Thank you Dave.
The F6 was caused by one of the terminals coming slightly out of the top module.
Machine then shows F2. Is empty of water and drain pump running.
Unfortunately, I managed to short the wire on top of the float switch against the element body! Rookie error, but cant believe they leave an exposed terminal there with no plastic sheathing etc.
Anyway.
Machine now shows F1. Presumably either the float switch or module has welded contacts due to the short. Expect F1 to be float switch activated. Bloody nightmare!!
Back to the F2 – this can only be caused by the pressure switch clipped onto the sump?
I thought this was only a pressure switch for the heater (like what Miele have, where wash pressure has to be present against heater pressure switch to allow element on).