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

rapid increase in boiler pressure

Discussion in 'Plumbing and Central Heating' started by Ianleics, 3 Apr 2021.

  1. Ianleics

    Ianleics

    Joined:
    3 Apr 2021
    Messages:
    2
    Thanks Received:
    0
    Country:
    United Kingdom
    Boiler is a Wocester 280, with an external expansion vessel fitted. One minute the boiler was working fine, the next minute when a demand is applied, (eg. hot water), the pressure shoots up from half a bar to over three in just a few seconds. Safety cut out trips and shuts of burner. Lots of unpleased knocks and bangs from boiler as pressure rapidly drops back down again. I know the expansion vessel regulates the pressure, but having had a vessel fail before, the speed of the pressure change is MUCH faster with this problem. I've tried draining and refilling the boiler in the hope of an air lock, but no change. Any ideas what the problem could be?
     
  2. Sponsored Links
  3. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    23,966
    Thanks Received:
    10,066
    Location:
    Livingston
    Country:
    United Kingdom
    stuck pump
     
    • Like Like x 1
  4. Madrab

    Madrab

    Joined:
    4 Oct 2012
    Messages:
    8,554
    Thanks Received:
    2,479
    Location:
    East Renfrewshire
    Country:
    United Kingdom
    +1 .... check pump ... no flow through the boiler = water overheat and expands creating rapid pressure rise + boiler shuts down being too hot. PRV bangs open to dump pressure as system is over pressurised.
     
  5. oph

    oph

    Joined:
    20 Jun 2010
    Messages:
    8,782
    Thanks Received:
    1,516
    Location:
    Sussex
    Country:
    United Kingdom
    Worcester 280??

    Discontinued in 1997. 24 years ( at least) for a combi is phenomenal.

    Start saving though
     
  6. Millwright

    Millwright

    Joined:
    31 Mar 2013
    Messages:
    276
    Thanks Received:
    19
    Country:
    United Kingdom
    No it doesn't. It allows for expansion.
     
  7. Ianleics

    Ianleics

    Joined:
    3 Apr 2021
    Messages:
    2
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks for your help folks, you were correct, it was the pump that was the problem.
     
  8. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
  9. Sponsored Links
Loading...

Share This Page