(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 15 of 55

Thread: Shutoff Valve in Hot Water Line of Water Heater

Hybrid View

  1. #1

    Default Shutoff Valve in Hot Water Line of Water Heater

    Is there any model code, manufacturer's installation instruction, or just plain reason that prohibits the installation of a shutoff valve in the hot water line coming out of the top of a water heater?

  2. #2

    Default

    Not that I know of. Many HW tanks have shutoffs at both the inlet and outlet.

  3. #3
    In the Trades Gary Swart's Avatar
    Join Date
    Sep 2004
    Location
    Yakima WA
    Posts
    7,246

    Default

    You should put a valve on the hot water line so that you can flush the tank without washing crud into it. One on the cold intake side isn't so useful, but with one, you could remove the tank without turning off the entire house water, and it's cheap enough to do. I use full flow ball valves.

  4. #4
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,633

    Default valve

    Some, not "many", water heaters have valves on both side. I run across ONE every ten years or so. And the one on the cold side is REQUIRED by all codes, even though someone says it is "not useful".

  5. #5

    Default

    Most of my previous experience is with larger tanks used in apartment buildings. They almost always have two shutoffs.

    Recently, however, most of the residences I have worked in have zero shut-offs, which means no water until their tank is replaced (or until I install the CW shutoff).

  6. #6
    Senior Robin Hood Guy Ian Gills's Avatar
    Join Date
    Jul 2007
    Location
    USA
    Posts
    2,781

    Default

    Are all of you completely mad? Or is it 1 April?

    Even a DIYer knows this one, which says something.

    It is incredibly dangerous and absolutely against code to have a shut-off on both the inlet and outlet of a hot water heater. If both are closed, the WH relies completely on the proper functioning of the PRV to deal with pressure/expansion changes and faults if the heater is left on.

    If the PRV fails, then we start to see explosions of the type some of you post links to on this site every now and again.

    My neighbor has valves on both the inlet and outlet of his WH and I live in fear. Say he shuts them both off and forgets and the PRV fails?

    Shut-offs on WHs should only be installed on the cold side. That way, the fixtures and fittings (think washer hoses) of the hot supply will also take the strain of any increase in pressure should the PRV fail and there is fault with the WH. There is therefore less chance of a boom.

    How many bombs are you guys making?

    LONG LIVE D.I.Y.
    Last edited by Ian Gills; 12-16-2008 at 11:52 AM.

  7. #7
    Master Plumber Dunbar Plumbing's Avatar
    Join Date
    Apr 2005
    Location
    Northern Kentucky/Greater Cincinnati Area
    Posts
    2,943

    Default

    Quote Originally Posted by aaronm View Post
    Is there any model code, manufacturer's installation instruction, or just plain reason that prohibits the installation of a shutoff valve in the hot water line coming out of the top of a water heater?

    One of the most dangerous situations you create.


    Two valves off, water heater kicks on and the T&P is clogged...


    A pressure cooker that when it explodes, will kill and destroy your property.

    Having the ENTIRE plumbing system to use as a buildup for when a supply line blows or forces a fill valve to malfunction, anything is better than containing that water heater expecting that $7 relief valve to open up when you need it most.


    I've removed every hot side shutoff on every water heater I've replaced, no exceptions and I've warned every customer of the ones I've beared witness to.

    Things can and will go wrong in plumbing and just because you know how your plumbing system operates, doesn't mean your wife, kids or the incoming new property owners know what kind of bomb you built in the basement.
    Read what the end of this sentence means.

Similar Threads

  1. Water heater shutoff???
    By moonapprentice in forum Water Heater Forum, Tanks
    Replies: 3
    Last Post: 08-04-2011, 11:31 PM
  2. water heater hot water line shut off valve
    By astro46 in forum Water Heater Forum, Tanks
    Replies: 4
    Last Post: 06-09-2010, 07:01 PM
  3. Kitchen faucet hot line slow after water shutoff
    By GregN31 in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 1
    Last Post: 06-08-2010, 11:32 PM
  4. Shutoff Valve in Hot Water Line of Water Heater
    By aaronm in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 41
    Last Post: 12-22-2008, 07:38 AM
  5. Remote sensor shutoff valve for water heater
    By lotuseclat79 in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 7
    Last Post: 08-09-2005, 12:50 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •