It seems the Netamo is a good thermostat, I am sure there are others.
I made a mistake, I will now admit the Horstmann HRFS1 was a load of rubbish, I don't want to see others make the same mistake. I have since making my errors, and I see getting the MiHome eTRV heads also as an error, found the whole idea of central heating control seems to be a few good products and a load claiming to be good but are in fact flawed in one way or another.
Hind sight and hind sight is easy, I should have played safe and gone for EvoHome, however I tried to do it on the cheap.
Controlling the room is easy, it is the controlling of the system which is hard.
The condensate boiler turned everything on its head. Before the condensate boiler you could have fitted a motorised valve to every room each controlled with a thermostat and wired all the micro switches of the valves in parallel so if any valve is opened then the boiler runs. However when the condensate boiler arrived on the market we then wanted not to switch a radiator on/off but vary the flow so the boiler follows the valves with the flame raising and falling to match demand no simply switching on/off.
So the motorised valve is on/off and the thermostatic radiator valve is variable not simple on/off so we are forced to use the radiator valve, it is the same with thermostats, most are on/off there are some like Nest which do have a system where they can actually tell the boiler to adjust flame height, using OpenTherm.
The problem is finding out which do what, Worcester do a
boiler controls explained and it tells one nothing, a simple label saying "hysteresis software included" would tell one which are simple switches and which have some thing extra, but to find out one has to down load the instructions PDF and read very carefully.
I looked at one the other week and at first is seemed the same as EvoHome in that it uses the sensors in the eTRV to tell the thermostat with is not really a simple thermostat but a hub which collects all information then in turns tells the boiler what to do, but as I read more carefully is still uses the old idea of a thermostat in the coldest room.
My own house is simple, open plan, put thermostat between living and dinning room and TRV's upstairs and it works a treat, mothers house with doors on every room and a hallway, very different, living room gets morning sun through bay windows and the temperature shoots up, then evening the sitting room gets evening sun so then that room shoots up temperature wise, so in mothers house the eTRV is required.
The same design but North / South not East / West and the result would be different, Even a garage or fence which masks the sun would charge it. I still can't work out why once down stairs was sorted up stairs seemed to run A1 with simple TRV's I will guess it is the heat raising through the floor?
My house original design one central gas fire, mother house original design three open fires and a solid fuel cooker, there were louvred windows in kitchen to let out the heat even then often cooked with back door open. As far as control goes my first house was best with gas hot air heating ducts took air to every room and vents in doors allowed it to return to boiler whole house was even heat, however blowing air across single glassed windows resulted in huge heat loss so very expensive to run. And of course all rooms same temperature.
