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expansion tank getting waterlogged

eagleone
eagleone Member Posts: 2
in THE MAIN WALL
I have a commercial boiler 714000 Btu for heating a 1192 gallon domestic hot water storage tank. It has been working for over 10 years with no problems. Now the expansion tank is filling daily and blowing off the relief valve by morning. Steel expansion tank 14 gallon. I found air leaks on the sight glass valves and drain valve. Replaced everything except the B&G airtrol inlet valve. could the inlet valve be acting like a check valve not allowing the pressure to reduce as the water cools or is there something I'm missing.

Comments

  • Big Ed_4
    Big Ed_4 Member Posts: 2,929
    Sight Glass

    If you have a sight glass on the tank , replace the glass and washers . Also check the shut off valves packing .. You could also have a leak in the top of the tank. That air trol keeps the air from migrating from the tank in to the system. There is no working parts besides the adjustment vent...

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  • BobbyG
    BobbyG Member Posts: 79
    your post says waterlogged - so...

    This is the best explanation I have found about how it is all supposed to work.

    [url=http://www.bellgossett.com/homeowners/CompressionTank.htm]http://www.bellgossett.com/homeowners/CompressionTank.htm

    One quick question, was there a auto air vent recently added?  I'm thinking if you got rid of air,  instead of sending it to the tank, it would cause the tank to waterlog faster...

    I don't know enough about your situation to say that is the problem - only one thing to check.

    Hope this helps.
  • eagleone
    eagleone Member Posts: 2
    Sight glass has been changed

    I changed the sight glass assembly complete with new valves and checked the the tank and all valves with bubble solution. no air leaks
  • Big Ed_4
    Big Ed_4 Member Posts: 2,929
    edited February 2010
    Soap Bubbles

    Good ... But where is the leak. If I was there I would spray the whole tank and valves with a spritz bottle of Megabubbles after draining and refilling the tank again ... That stuff will rise up and show you the cuprit ....

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  • Coany
    Coany Member Posts: 91
    Make certain the feeder isn't leaking by.

    Is there a tankless coil? another potential source of excess pressure.

    There was an error rendering this rich post.

  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669
    air leak

    Is this a closed loop system or is it a domestic hot water heating system that has fresh cold water going through the boiler.

    If it is a closed loop system ( heat exchanger between boiler and domestic water ) then you have an air leak somewhere in the tank above the water line.

    If it is an open system ( domestic water goes through the boiler ) then I suggest a new bladder tank.
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