Thanks for all the help and advice. I now have a better understanding so will taken a look at the existing wiring. I think I might just need to add a permanent live and neutral to my existing wires..... just need to figure where from!?
It seems with my lack of inderstanding that I had...
I am a novice with regards to central heating systems but have managed to change like for like parts on my system in the past..... However, I'm a little stuck with my latest task. I'm looking to replace my cyclinder thermostat which is a Drayton HTS3 for an electronic dual cylinder thermostat...