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Venturi system/purging relief valve

jdl
jdl Member Posts: 13
in THE MAIN WALL
Yes, it was replaced. It's a Watts ET-30. It is less than a year old. Could it have failed?

Comments

  • jdl
    jdl Member Posts: 13
    Venturi system/purging relief valve

    Hi all. I have an oil fired boiler with a venturi 1.25" single pipe h/w system. I had three radiators removed from the loop and a new boiler installed at the same time. The plumber who removed the rads just capped off the feeds. It heats good, but the relief valve purges when the system has been fired up for a while. Could this be due to back pressure from the rad removal, or would you suspect the expansion tank?
  • Mike Kraft_2
    Mike Kraft_2 Member Posts: 398
    Relief

    The valve is "purging" due to pressure is exceeding the PRV's rating.There could be several reasons.The expansion tank.....was it replaced with the new boiler install?If so it may not be sized correctly.If it is under sized in a closed system like yours when the boiler firs there maynot be enough room for expansion.If this is the case the PRV will blow off.There is a method to sizing a tank correctly.You have an 1 14" main and iron radiators that is a considerable amount of water.

    what type and size is the expansion tank?

    cheese
  • Mike Kraft_2
    Mike Kraft_2 Member Posts: 398
    I'm Guessing..............

    it's undersized.Cut and paste this link and do the math.Let us know what you ccome up with.

    cheese

    http://www.amtrol.com/pdf/extrolbroch.pdf
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