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Re: Crowne Combination Boiler

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Steve_210
Steve_210 Member Posts: 646
in THE MAIN WALL
I have a Crowne combination boiler MWC116 for natural gas.  We recently disconnected the Domestic hot water side and installed an indirect as tthe customer did not have enough hot water.  Since then the relief valve started to weep at about 160 degrees.  The pressure gauge on the boiler does not increase.  That is what I am finding strange.  If it were a blockage to the expansion tank or a bad expansion tank surely the pressure would increase.  There is the possibiltiy of a bad gauage.  Just wondering if anyone has come across this on these boilers or is there a common problem with these units?

Thank you

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  • Ironman
    Ironman Member Posts: 7,376
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    Relief Valve

    I'd try changing the relief valve first and see what happens.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Steve_210
    Steve_210 Member Posts: 646
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    Sorry

    I forgot to mention I changed th reilef valve already
  • Ironman
    Ironman Member Posts: 7,376
    edited July 2012
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    Expansion Tank?

    If the expansion tank was marginal, the extra water volume and higher temp required by the indirect may have tipped the scale against you.



    Also, are you pumping away or toward the expansion tank?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Paul48
    Paul48 Member Posts: 4,469
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    Check

    the pressure with a  gauge on the boiler drain.You may have to add another expansion tank in addition to the internal one.
  • j a_2
    j a_2 Member Posts: 1,801
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    location

    Without looking at the book and seeing how its piped in I am thinking you have to relocate the expansion tank, If the unit has a valve inside that closes/shifts due to priority then you have isolated the expansion tank from the indirect
  • Steve_210
    Steve_210 Member Posts: 646
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    Crowne Combination Boiler

    It's a combination boiler so the expansion tank is on the boiler but I am pumping away from the expansion tank.  I will check the pressure with a new pressure gauge.  It is possible that the one on the boiler is not working properly as it does not move when the water is heating.  I don't think the unit can have any valve that closes or shifts due to priority.  Again, it is a combination boiler.  The brased plate heat exchanger has been made redundant. We are not using the Domestic hot water side of the combination boiler.  I cannot see how the expansion tank could ever be isolated from the heating water but maybe I am missing something. I will check the pressure with an independant gauge.

    Thanks again for all your help guys!
  • CMadatMe
    CMadatMe Member Posts: 3,086
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    ByPass

    Check the by-pass piping in the boiler and make sure there is no obstruction. That boiler is a Basi Rivera rebranded.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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