HA thermostats for hydronic underfloor heating system (UK)

Our house has 16 hydronic UFH zones controlled through 10 wired thermostats. The system was installed by a previous owner and, since purchasing, I’ve swapped out all of the single temperature rotary thermostats for programmable ones. Each circuit is a wired connection which connects to one of two Heatmiser UH8 wiring centres.

I have the temperatures set pretty much the same on all of thermostats (a combination of Honeywells and Draytons) but, if we decide to reprogramme the temperatures, I have to go around and change all ten of them! Reprogramming isn’t something I do often but it would be nice to have individual control or to be able to synchronously change all thermostats or a subset of them from a single interface.

In the past year or so I started using HA to control our batteries and immersion heater and am considering using HA to be able to synchronously change the temperatures of any or all thermostats using an automation in HA. Trouble is, the cost one smart thermostat is one thing, but to change ten of them gets expensive. I could group zones together, to some degree (as ten really is stupid overkill) but I would still need to buy a fair number of thermostats even so.

What HA programmable thermostats are considered decent quality yet reasonable value at the moment in the UK?

I suspect that I “simply” need something which acts like the existing thermostat , is wirelessly programmable through HA and which works with a live, neutral and a switched output. The system isn’t modern and fancy (as you get in new properties).

Thanks

Do you mean TRVs? They will probably not work since the temperature sensor is on the device.
Unless you buy a premium version which can have external sensor.

Have a look at this thread since you have live and neutral.
Underfloor heating with zone control - Share your Projects! - Home Assistant Community

No, not TRV’s - we don’t have any radiators. We have room thermostats - this sort of thing : Honeywell Home T3 Wired Smart Thermostat Kit - Wall Thermostat with Flexible Programming & ECO Mode - Battery Operated, Compatible for Combi Boilers & Heat Pumps - CM907 Replacement (T3C110AEU) : Amazon.co.uk: DIY & Tools

Ok. so you just need the thermostat.
Search here for thermostat and you will get some options.
Database of Zigbee devices compatible with ZHA, Tasmota, Zigbee2MQTT, deCONZ, ZiGate and ioBroker

Thanks . That thread that you suggested earlier is very interesting and helpful too.