I was assuming that the very light grey wire was the one from the boiler but if it is - and the blue you mention - then there is no obvious supply anywhere in the pictures.Saying that, I would assume the cable with the Blue Neutral is from the boiler?
This is my best attempt.
View attachment 159141
Please verify before doing anything.
E.g. You could disconnect a 'FROM STAT' wire - isolate safely - and see if it stops working,
They both need connecting to L, N & E and then
replace one 'TO STAT' with COM(1) and one 'FROM STAT' with HEATING ON(3).
They both need connecting to L, N & E and then
replace one 'TO STAT' with COM(1) and one 'FROM STAT' with HEATING ON(3).
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