Smart Thermostat recommendations?

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I'm looking to get a new combi boiler fitted soon, likely a Viessmann.
The combi boiler will be servicing about 9 radiators (including 2 towel radiators) and 2 showers in a 3 bed flat.

I'd like a smart thermostat system for this, but am a bit flummoxed by the options especially the zoning options.

The main brands seem to be Nest, Hive and Tado, so I'm guessing I'll go with one of these, but does anyone have advice on what to go for?

What I'd like to be able to do with a smart thermostat is set a temperature in a given room without affecting temperatures in other rooms.
For example, set my lounge at 20 degrees during the day, but have a freezing bedroom during the day as I'm not in there (as that would save money - right?).

I'm confused on how effective a single thermostat could be unless you want your whole house the same temperature? The Nest seems to be the most intelligent with motion sensor and learning options, but seems to need a separate heat-link for every zone you want.

Anyway, any suggestions or tips welcome.
 
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Wiser Drayton or similar.

No need for a CH zone valve as every rad can be its own zone

A modern, smart, app based interface which allows macro or micro contol

Individual, user / room input possible,

Cheap.

Works quite well if you are able to contemplate a heating system beyond on-off of old.

But go with a heating company for the system (Honeywell, Wiser, etc).

Tech company solutions like nest/hive, I'd avoid.

Imho. Ymmv. Etc, etc
 
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Drayton Wiser or Honewell Evohome for full control over each Radiator.

They have a Central Controller Each Radiator Valve is Digital and talks to the Controller to switch the Boiler On/Off depending on demand from each Rad
You can set various temps throughout the Day.
Can be integrated into Alexa, etc.

I have a similar No of Rads with a 20+ Year old Boiler and have been looking at the Honeywell Kit.
About £500 - £700. You don't need to have them on all Rads. i.e. Spare Room you may want to keep at a low constant Temp.

You can also get standalone programable TRVs where you set Temps and Times.
They do not switch the Boiler.

I am a DIYer looking at improving comfort and Gas costs.
 
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On their own, they will not switch the Boiler On/Off
You need the Central Controller.
If a connected Smart TRV is below the set Temp, it opens the Radiator Valve to allow Water into the Rad and signals the Controller to Fire the Boiler.

I have not looked into Tado very much. I was not aware that their TRVs could talk to the Controller.

https://wiser.draytoncontrols.co.uk/how-wiser-works

https://support.tado.com/en/article...tor-heating-systems-with-a-central-thermostat

https://getconnected.honeywellhome.com/en/evohome
 
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I was disappointed with Nest Gen 3, they have removed support for the Energenie MiHome TRV heads, and the remote sensors have not been released in UK yet.

The problem is few people have had more than one smart system fitted. I found the anti hysteresis software with Energenie was OTT, so set to 20°C and it can take 3 hours to get there, so would set at 22°C for an hour, then 20°C.

I note the Drayton Wiser claims to have algorithms to stop that, not a clue if they work.

Both Drayton Wiser and Honeywell EvoHome the OpenTherm option is an add on extra. The Drayton Wiser the OpenTherm add on is only designed for the single channel version, although seen reports it still works with multi-channel, however the idea of having two things trying to do same thing must be flawed, so either TRV or motorised valves, seems little point having both, EPH do thermostat with OpenTherm that will run as master/slave with motorised valves, but they done work with TRV heads, and can see the point, it is either or not both.

I used Energenie and the big down side was no manual control, it needs a phone, tablet or PC, I can't walk into room and simply push a button on the TRV head to heat up room, so in many ways the cheap eQ-3 work better. Single button switches Eco/Comfort.

Which asks the question how many rooms with smart TRV heads? My bluetooth eQ-3 cost £15.

Next why smart? If you mean geofencing say geofencing. The Nest Gen 3 geofencing worked well 12 months ago, but today it is turned off as unless I walked past the thermostat it was turning the heating off. Some thing went wrong when Nest taken over by Google.

I don't know how geofencing worked, was it simple on/off or did it slowly allow home to cool more the further you are away from it? I think on/off as there was a comfort and Eco setting, so once geofencing triggered then went to eco.

However there seemed to be no setting to say switch back one once within 20 miles or 10 miles, clearly to reheat the home takes time, so I have rooms timed in sequence so first rooms I am going to use are heated first, my system no way to set that up using geofencing.

It is rare I remember to look at phone and set heating, odd I do remember with cooling, will turn on AC before I start for home. I am sure I could use IFTTT to auto turn on the AC, but did not find IFTTT easy to set up.

So most smart features I have turned off, auto anti legionnaires, auto programming, etc. Theory the thermostat should learn practice it seemed to have a mind of its own, and turned the temperature up/down throughout the day.

To be fair likely doors being closed or left open, without a sensor on your doors it does not know, I know leave living room door open to hall and temperature in living room drops, leave kitchen or dinning room to hall doors open, and living room warms up, wall thermostat in the hall.

So what do you want "Smart" to do? The eQ-3 TRV head if cooled quickly assumes a window has been opened and can be programmed to turn off for set time, I use this in kitchen, it auto turns off heating while I am unloading car, but the eQ-3 is bluetooth only and to one device, I control 3 wife controls 2, and in the main simple timed events. The energenie needs a hub and connects to wifi and can use IFTTT but in real terms does less than the eQ-3.

There is also the Terrier i30 which is a stand alone electronic TRV head, I would say you want 2 or 3 points which can turn on the boiler, but for most rooms the cheaper programmable TRV heads are good enough.

Using building management and the Myson iVector fan assisted radiators you can have fast response times both heating and cooling but look at the price, in the main we use near enough engineering, so you have to decide how far to go.
 
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What are your objectives?
What features do you expect the control to offer you?
Do you expect to make savings or just improve comfort?
Which boiler specifically as some smart controls will not work well with certain boilers if you're using bus controls rather than ON/OFF.
 
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The Drayton Wiser the OpenTherm add on is only designed for the single channel version, although seen reports it still works with multi-channel,

Not sure what you mean here but the open therm module socket is on the controller on my 3 channel wiser kit?

Wiser does Relay, Load comp and open therm boiler actuation.
 
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On their own, they will not switch the Boiler On/Off
You need the Central Controller.
If a connected Smart TRV is below the set Temp, it opens the Radiator Valve to allow Water into the Rad and signals the Controller to Fire the Boiler.

I have not looked into Tado very much. I was not aware that their TRVs could talk to the Controller.

https://wiser.draytoncontrols.co.uk/how-wiser-works

https://support.tado.com/en/article...tor-heating-systems-with-a-central-thermostat

https://getconnected.honeywellhome.com/en/evohome

Thanks for those links, that did help me get my head around some of this.
At the moment I'm erring towards a TADO including the add-on TRVs.

I have a friend who has used the Honeywell and TADO and they much preferred the way the TADO app worked.
 
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I was disappointed with Nest Gen 3, they have removed support for the Energenie MiHome TRV heads, and the remote sensors have not been released in UK yet.

Which asks the question how many rooms with smart TRV heads?

Next why smart? If you mean geofencing say geofencing. The Nest Gen 3 geofencing worked well 12 months ago, but today it is turned off as unless I walked past the thermostat it was turning the heating off. Some thing went wrong when Nest taken over by Google.


So what do you want "Smart" to do? The eQ-3 TRV head if cooled quickly assumes a window has been opened and can be programmed to turn off for set time, I use this in kitchen, it auto turns off heating while I am unloading car, but the eQ-3 is bluetooth only and to one device, I control 3 wife controls 2, and in the main simple timed events. The energenie needs a hub and connects to wifi and can use IFTTT but in real terms does less than the eQ-3.

Thanks for your reply. I think I have rules the Nest out as I cant see their remote sensor product, unless you have different zones which I understand requires literal plumbing zones to be in place.
I would want 5 rooms with TRV heads, as I probably wouldnt put them in the bathrooms.

I want smart so that I can manage the temperature using an app, and set different temperatures in different rooms. The alerts and checks on cold pipes seem like a useful feature as well.
I'd also want more than one person to have access to the app to manage the settings which TADO appears to do, but I'm not sure about Hive.
 
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What are your objectives?
What features do you expect the control to offer you?
Do you expect to make savings or just improve comfort?
Which boiler specifically as some smart controls will not work well with certain boilers if you're using bus controls rather than ON/OFF.

My current boiler (that is to be replaced) offers on/off schedule twice a day (no per day setting, its just on/off twice a day).
I'd want the new control (with new boiler) to allow me to set different schedules for different days, as well as a boost option. I'd want to manage this via an app as well as allow multiple users to manage it.
I dont expect to make savings, but I do want to be able to ramp up temperature in one room without affecting another.
I haven't made a final decision on the boiler yet as I want to decide which smart thermostat will serve me best, then make sure the boiler can support it.

One of the rooms has 2 radiators that I was hoping I could put the smart radiator thermostats on, but then I'd use the main thermostat in that room to set the temp, then the other rooms would just be managed by the smart radiator thermostats. Although I think I read they work better if tied in with a thermostat like this.
https://www.tado.com/gb-en/wireless-temperature-sensor-overview

So currently, I think I'm narrowing it down to Tado or Hive. Mainly due to the radiator add ons. Nest dont seem to do it, a friend really didnt like the Honeywell setup and app features, and I've discounted the Drayton Wiser - possibly unfairly, but this chart doesnt like the app much.
https://boilerhut.co.uk/services/tado-smart-thermostat-installation/
 
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From what I have read in many places, Honeywell works really well and does pay for itself.
It takes a few Weeks to fine tune I have read.
It does look a bit dated compared to Tado and others.
It can be integrated with Alexa and Google Home.

The Honeywell can certainly link two TRVs in a single Room or control them from an in Room Thermostat.

Vaillant have their own System that may be worth looking at.
I believe they use their own comms protocol. eBUS???
They don't seem to be readily available to the public unlike Tado, Honeywell, etc where you can easily buy additional TRV Heads.

Tado have a Product Finder and Chat option
Probably worth getting some recommendations from them if you are considering it.
 
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Not sure what you mean here but the open therm module socket is on the controller on my 3 channel wiser kit?

Wiser does Relay, Load comp and open therm boiler actuation.
The Opentherm module in the 3 channel only triggers the boiler if there is demand on heating channel 1, it ignores demand on heating channel 2. I also don't know for certain that the module is actually sending Opentherm signals to the boiler...it may just be closing the circuit.
The optimisation on the Wiser is pretty good.

@floob Your half and half idea of control won't work. Consider- you have your sitting room with WiFi rad valves, dining room with ordinary trv. You want sitting room warm- fine, valves set to temp and call for heat. The dining room is going to heat on the same schedule as the sitting room.
Only by going full controllable heads can you have an individual schedule (temperature and time) for individual rooms.
You also have to watch system efficiency- if only 1 rad is calling for heat and that rad is quite small (below the bottom range of your boilers modulation capability) then you may get into boiler cycling.
From a comfort pov, you may find that you want to leave the hallway (and bathroom) rads on conventional TRVs rather than smart ones to keep some background heat in those spaces- also avoids cycling and low efficiency probs as above.
 
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Well most will do what you want which is simple switching from several sources. Guys I know rate Honeywell and you get personal support from the evohome shop but I'm told it can be tricky to set up so buy from somewhere you'll get support rather than just sell you a product.

Heard good things about Wiser, know no more than that. Tado has dropped support for bus control (slight improvement in efficiency) but will do the job.

You're right to think about boiler brand and working with controls but if you're not going bus control you can swap as you like.

Personally I have bus control with weather compensation, normal but good quality TRV's in all rooms except the room with the main thermostat. Does it work well? Certainly does but if you asked me does it work significantly better than anything else I'd mention it's officially reckoned to be a 4% improvement in efficiency (I think more) but I use it to monitor the boiler remotely not to control the heating remotely. Myself I have no need to control the system from somewhere else and am puzzled by people who do but they undoubtedly exist in great numbers.
 
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