In the recent bad weather I had to drive drove through a couple of v deep puddles ( about 12-18" ) and now have a real problem with my radiator fan, which races away as soon as I switch off the engine ( 2L Turbo Diesel ) and continues to race until the battery is dead or until I disconnect the battery. Has anyone had a similar problem? Is there a solution? My garage is stumped unfortunately ( local and not Skoda ).

Sounds like you might have got some water in the fan control module, not sure where that is though - maybe on the back of the fans?

I am assuming this is not just a DPF regeneration as you say it carries on until battery is dead.

If you can locate the fan controller (Can anyone help here?) then you might be able to dry it out with a hair drier.