On Feb 17, 11:05 am, Tom wrote:

There is no under unit drip tray with additional float valve

That sounds strange as the float element for this model is available
he

http://www.espares.co.uk/part/dishwa...nit-float.html

and the
castle like overflow near the lower wash arm in this model is merely a
blanking plate

....but then I guess not given this - the water would never reach the
base.

I was going to suggest perhaps the filling mechanism is on a timer to
limit any overflow condition, but I would've thought the conventional
float valve would be easier (not least given the provision for the
overflow turret). Besides which, if your pressure sensor was dodgy the
timer should've prevented the flood.

Could the pressure sensor be dual-stage e.g. first stop for 'machine
full', second for 'overfilled'? (the number of connections to it will
give this away). A potential single point of failure but perhaps it is
usually quite reliable.

Mathew