OK analogue is an infinitely variable control, digital is on/off control, I can see how a thermostat can be either, but not really a timer, all timers are digital they turn the heating on/off.
Your diagram shows 6 connections, if we include earth, the power it seems is 230 volt (low voltage) and the relay contacts any voltage you like called volt free so could be extra low voltage.
The last picture shows 6 wires, we can see the earth, and the line and neutral going into the switches fused connection unit (FCU) but the picture of the 4 core cable tells us nothing, we don't even know if this is before or after, low or extra low voltage or a combination of both.
With central heating boilers we have two broad types, those which have the valves and controls built in, and those where the valves and controls are external. Often called Combi and System boilers. We also have two electrical control methods, on/off or digital and variable output or analogue, the latter often has connections to the e-bus, unlikely you have an e-bus control, however it could be 24 volt or 230 volt and it is important we don't mix them.
In the main system boilers are controlled by the motorised valves, and the motorised valves in turn are controlled by timers, thermostats or a combination of the two, where combi boilers often only control is a thermostat direct to the boiler.
Today often the main control is with the return water temperature, we have the ability to turn on/off electrically, but the minute by minute control is with the water and the thermostatic radiator valve (TRV) together with the lock shield valve. My TRV heads are electronic and include time as well as temperature.
But as it stands not a clue what you need.