Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Just a little leak.

Dave Faust
Dave Faust Member Posts: 51
One of our water filled heating systems has been loosing water at a rate fast enough to leave the rooms on the top floor without heat in about 3 days. Boss says it's a leaking Hoffman #79 air vent, but I only find a very slight leakage from the 12 vents. I don't think it's enough to cause such a water loss. How much is too much? (his fix is to valve em off).
I replaced the (non functioning???) automatic fill device, but I don't expect it to do anything except partialy mask the problem.
Thanks all.


  • No other visible leaks?

    I'd suspect a leaking boiler. If you see white "smoke" coming from the chimney, that's steam from a leak in the boiler.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • JK_3
    JK_3 Member Posts: 240
    I think steamhead is right.

    if you can raise the top cover out of the way enough to remove the draft hood there is usualy visable evidence of it.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    Life is Good !! Enjoy it !!
  • clammy
    clammy Member Posts: 3,111
    buried piping

    I have ran into this and was common pratice in my area was to run baseboard loops under the slab and i myself have dealt with a few of them ,to be sure check your fill pressure and isolate any 1 st floor loops which may be underground ,the first sysmptom of a water leak always appears on the second floor as air promblem so you bleed the system and then 2 or 3 days later your back with a air promblem this has been my experwence but i have also on older wet base arco,ideal seen section leaks that did not give the tell tale sign of white smoke from the chimmey but lost small amounts of water and had air promblem every few days upon finally replacing he boiler we found water leaking froim lower push nipples the water was leaking right down into the slab and unnoticed ,the leak was not big just a small drip but enough to lower the system pressure and feed some fresh water in causinmg both air in the system and noisey 2nd floor baseboard and over a week enough to stop proper function of that zone,another way to see if this is happening is to drain soem water out ooof the boiler and see how orange the water is ,if it's bright orange you can figure you have a leak and your taking on fresh water which is eating your boilers cast i know i have seen it and fixed the slab leak and the orange water was athing of the past if you cannot find the leak at the boiler then see if you can isolte the boiler and using nitrogen pressre test the whole piping system with 30 lbs you will find the weakest linkj ,also if you have auto vent through out the house for air realted promnblems why not remove and plug them and install one central air elimator like a spriovent and have your pumps or pump on the supply side i have yet to install a system pumping away that has had any air related promblems espically using a spriovent,hope it helps peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
This discussion has been closed.