1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Glow-worm flexicom expansion vessel pipe connector nut leaks

Discussion in 'Plumbing and Central Heating' started by zeroid, 29 May 2021.

  1. zeroid

    zeroid

    Joined:
    4 Sep 2011
    Messages:
    16
    Thanks Received:
    0
    Country:
    United Kingdom
    Replaced this expansion vessel today, but couldn't stop the connector leaking (EV was supplied with two fibre washers, I tried one first then both). I did not tighten the nut much at all initially, but that's what I resorted to in the end and have now damaged the pipe.

    I've got a replacement EV pipe coming Tuesday, but what's the trick with these so I don't mess up that one too? I suspect its to do with making sure the mating face is exactly aligned with the threaded part on the EV as the nut is tightened / may have been some corrosion or muck on the old pipe/nut that made it difficult to fit right.

    ev-pipe-1.jpg ev-pipe-2.jpg
     
  2. Sponsored Links
  3. Madrab

    Madrab

    Joined:
    4 Oct 2012
    Messages:
    8,036
    Thanks Received:
    2,274
    Location:
    East Renfrewshire
    Country:
    United Kingdom
    TBH you shouldn't really be in there unless you have the right equipment to ensure that everything is working correctly and the boiler is firing properly, once the room sealed case is re-attached.

    As far as the pipe is concerned then everything needs to be clean, corrosion free and lined up correctly. Shouldn't need tightened up too much. Is it a proper Glowworm part you are using and are the seals the correct size.
     
    • Like Like x 2
  4. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    63,985
    Thanks Received:
    4,583
    Location:
    London
    Country:
    United Kingdom
    What pressure did you put into the replacement EV ?

    Was the old one really failed?
     
  5. aptsys

    aptsys

    Joined:
    16 Sep 2007
    Messages:
    1,852
    Thanks Received:
    147
    Country:
    United Kingdom
    You shouldn't need to be cranking too hard. I assume it was not cross threaded and the mating edges are relatively flat?
     
  6. dilalio

    dilalio

    Joined:
    20 Mar 2009
    Messages:
    7,766
    Thanks Received:
    1,247
    Location:
    Potters Bar
    Country:
    United Kingdom
    Fibre washers go in your mouth 5 mins before you fit them... So that they start to swell up and make the seal once in place.
     
  7. Sponsored Links
  8. zeroid

    zeroid

    Joined:
    4 Sep 2011
    Messages:
    16
    Thanks Received:
    0
    Country:
    United Kingdom
    Yes, definitely wasn't cross threaded, I was screwing the nut on easily with my hand. I think the mating edges just weren't perfectly aligned as I tightened the nut more.

    Old one was spurting water from the schrader valve when pressed. There was still loads of water in it sloshing around on what should be the air side when I removed it.

    New one came pre-charged to 1.5 bar which I checked.
     
  9. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    63,985
    Thanks Received:
    4,583
    Location:
    London
    Country:
    United Kingdom
    Sounds pretty bad.

    But sometimes if you drain all the water from the air side and then recharge they will last a bit longer.

    A good test is to depressurise water side and see if they will hold the air without leaking too much.

    If boiler is to run at 1.5 bar cold I find a little less air pressure works better.
     
  10. zeroid

    zeroid

    Joined:
    4 Sep 2011
    Messages:
    16
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks but the one you see in the picture is the replacement so no worries there. Just didn't plan on needing a new EV pipe too.

    The old one was so bad I had to re-pressurise the system every day the heating had been on, until I figured out to empty one of the rads by half as a temporary "expansion vessel". I've just been waiting till I didn't need the heating to get the job done.
     
  11. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    63,985
    Thanks Received:
    4,583
    Location:
    London
    Country:
    United Kingdom
    I have often use a rad as a temporary EXV.

    Usually after the user has done this "English" thing of bleeding all the rads before the winter thus depriving their system of anywhere to expand to when the EXV has never been checked and repressurised!
     
Loading...

Share This Page