Smart thermostat set up

the_sphinx82

Hello, I wish to install a new smart thermostat to my combi boiler Vailant ecotec pro24. I have a box on the wall, that I think it might be an old thermostat (and the previous owners must have lost the remote part, it may be this https://www.heatingcontrolsonline.co.uk/horstmann-hrfs1-programmable-wireless-thermostat.html ). Should it be easy to replace it with a smart thermostat by myself?Any advice? Thanks for your help 

womble12345

I installed a Hive system myself, take a look online at the Hive installation manual. The hub was wired in by the boiler, the wireless controller went where the old thermostat was. The tricky bit is figuring out which wire does what on the old controller.

bob_a_builder

Your link wasn't working ( an extra ')'  ) on the end 
Here is a link to the manual of your Stat  - LINK which shows current wiring 

The Nest E Smart thermostat is designed to replace existing thermostats in that it duplicates the existing connections you have there  i.e. the NO and Com(mon) connections and as such could replace that control box ( or indeed be connected in parallel)

The Next E  equivalent box ( actually a grey circle ) is battery powered - just requires 2 connections connecting to the existing NO and Com connections in your existing control box (in your picture)

https://www.toolstation.com/nest-thermostat-e/p12651