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

WORCESTER 350 COMBI EXPANSION VESSEL ALTERNATIVE NEEDED.

Discussion in 'Plumbing and Central Heating' started by slpjslpj, 18 Oct 2020.

  1. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi there,

    I have a worcester 350. The expansion vessel, part number 87161425060, is obsolete and I can't find anyone with stock.

    So I need to fit an external vessel fitted instead. The size is 10 litres and there are plenty to choose from. Easy enough.

    However, the original expansion fitting into the 350 boiler is a push fit tube with an O-ring.

    upload_2020-10-18_15-45-36.jpeg

    Can anyone tell me how the entry to the boiler can be blanked off so the tank can be removed?

    Or tell me if there is another expansion vessel for a worcester that fits this way, that can be used as an alternative to an external vessel?

    Thanks in advance.
     
  2. Sponsored Links
  3. muggles

    muggles

    Joined:
    28 Oct 2005
    Messages:
    13,342
    Thanks Received:
    3,077
    Location:
    Daventry
    Country:
    United Kingdom
    Is the current vessel leaking or is it just the membrane that's failed? If it's just the membrane, leave the vessel in place and fit an external one.
     
    • Like Like x 1
  4. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi there, thanks.

    I did think of that, but the vessel is leaking a bit through the schrader valve. Not much, but it can only get worse. All that holds back the leak is the plastic cap on the schrader. I could seal it with something, but when the diaphragm eventually lets the full system pressure into the air space, I'm worried the cap would just pop off.
     
  5. Alec_t

    Alec_t

    Joined:
    18 Mar 2017
    Messages:
    758
    Thanks Received:
    132
    Location:
    Wales
    Country:
    United Kingdom
    It's already doing that, hence the leak from the valve.
     
  6. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Ah right, thanks Alec.

    But it is only a dribble, and the vessel does accept a recharge, albeit it loses it over a week or three. So my thinking was that the diaphragm isn't split, just kind of porus.

    Really I know I have to replace the 350 with a modern boiler. But it's a bigger job than just a simple swap, because of the kitchen layout. So this will only be a temp' fix until spring.
     
  7. muggles

    muggles

    Joined:
    28 Oct 2005
    Messages:
    13,342
    Thanks Received:
    3,077
    Location:
    Daventry
    Country:
    United Kingdom
    If it's only a temporary fix until Spring, take yourself down to the local Halfords and buy a new Schraeder valve core and a removal tool. Replace the valve core and that should cure the leak, then stick an external vessel on it somewhere. The diaphragm will be split, might only be a small split, but I very much doubt that it's just porous.
     
  8. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi, I've got shrader valves and a key - been cycling for 50 yesrs. . But when I look into the valve on the x - vessel, there doesn't seem to be any removal notches. I'll have another look though. If you say it's posible, that'll be a big help. Thanks.
     
  9. Mottie

    Mottie

    Joined:
    27 Feb 2017
    Messages:
    18,866
    Thanks Received:
    1,887
    Location:
    Essexshire
    Country:
    United Kingdom
    Get a metal valve dust cap.

    ED74C36B-D1A7-4A7D-A2CD-601E6F6615E7.jpeg
     
    Last edited: 19 Oct 2020
    • Like Like x 1
  10. Sponsored Links
  11. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Good idea, thanks.
     
  12. Mottie

    Mottie

    Joined:
    27 Feb 2017
    Messages:
    18,866
    Thanks Received:
    1,887
    Location:
    Essexshire
    Country:
    United Kingdom
    I have something similar to this on my pressurised heating system for bleeding air. Pretty sure the cap part is the same thread as a tyre valve. Worth chancing 88p to find out!
     
    • Thanks Thanks x 1
  13. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Yep cap is the same thread. And by coincidence I happen to have metal caps on a classic car I have. I'd forgotten. Put one on the x vessel today with a bjt of ptfe for extra sealing. Bit of soapy water now not showing any bubbles. Next job is to put an external vessel in the system.

    It's a bloody shame they don't make this vessel anymore, as the boiler is as good as gold otherwise and has never shown a fault in 22 years. Consigned to a scrap heap for want of one obsolete part. But if the cap works, I will delay changing the boiler for longer.
     
  14. Madrab

    Madrab

    Joined:
    4 Oct 2012
    Messages:
    8,244
    Thanks Received:
    2,356
    Location:
    East Renfrewshire
    Country:
    United Kingdom
    Just buy a metal valve cover - done it loads of times - they have rubber seals in them and they shouldn't blow off.

    [​IMG]
     
  15. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    23,521
    Thanks Received:
    9,721
    Location:
    Lanarkshire
    Country:
    United Kingdom
    If water is dripping through the schrader then so will the air when you pressurise it, so change the valve insert and pressurise properly and see if it holds
     
    • Thanks Thanks x 1
  16. slpjslpj

    slpjslpj

    Joined:
    11 Jan 2018
    Messages:
    26
    Thanks Received:
    0
    Country:
    United Kingdom
    Re-pressurised the x vessel, metal cap on, and pressure holding. Shrader valve is leaking a bit, but the metal cap with a bit of ptfe (belt and braces) has done the job.

    Interestingly, although initially there was a little water ejected from the shrader, now only air is expelled. So even though the diaphragm must be leaking for water to come out, it must be a very small leak.

    Gives me plenty of time to fit an external vessel and or swap the boiler next year for a new model.


    Thanks all.
     
  17. Ihavenojob

    Ihavenojob

    Joined:
    7 Jan 2010
    Messages:
    10,109
    Thanks Received:
    1,537
    Location:
    Dystopia, a small island too close to Europe
    Country:
    United Kingdom
    It could just be a build up of condensation.
     
Loading...

Share This Page