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Wet return to boiler feed pump

This may be a stupid question, but I cant come up with a good reason why this won't work. 

 In an existing one pipe, parallel flow steam system where the mains and radiators have all necessary vents and wet returns, but the water feeder is flooding the boiler due to inadequate water content.  Why can't a boiler feed pump be installed without any traps being installed?  The wet returns will keep the steam out of the receiver and the receiver will give me the water volume needed for the boiler to complete its cycle.  I can also see that the residual steam pressure at the end of the main will be pressing down on the condensate and the pump separates it from the pressure in the boiler raising the water level in the tank, but I have about ten feet of height to pipe the receiver vent to the ceiling allowing the water to stack at the tank.

Any help would be greatly appreciated

Thank you.


  • Jamie Hall
    Jamie Hall Member Posts: 22,952
    Some arrangement of the sort

    might work.  However...

    You'd be much better off seeing if you can figure out why the existing setup isn't working right.  If this is an automatic feeder, which it sounds as though it is, it is unlikely in the extreme that it is "inadequate water content" (presumably in the boiler) that is the problem.  It is much more likely to be slow return, for one reason or another.  Sometimes this is cruddy returns.  Sometimes it is just long lines.  In the former case, cleaning them may help.  In the latter case, most automatic feeders have some kind of capability to set a time delay between when they sense low water and when they trip, and most also have a way to set the amount of water they feed.  Before you even think about the expense and trouble to install, never mind maintain, a boiler feed pump, work on that aspect first.

    In the highly unlikely event that it really is inadequate water content, again you would be much better off, in my opinion, putting a condensate reservoir on the wet return line near the boiler -- basically a tank connected to the wet returns (and, ideally, the dry return if any, or even with an equalizer to the steam main).  Make it any size you want.

    I might point out that if your problem is, as I expect, a combination of a slow return and an overactive automatic feeder, you may have the same problem, only worse, with the controls on a boiler feed pump...

    I am really adverse to adding any mechanical complexity to a system which can and should operate entirely on its own, by gravity.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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