Our house came with downstairs underfloor heating, rads upstairs
The heating has been split across 3 zones, – 1 upstairs, 2 downstairs
We’ve got 3 wireless Wunda room thermostat/controllers

What’s the best solution for something that I can use to control the heating from my phone – including when away from home?

We have 8zones of heatmiser. Seems to do the job.

Plonk the app on your smartphone and log in for internet connection appears to be the advice on their website. Which is similar to the advice for Hive systems.The only downer appears to be it only working on 2.4GHz wi-fi which suggests that security may not be all that if you connect to it remotely.

Are you discounting wunda smart? It’s the system I’m considering after looking at the options. Assuming your wunda thermostats would work with it but might be 2 different systems.