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ChrisJChrisJ Member Posts: 11,272
On a natural vent water heater is there any minimum requirement on how high up the elbow in the vent must be from the vent hood?   For example if height is tight can the elbow be an inch above the vent hood?

I understand the vent must pitch up towards the chimney but cannot find any spec on height before a 90 deg bend.

Sorry if this is a dumb question but I feel its better safe then sorry.
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


  • IronmanIronman Member Posts: 5,817
    The Elbow...

    Can connect directly to the vent hood, assuming the rest of the vent is properly installed.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • Tim McElwainTim McElwain Member Posts: 4,392
    It is often a good

    idea with that type of condition, no rise, to actually increase the flue one size. My recommendation for all water heaters today is no less than 4" pipe and make it double wall all the way.
  • j a_2j a_2 Member Posts: 1,796

    Hello  I was wondering, if you were to up size off the draft hood and that was the only appliance venting into the chimney, what size would you use for the 7 times rule....My understanding is nfpa 54 2002 says size off the draft hood diameter...I look fwd to your answer....
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