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How much low water fresh-water feeding to boiler is acceptable?

Your thinking is excellent, it is not about money, at least as a means to track and document a benefit. With that mindset, seeking a payback, the bean-counters pat themselves on the back while the contractors replace the boiler...

Absent the delay feature and with it regardless, a counting meter is the best way to document what you are losing of course.

Assuming that you account for normal draw-off (LWCO blow-down which should be routine), your actual make-up should be zero in theory. In actual practice though? You would get as many answers as you would have people to ask.

On a smaller system, a single family small house, a quart a month might be a lot if the system is "tight". On a larger system with more potential for wispy losses, maybe a gallon a month? That is me just being optimistic of course.

But if you are getting a few gallons a day, that is a cause for alarm. As you know, this is a vicious cycle.

Any underground piping? Visible leaks? Might there be a leak in the boiler above the waterline (which does not show up as "water in the combustion chamber" but loses steam nonetheless?

One source of steam loss, if your system is 2-pipe steam with traps, is that a failed trap will pass steam to the return. It may escape via your condensate pump vent or a main line vent which may also be stuck open. It is all a matter of intimate knowledge of your piping system.

My $0.02



  • sreja
    sreja Member Posts: 175
    How much low water fresh-water feeding to boiler is acceptable?

    Hi guys,

    We have a 1yr old peerless 211A-08 boiler (35hp) that is heating a 14 unit building (and seems sized right according to my calculations).

    There is a condensate pump in the basement.

    My question is -- how often should the low-water cutoff be triggering the feeding of new fresh cold water during normal operation?

    Or put another way.. at what point should i start getting concerned that it's bringing in too much fresh water too frequently.

    Dan's books recommend some very cool delay-based low-water probe and feeder which i love, but our steam guy says it's not worth the cost in terms of the money we would save. But then i also know that it's not just about saving money but saving the health of the boiler as well.

    What are your thoughts?
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