Fisher and Paykel DD603

I had a phonecall asking me to look at a F&P dishwasher – apparently the local engineer has taken seriously ill and they suggested the lady called me.

I have only ever seen one before (and there were mice living in it), so I’m a bit out of my comfort zone here.

It has a F1 anti flood tripped error in the top drawer and the bottom drawer is completely dead.
I have had the drawers out and there is no sign of any leaks or dampness – there are signs of water being in the base at some point, but it is 15 years old, so it could just be condensation over the years. I can’t find a way to cancel the error, so all it does is pump out and beep.

I did a search and read that if the lower heater has blown that it can cause this. It has had a new upper control panel recently, so is there a chance the lower one has just packed in and it is unrelated?

Any help would be greatly appreciated.

Grant