Thanks for all the help Ian, attaching pictures of the Alpha smartstat - to be honest, feels quote cheap and toyish!!!
Q1: Do I really gain anything from replacing this with a Nest - tbh, I've already ordered it so, its kind of a moot.question - physically, the Nest is a damn sight prettier!!.
Q2: Does Nest have remote thermostats that it can be linked with, i saw some posts on the internet which suggest you can add per room thermostats, but the google.site doesnt list any. I ask cos, it would be much easier for me to install rhe nest unit in the kitchen on the outside of the tall cabinet the boiler is installed behind.
Again, thanks for your patience.- I grew up.in Asia, where constant sun means a boiler is.something you boil eggs in!!