The LCD on my Centaur TC7 programmable timer was becoming unreadable so I bought a Honeywell 7 day one channel programmer. On installation I followed the same wiring pattern but the Honeywell system did not fire up the boiler. It is a universal backplate. I rechecked the wiring but no difference . I have asked for help from B and Q staff and a boiler servicer who both said the wiring should work. I contacted the technical support line for Honeywell and they also said it should work but as it does not I should consult an electrician.....
Anyone had a similar problem and / or any ideas on how to resolve?