Tado X wiring setup

Zoidberg

Hi all,

We recently received a Wireless Smart Thermostat X - Starter Kit and two Wired Smart Thermostat X.

The previous system had 3 zones, 1 Hot Water Cyclinder Zone and 2 Central Heating Zones.

The old programmer (ThermaQ TQX0027, also known as ESi ES3247B) controlled these zones.

The old thermostats are ThermaQ branded but don't have a model number. They are fairly basic and weren't programmable, the only option available was to set one temperature. Each thermostat only came on when the programmer turned on the relevant zone.

My thinking was that I would install the Wireless Receiver X to replace the programmer, this would control the Hot Water and Central Heating Zones, the old programmer could turn on each CH zone independantly but as Tado only offer one CH Zone option they would both be wired into here as one zone but the wired thermostats would control each zone anyway.

The Wired Smart Thermostat X's would replace the old wired theromstats. I've not currently decided what to do with the Wireless Thermostat that came as part of the starter kit so can disregard that for now.

Here photos of the setup:

Old Programmer

Wireless Reciever X

Old Thermostats

Wired Smart Thermostat X (2 CH zones)

Wiring Centre (ESWCPCB3CBW)

From wiring centre installation manual

The wriring changes I've made are

Old Programmer to Wireless Reciever X

N → N
L → L with Bridge to HW COM and CH COM
CH1 ON → CH NO
CH2 ON → CH NO
HW ON → HW NO

Old Thermostat to Wired Smart Thermostat X

N → P1
L → L
NO → NO

The issue

I thought the above setup wouldn't cause any issues as on the Tado app you can set the Wireless Reciever X as an additional zone controller which would enable power to the zone thermostats.

What I thought would happen is, for example, zone CH1 would call for heat. This then results in the Wireless Reciever calling for heat as well which should open the CH1 Zone Valve and fire up the boiler. However what acutally happens is that I can see the call for heat registered on the Wireless Receiver as the light comes on. I can hear the CH Zone Valve open and the pump start but after a few seconds it stops and the CH Zone Valve closes.

I did manage to get the CH to work but only if the HW is currently on and activily heating. If when HW is on and I turn either or both zones on the radiators heat up as expected however once the temperature is met it continues to run until the system is switched off in the Tado app.

I also found that the HW works as expected however neither CH zones work when they call for heat individually.

From the wiring centre documentation above it mentions that for smart thermostats that "Links should be put into the programmer strip from L to CH1 & CH2 to ensure that the Room Stat L/1 terminal is always live". Would this resolve my issue? I don't think it would as Tado X runs on batteries and the CH zones are activated from the Wireless receiver anyway.

I might be missing something obvious but the the only thing I can think of is that the N from the Thermostats needs to be used and a change in the wiring centre may be required?

I appreciate this is a long post but I wanted to give as much detail as I could. Please could you review my setup and let me know what I should change to get this working? Let me know if you have any questions or need any further information.

Thank you

Zoidberg

Update - well after writing all that, it could be possible that it is working after all. I think I’m used to the old thermostats immediately acting and the boiler firing whereas for Tado there seems to be some sort of delay? Do they also stop requesting heat after a certain point, for example if I set it to 21.0 it seems to stop around 20.5? If this is true it’s different to how the old thermostats work so will get used to it!

I’ll continue to monitor it and keep you updated.

Zoidberg

Everything appears to be working correctly. I'll put this down to user error and me not understanding how the Tado Thermostats work.

Hopefully the images of the wiring setup above will help others who have a similar setup, no changes to the wiring centre were required. In addition to the wiring shown for the Wireless Reciever and Thermostats you need to ensure that for each Tado Thermostat that the Wireless Reciever is set as an Additional Zone Controller under the Tado Thermostat settings within the app.

If any Tado staff see this then it might be worth updating your documentation as it was showing my setup as not being compatible when I checked a few days ago.

Thanks all for reading and feel free to post if you have any questions!

wateroakley

@Zoidberg Welcome. Pleased to hear you've got your system working.

RayLee

@Zoidberg I have the exact same setup.

So with your wiring, do you still have independant heating upstairs and down? or does it all work as one channel for heating and one for hot water?

I was under the impression that 2 wireless receiver X's were needed to have it all work but that'd be ugly and messy.

Zoidberg

@RayLee yes with this wiring setup I’m still able to control Central Heating Zone 1 and Zone 2 independently using schedules set within the Tado app.The Hot Water also works as expected.

The wireless receiver will turn on both wired zone thermostats when either calls for heat but as it’s up to the thermostats to control the zone valves they both still operate independently.