it would appear that the DHW flow sensor is the fault.
The diaphragm within the body of the valve may have a small hole in it which stops it operating properly. I have the same bl**dy boiler. I am trying to find a supplier as we speak because I have traced the problem
Ken, November 2007
The obvious answer would be the diaphragm in the water valve boiler model would help
BENDAN, November 2007
i had this problem with my boiler and it was the divertor valve i replaced it and it works fine now
karen, November 2007
We have a similar fault on an F24e model. Did you have any joy fixing yours. I suspect it is the 3 way valve.