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400000 btu pool heater has flow

MarkMillMarkMill Posts: 1Member
edited August 8 in Domestic Hot Water
I was given a 400000 btu pool heater and replaced gas valve, control board, igniter. I ran 1.25 pipe for 50' then down to an existing .75 pipe for another 25' to the heater. Via manometer the static pressure is 7.8, however manifold pressure will not go above .5 ". My meter is a 275 CHF. I was wondering if the new gas valve was bad, but now think the meter is insufficient. The previiis heater was 260000 btu and ran ok until it died.
Thank you for any help.


  • ZmanZman Posts: 4,969Member
    edited August 9
    Your meter is too small for 400K. Your gas pipe is undersized.
    This would be a good job for a pro...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JohnNYJohnNY Posts: 2,265Member
    Yeah. Pipe's too small and you don't have 400,000 BTUs available anyway.

    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
  • HVACNUTHVACNUT Posts: 2,254Member
    The 275 meter is spec'd for, wait for it... 275,000 BTU's.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,853Member
    meter too small, pipe too small. should be 1 1/2" right up to unit
  • hot_rodhot_rod Posts: 11,608Member
    edited August 9
    got enough pocketbook to feed that beast, if you do get it connected? :)

    I consider pool heaters as my mother put it when we left doors open, " I'm not paying to heat the great outdoors"
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • ChrisJChrisJ Posts: 9,809Member
    edited August 9
    HVACNUT said:

    The 275 meter is spec'd for, wait for it... 275,000 BTU's.

    To be fair he probably didn't know 275 cubic feet per hour equals roughly 275,000 btu/h.

    Before anyone says it.
    Yes, also to be fair he shouldn't be running gas piping and hooking up appliances if he doesn't know what he's doing either.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ZmanZman Posts: 4,969Member
    Unless you are at 10,000 feet with 713 btu/cf,then it is 196,075 :)

    I was not comfortable giving specific advise and having him blow his silly self up.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JUGHNEJUGHNE Posts: 5,713Member
    You could possibly change to a 2 PSI system.
    NOT a DIY job.
    Might cost you 1-2 months of gas though.
    The better things in life cost money. :)
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