Smart Heating - Options - Thermostat and TRVs


I know there are a few threads on this topic, but instead of hi-jacking an existing one, I decided to start a new one. I’m based in Ireland and therefore the UK and Irish heating options are more or less the same.

The purpose of this thread is a discussion on options, pros cons etc

From what I can gather most people have either gone with the below which provides numerous options :

These kits

  • Nest 3 (as it heats water separately) - Community Developed Integration
  • Honeywell Evohome - potential Official integration sometime (but don’t hold your breath) - Community Developed Integration
  • Netatmo - WIP Community Development Integration

and or these Smart TRVs

  • Danfoss LC13 - Official and Community Development Integration
  • Pop - Community Developed Integration
  • Honeywell Evo

I’m also aware of Fiabro new TRVs.

Based on the prices of the Smart TRVs on all the above or close to the same price point. So i guess its a personal preference and/or home heating set up.

For those with Danfoo and Popp TRVs what thermostats do you use ie non smart ones?

I currently have 2 zones, upstairs and downstairs. I like the idea of each room zoning, however the price points are high and as such I need to calculate my ROI on the options.


I installed Hive about a month ago and love it.
I much prefer the look of the thermostat compared to nest.
It integrates great into SmartThings with the device handler someone on here created.
And I’ve now set up loads of pistons on WebCore to automate it :slight_smile:

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I have the Honeywell system. Unless you a knowledgeable about heating It is NOT a user installable system. That may be a key part of your decision making. It does appear that Honeywell’s system is well thought out and high end but with that comes a number of issues not least the install. It also relies on a weak comms system that is flaky in a larger home. I do however have it working with ST to an extent. From what I understand TRV’s (on their own) are not a great way to go except in a smaller room.

@Steveuk23 Hive interesting , I missed that integration. Thanks for the info.

@davidj I wouldn’t have the knowledge and I know I need to add a third zone ie for water only and that requires pipe work.

How have you integrated it into ST, by your own means or did I miss a community developed version?

Just search on here. There is a community smartapp created by CODESAUR. It appears to be no longer supported but does work well. It does NOT however support Hot Water.

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Was just looking this up, and noticed Hive have posted they are working on Smart TRV’s :+1:

That’s good to know.
Knowing Hive though they will probably be a lot dearer than other models like tado for example.

In the interests of providing additional information…

Nest do not sell TRVs that can be integrated with their Thermostat. You could instead install your heating as a ‘multi zone’ setup with multiple Nest Thermostats.

Ecobee support for non-US markets is very poor. They also do not themselves do TRVs and again you could go the multi zone approach.

Tado do sell both a smart Thermostat and their own TRVs, they also support a multi zone config again by using additional Thermostats and you could in theory mix both approaches. Uniquely Tado support both OpenTherm also supported by Nest and unlike every other smart thermostat brand they also support eBus as used for example by Valiant and Worcester-Bosch

A device handler for Tado is available here -

Apologies if this has been covered. I’ve looked through the forum for an answer. I have a Nest 3rd Gen learning thermostat and I have a single zone heating system. I would like to have Smart TRV’s to not bother heating the bedrooms in the day, and then heat bedrooms in the evening and first thing (but not downstairs first thing). I’m comfortable using pistons etc on WebCore, but was wondering what the options are.

Are there any TRVs which can call for heat from Nest and turn on the heating? If not, which TRV’s will work with Nest and copy the schedule etc. Thanks

In the post above, I refer to the ScheduleTstatZones which is the most advanced zoning smartapps under ST. The smartapp can do your use case and much more using virtual zone devices…

I am not aware of any TRVs that integrate with Nest especially none that would share schedules.

This is partly why I am or will be switching from Nest to Tado myself.

For Nest the best option I can see is to configure your heating in zones and use multiple Nest Thermostats - one per zone.

Alternatively if you have TRVs - smart or otherwise and have a Nest thermostat in each room then if the TRV is set to the desired temp it will stop heat entering the radiator, if the adjacent Nest was set to the same temp it would spot this and cease calling for heat. This approach is not desirable for a number of reasons, first the extra cost, second the heat sensors of the TRV and Nest will likely not match perfectly, third, as you raised the inability to share schedules etc. So either a zoned setup or a different product e.g. Tado is a much better choice.

Is there not a way to simply add some kind of On/Off Z-Wave Switch to the existing Thermostat (Wired) which can then trigger if ST Sensors are a certain temp or if the App calls it ?

I am still on this dilemma myself. Evo or not. Does the intelligence of a smart stat out way the control of evo?

I imagine this thread will start heating up now the cooler weather is arriving (pun intended).

I really don’t know what to do with my set-up. I’m figuring I might get smart TRVs installed on all the radiators in the house and then rely on the devices that are already in the rooms like door and motion sensors, to control them (as those devices already report on temperature). Has anyone tried that?

The other thing that I’m questioning is why smart thermostats are so expensive? Essentially I need a switch which connects to the Vailant combi boiler and turns it on or off, don’t I? Why are they all around £150?



Smart TRVs work by not turning the boiler off directly. If they did this then when a single room was at the desired temperature all other rooms would stop getting heat even if they were not yet warm enough.

Smart TRVs work firstly the the same way as normal TRVs in that they turn the radiator off that they are connected to. They then also send a report to the master controller to say they are ‘satisfied’. If all thermostats and/or smart TRVs report they are satisfied then the boiler does indeed get turned off.

So a Smart TRV contains the following capabilities -

  1. A temperature sensor (supposedly the Tado ones actually have two)
  2. A motor to drive a valve to shut the radiator off (somewhat equivalent to a dumb TRV)
  3. The circuitry to manage the above and communicate with the master controller
  4. The batteries

It would certainly be nice if they were cheaper but considering the above they are a fair price. The Tado Smart TRV retails at £69.99, a Tado Smart Thermostat at £119.99 and a starter kit consisting of a Smart Thermostat and Bridge at £199.00. (You don’t have to have the main Smart Thermostat but you do need a bridge, you could therefore instead get a bundle of a bridge and a single Smart TRV for £119.99)

Vailant do resell Tado themselves and might charge more but you could use standard Tado items. You would realistically need either a Tado Smart Thermostat or the Tado Extension Unit as well. In your case the Tado Smart Thermostat Starter Kit might be the best option along with the TRVs.

I would take it with a pinch of salt but in theory the Tado system should delivery energy savings and eventually pay for itself.

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Good info there from @jelockwood. In case it helps, I use the Genius Hub system which is very similar. One key point I had to consider was the number of radiators we have and the number of separate “zones” I wanted each with differing schedules or modes. At the time, I chose Genius Hub as it was the only system I could find that supported more than 10 zones. Maybe that’s not an issue for you though and maybe Tado support more than 10 zones now.
Prices appear similar: £130 for the Hub, £60 for a Dual Channel Receiver (to replace your existing controller - dual channel as one if for hot water and the other is for the central heating) and then £60 for each TRV. You can add optional room thermostats for £70 (the TRV isn’t the ideal place to measure temperature) and movement sensors for £45.

This is a Z-wave system that runs on a separate network in parallel to SmartThings so you can’t directly use your existing door and motion sensors. You can use the community Heat Genius Hub integration however to link in your existing sensors and then use webCoRE to enhance automation. The Genius Hub has native smarts of its own of course including “Footprint” mode that uses its own movement sensors to turn heating on and off when rooms are unoccupied and which can learn usage patterns for each day of the week to pre-heat rooms etc. I find that very useful.

Thanks for the info @jelockwood, and for highlighting the fact that perhaps I didn’t articulate my questions effectively.

The first question was specifically about controlling smart TRVs using other SmartThings devices. One of the frequent criticisms of smart TRVs is that the temperature sensor is in the same unit that controls the valve, so is placed on the radiator. Given that in the rooms where I have TRVs installed I also have devices such as motion sensors which also report temperature, there should be a way that the decision to open or close the radiator valve in the TRV is not based on the temperature reported on the TRV itself, but on the temperature reported from the other SmartThings devices in the room. Therefore, by being placed away from the radiator and in a place better suited for a thermometer, we can get more accurate control on the temperature of the room. I wonder if anyone has any thoughts on this or experience of trying to configure it?

The other question was regarding the switch which tells my boiler when to turn the central heating on and when to turn it off. I currently have a Drayton Digistat+3RF Wireless Thermostat, which consists of two parts:

  1. The temperature sensor and program controller unit.
  2. The SCR (single channel receiver) which is attached to the boiler, and turns it on or off depending on the wireless RF signal received from temperature sensor and program controller unit.

Given that I there is sufficient intelligence to use my SmartThings Hub (timings) and and SmartThings devices (temperature) to manage the temperature sensor and program controller role of unit 1, I would like to replace the Drayton Digistat+3RF Wireless Thermostat with a SmartThings solution.

However, what can I buy that covers the functionality provided by unit2, the SCR? Essentially, it’s a smart switch, isn’t it? What I want is something that turns the boiler on or off when SmartThings tells it to. It’s as simple as (or simpler than) a SmartThings Power Outlet, no? Why are they over £150 when the power outlets are sometimes cheaper than £30?

I understand there may be some intelligence required for efficiency. For example, not fluctuating on and off etc. But is it really that which makes them so expensive?



Thanks for the info on Genius, @black-paladin. That’s really useful, and exactly what I’m looking for. It’s a shame it runs on a seperate Z-wave system rather than intefrating into SmartThings directly, but the fact you can link your existing sensors is really good news.

Interestingly though, the SCR they provide,, could well be what I’m after in my second question, if it could work without the Genius hub, but I imagine it can’t - I’ll have a Google.



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