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Discuss Alpha cd35c intermittant hot water (pulsing) in the Plumbing Forum area at UKPlumbersForums.co.uk.

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  1. GRUNT16V

    GRUNT16V Guest

    HI
    Im having problems with the above boiler !
    ch heating is fine but the hot water is hot cold hot cold etc whenever the dhw tap is on,
    i was told it was a simple fix involving the diverter valve diaphram BUT i looked in there and looking at it its not the conventional valve we all know are these known for failing? . Is there anything else it could be ie flow switch etc
    Im also looking at a scale reducer (pre boiler) are the aqua-dial scale inhibitors any good??
    Many thanks for looking
     
  2. Alpha man

    Alpha man GSR

    Either a blocked hw heat exchanger and temp sensor, as you have found out - they have no diaphragm and wont be divertor or motor either for this fault!

    My money is on the DHW heat exchanger.

    Is the boiler is under manufactures guarantee?
     
  3. GRUNT16V

    GRUNT16V Guest

    My money is on the DHW heat exchanger. ooooooooooo crap

    Is the boiler is under manufactures guarantee? i think so

    many thanks
     
  4. Alpha man

    Alpha man GSR

    Phone Alpha and find out if your still under guarantee!! may not cost you a penny??
     
  5. GRUNT16V

    GRUNT16V Guest

    is there anyway of descaling it with the heat exchanger in situ ??
    also do you know if the aqua-dial scale inhibiter filters are worth the money as i live in a hard water area ?
     
    Last edited by a moderator: Jan 25, 2011
  6. Alpha man

    Alpha man GSR

    Its best to remove the H E and bench de-scale it! Manufactures dont normally recommend de scaler units.

    Where abouts do you live?
     
  7. GRUNT16V

    GRUNT16V Guest

    somerset
     
  8. Alpha man

    Alpha man GSR

    Too far for me, Alpha will be your best bet sadly!
     
  9. GRUNT16V

    GRUNT16V Guest

    do you know if aquadial filters are any good??
     
  10. Alpha man

    Alpha man GSR

    They never used to be! Google it?
     
  11. GRUNT16V

    GRUNT16V Guest

    I have to no avail ! what pre boiler filtration do alpha recommend ?sorry to go on !
     
  12. Alpha man

    Alpha man GSR

    They dont for mains water, if its heating water then its a Fernox TF1 on the return pipe to the boiler.
     
  13. GRUNT16V

    GRUNT16V Guest

    so you dont have to have a filter on the feed from the mains to the boiler, just a tf1 on the ch circuit is this right ??
     
  14. Alpha man

    Alpha man GSR

    Yep, unless you think you need one, or phone the manufacture and ask them what they think, at least you will know either way then.
     
  15. GRUNT16V

    GRUNT16V Guest

    will do !
    in your oppinion what would you fit on the mains water feed if you were in a hard water area
     
  16. Alpha man

    Alpha man GSR

    Proper water softener.
     
  17. sonyso

    sonyso New Member

    I had a Alpha CD/35C fitted in 2008, from the first week i have had the same problem and that is intemitten hot and cold water. Whilste under guarantee Alpha came out numerouse times with the same problem, they fitted a new exchange and in that time i also paid to have a total flush out of the system to rid it of the black slime that accumilates in the sytem. its okay for a while but then back out they have to come. a few things have been changed on the boiler but its back to hot then cold. I actually paid Over £200 6 months ago for alpha to come out as the guarantee had run out and the plumber said it could be the water flow was too high, so we made sure it was under half turn on the tap. it was better but has now gone back to where we have to run a full bath of was is supposed to be hot water but its cold to get the smallest of hot water to finally come through, we also have to have the sink tap on as well. its a good job im not on a water meter as there is much waste just for a small amount of bathwater to get a bath in. As i said this has been an ongoing problem since i had it fitted in and nver really been resolved, i have had a private plumber in and he has no idea why its doing this. Can someone help me coz im ready to kick the thing off the wall. I think being a woman the guys who have been out have done a quick fix and told me bull****. If i had just started to get this problem then i would replace the parts or the boler but as i said we had them out at least once every two weeks in the first 3 months becouse of this problem i have never had a decent hot running water without its running cold at some point. I must say that the downstairs tap after a few seconds is scolding and keep that way …..any suggestions please
     
  18. rpm

    rpm Trusted Plumber Top Contributor!!

    Welcome to the forum Sonyso, really sounds like you`ve had the run around for the last 8 or so years and no wonder you want to kick it off the wall!
    There are members here from your neck of the woods and hopefully one of them will see your post later when they have finished for the day and respond, maybe you could reply saying which town you live in. If that fails try posting again in the link below.

    I'm looking for a Plumber or Gas Engineer
     
    • Like Like x 1
    Last edited: Jan 11, 2017
  19. Dotty

    Dotty Guest

    Meanwhile, here endeth the thread.
     
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