I am getting a fault light on fan/flue for the 35/80ie boiler. I have changed the pressure switch but that didn't solve the problem, and I have tried a new pc board again no solution.
When I switch on the boiler the system seems to run ok up to the point of the air pressure switch being proved then the fault light comes on

Tony, July 2009

Try cleaning the venturi on the fan where the aps tube is connected, and the fan impellers if dirty.

Ian, July 2009