Replacing old Room Thermostat

Hello!
I have an old Siemens RAA02.1N room thermostat and wish to upgrade to a programmable room thermostat. Can it effectively be replaced by any programmable thermostat?
The wiring is 3 core + Earth, live to point 1, Neutral to point 2 and switch to point 3.
Can anyone recommend a fairly cheap but good programmable room thermostat?
Excuse me for sounding thick!

I like to use the honywell cm901 £43 from screwfix.

Thanks for that. I have had a look at the thermostat and it looks like it only requires a live and neutral. The original has the switch wiring in too. Can this wire just be left in a terminal block?

mhurdman said:

Thanks for that. I have had a look at the thermostat and it looks like it only requires a live and neutral. The original has the switch wiring in too. Can this wire just be left in a terminal block?

Click to expand...

What sort of boiler do you have, Combi or Regular (HW cylinder, usually in airing cupboard)?

Don't forget that the Siemens is just a thermostat while the CM901 acts as time switch and thermostat. Do you want to replace your time switch as well?

If not. the Honeywell DT200 thermostat would be a suitable replacement for the Siemens

If you want to go the whole hog and replace timer and thermostat then the CM901 is the way to go, but if you do you may need to retain the old time switch for the hot water (not if you have a combi).

It is just a regular boiler. The main aim of changing the thermostat is having something more flexible than just a fixed temperature. I tend to leave the heating/hot water on constant, but just turn down the thermostat when needed. However, i have seen the digital thermostats that can programme in different temps at different times of day (so lower during the night/when out at work etc)
I see on Screwfix the Horstmann Digital Programmable Room Thermostat (Screwfix code 17585) Would this be a viable replacement? I dont particularly want to change the timer as well.