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Leaky vents

Jeffrs Member Posts: 36
Hello all,

My water level keeps diminishing at a rate where the LWC comes in maybe once a week to once very two weeks. All my radiator vents were hissing and sometimes spitting just a little once the radiators were hot, so I replaced them with maid o mist vents. I have no buried lines and after inspecting all other plumbing, cannot find a leak, so I suspect because of the leaky vents. Is it likely that these vents are leaking due to pressure? Is there any other causes that would cause both sets of vents to leak once under steam pressure?

Also my water level bounces a bit, I have tried skimming the boiler a couple of times slowly with no success, any suggestions? Would any other reasons other then contaminated boiler water causing a bouncing water line?




  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Spitting and hissing

    I would certainly look at your pressure. Take off the pigtail, and pressuretrol, and make sure there is no build up in the pigtail, preventing the pressuretrol from feeling the pressure. This would be a good time to add a 0-3 psi gauge so that you know what the pressuretrol is doing. The over-pressure can force enough water out of the boiler to simulate a low-water condition.

    While you are spending such quality time with your boiler, have a look at the main vents on the dry returns. If they are inadequate, or non-functional, you may have increased fuel use, and uneven heating. If all is well with the system, you should not hear the rad vents at all.--NBC
  • Jeffrs
    Jeffrs Member Posts: 36
    High pressure?

    0-3psi gauge is on its way. Pressuretrol is set to lowest setting of .5 in and 1 on the differential. Current 0-30 gauge can read as high as 4-5psi, whether that's any accurate at all, who knows, hopefully the new gauge will confirm or deny. Pig tail seems to be clear. I added main vents last year, also maid o mist vents, they work with out any issue, no leaks under pressure, nice and quiet. How can I tell if I have adequate main venting though?

    If my pressure is going that high, are you suggesting that it maybe the high pressure pulling the water out of the boiler causing the water level to bounce? Or is it still likely to be water contamination?

    Thank you again,