If your boiler is showing ‘Con’ message on main display it means that your main PCB or possibly display PCB has failed and will need to be replaced. ‘Con’ message means that there is a communication error between main board and display board. Both boards are connected directly with pin connectors so that takes out a possibilty that a ribbon cable could have failed. Vaillant PCBs from R1 and R2 Eco Tec series are known to be unrelaible and ‘Con’ message is just one of the ways that PCB boards fail on those boilers.
It does happen that those boards simply fail when the boiler is turned on and off at the spur switch and unfortunately it has happened to me on more than one occasion.
Video below show a a Vaillant Eco Tec boiler with ‘Con’ fault problem.
If your boiler is showing ‘Con’ fault code on the main display and you are in my area (Check areas covered on this web site) – please get in touch to have it repaired.
The same boiler after repair below:
If you need a boiler repaired and you are in SE or SW London you can contact me here plumber Crystal Palace