Hi Nigel, F7 means there is a fault with the flow meter.That is a small unit on the filling chamber on the left side.It will be best to get an engineer to fit a new air break with a flow meter in it as it gives less problems later on. Try Glen Dimplex / Stoves or a local engineer who can get one from Inter-spares or A.W spares in Norwich.
FOXY, July 2009