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Water pressure and efficiency

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by stoney28, Nov 8, 2013.

  1. stoney28

    stoney28 Member

    Joined:
    Oct 12, 2008
    Messages:
    59
    Loc:
    Northern NY
    I've got an EKO 40 with 500 gallons of storage. Earlier this year I had a leak in the boiler which has since been welded. I've been cautious about running up the pressure since then, so I'm only running the pressure (at full temp 180F) at about 15 to 18 psi. Will this affect the efficiency of the boiler? Are there any other problems that could come up?

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  2. BoilerMan

    BoilerMan Minister of Fire

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    Apr 16, 2012
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    1,575
    Loc:
    Northern Maine
    Short answer is no. Water pressure has no effect on heat transfer efficiency, as long as there is no boiling. Some boilers (Garn, Empyre, etc.) are open systems meaning they are vented to atmosphere at a high point and run at zero pressure. 15-18 psi is a good place to be at full temp.

    TS
  3. stoney28

    stoney28 Member

    Joined:
    Oct 12, 2008
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    Loc:
    Northern NY
    Thanks
  4. maple1

    maple1 Minister of Fire

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    Loc:
    Nova Scotia
    I keep my pressures fairly low - around 6-8 cold to 12 hot. No issues that I've seen, and I'm circulating around two storeys.
  5. stee6043

    stee6043 Minister of Fire

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    Aug 22, 2008
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    Loc:
    West Michigan
    Low pressure may not impact the boiler but are your pumps rated to run at a certain pressure? Some brands/models don't like low (perhaps sub 10) pressure.

    My system holds at 12-14 psi cold. 25-26 psi typical max pressure when she's all up to temp.
  6. maple1

    maple1 Minister of Fire

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    Loc:
    Nova Scotia
    Think I'm Ok there. Alpha specs. min 0.75psi @ 167°, 4.06 psi @ 194°. Mine is on my return line so would never, or very rarely, see much above 167°. If it did my system would have to be pretty well up to temp which would be in the 12psi range.

    I did have issues with getting all the air out of my upstairs zones when I first started up with the new boiler, lots of frigging around there with hoses going here & there - but once I got those purged haven't had any more air problems.

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