Good to find we are in touch.
I have moved on a little since my question. Machine has been unplugged for a day or so, but early this morning I tried again and got the 57 again. Then since it was clear there was no water coming in I filled it by putting mains power into the terminals of the inlet valve until the side reservoirs were full, disconnected, then turned the machine on. 57 again, but it followed the cycle from this point and gave me 10 minutes of hot water wash, counting down to zero. Then I reconnected the inlet valve to its internal wiring and switched on. 161 showed and it went through an apparently complete cycle.
It showed 170 odd when switched off and on again and I decided to wait and give it another load to wash this evening. There is clearly an intermittent problem centred on the water inlet but whether it is the valve or the solid- state program or a sensor switch somewhere I cannot tell, having no wiring diagram or process description (I do not for instance know whether it uses softened water for the initial rinse).
Monday morning. Machine has now gone though 3 satisfactory washes, but I would appreciate any hint as to how to prevent the trouble recurring. I have ordered a replacement water inlet valve, reckoning on a 75% chance the trouble was there.
Interesting tip. Machine has now given us 6 or more correct cycles with the old water valve, and the new one may take some days to arrive. I will keep it just in case and try the spray if and when I get trouble.
Still getting reasonable service from the machine so will leave alone for the moment. Thanks. Goodbye
Machine still behaving. I don't see anywhere on your pages to finally report Good service, but apart from the initial administrative problem which caused me to find my own solution, I can still do so.