So boiler guy reckons it's the PCB as all else is working as it should
- just not receiving the right signals.

A new one is £200 from main suppliers. But ebay has new ones at about
£40 - are these really genuine parts. I guess I'd have to fit it myself
as company probably won't touch them.

https://bit.ly/3kVFOx2

https://bit.ly/3j6ugqi