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Uneven Mains

Jeff_101 Member Posts: 12
my steam main vents on the slower side. (They are up on a nipple). Usually, I would feel a RUSH of air movement as the steam was pushing through the main; this time, I did not get that rush and it did not seem to expedite the steam through that short main any more quickly...

What can you suggest next. I did already clean the pigtail, pressuretrol and blowdown and have checked the safety valve. My plumbing supply guy sold me the powder stop leak that you mix with water and pour into the top of the boiler.


  • Jeff_101
    Jeff_101 Member Posts: 12
    Uneven Steam Main Heating

    Yesterday, I had a slight leak in my stema boiler. Used bolier stop leak, followed the directions and luckily, no problem (Well for today anyway!)

    However, after the boiler was cleaned of the stop leak and began to steam, the water began priming and foaming a bit and seemed to carry a little water up with the steam. ( I tested the quality of the water using the sight glass method by closing the bottom cock and seeing if water purged over the top one...sure as hell it did..so I knew the steam was either too dirty or not dry enough) So, I drained and cleaned the boiler more thoroughly and the steam dried out and the house began to heat...except now, one of my mains heats more slowly than the other. I have used Steamheads calcs to put in proper main vents and my pressuretrol is set according to Dan's specifications - 1/2 in..and 1.5 out...NEVER had any issues like this before....the steam always reached each rad at the same time and I had wonderful EVEN steam heating...what could have caused this? I have no short cycling...just a slower heating main!
  • stop leak stops vents too.

    Vents are nothing more than a calculated leak. Your vents AND your safety controls now have stop leak in them.

    Hopefully your relief valve still works.....

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