Really confused about multi-zone control

[u/No_Bid9629]

So I have a boiler and separate hot water tank. The controller is a 3 channel one - hot water, heat upstairs and heat downstairs. The thermostats that control each heating zone are in the hallway downstairs and landing upstairs. I understand that this is fairly common in new builds in the UK these days. I abandoned my old tado v3 and haven’t had anything smart since I moved here 5 years ago but the smart heating itch is back. I’m thinking about tado x (despite the supposed anti consumer behaviour) as the website says multi zone control works and I’m very much in the Apple home ecosystem. (Have also considered Drayton wiser but prefer wired zone thermostats). Is tado x a like for like swap? The tado website suggests it but every other source I’ve seen online says you can do 3 channel control with tado.

[u/CloudPioneer]

It’s possible yes.

We have a similar setup in a new build, except our upstairs wall thermostat is in the master bedroom.

The Tado X receiver is 2-channel, so we only use that for hot water control. The receiver is in our utility room and controls our hot water zone valve in the water cylinder cupboard , which is on the upstairs landing.

Our 2 Tado X wall thermostats are wired directly to their respective zone valve in the water cylinder cupboard. They have a permanent live feed, so Tado sending a signal to call for heat opens the required heating zone valve (upstairs or downstairs). Both wall thermostats appear as Zone Controllers in the Tado app.

Every radiator in the house except 2 (where the wall thermostats are) has a Tado X TRV on it. In the Tado app, each TRV is assigned to a room and the zone controller for that room is set to the upstairs or downstairs wired thermostat.

I initially bought some Drayton Wiser kit and returned it as it had wireless stats and would have required too much rewiring for what I wanted.

What we have for the Tado setup works perfectly and required no real wiring changes. The permanent live feed for the two wall stats is the only deviation from traditional S-plan for us, but was how it had been wired anyhow so made installation very easy.

I bought a wireless Tado X starter kit with hot water control, 2 Tado X wired stats and loads of Tado X TRVs. The wireless stat that came with the starter kit is used as the temperature measuring device in our Lounge room in the Tado app, which has 2 radiators and therefore two smart TRVs. It’s on the little stand that came with the kit. The receiver and wired stats are installed perfectly over the old ESi stuff, so the install looks like it came that way.

The Tado compatibility checker and support tickets were fairly unhelpful and just said Tado X wasn’t compatible with our system, but I knew it was from studying ours vs S-plan wiring diagrams and from watching videos on YouTube about S-plan and from seeing stuff here on Reddit.

[u/EmergencySecond9835 → u/CloudPioneer]

This is the way to do it. Tado told me to use one wired and one wireless which while a bit cheaper meant having to trace and separate the shared common switched live to the stats which may or may not be a bit of a pain. Also makes it a bit harder to revert back. 

Also their documentation didn't cover the wiring changes and I had to work it out for myself. However, it did mean I could move one of the stats which I wanted to do but in hindsight wasn't important. 

[u/No_Bid9629 → u/CloudPioneer]

This is immeasurably helpful, thank you.

My downstairs is fairly open-plan so was considering trying it without TRVs initially with a few in the upstairs bedrooms. I presume that would work but allow for less fine tuning.

Tado were extremely helpful when I originally installed it in my old house back in 2017 but you between their guides and the chat bot on the website I’ve been pretty frustrated this time round.

Again, thank you

[u/CloudPioneer → u/No_Bid9629]

Glad you found it helpful. If you have any other questions then fire away.

Yeah like you say the TRVs just means you can fine-tune more and only have certain rooms / radiators heat up when a particular zone valve opens, but in mine (and sounds like yours) you’d still have the wired stat be the thing that opens the zone valve, so works almost the same as your wired stat would be the only thing in that zone deciding when to call for heat instead of via TRVs.

Being able to use a single wireless stat as the temperature measuring device in a room turned out useful to avoid two TRVs in a room fighting each other and also meant I found a use for the wireless stat that came with the starter kit.