Is a WH supposed to be raised off the floor?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by walkman, Apr 28, 2008.

  1. walkman

    walkman New Member

    Messages:
    26
    Location:
    San Diego
    Is there a requirement/advantage to raising it off the floor?

    I'm asking because my old water heater had 2" legs underneath it. It looks like the new ones are flat on the bottom.
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,051
    Location:
    New England
    It's not a bad idea to install a WH in a drain pan, but no, with the new federal requirements, WH generally do not have to be raised up. If the floor typically got wet, you might want to raise it for that reason. Note, some locales require it in places like garages, but the new federal requirements make the new designs safe from gasoline vapors, so the added height does not add safety in that front, but still does from possibly being hit by a car in the garage.

    Check with your local inspector and follow the installation requirements. If the two don't agree, do what the inspector says after showing him the instructions - he may relent, and he may not.
  3. Ian Gills

    Ian Gills Senior Robin Hood Guy

    Messages:
    2,777
    Location:
    USA
    It varies but generally in a garage it must be 18" off the floor.

    In my basement, my WH is flat on the floor. They no longer come with the short legs you mention because they were easily damaged and made moving/removing the WH more difficult.

    It was easier moving the new one in than taking the old one out wasn't it?
  4. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,714
    Location:
    Central Florida
    I think the regs vary depending on whether it's an electric or gas-powered WH. In any event, raising it off the floor makes attaching the hose to the drain a lot easier.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,680
    Location:
    Cave Creek, Arizona
    heaters

    IF it can be impacted by an automobile, it MUST be 18" above the floor regardless of gas or electric. Otherwise it depends on whether the city has adopted the latest gas code to allow the FVIR heaters to be on the floor. The reason for legs was that the old heaters drew their combustion air from underneath the heaters. The new ones draw it in from the sides.
  6. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,714
    Location:
    Central Florida
    Any idea why this is? Coincidentally (perhaps) the federal rule for bumper height (passenger cars only) is 16"-20".

    I've seen other "expert" sites that claim there must be physical protection for a WH from impact by automobile, and that anything installed in a garage which could generate a spark to ignite gasoline fumes must be 18" above the floor -- including washers and dryers. They mention "national mechanical code" -- can anybody quote chapter & verse?
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,680
    Location:
    Cave Creek, Arizona
    heater

    Of course. It is to raise the heater high enough so that a car cannot run into it. The alternative is to install bolster pipes in front of the heater to protect it.
  8. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    I have seen a ton of washer dryers in the garage...that is how they did it here in the 60's through the mid 80's. Never saw even one raised up off the garage floor. When you think about it , that would seem to be a loophole in the code!
  9. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    Water heaters down here are typically installed on the floor in the garage, without bollards. Gas water heaters must be 18" off of the floor.
  10. Squ1rrel

    Squ1rrel New Member

    Messages:
    69
    Location:
    Texas
    It may be for combustion reasons...every garage I've ever seen has oil stains on the floor.
  11. gear junkie

    gear junkie Plumber

    Messages:
    67
    Location:
    Virginia Beach, IPC country
    We put them on stands here because the gas vapors sink and a spark from a gas W/H could set it off. We do put bollards in front of the stand since a stand won't stop a car.
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,680
    Location:
    Cave Creek, Arizona
    heaer

    The FVIR burners stop the ignition of gas fumes, so they can be on the floor if your locale has adopted the latest gas code.
Similar Threads: supposed raised
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & How are you supposed to Tee a 2" drain pipe inside a 2x4 wall?? Oct 12, 2013
Plumbing Forum, Professional & DIY Advice, Tips & Help me figure out how these rough-ins are supposed to form the bathroom May 28, 2011
Plumbing Forum, Professional & DIY Advice, Tips & Which way is the cold water handle supposed to turn? Mar 14, 2011
Plumbing Forum, Professional & DIY Advice, Tips & When am I supposed to use Brass tube support sleeve Sep 8, 2006
Plumbing Forum, Professional & DIY Advice, Tips & Sealing Raised Foundation Sewer Outlet Opening Mar 2, 2013

Share This Page