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hot water boiler for baseboard gurgling

thomasmccown
thomasmccown Member Posts: 5
edited November 1 in THE MAIN WALL

My boiler Installed 2000, has always had a gurgling noise like the system is lacking water or has air in it. I have checked and double-checked the boiler pressure (17 psi) and boiler temp (170*) it has a "Spirovent" and auto feed. Many years ago the baseboards had bleeder valves on them in several places. Plumber who installed new boiler said I didn't need them so he removed them and plugged the hole with a threaded brass plug.

I can purge the system or have it done and it lasts for maybe a week and starts again.

There do not appear to be any leaks in the system, yet I'm baffled where the air is entering the system.???

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 24,556

    Air can only enter the system at a location where the pressure is less than atmospheric, either with the pumps off or the pumps on.

    Where are the pumps in relation to the expansion tank?

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • yellowdog
    yellowdog Member Posts: 165

    If the pump is too close to the spirovent, I have seen air get pulled in thru it.

    thomasmccown
  • hot_rod
    hot_rod Member Posts: 23,108

    Is the Spiro working? They can get plugged or the floats inside hang up. If air is passing thru itr, you should hear it being expelled, sometimes a little water dribble. Might be worth a drain down and open the Spiro at the middle seam.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    thomasmccown
  • thomasmccown
    thomasmccown Member Posts: 5

    There is only one pump and it is a few feet below the expansion tank

  • thomasmccown
    thomasmccown Member Posts: 5

    This is the second Spirovent I have installed in the system because my plumber thought that may have been the problem. Did not change anything.

  • thomasmccown
    thomasmccown Member Posts: 5

    Not sure where the Spirovent should be in relation to the pump

  • mattmia2
    mattmia2 Member Posts: 10,754

    The circulator should be pumping out of the expansion tank and the spirovent should be there. If the circulator is pumping in to the expansion tank and the circulator is pumping away from the spirovent it can put the vent in vacuum and suck air in.

    Any water at the relief valve?

    I'd start by turning the water feed off and watching the pressure closely over a day then a couple days then weeks to see if it is losing water and bringing air in with fresh water.

    thomasmccown
  • thomasmccown
    thomasmccown Member Posts: 5

    Mattmia2 Thanks I will check this out

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,283

    It could also be an expansion tank issue. The expansion tank should be able to be isolated from the system with a valve. If not you would have to drain the system and remove the tank to check the air pressure on the bladder side of the tank.

    Not having the proper air cushion in the EX tank can cause this issue as the water is heated and cooled it expands and contracts.

    thomasmccown

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