house is roasting even though the radiators have TRVs fitted
I realise the water will still circulate boiler to by-pass valve and back, and the by-pass valve may not be in the boiler, so there may be some hot pipe work, but no radiator should get hot when TRV's are fitted, so something else is wrong.
I do find the *12345 on a TRV head is a bit useless, but when swapping to an electronic head, the question is do you want it linked? The knee-jerk is to say yes, but to fire up a boiler which can only modulate to around 6 kW to supply a radiator which is only 2 kW, there is clearly a problem.
I have one linked TRV head, also a wall thermostat connected to same hub
this is 09:48 this morning, living room at 21.5º and wife's bedroom at 20ºC neither as one would expect this time of year will activate the boiler, there is also a second hub,
which also can do domestic hot water, also switched off,
showing hall at moment is 23ºC.
But the other 9 TRV heads are not linked to the boiler other than by water, 5 like this
only show what set to, (eQ-3) when I got them in 2019 they were £15 each, price has gone up since then, three I can only set and read with phone or PC, the energenie were the first I got. Kasa is the odd one out,
not recommended as it eats batteries, but like the Drayton Wiser it does give one a chart showing how the heating has preformed.
But non linked TRV heads can be set a bit on the high side, as they will only work if boiler is running, but the linked TRV head, will clearly start boiler running, and the room temperature varies, so this room 21.5ºC at the wall, 19.8ºC at one radiator and 21ºC at the other radiator, and in hindsight, it may have been better to have used a wall thermostat rather than a linked TRV in wife's bedroom as radiator under a window so tends to be a cold spot in the room, so fires up boiler when not really needed.
Not looked at Hive, but from memory my Wiser can have up to 9 thermostats connected to the same hub, and so we enter the debate of linked or non-linked TRV heads, and it does depend on the home and the boiler.
With a boiler like mine, old digital i.e. either on or off, it does not matter so much, but with the modern analogue boiler, be it ebus controlled with likes of OpenTherm or return water controlled, we want to keep to analogue control as much as we can, so the likes of Wiser hubs with built in OpenTherm if the boiler supports it, will work far better to the old on/off thermostat.
And the way I can set room by room, so when due to return home, first kitchen is warmed, then dinning room, followed by living room, then much latter bedrooms, means the boiler can put all its output into rooms which need it, not heating bedrooms well before required.
However, I have found geo-fencing to be a complete flop, as can't set distance from home when it starts.
. I’ve attached the picture he sent . Does this look ok and is it a straight swap for a similar Horstmann wireless system. I’ve told him the hive will need the new back box fitted and rewired by a heating engineer or electrician. Any help much appreciated 
