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False Pressure Release Time?

I have an average size two pipe home vacuum low pressure system that is well maintained, and have learned quite a bit here and over the years. There is false pressure after the heating cycle has been satisfied. Two questions that I couldn't find info upon searching, as I think I noticed higher than normal false pressure:

1) How long should it take for the False Pressure release to return to zero? Estimated -15 lbs to 0. Meaning, is it being release fast enough, via Hoffman 76? Two Main vents - Hoffman 75s.

2) Is this high (if it's high) false pressure harmful to a system?

Hopefully, this is enough info, but can certainly provide more as needed.

Thanks, Keith

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,173
    I'm not quite sure I know what you mean by "false pressure". Do you mean a vacuum which the system drops into after it has fired? Or that the pressure stays up after the system quits? Or what?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • kredmore
    kredmore Member Posts: 53
    negative pressure that the system drops into after heating cycle is satisfied.
  • Jamie Hall
    Jamie Hall Member Posts: 23,173
    That's referred to as a vacuum. I suspect that you are referring to 15 inches of water vacuum, not 15 psi -- which would be extraordinary.

    The longer it sits there, the better -- that simply means that the system is nice and tight and extracting more from the residual heat in the boiler.

    It's a very good thing...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    SWEI
  • kredmore
    kredmore Member Posts: 53
    ok, thanks. sounds like all is good!