Hive Multizone

You can have three channel Hive system. There is a way to pair two systems to the App. This video might be of use:

 

I note Wiser also does two heating zones, but it depends what you want, fit an electronic head on a TRV and it is a motorised valve and thermostat combined, but without a micro switch.

So it is down to what control you want.

I note with Wiser it has an OpenTherm module, but that's clearly no good if boiler not opentherm enabled.

The Hive and Wiser TRV heads are expensive, you can get cheaper heads, but it's all down to what you want.

 

I have just watched @Teki linked video, there is clearly a major problem with the use of a common back plate for the twin and single channel thermostats, it is two easy to put the wrong unit on the back plate, you could clearly also replace with wrong unit, but having two units side by side with the same back plates is just asking for problems.

 

As said the TRV's control the room temperatures, however they can't turn the boiler on/off unless linked to a wall thermostat or hub.

So the standard was to fit a wall thermostat on a lower floor as heat raises, in a room with no outside doors, clearly as opening a door will cool it down, and no alternative heating again clearly as that will inhibit the boiler running, and in a room normally kept cool, so it turns off faster when warm weather arrives.

What they did not say was in a room which cools faster than the rest, but that is also required to ensure the boiler turns on as the home cools.

I don't know about your home, but my home there is no such room, so only real option is either link the wall thermostat to the TRV's or have multi wall thermostats in parrellel, as long as boiler is running the TRV's can stop over temperature, but need wall thermostats to stop boiler cycling.

Using both zone valves and TRV's seems daft, they both do the same thing, but I did find thermo syphon can cause upper floors to heat up if the TRV is on the return, but not enough to really worry about.

So yes I use both, the zone valve turns off whole flat or whole house, but if all TRV's are off no real need, but only main house has programmable TRV's the flat TRV's can not be programmed.

We use upstairs and down stairs rooms through the day in main house so zoning upper and lower floors is pointless.

 

Have a look at Wiser as @MGW suggested. You then have the option of smart TRVs in the future.