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  1. #1
    Join Date
    Jun 2014
    Posts
    3

    Default Replacing a non potable expansion tank

    I purchased a new one to replace the one that I have that is leaking.

    I turned off the water main, and opened a faucet to relieve the water pressure that was coming into my house.

    I then turned off the water supply to my existing expansion tank.

    My question is how to remove the old expansion tank. Should it be as simple as unscrewing the old one, and then screwing in the new one ?

  2. #2
    Join Date
    Jul 2009
    Posts
    165

    Default Re: Replacing a non potable expansion tank

    levinll,

    There are several expansion tanks used on residential hot water heating systems; the site below has photos of the 3 most popular; this is from the Home Improvement 1-2-3 book.

    Click onto the site below; then click onto "Home Improvement 1-2-3"; then scroll down to Chapter 12, and click on "Heating, Ventilation, Air Conditioning"; scroll down to 516: "Replacing an Expansion Tank"

    There is a procedure for adding air with a bike pump to a diaphram system if it isn't leaking; also for draining a waterlogged system; if replacing the tank with a new one is necessary, there is also a warning that waterlogged tanks can be very heavy to remove & easily slip out of your hands, causing damage to the heating system, personal injury, or both.

    Please post back if you have any further info; if you have a photo host site elsewhere, you can post some photos of the ET you are trying to repair or replace, and redirect them to https://advice.thisoldhouse.com

    http://books.google.com/books?isbn=0696213273
    Last edited by Pelton; 06-04-2014 at 04:55 PM.

  3. #3
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,767

    Default Re: Replacing a non potable expansion tank

    "My question is how to remove the old expansion tank. Should it be as simple as unscrewing the old one, and then screwing in the new one ?"

    That depends on your type of expansion tank connection.

    Remember that the new tank is pre charged (usually at 20 psi) and you will have to increase this pressure to match the house pressure.

    Not sure? don't take chances, hire a plumber. A mistake will wreck the new tank.

  4. #4
    Join Date
    Jun 2014
    Posts
    3

    Default Re: Replacing a non potable expansion tank

    My expansion tank has a rust spot that water is dripping out of.

    When I picked up the replacement tank from my local plumbing supply company, i inquired about adjusting the pressure of the tank. They said I didn't have to.

    Back to my original question. Does this tank simply screw off ?

  5. #5
    Join Date
    Jul 2009
    Posts
    165

    Default Re: Replacing a non potable expansion tank

    Quote Originally Posted by levinll View Post
    My expansion tank has a rust spot that water is dripping out of.

    When I picked up the replacement tank from my local plumbing supply company, i inquired about adjusting the pressure of the tank. They said I didn't have to.

    Back to my original question. Does this tank simply screw off ?

    levinll,

    You still haven't told us what your expansion is being used for---there are ETs that are used for well-water systems, then others that are used for heating systems, etc. please advise what your tank is connected to & whether it is a long, steel tank or one that looks like a squat propane tank connected to an outdoor gas grille.

    Please include photos.

  6. #6
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,767

    Default Re: Replacing a non potable expansion tank

    Let me tell you how to send photos: upload them onto a host like photobucket and then give us the link.

  7. #7
    Join Date
    Jan 2008
    Posts
    2,203

    Default Re: Replacing a non potable expansion tank

    By looking at the new tank and the way the old one is installed, how to swap them should be obvious- and most do simply screw on. Clean the threads, use three of four wraps of teflon tape wound in the right direction, and there you are as far as that goes- but there is further to go as the others have noted.

    There is no one pressure suitable for every installation no matter what the salesman tells you. If the new tank doesn't come with instructions on how to properly adjust the pressure then the manufacturer will have that available (usually 0nline). Do that wrong and you will have trouble, right up to destroying the diaphragm in your new tank rendering it useless junk and damaging the piping in what you're supplying. You wanna chance that then go right ahead- it's your time and money, not mine.

    Phil

  8. #8
    Join Date
    Jun 2014
    Posts
    3

    Default Re: Replacing a non potable expansion tank

    I think I'll call a professional. No need to do any damage. Thank you for your time.

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