On Sun, 26 Feb 2017 11:17:02 -0800 (PST), Murmansk
wrote:

I'm soon going to be moving into a new (to me) flat that has a new combi boiler with an old fashioned wired thermostat. The timer is mounted on the front of the boiler and is a very crude mechanical thing with little switches.

Part of me wants to install a Hive system but as a halfway house I'm wondering about about replacing the basic thermostat with a digital one - then I could leave the boiler on constant and set some fancy varying programs via the thermostat - different times and temperatures on different days.

Does my proposed setup and sound practical and can anyone recommend a stat please?
Exactly what I did here quite a few years ago. I replaced the old
wired thermostat with a Siemens RDE10 digital thermostat, 7 day
programme, 12 high/low settings per day. It has has two temp settings
(high and low) but no off, however I just use the boiler timer if I
want an off setting.
The RDE10 works off an AA battery, and just has a one set of volt free
contacts (ie a switch) for the boiler control, so didn't need any
additional wiring to that which was there for the old room stat.
Battery lasts 3+ years.
The RDE10 was about £30, but is obsolete now. There are probably
similar things around.