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Viessmann WB1A F5 error

Discussion in 'Plumbing and Central Heating' started by MikeAustin, 4 Feb 2016.

  1. MikeAustin

    MikeAustin

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    I know there is a fix for this. My boiler is nearly 10 years old and I have seen this perhaps 5 times over this period. Just pressing the reset has always cured it. It happened 2 days ago, and a reset cured it. It happened again today but a reset did not cure it. However, I switched power off and on again, left it trying to start for a few minutes and it is going again.
    My question is whether this failure is now likely to get more frequent, needing a call out to get it fixed. If it is likely to settle back to the same failure rate with a simple reset cure, I will not bother.
     
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  3. simond

    simond

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    Might be fan flap sticking with dampness, but most have been modified by now. Normally causes problem within a few years, not 10. RGI needed.
     
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  4. MikeAustin

    MikeAustin

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    I guessed as much, but I did wonder if it had anything to do with a service I had two weeks ago - the first service for about five years.
     
  5. Agile

    Agile

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    That all depends on what was done during the service! How long did the service take?

    I and the manufacturers always recommend annual servicing.

    I also have rarely seen that fault on older boilers as it usually occurs during the first three years. But is can occur at any age. How frequently it will occur in the future is impossible to predict.

    But it requires a gas reg engineer to fix and the best fix is not what the manufacturer recommends.

    Tony
     
  6. MikeAustin

    MikeAustin

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    Hi Tony. As it happens, I got a call from Viessmann support on this (they had my number from a previous issue). The agent described the flap fix (to be performed by an RGI) that has been mentioned elsewhere on this forum. I asked about whether something from the service could have triggered an F5, but he thought not.
    The service took maybe 45 mins. The burner was not opened for this. I remember the good old days when they came with dustpan and brush!
     
  7. Agile

    Agile

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    I cannot imagine what he did for 45 min if he did not open the combustion chamber.

    They do not need to be opened every year but generally though to be good, to only open them every 3-5 years as long as the flue gas analysis is correct.

    Good support for Hugh at Viessmann to call you!

    Tony
     
    Last edited: 12 Feb 2016
  8. MikeAustin

    MikeAustin

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    Today, after having another F5, I called out a Viessmann recommended RGI - a good one! He fixed the flap (referred to as 'mixture damper' in the service manual) in the normal way, being quite familiar with the problem. He took a photo when he opened the burner, because this is what he found:


    He thought I should send this picture to the previous guy who serviced it 3 weeks ago and ask for my money back. That guy had told me it was not necessary to open the burner. The new guy said that opening and cleaning the burner - and checking the flap - should be routine servicing for this boiler.
     
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  10. Agile

    Agile

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    So when was your boiler last opened up?

    Do you know what the flue gas analysis reading was?
     
  11. Agile

    Agile

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    I find it hard to imagine that the gas analysis was within the spec with that amount of dirt inside.

    Do you know what the flue gas readings were?

    Tony
     
  12. MikeAustin

    MikeAustin

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    There was some sort of seal on the gas supply that the RGI said he had opened for the first time, indicating that the boiler had not been properly serviced since new (10 years) The boiler would not have been opened for at least 6 years. I don't know the flue gas readings from the other guy's service a few weeks ago. They are probably on his inspection sheet, but I don't have that with me.
    The RGI said that the burner and stone (I forget what he called them) parts have not got much life left in them and would need replacing soon. I will ask him to do that at the next service. He did say that the boiler sounded OK without any kettling. I asked him about flushing the HE to remove possible deposits but he thought that was probably not necessary.
     
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  13. muggles

    muggles

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    I'd have thought you could probably bu99er around with the gas valve enough to bring it back in again Tony. That's probably why the original "service" took 45 minutes - the monkey doing it was adjusting the GV to bring it back into range
     
  14. Agile

    Agile

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    I always ask the owner to try to find out when they have last been opened.

    Of course many just don't know, don't know how long it took, have any invoices etc. Boilers are just not high up on the interest list. Ask about their car and of male they will know all of the service history in minute details.

    The problem with a pile up of dirt like that is that it causes differential heating of the HE coil which is not very good for it.

    Tony
     
  15. MikeAustin

    MikeAustin

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    Hi Tony. Thanks for your interest. Here is the service/maintenance record:


    I note that many appliance items, including the burner, are ticked off as correct when they were not inspected. I am claiming a refund.
    BTW, I connected up the earth bonding today.
     
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