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There was no hot water so repressurised as the pressure wass low the red light remained on but occassionally when turn hot tap on the green light comes on there is hot water then it shuts down and red ligth comes back on. it is vokera boiler. can you help as the call out is 175 pounds!

Posted by rebeccashaw8 on

  • rebeccashaw8 Aug 06, 2008

    the so called soloution is something i can not understand nor believe is a viable soloution .the boiler is flahing red not green and has been repressurised and still no hot water but if you put hot water tsp on it fires up for a couple of seconds then cuts out any ideas why before i have to pay a call out fee of 175!



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U need to go with a professnol repairer

Posted on Aug 06, 2008


Benjamin Patri

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These sure were not out for long. The bright red button is a pressure release valve which could be faulty hence allowing water to bypass out of the system and not having hot water. Try strapping a bag around the pipe that goes outside and see if it fills with water. To top up your system look on the pipes just below the boiler. There should be a cold filling loop or a connection for one. If not get one from a plumber and ask them how to fill system up, its straight forward enough and your problem should be fixed with this info

let me know if you have further questions

my best to you

Posted on Aug 05, 2008

  • Benjamin Patri
    Benjamin Patri Aug 06, 2008

    I'm sorry but this is a rare boiler to have. After doing research on this boiler. I found that the following information will fix your problem.

    "This is a common problem, google 'Vokera diaphragm excel' etc to find postings.

    The 96e manual can be downloaded as a pdf from the Vokera website ( ,literature, discontinued products)

    The boiler knows you need hot water when a fulcrum arm is moved when
    you turn on a hot tap, this operates a microswitch. The most likely
    cause of your problem is that the arm is not moving because the
    domestic hot water diaphragm has a hole in it.

    You need the manual, look at page 33 for the exploded diagram of this
    bit of the boiler. Turn off the boiler and disconnect from the
    electricity, turn of the cold water going in. Remove the case. Remove
    the fulcrum arm by unscrewing the slot headed pivot screw. Remove the
    grille below the boiler to improve access (two cross headed screws
    right & left front) remove the five screws (posidrive/spanner) from
    the brass cover over the diaphragm. Remove the shot diaphragm and
    carefully clean off all traces of it left stuck on the plastic pusher
    plate and the brass insides; this is important, if you don't do this
    the replacement will not last long. Fit a new diaphragm and
    re-assemble. If you get drips from where the actuating pin passes
    through the brass cover you need a new 'o'ring holder guide thing. This
    is provided as part of service kit t0019, fitted in a standard Vokera
    service. If this does not fix the problem (it should) then it is
    possible that the microswitch is faulty, replacement is
    straightforward, cut the leads to the old and wire in the new with a
    chocolate block connector or use the crimp connectors supplied with the

    In general you should be careful working on gas appliances, as mistakes
    could leave them in a dangerous state (though diaphragm replacement
    isn't too risky IMO)

    Your boiler has presumably not been properly serviced for a couple of
    years, now might be a good time to get it done, it will prevent other
    common ailments such as hot/cold domestic hot water temperature
    cycling, wild fluctuations in pressure associated with using the
    central heating, and it also gives a general safety check. Phone Vokera
    for a local trained service man. Always use someone familiar with your
    specific boiler, generalists can be costly and slow as they learn the
    quirks of your boiler at your expense."

    Information from



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