Hot water issues Worcester 24cdi

Discussion in 'Plumbing and Central Heating' started by simonjrwinter, 17 Dec 2011.

  1. simonjrwinter

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    My daughter has just moved into a flat with an old Worcester 24cdi boiler. The CH works fine as did the hot water (really good and hot) until a few days ago when the water would run barely tepid.
    I contacted a Ch engineer who told me the heat exchanger could be blocked (a common problem with these so I'm told)
    I have just replaced the heat exchanger and renewed the diaphram in the diverter valve. The water is now much hotter, but even with the water control turned up all the way it is still not REALLY hot (you could stand under a show at this temp with no cold and it would be quite comfortable) is there anything else I should check? Any advice greatly appreciated

    Simon
     
  2. 45yearsagasman

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    You must check that the rads are not heating when the hot water is on.
    This is best done when the rads have been off for a while and are cool.
    If they do heat, then the diverter valve is passing and requires repair or replacement.
    Remember a 24cdi will only raise the water temp by 35C. Not great when the incoming water temp will be in single figures.
     
  3. simond

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    Really?????? News to me. :LOL:
     
  4. 45yearsagasman

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    OK at 9ltrs its 38deg and at 10 its about 34 so whats your point?
     
  5. simonjrwinter

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    When I was dismantling the boiler I did not remove the hot water thermistor, but it may have been dislodged. Would re-seating it with new heatsink compound make any difference?
    Thanks

    Simon
     
  6. Agile

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    I think that Simon's point is that a a flow rate of say 6 li/min then the boiler is capable of heating to water to a higher temperature!

    Tony
     
  7. simonjrwinter

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    Yes, before it went wrong and I "fixed" it, the water was propery HOT as it should have been. Now it's not to hot to hold your hand under.

    Simon
     
  8. BARNY78BG

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    did your daughter move into the flat recently or a few months ago before the temperatures started to drop?
     
  9. simonjrwinter

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  10. BARNY78BG

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    temps and flow rates need to be checked per manufacturers instructions before replacing parts
     
  11. simonjrwinter

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    OK, but if it was working fine before what would that acheive?
     
  12. Dan_Robinson

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    Knowledge and facts dear boy, knowledge and facts.
     
  13. Blooflame

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    I presume it's the same temp at the taps? Wonder if you can isolate dhw out (gate valve) and check there is definitely no flow at the hot taps? If there is then the mixer valve seal is kaput and mains being drawn in
     

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