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curious problem with expansion tank

Chas_4
Chas_4 Member Posts: 29
in THE MAIN WALL
If I let it get cold, it leaks in a couple of spots. As long as its hot its fine. Im afraid to fix the leak this time of year. Might bust the boiler taking the coil out.

Comments

  • Mike Dunn
    Mike Dunn Member Posts: 189
    pressure fluctuations

    Customer calls and says that when primary is up to temp at around 140F to 180F pressure is at 12-14psi. When the boiler went out on reset and the primary got down to around 60F the pressure was at 0psi. When boiler came back online and high temps were reached again then pressure was back to normal. Isn't the expansion tank suppose to prevent this if the pressure is set when the water is cold?
  • hvacfreak
    hvacfreak Member Posts: 439


    sorry , didn't read before I replied...that is weird...perhaps gauge is wrong.

    Or this one...gauge is correct but initial ( static ) fill pressure is low ( waterlogged tank with low initial fill pressure ).
  • Derheatmeister
    Derheatmeister Member Posts: 1,579


    Yes i think also low pressure and waterlogged tank!Check the schreoter Valve on the expansion tank if H2o comes out replace the tank! Or recharge the tank to about 2 psi less that the fill Pressure ,Do this when the expansion tank has no pressure on the wet side,Make sure that the Schreoter Valve is not leaking and cap it.! Check system (make it reach max temp) there can be minimal pressure Increase.HM
  • Mike Dunn
    Mike Dunn Member Posts: 189
    ex tank

    I will try this tomorrow and reply with results. Thanks guys!
This discussion has been closed.

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