(206) 949-5683, Top Rated Plumber, Seattle
Page 1 of 2 12 LastLast
Results 1 to 15 of 19

Thread: Water heater expansion tank

  1. #1
    DIY Junior Member igornys's Avatar
    Join Date
    Oct 2013
    Location
    New York
    Posts
    14

    Default Water heater expansion tank

    Expansion tank on my 50 gallon water heater become full of water so that I decided to replace it ordering the same model (Therm-X-Trol ST-12) that I had before.

    The tank was installed horizontally above the heater (see below). Now when reading installation manual, I see that according to the manufacturer, the tank has to be installed vertically.


    Name:  Schema.jpg
Views: 276
Size:  17.2 KB

    What would you recommend?

    My plans is to change the tank location as showed at the picture on the right as there is a wall on the right of the water heater so that I can provide support for another end of the pipe easily.

    Also, when installed this way, the bottom of the tank will be below the top of the water heater (see second picture below), is this permitted?
    Name:  new_1.gif
Views: 285
Size:  4.8 KB

    Thanks a lot for the response
    Last edited by igornys; 10-08-2013 at 10:28 AM. Reason: Wrong image downloaded

  2. #2
    In the Trades Gary Swart's Avatar
    Join Date
    Sep 2004
    Location
    Yakima WA
    Posts
    7,246

    Default

    If that is what the installation directions say, I can't argue that point. However, the installation for thermal expansion tank I have allowed for it to be installed as your old one was. The main caution with any installation was to be sure there was a good support. The drawing you have with the tee would work. Mine is just a tee in the main line with the tank suspended below. The main line is strapped to floor joints. The height is of no concern.

  3. #3
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,221
    Blog Entries
    1

    Default

    You mean this part of the instructions?

    Mounting Position

    One benefit inherent in the Therm-X-Trol® is the ability to
    mount the tank in any position. Due to the use of a heavy butyl/
    EPDMdiaphragm or butyl bladder, the Therm-X-Trol® can be
    mounted in an arrangement that best suits the installation space.

  4. #4
    DIY Junior Member igornys's Avatar
    Join Date
    Oct 2013
    Location
    New York
    Posts
    14

    Default

    Terry, Gary,

    thanks a lot for the quick response.

    I was looking at the on-line installation instruction provided by Home Depot.

    The limitation is described in the section on the left, last sentence in the warning #5. Please note, that PDF manual was revised on 8/06 (see on the bottom).

    After your response I compared it with the printed instruction that came with the tank (dated 11/11) and this very last sentence about the position is missing there … Also, instruction available at Amtrol directly does not have this limitation.

    I assume that the modern Amtrol tanks can be installed in any position.
    Last edited by igornys; 10-08-2013 at 12:49 PM.

  5. #5
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,221
    Blog Entries
    1

    Default

    I called Flexcon, the brand that I mainly install, and they say the Flex-ST5 can be mounted horizontal as long as it's supported.
    They don't want the dead weight putting pressure on the pipe.

    I either go vertical with fittings off the water heater, or if I wall mount the expansion tank horizontally; I strap it.

    Last edited by Terry; 10-08-2013 at 04:40 PM.

  6. #6
    DIY Junior Member igornys's Avatar
    Join Date
    Oct 2013
    Location
    New York
    Posts
    14

    Default

    Terry,


    Terry,

    thanks a lot for the response - I actually installed support when replacing tank earlier today.

    My major concern was weight in case tanks is leaking/become full of water. Specifically in my case the tee has 1/2 “ connection when my Amtrol tank has 3/4" connector so that I had to use an adapter increasing the lever.

    Name:  WaterHeater1.jpg
Views: 286
Size:  53.6 KB
    Last edited by igornys; 10-08-2013 at 07:42 PM.

  7. #7
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,447

    Default

    If the strapping is installed well, it should be more than sufficient to hold the tank in position when it eventually fails. They all do, eventually, but it depends on the water quality and how well you maintain the pressure so the bladder doesn't get stretched to the limit. Since it's close to he wall, you could put a shelf bracket underneath it...some I've seen (and use in my garage to hold some lumber) are rated at as much as 1/2T...any 'normal' one should be more than enough as a backup, should you not trust your strapping.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  8. #8
    DIY Junior Member igornys's Avatar
    Join Date
    Oct 2013
    Location
    New York
    Posts
    14

    Default

    Strapping should perfectly hold 4 gallon tank even if full of water, but as a former Defense Industry Engineer :-),  I don’t trust mounts that have extra degree of freedom. The wall is unfortunately a bit too far to use a shelf bracket to support.

    As for the tank itself, the previous one was installed ~1 month ago by a plumber who replaced the old water heater and the original Amtrol tank. Not pre-charged + almost 90 psi water pressure made it failed soon (the tank installed was not Amtrol, but some noname ).

    This is why I started looking on-line to better understand what was done wrong. I hope I did it right now, also pre-charged and lowered the water pressure.

  9. #9
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,687

    Default

    I prefer to mount the tank vertically, above or below the pipe, directly into a tee so there is no lateral stress on the connection. But, if it is supported properly, it can be located in any position. I also put a valve on it so it can be service or removed without shutting off the water and draining pressure out of the system.
    Last edited by hj; 10-09-2013 at 07:03 AM.
    Licensed residential and commercial plumber

  10. #10
    DIY Junior Member igornys's Avatar
    Join Date
    Oct 2013
    Location
    New York
    Posts
    14

    Default

    Quote Originally Posted by hj View Post
    I also put a valve on it so it can be service or removed without shutting off the water and draining pressure out of the system.
    How often do you typically replace the expansion tank?

    As for the service/pressure maintenance – indeed having a separate valve would be more convenient.

    I assume, however, that closing the incoming could water to the heater/opening hot water faucet at the location nearby for a couple of minutes will be enough to measure the actual tank pressure.

  11. #11
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,221
    Blog Entries
    1

    Default

    I also put a valve on it so it can be service or removed without shutting off the water and draining pressure out of the system.
    I would like to watch you replace an expansion tank without draining off the pressure first.
    That thing holds about two gallons of water at house pressure.
    I think someone is going to be pretty wet.
    Last edited by Terry; 10-09-2013 at 08:43 AM.

  12. #12
    DIY Senior Member Reach4's Avatar
    Join Date
    Sep 2013
    Location
    IL
    Posts
    1,285

    Default

    He used a valve with a drain, and he remembered to put the drain on the correct side.

  13. #13
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,662

    Default

    Quote Originally Posted by Terry View Post
    I would like to watch you replace an expansion tank without draining off the pressure first.
    That thing holds about two gallons of water at house pressure.
    I think someone is going to be pretty wet.

    I would hope She is wearing a T-shirt and no bra.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

  14. #14
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,221
    Blog Entries
    1

    Default

    He used a valve with a drain, and he remembered to put the drain on the correct side.
    Well...............that tiny little pin hole will take a while to drain 2 gallons under pressure.
    I've seen the ball valves for that connection before, but then I think about how much water is trapped in that tank, and I think about the dunking I would take spinning it off.
    The small drain there, I guess you can stand there with a bucket and try to catch it without getting wet as it's spraying at you under 60 PSI pressure.
    I would rather shut shut the water heater off and open a faucet.

    And Don, I just wear a T-Shirt.
    Last edited by Terry; 10-09-2013 at 12:30 PM.

  15. #15
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,447

    Default

    FWIW, while I like having one there, having a valve between the ET and the WH is not code. You could forget to open the valve, and then the ET is essentially useless. If the ET has failed, then at least if it was hanging vertically, you'd not have any water under any real pressure...you might not get wet taking it off. Horizontally, is another issue.

    Also, if your static WP is 90psi, you should add a PRV! Residential settings are required to be NGT 80psi.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

Similar Threads

  1. Water Heater Expansion Tank
    By Roccoo in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 3
    Last Post: 12-01-2009, 04:55 AM
  2. Location of expansion tank w.r.t. water heater
    By jdf405 in forum Tankless Water Heater Forum
    Replies: 3
    Last Post: 07-10-2009, 01:34 PM
  3. Expansion tank needed on water heater?
    By Mike16 in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 10
    Last Post: 12-10-2008, 06:01 AM
  4. Expansion Tank for a Hot Water Heater
    By driem in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 20
    Last Post: 10-28-2008, 06:01 AM
  5. No Expansion Tank for Water Heater
    By vasanvasan in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 3
    Last Post: 01-14-2006, 06:34 AM

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
  •