built in D/W

Called to a built in dishwasher today, really cant say what make as the labels were rubbed away bad and no instruction book etc, about seven yr old, no flood protection at base and a 4 tagged resettable thermistor/stat sat ontop of the heater box. machine constantly pumping and element came on with no water in it, wont move on from pumping to take water, just pumps pumps pumps and heater on without any water in, stripped down and found no blockages of any sort, although when i first checked the stat it had gone o/c so i reset it.

Faulty thermistor maybe? there is also a timer at the base front of this d/w.

Thx
Lee