LSI 61 Dishwasher doesn't finish cycle?

I have a fault with my LSI 61 dishwasher which I was hoping somebody might be able to help me with?

MODEL: LSI 61 UK

The observed symptoms of the fault are as follows:

1. When a wash cycle is selected the dishwasher now regularly (but not always) stops after 10+ minutes
2. When the dishwasher door is opened after a failed wash the water is cold, the powder is still evident in door and the water has not drained from the bottom of the machine.
3. After a failed wash the green cycle selection LED is not illuminated at all (normally flashes at the end of cycle and then turns solid when a cycle is selected for the next wash), when the "P" button is pressed the LED illuminates.
4. When a soak cycle is selected the water is pumped away immediately and the soak cycle completes successfully.

Comments on the web indicate similar issues have been traced to the water heater or a thermostat? Would you expect this to be the case based on the description above and considering it is an intermittent fault? Is there anything further I can do to diagnose / confirm the root cause of the fault?