Why didn't installer change it, or advise you?
Also, my thoughts.
Alternatively, the new single channel Hive is now compatible with OpenTherm,
As you say, things have moved on, in theory not need for a wall thermostat. The TRV can do it all.
There are three aims, one comfort, two cheap to run, three cheap to install. They don't go hand in hand all the time, so you have to decide on what route to take. We are shown pretty pictures
of how the different systems work, but our homes vary so much, there is no one system suits all. I have lived in four houses, and every one different.
You don't want to spoil the ship for a half a penny of tar, but also you can spend hundreds of pounds on control.
I have made my share of mistakes, but the number of rooms in the home, insulation, doors or no doors, halls, stairways, and landings, all change how the heating works, sometimes a simple curtain can change how it all works, when put on the stairs.
I have two pumps, two motorised valves 4 standard TRVs, 9 programmable TRVs, 1 linked programmable TRV, three wall thermostats, and I will admit I have wasted money on what at the time I thought was the bees knees. Size and layout of the house makes a huge difference. And my degree is not as a heating and ventilation engineer, I am just an electrical engineer, I am pleased with Wiser, I was disappointed with Nest, but I have not tried Hive.
I looked at cost, Wiser TRV head £40, Hive around £55, not that I will change all my heads, but although the Wiser base is more expensive, total is cheaper, so you need to consider in fullness of time, what do you want? I bought expensive Energenie TRV heads, which are not better than my cheap Kasa head. And nowhere near as good as the Wiser head. What do you want to spend.
