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

Worcester Greenstar 30Si - intermittent hot water

Discussion in 'Plumbing and Central Heating' started by ilikewatchingtv, 30 Jun 2012.

  1. ilikewatchingtv

    ilikewatchingtv

    Joined:
    4 May 2008
    Messages:
    93
    Thanks Received:
    3
    Location:
    Lincolnshire
    Country:
    United Kingdom
    Hi All,
    Looking for some advice regarding my Worcester Greenstar 30Si. When there is a demand for DHW the water is hot for a few seconds, then cold, then hot etc...
    The thing is that I had the same thing around this time last year and called out a central heating engineer. The engineer diagnosed the problem as a scaled up heat exchanger and was all set to remove and clean/replace the exchanger until he discovered that due to the boiler design it would be extremely time consuming to remove.
    Instead he suggested adding a limescale remover to the CH system (directly into a radiator) and then running the central heating for a couple of days.
    Now, I don't know anything about central heating, but I could never understand the logic in this method - how descaling the CH would fix the issues with the DHW.
    However, this approach worked perfectly - after the CH had been on for 12 hours the DHW problem had gone and everything has been fine for 12 months until the last couple of days.
    My question is, is there a good reason why this should have worked? if so, was it due to adding the limescale remover, or was it just due to running the CH?
     
  2. flameport

    flameport

    Joined:
    10 Mar 2007
    Messages:
    8,106
    Thanks Received:
    1,483
    Location:
    Poole, Dorset
    Country:
    United Kingdom
    The limescale remover (whatever that was) will do nothing if added to the CH - the water in there is continually recirculated, so you won't get any scale buildup.
    Therefore, if nothing else was done, it was running the CH for 12 hours which fixed the problem. Possibly there was some other blockage or restriction which was cleared by using the CH.

    Any scale would be on the other side of the heat exchanger, where the cold mains water enters and is then heated before going to the outlets.

    Heat exchangers are easy to descale once removed.
    If removing it is considered too difficult or time consuming, they can be descaled without removing if you have the correct machine.
     
  3. ilikewatchingtv

    ilikewatchingtv

    Joined:
    4 May 2008
    Messages:
    93
    Thanks Received:
    3
    Location:
    Lincolnshire
    Country:
    United Kingdom
    Thanks for the reply, - I must admit that I couldn't figure out how adding the scale remover (actually X200 noise reducer) to the CH could have improved the DHW, but as it appeared to work I thought I must be missing something!

    I will try running the CH for a bit to see if there is any improvement, and if not look at getting an expert in to take a look.
     
  4. 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

     
Loading...

Share This Page