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overfeeding steam boiler

Jim Pompetti
Jim Pompetti Member Posts: 552
Crown boiler (steam) BS1380ENPZPSU , has been overfeeding it has a Cyclegerd CG400-2090 with a ZXT-24 (which is displaying 000 all the time .Has anyone had this or similar problem.


  • Fred
    Fred Member Posts: 8,541
    Is supply water leaking past the bypass valve? It has to overfill from either a auto feed and the meter isn't registering it or the supply valve.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,575
    Is there a hot water coil in the boiler, which may be leaking?—NBC
  • Jim Pompetti
    Jim Pompetti Member Posts: 552
    NO . New install
  • Steamhead
    Steamhead Member Posts: 16,272
    Either the bypass valve is leaking or the valve in the VXT is. Try taking apart and flushing out the VXT valve and see if that helps.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Big Ed_4
    Big Ed_4 Member Posts: 2,377
    Cut the feed lines below the valves and see if any are leaking .. Called the union test ...
    I have enough experience to know , that I dont know it all
  • GBart
    GBart Member Posts: 746
    Damn dry base boilers should be outlawed.
  • GBart
    GBart Member Posts: 746
    They don't hold a lot of water, you could be running low on a cycle just to fill the system with steam and then the auto feed comes on then at end of cycle when the condensate returns you are over full.

    You would have to witness it to be sure, set a delay for fill on the VXT, that's why that option exists.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,575
    I would think that every boiler, rated for steam should have enough water content to fill the system, with steam, without needing to trip the LWCO, UNLESS the pressure is so high that a substantial portion of the water is pushed up into the dry returns.
    Weil McClain must have been a little weak on water content, because they showed the alternative reservoir tank piping on some boilers.—NBC
  • GBart
    GBart Member Posts: 746
    Unknown, I've seen small dry base boilers and wet base put into large homes that did not have enough volume to fill the system and have enough water still in the boiler. Seen systems with slow condensate return due to old piping.

    This type of problem needs baby sitting, several cycles need to be observed and what is happening will present itself.
  • Jamie Hall
    Jamie Hall Member Posts: 21,555
    I don't buy it. Let's suppose that for some unfathomable reason the radiation in the building is the least efficient, in terms of surface are for a volume -- a cube. And let's suppose that that cube has an EDR of 1200 square feet. Now That cube will have a volume of approximately 3000 cubic feet. To fill that volume would take 1.7 cubic feet -- or about 13 gallons. Granted, that's a lot of water. But is our radiation ever so inefficient? Let's suppose instead that it's in a more feasible shape -- say a panel radiator, double faced, with an inch between panels. That's still a pretty big panel -- 24 feet on a side. But the enclosed volume is only 50 cubic feet, which equates to only 0.2 gallons of water converted into steam.

    I don't see how, even with a really small boiler, one can claim that because the boiler doesn't have enough water volume that you will have trouble because it can't fill the system with steam.

    Where you can have trouble is with slow wet returns. It's not a bit difficult to visualize a scenario with a few gallons of water backed up in a slow return. It's even less difficult if the pressure is high enough to back into what should be a dry return.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England