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Boiler's not working F.75 just comes up any ideas

Discussion in 'Plumbing and Central Heating' started by cryan1974, 4 Feb 2011.

  1. cryan1974

    cryan1974

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    system won't egnite, got no heating or hot water. F75 just keeps coming up
     
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  3. Agile

    Agile

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    Youn dont even bother to tell us that its a Vaillant ! Do you think that we are clairvoyant?

    As the forum advice suggests you will see so many previous posts covering this fault!

    There are several possible causes.

    Start by pressurising to 1.5 Bar.

    Tony
     
  4. Bunnyman

    Bunnyman

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    Usually pump pressure switch but maybe pump
     
  5. Boilerman2

    Boilerman2

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    Very common Vaillant fault try a new Pump pressure sensor! ;)
     
  6. dreadnoughtheating

    dreadnoughtheating

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    Yeah, so its a Vaillant, but has anyone suggested he checks the pressure gauge to make sure the needle is in the lower section of the grey zone first?

    (or, indeed looks in the book that we all leave in the boiler compartment ;) )

    DH

    EDIT, edit, edit. Tony did :rolleyes:
     
  7. combispecialist

    combispecialist

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    how bigs the system????it may need another expansion vessel fitting or vaillant do an "f75" kit for intermittant issues
     
  8. gas4you

    gas4you

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    Probably just crap in the pump pressure sensor.

    Just remove and clean it out ;)
     
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  10. Bunnyman

    Bunnyman

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    Dreadnought totally irrelevant where pressure gauge is on f75 fault
     
  11. dreadnoughtheating

    dreadnoughtheating

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    Bunnyman, can only say that last F75 fault I attended, a quick burst up to 1.2 bar (on the guage, not using - button) has lasted 2 months. Maybe I, and customer, got lucky?

    take your point though.

    DH
     
  12. Bunnyman

    Bunnyman

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    Push in pressure up can get em workin but usually luck! If u drain boiler then switch on an press the minus button,if digital display reads above 0.2 u know sensor is knackered or blocked,only £20 anyway.also u can check when boiler is pressurised , just turn boiler off an hold minus in and turn back on ,it will show pressure reading then when pump kicks in display should go up at least 0.2
     
  13. dreadnoughtheating

    dreadnoughtheating

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    Thanks for that BunnyMan, I can guess from this reply and your others in the CC, that you must look at a heck of a lot more Vaillants than I do ...

    DH
     
  14. Bunnyman

    Bunnyman

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    I am afraid it's all I know! Lol!
     
  15. Agile

    Agile

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    If its not convenient for me to go immediately I usually find getting the customer to increase pressure will get it going for a few days.

    I also find EXV pressure needs to be correct to avoid F75.

    Tony
     
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