SMEG DWF64SSE won’t drain, then won’t fill

Hi
New here

Above unit, initially failed to drain properly. Otherwise was working fine. Expected it to be blocked filter or something like that.

Gave it a clean, made sure waste pipe etc were clear. Ran a cycle empty to make sure and flush the system. All was fine, except residual water still inside.

Put the thing back in it’s hole. Now it won’t fill.

Fault lights- There are only 4, not 5 like some info suggest.

(reading left to right lights 1,2,3,4)
Turn it on- lights 2,3,4 illuminated
quiet mechanical/ticking noise for 20 seconds, then lights 1,3, illuminated

We have pulled water through the system, warm water in the sump, drawn into a bucket, very little debris.

Water supply is healthy.

What is the error code telling me exactly?

What can I do about it?

Urgent help required, before fairy-hands syndrome kicks in.