Viesmann Boiler F5 Fault?

[gouldy83]

I've looked through manufacturers book and searched the internet but have struggled to find out what the F5 fault might be?

The boiler model is Vitodens 100

Any help or ideas would be gratefully received

Thanks

 

[Dotty]

F5 is usually to do with the fan, check the cables and plugs and the fan itself.

 

[gouldy83]

thanks very much

 

[ferret]

F5 is air pressure switch fault check it and leads and replace if nescessary , they are quite cheap.

 

[Ultimate P & H]

For anyone who may search this in the future, there is a common fault on the Vitodens that brings up an F5 fault. In the fan outlet there is 'flapper valve' which is designed to pevent water ingress when not working...it sticks. When this happens (regularly) it will give you an F5 fault.

It can be removed cleaned and lubed which will rectify it for a while, but, in our experience it's a matter of time before it sticks again. We have been told by someone within Veissman that their engineers quite regularly remove the 'flapper' bit and throw it away. You do need to leave the rest of the valve in place though as it forms a gas tight seal.

 

[steosman]

Ring Viessmann tech support. As said by ultimate it's the flap on the fan outlet, i was told about this during Viessmann training course but can't remember what they said to do to rectify.

 

[Ultimate P & H]

Their advice is to clean thoroughly and apply a smear of oil to the pivot point, have done this in the past and it works for a while. The best fix in my opinion is to replace the valve...except at some point it will probably start sticking!

 

[CMairiD]

The new fan flaps have a lip that prevents sticking.

 

[Ultimate P & H]

Excellent, it was always a matter of time until they resolved this one.

 

[ljrgas]

When I phones viesmann about this they told me to cut the rubber off.