Hi Peter, this most likely sounds like a PCB \ control board failure, most likely its not processing inputs correctly, and locking up, until it times out.
The cost of a new control board is around £140, you then looking at £50-100 in labour costs to have this installed, depending on your location.
I would therefore suggest you do not proceed with the repair as the cost for replacement makes it uneconomical.
Please provide your postcode if you would like a recommendation for an engineer to repair the unit
Good evening, I havent heard back from you in the last few days, do you still require assistance?
In the majority of cases if it resolves over night, it would be a lose connection (which would mean it will reoccur in the near future).
All other errors (which self fix over night), are normally due to sensors which have gone out of range, eg flood sensor or temperature sensor, and just being unplugged for a few hours allows them to re-calibrate (to a degree) when the machine is next turned on at the wall.