Do you currently have a mechanical thermostat to control the boiler?
No,
I have Popp TRVs reporting set vs measured temperatures to Homey, and flows controlling Fibaro relays that energise the boiler/zone valve demand (all of which seems to drain the TRV of batteries very quickly)
(I also have 3 electric UFH zones using HeatIt thermostats, but I understood earlier Tado will not work with these)
OK, so what you need is one tado wall thermostat to control the boiler via itâs relay (not the underfloor heating one). Then all the TRVs and the underfloor heating thermostat will talk to that to turn the boiler on when there is a heat demand.
I say donât use the underfloor heating thermostat for the boiler control as you will want that relay to control the zone valve.
In the tado app when you setup the system you define which thermostat controls the boiler and which thermostat / TRV is the temperature control for the room.
For my system I have the boiler Extension Kit. This is connected to the boiler via the digital bus connections so it can control the boiler water temperature rather than just switching it off and on. Then all my TRVâs and thermostats communicate with that to turn on the boiler. But that is optional and is only required if your boiler has variable control or no physical connection outside of the boiler location to switch it off an on.
Sorry, Iâm not sure what you meanâŚ
OK, so what you need is one tado wall thermostat to control the boiler via itâs relayâŚThen all the TRVs and the underfloor heating thermostat will talk to that to turn the boiler on when there is a heat demand
Are you suggesting this would go in the boiler cupboard where the Salus wiring centre is for the TRVs? Wonât it give another temperature reading (from next to the boiler). Isnât the add-on âwireless receiverâ supposed to be used like this?
âŚwired somewhere instead of where a programmer and thermostat would be in this?:
âŚ(not the underfloor heating one). I say donât use the underfloor heating thermostat for the boiler control as you will want that relay to control the zone valve.
I have 4 [wet] underfloor heating thermostats, not one. These are connected to Heatmiser wiring centre, then on to the boiler and have a manifold, that opens/closes supply to each of 4 zones rather than single zone valve).
For the radiators - the bit for which I think some kind of wireless receiver is needed, I indeed have a zone valve and a trigger for the heat demand from the boiler (I donât actually know if my boiler has inputs for variable control)
OK, so your setup would have 4 smart thermostats for the 4 underfloor heating sections, plus TRVâs on each radiator and 1 Wireless Receiver to control the boiler. That would replace the Thermostat shown in the diagram. However if your radiators are currently controlled by that thermostat in one of the rooms then you could just replace it with a smart thermostat instead.
Basically, each smart thermostat has a relay and can send a wireless heat demand to another device at the same time is operates the relay.
So somewhere you will need a relay to switch the boiler. This could either be a smart thermostat or a wireless receiver, depending on where it is placed.
Thanks @Adrian_Rockall
Basically, each smart thermostat has a relay and can send a wireless heat demand to another device at the same time is operates the relay.
Just so I understandâŚ
I saw that âSmart Thermostatsâ can send a heat demand, but are you saying that the TRVs also send a demand to the boiler which can be received directly by a Wireless Receiver, or that it will only work if the TRVs first communicate to a âSmart Thermostatâ which then sends itâs signal to the wireless receiver wired to the boiler via the wiring centre (junction box)?
TRVâs do indeed send a heat demand to the device connected to the boiler or to a smart thermostat.
When you add the TRVâs and thermostats to each room you specify which device is the controller for that room. So if all you have in a room is a TRV then that will be the controller and it will send heat demands directly to the device attached to the boiler.
For example my cloakroom and en-suite only have TRVâs so they request heat from the boiler when needed. My lounge has two radiators so I have added a smart thermostat to that room. That smart thermostat will then request heat from the boiler and set the percentage opening of each TRV.
Thanks for confirming. Iâll buy all the stuff and see if I can get it working and hopefully have a solution with a higher family acceptance factor
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I noticed on GitHub that a Shelly TRV (Wifi) will be supported soon. The Shelly TRV has a rechargeable battery and should last about 2 years on one charge.
However, the Shelly TRV is not yet available for purchase, you can only pre-order it at a price of 49.90âŹ. It will be delivered from 29.12. onwards.
Maybe this is a simpler and cheaper option than Tado.
When just focussing on TVRâs youâre missing one major feature that an integrated system like Tado or Evohome offers: true multi zone heating.
If you keep your living room thermostat and radiators as is, other rooms in your home will only get heated if the living room is cold enough to turn the central heating system on. Until that happens, all TVRâs may ask for heat but wonât get any.
If you put a TVR in every room, including the living room (and make sure there is a passthrough for the water to be able to flow when all valves are closed) then a centralised system like Evohome or Tado can operate the central heating based on any of the TVRs needs. It is very hard to mimic the behavior of a full climate control system in Homey by yourself.
That is not to say Homey cannot add to the intelligence of such a system, but it cannot properly replace it either. So my advise: go for a complete system that Homey van interact with, such as Evohome, Tado or alike,
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Thanks for bringing us back on track. My only experience of Shelley is 2 Shelley 1 switches that I have tried to use for controlling hot water circulation pumps and immersion heater (since they have higher amp rating than Fibaro switches). Both have been unreliable, showing as unreachable or disconnected and needing the mains to be flipped on and off to restart, despite both having uninterrupted line of sight to the access wifi access point. Hopefully the TRVs will be more reliable.
On the contrary, my whole intention is multizone efficiency. That is why I have 4 water-based underfloor heating zones on my ground floor, with a manifold and independent thermostat in each zone. (Unfortunately I chose at the time HeatIt thermostats, which it turns out donât accurately report the measured temperature at the thermostat and therefore report only set temperature, and thefore I had to buy also Aeotec multisensors for each room).
That is also why I have TRVs in each room on the first floor.
You are right that making it work properly is very hard with Homey. You need dozens of flows, and or many apps (Heating Scheduler, VThermostat, Virtual devices, FIbaro App, HeatIt App, Popp App, etc.)
By contrast, apart from the Popp TRV battery drain, everything is easily handled by dedicated âHeating Panelâ in the Fibraro HomeCenter (much like their alarm system) Before I purchased my first (now dead) Homey, I asked about these functions as dedicated Homey-developed functions and was told by somebody called âBramâ that these were under development. That was now more than 4 years ago.
So your advice to go with something like Tado is now what I am taking despite that it will have cost me more ~ÂŁ1000 in redundant equipment. The simpler, more family friendly UI and redundancy in the event of another dead Homey in winter is my case for removing my faith in a reliable situation that depends on Homey
I first went down that path. It worked, but was a lot of work. Also, it depended on wifi / Homey and was not easily adjusted by a noob user (everybody but myselfâŚ).
In the end I bit the bullet and went for a dedicated system (Plugwise ADAM in my case). Homey is still involved; it uses the presence detection to set the correct heating scheme. But the Plugwise system also works completely independent and all uses have easy control!
So, I replaced all my Popp TRVs and HeatIt wall thermostats with Tado versions. One of the TRVs came in a kit with a âWireless Receiverâ, which wires into your boiler (via your wiring centre) to demand heating and hot water. After a very tiring exchanges with Tado customer support, they informed me I had to buy âWireless Temperature Sensorâ, without which apparently the Wireless Receiver doesnât see / canât control the hot water.
So effectively, I have replaced the Fibaro relays, battery-eating Popp TRVs, and HeatIt thermostats, that donât actually measure the ambient temperature.
It turns out there are a few significant compromises. Despite being called âWired thermostatsâ, the Tado wall thermostats are also battery powered, and cannot be mains powered (which I somehow missed)âso in fact I now have more batteries to replace. These thermostats also donât have any ability to read signals from an external / floor sensor, so the only way to stop your wooden floors overheating is to set a blend valve on your your underfloor heating manifold.
It also turns out, although my [Vaillant ecoTec] boiler has eBus, Tado canât work with it and and so instead of modulated levels of heat demand, it can only be wired in relay mode (sending only basic on & off / switched live signals to the boiler). I wish Iâd realised that before the returns window closed, as this now means my opportunity to make my heating much more efficient has been wasted, right at the time that gas prices are quadrupling 
You might want to enquire about the wireless receiver. I have the old version of that and it connects to my boiler via the eBus (Also a Vaillant ecoTech boiler).
The unit is fitted next to my boiler and communicates wirelessly to the rest of the system. It is able to control the heating water temperature based on the demand for heat.
Also, my Smart Thermostat batteries last about 2 years so not a big issue with replacing batteries.
Hi Adrian, what brand and model of TRV you have? I have Immax (made also uder different brands in China) and the battery life is 2 months only.
I use tado, they only have one model.
Thanks. 18 months of battery life is incredibly good compare to my experience with 2 months only. 
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Of course the battery life depends on how many times the TRVâs have to make adjustments.
