cold to begin with, but he NEEDS a new relief valve. It should have relieved at 30#. If he can get to 35#, that is really bad. A pressure reducing valve is good to have, but you should put a backflow preventor on it as well so it can be used as an auto-fill.

    Tim
    Just a guy running some pipes.
  • Brad White_201
    Brad White_201 Member Posts: 52
    A footnote

    The 12 PSI cold fill pressure is for a one or two story house. 18 PSI for a 3-story house.

    These pressures allow for 4 to 5 PSI at the top of the system and one PSI for every 2.31 feet of elevation.

    Thus a building with a system height of 20 feet would need 8.65 PSI to get water to the top. Add another five PSI and you would fill the system to 13.65 PSI at the boiler.

    What Tim said about replacing the relief valve holds, you bet.
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