Discussion in 'Plumbing and Central Heating' started by Carlton74, 28 Nov 2010.
hi lads anyone know the fault code f5 on viessman vitoden 100 cheers
You need to be GaSafe registered to do this work.
It is exactly as I said earlier - **********an F5 fault.
Mr Carlton, its in the book what this fault code means.
But as explained above because it involves opening the combustion chamber you should call a registered boiler engineer.
The interesting question is should you leave it out!
An amusing comment from one of MM's colleagues was that its a manufacturers part which is fitted to the boiler, later models have it not fitted from new. Therefore the part should be refitted because at the time of manufacture viessmann did fit them.
Of course you could always call viessmann and ask them but the advice is still to get a registered engineer.
The Service and Installation book for the Vitodens 100 type WB1A contains an unfortunate entry. For F5 it states "Air pressure switch fault". This is a poor translation. It should read "Air pressure switch not satisfied". The fault is almost always a sticking air flap above the fan, and, as the Moderator says, you need to call a serviceman in. He should check for leaks at the heat exchanger flue outlet.
But it could always be a faulty air pressure switch.
However, based on practical experience of these boilers its virtually always caused by a sticking flap.
The amusing question is should it be just removed ! My answer is yes but that was not what MM's colleague said!
I have F5 on my boiler this morning too.
I had a boiler engineer look at it yesterday and he said its a viesmann call out job. Still trying to get through to them, engaged tone, since 8am.
The boiler is 2.5 years old, will they come out at all?
Sounds like he just doesn't know what it is.
Bet it's the jimmy flapper on yours as well. Simple fix.
If its a sticking flap, what is causing it to stick?? Gunk?
If so, would a hoover do the job?
Sounds like it could be, whats the fix?
I did mention about flappy after looking at these forums yesterday but he said that there was nothing to indicate any serviceable parts inside the case bit and taking the cover off would mean replacing the gasket which he didnt have on him?
Edit: Viesmann said its still under warranty and have called an engineer, will update later with his findings.
F5 is Fixed!!
Warranty Boiler engineer came out under warranty.
The small square flappy thing sits on a rubber seal. Over time, this rubber seal sweats and becomes sticky with use. When the flap rests on it for a time when the boiler is off, it sticks to the sticky seal! The fan cannot blow it off, thus the air pressure switch says no go as we cant get the exhaust gases out of here!
The solution is to remove the rubber seal with a stanley knife!
New parts have a different design whereby it doesnt rest on the rubber seal at all, but a small nodule thus reducing the chance to stick.
Job done, warm house back!!
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