Hive Dual Channel, the wiring connections are exactly the same and would be a straight swap.
Maybe but maybe not, as it seems the thermostat in use is using the volt free contacts. Hive and Drayton wiser use the same base, and single channel versions are volt free, but multi channel versions need to have 230 volt control, in the main this is not a problem, as the typical method is for the thermostat/programmer to work the motorised valves, then the valves work the boiler.
There was at one time a 24 volt motorised valve, but most have now been replaced, so unlikely to find one. But to jump in and say you don't need volt free, although likely true, would be wrong as in some cases volt free is required. Nest is volt free for example, however Nest does not link to TRV heads.
This
Guide may help, it does depend on house design and boiler design, and nearly any thermostat can be made to work, just some are easier to wire in to others, and the whole reason why I have Nest is only two wires main house to where boiler is, and the Nest thermostat send all info and is powered by two wires. But as far as how well it works, in my house not very well, mainly due to my hall cooling too slowly and not linked TRV heads.
But my last house one thermostat worked A1, being an open plan house and thermostat between the two main rooms. I keep on repeating because it works well with one house, does not mean it works well with all. Oil boilers in the main cycle on/off, where gas boilers in the main modulate (turn down) so gas boilers lend themselves to TRV control far more than oil ones do.
In the main the TRV is king, the wall thermostat is just to turn off boiler in warm weather, knowing that I fitted electronic TRV heads when living with my mother, a house with internal doors, the problem was the anti hysteresis software was OTT, so turning the temperature from 16°C to 20°C at 7 am it was nearly 11 am before at 20°C, so I cheated and set it to 22°C then back down to 20°C at 8 am, this worked well. However it clearly would not work with geofencing.
The Drayton Wiser TRV claims to have cured this using algorithms that work out how long it takes to heat the room, and you can set time you want room at a temperature rather than when you want it to turn on, and it works out when heating needs to turn on, as is claimed to work better than most with geofencing.
But if you don't want geofencing then no reason to get such an expensive system.
Around this time last year we had high winds, and my local EE mast went down, this resulted in Nest turning to Eco mode as it thought I was not home, but each time I approached the thermostat the built in PIR detected me, and turned it back to Comfort mode, it took me nearly 24 hours to realise what was going on, and why house was cool, easy enough to turn off geofencing, but I had not realised that was the problem.
My TRV heads well at least 4 of the 9 electronic fitted can do geofencing, but never used it, they don't link to the Nest thermostat, so I have paid an extra £27 each for geofencing I don't use, the eQ-3 without it were only £15 each in 2019, and they have window open detection, so when I unload the car, it auto turns off kitchen radiator for 20 minutes so I am not heating the street with front door open.
So first question has to be what will smart controls do for you, second question is what boiler and system have you got, I will freely admit for me Nest Gen 3 was a mistake, I was told it would work with my existing Energenie TRV heads, and it does not. However if you don't want to link the TRV heads, then it may work for you.
I have been automating other things in my house, which was why I used Energenie in the first place, same hub does light switches and TRV heads, TCP is the similar, it does not need a hub, but it does do heating as part of a wider control.
Using Zigbee hubs each device can act as a relay for the next, so you light bulb can help the TRV send a signal, to be frank a lot of it goes over my head, but my wife seems to have lost the use of her fingers, rarely uses a light switch now, she seems at 69 to work out these things better than me at 72, but to be frank as to heating, the use of electronic TRV's has helped with a 14 room house, being able to turn down rooms not in use, but the wall thermostat being smart was a waste of time.
