(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 5 of 5

Thread: expansion tank replacement proceedure?

  1. #1

    Default expansion tank replacement proceedure?

    Can someone walk me through the proceedure of replacing an expansion tank.

    This is an inline tank with the air valve at the bottom. Pre-charged to 12psi.

    Is it as simple and shutting off the water/boiler, unscrewing and screwing the new one on?

    Thanks,

    Jim

  2. #2
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,374

    Default

    Shut off the fresh water makeup valve, too (if you have one). Relieve the pressure in the system, then unscrew the old one (it will likely be heavy since you're probably replacing it for a failed bladder - it is full of water), install the new one (use pipe dope and/or teflon tape), repressurize the system by turning on the make up valve and you are nearly done. If you have an auto air extraction valve, you probably are done, if not, then you may have to purge some air. My unprofessional experience.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  3. #3

    Default

    replaced the expansion tank last night. No more water coming out the PRV. Thanks for the help.

  4. #4
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,374

    Default

    One of the pros will probably comment, but you may want to put some more air in the tank, as the bladder will be stretched more than it needs to be if it is only at the 12 pounds. To get the pressure right, you need to relieve the pressure first, then check the pressure, add as necessary. I thought you were putting it in a boiler circuit, and 12 pounds is right for it. On a house potable water system, I think it needs to be higher. Saw somewhere else on here that it should be higher than your normal pressure.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  5. #5

    Default

    it is in a boiler circuit. Should the pre charged 12psi be enough. It is only for baseboard heat not for potable water.

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
  •