I will start with the central heating control pluses and minuses.
1) Hive, does link to Hive TRV heads, but the main wall thermostat needs to be in a cool room under 22°C as at 22°C the demand for heat from the TRV heads stops working, also it is simple on/off no Opentherm option. Two versions single with volt free contracts and duel with no volt free contacts.
2) Nest does not link to any TRV head, the USA version has remote sensors, but not released for UK version, so it only controls one room, great for open plan or hot air central heating. Nest e is battery powered base so good option when lacking neutral. The Nest e is heating only, the Nest Gen 3 is heating and DHW, all volt free contacts.
3) Honeywell Evohome has a wall hub/thermostat that allows you to set TRV's without need for a phone or PC, it was one of the first to come out, the OpenTherm module is an extra.
4) Drayton Wiser is claimed to have the best TRV heads with clever algorithms to work out when heating needs to go on to get room warm for set time, the wall unit comes in three versions single, duel or triple channel officially the add on OpenTherm only works with single channel as with Hive two and three output no volt free, only single channel is volt free.
5) EPH do an OpenTherm system for multi wall thermostats, one set as master others set as slaves, but does not link to TRV heads, since a TRV electronic head is a motorised valve it does not really make sense to have TRV's and motorised valves, however many homes do, there is always an exception, I have motorised valves to select flat or main house, but TRV's to select which room.
6) Tado sorry don't know much about it, I know one version is OpenTherm there is also a non OpenTherm version.
7) Moes about the cheapest, again around 4 versions, the ebus system used I am told does not lend itself to work with OpenTherm sorry don't know much about them.
8) MiHome Energenie to my mind the link TRV to wall thermostat is wrong way around, the wall thermostat tells the TRV what temperature to set at. (Needs a hub)
Often the same system can do other things, I have Energenie
View attachment 264225 which does light switches neutral free, sockets both fixed and free, energy monitors etc. I started in mothers house and it worked well, so moved to this house and expended, then had to remove some of the items, one double socket and three light switches removed from service, and touch wood now works OK, however not perfect.
The TRV heads have OTT anti-hysteresis software, so set 22°C at 7 am and 20°C at 8 am to counter the OTT anti-hysteresis software which means will not work very well with geofencing, the IFTTT (If this then that) was free, but think now there is a charge, the sockets and light switches have three slots, I wanted 4 so used IFTTT which did work.
The neutral free light switch worked great with BA22d and E14 bulbs, small problem with GU10, but G9 caused a real headache. With the G9 it would not switch off, had to add a load capacitor
View attachment 264226 then found a shimmer when switched on, the small G9
View attachment 264227 is about the same size as the smoothing capacitor inside the large one, the large one did not flicker, but the glass covers would no longer fit.
I also use zigbee, we have one remote control with zigbee, so clearly made, ours came from Lidi, but we had no problem getting remotes for energenie we have 4 of them, two used as bedside light controls as no two way switching in our bedrooms. The smartlife app seems to only work with phone, there is a PC version but very slow, even the phone is slow, however in the main smart bulbs are set to switch on/off with time.
I have one odd one out, still to be fitted, seen here being tested
View attachment 264228 View attachment 264229 the smart relay combines a standard light switch and zigbee phone app so I can switch lights on/off like a two way switch, it is designed to go on our landing so one bulb for going to toilet at night, but 5 bulbs to light the stairs. The smart relay
View attachment 264230 sends extra low voltage to light switch, so lends its self to the British system. The EU system takes a neutral to light switch, the British does not.
I do like the smart bulbs, not only do they dim, but also change colour so some ambiance rather than dimming with a dimmer switch where colour does not change.
I am looking at curtain and blind controls, to keep rooms cool when sun comes out, but nothing done yet.
We have Nest Mini's very good for radio and playing music, and asking how to spell words, but when we tried to use with energenie it was like a mischievous little boy, the hay google turn off instead of turning off music turned off the lights, it said turning off five switched, but ask it to turn lights back on, got I don't know how to do that yet, don't want it to mess up central heating so energenie link removed.
We have Nest Gen 3 central heating thermostat and did have geofencing set up, until earlier this year the EE mast was taken out by high winds, and the heating went to eco mode, the Nest would return to comfort mode as we walked near the thermostat, which resulted in us not realising why house was cool.
With the geofencing we could set eco and comfort temperatures, but no control of distance from home before it turned up the heating. So all the clever bits of Nest Gen 3 have now been disabled. Heating set by time only.
The cheap bluetooth eQ-3 TRV heads (£15 each) work in some ways better than the expensive energenie ones, as the cheap ones detect sudden drop in temperature and turn off for a set time so switch off heating while I unload the car after shopping. Also you can set the eQ-3 at the TRV, no need to use phone or PC.
When I get home I tend to put my phone on charge, not walk around with it glued to my ear, so having to get the phone to alter things is not in my mind good, I want to retain manual control as well. The energenie TRV heads need to alter on PC or phone, no real manual option, the eQ-3 I walk into the room press one button on TRV head and it swaps from eco to comfort mode.
I have talked about opentherm, open plan, hot air central heating, and I have lived in 4 homes each different, the last house had a Myson fan assisted radiator (3.5 kW) standard radiator (4 kW) and a gas fire (4.5 kW) in the living room, there was no need for geofencing or internet control as the room would soon heat up. And this is the point, every home and every family is different, because some thing works well for me does not mean it will work well for you. Mother house has a condensating modulating boiler, so did not want a wall thermostat that turned on/off too often, wall thermostat was to stop cycling on warm day, this house on/off boiler so on/off thermostat is fine.
So you need to select what suits you.
