Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

400000 btu pool heater has flow

MarkMillMarkMill Member Posts: 1
edited August 2019 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 Member Posts: 5,622
    edited August 2019
    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 Member Posts: 2,424
    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 the Boilers and Hydronic Heating Systems Course Instructor at NYC's Mechanics Institute, 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.
    John also oversees mechanical installations and maintenance for metro-area clients with his family's company, Gateway Plumbing and Heating along with his brother/business partner.
  • HVACNUTHVACNUT Member Posts: 3,092
    The 275 meter is spec'd for, wait for it... 275,000 BTU's.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 6,744
    meter too small, pipe too small. should be 1 1/2" right up to unit
  • hot_rodhot_rod Member Posts: 12,954
    edited August 2019
    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 Member Posts: 10,677
    edited August 2019
    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 Member Posts: 5,622
    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 Member Posts: 6,628
    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. :)
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!