Two zone setup query and ‘calling for heat’ issue

Afternoon all


Dual zone, upstairs and downstairs - Honeywell CM707 controllers changed to wired smart thermostats

Water controller changed out to an extension unit

all TRVs changed to Smart TRVs

I have the well documented issue that only when the Smart Thermostat calls for heat will a room warm up based upon that rooms settings and this works as expected, however, if TADO change the setup so a TRV can call for heat will it work, surely a signal is required to open the zone control valve?

any others with similar experience?


  • All sorted, TADO support had to make some configuration changes - I think they have created Zones for TRVs upstairs that talk to the upstairs smart thermostat and same for downstairs

    I can now call for heat by individual room without having to set the Smart thermostats first - if others have the same issue raise with TADO support who were very helpful

  • Hi SDF1965,

    I know you have just posted this but I think you might have resolved the current issue I am having!

    I recently bought 2 wired smart thermostats and 4 TRVs.

    I wanted to have 1 TRV linked to the downstairs thermostat and 3 TRVs linked to the upstairs. I just wanted confirm - are you saying that Tado support were able to make the relevant changes to link the TRVs to the relevant smart thermostat?

    At the moment I think all the TRVs are linked to my downstairs thermostat and the app doesn't give the option of pairing TRVs with different smart thermostats. I was considering whether I needed to ditch the system if I can't have TRVs linked to different thermostats!


  • Hi @Sags , there seems to be a mode of operation that we, the users, can't change and it does need TADO support intervention

    I raised a case but also made a phone call and left a message as we had no hot water, TADO support then replied and we used the chat channel to work through the issue.

    Suggest you raise a case and send it in, detail your setup which seems to emulate mine with the separate zones, explain which ones are upstairs and which are down and I am sure they will resolve for you

    Now mine has been done and I have integrated with Amazon Alexa it works really well and I can simply say 'heat room x to 21 degrees' and it works exactly as I hoped it would, best of luck 👍️

  • Hi SDF1965,

    I believe I am having a similar issue. I have two Tado thermostats - one for the living room, the other for the rest of the house. At the weekend I installed two Tado TRV's and whilst they calibrated and the app shows a call for heat, no heat is actually sent. I contacted Tado three days ago and have had zero response so far.

    Fingers crossed I'll receive a response very soon.

  • @Three , if you raise the temperature on the smart thermostat to say 22 degrees then set the temperature on your Radiator TRVs to say 21 degrees does that fire up the boiler and heat your radiators?

    If so it does sound like the issue I had where the room Thermostat had to be calling for heat, - if you have no heat phone Tado and tell them, this is a voice message service and in parallel raise support request, I found that helped TADO service agents understand and get in touch

  • I had a very similar issue. Initially tado support told me that what I wanted to achieve was not possible, but by persevering and sharing this discussion with them they were eventually able to configure two zones and associate the TRVs with the correct zones.

    It would be great to have this option in the app eventually, and not have to contact support (which I'll have to do again when I add more TRVs). My HomeKit setup already has two zones configured, so I'd imagine the tado app could even work this out itself.

  • @Undeleterious , it is odd that users don't have access to these types of configuration settings, I would have thought it pretty straight forward to have a 'zoning' option that you then add TRVs to

  • ahmedt
    edited November 2020
    @SDF1965 May I ask how is the thermostats wired to the boiler and zone valves. I am looking at tado productS and have the same requirements as you.

    It’s not clear to me what I need as I have a Honeywell junction box near the boiler that has wires to the Honeywell value for zone 1 and 2. Do I need rewire/replace the junction box for the tado stats control the values ?

    My setup.

    Zone 1 Honeywell digital thermostat and st programmer for hot water and heating wired
    Zone 2 programmable Wired controller in the passage outside bedrooms
    Boiler. Honeywell junction box and zone values
  • @ahmedt , I didn't need to complete any re-wiring, I replaced both wired thermostats with wired smart thermostats, an extension kit replaced the water timer and I installed TRVs on all radiators.

    I needed TADO to create a new zone for hot water and then assign upstairs TRVs to the upstairs Smart Thermostat, likewise downstairs TRVs to down stairs smart thermostat

  • Hi. How did you get in touch with tado? I've tried giving a call and dropping messages, I have the same issue (even had honeywell 707 and swapped to thermostats, with wanting trvs for heat!).

  • I opened a chat channel and resolved all my issues through that...prior to that and after installing the ext kit I had no hot water so i did call the support number and left a voice mail so perhaps that helped to prioritise my case

  • @SDF1965 do you have the honeywell programmer for heat and water. I am in the progress of replacing them. Can pointers on wiring would help me. Also i have no idea how i will replace the towel radiator chrome valve :(
  • ahmedt
    edited November 2020
    I have setup my Tado devices however not getting heating on zone upstairs for the bedrooms tbh i dont know who is calling for the heat TRV or the smart stats
  • Hi @SDF1965 - I'm hoping that you will be able to reply to me.

    I have the exact same issue as you, in that TRVs are not able to get heat unless the smart thermostat of that zone is also requesting heat. I contacted support and they said that what I'm looking to do is not possible. Their response was:


    From the information you have provided, we understand that you have a heating system as described in the 2nd option in this Help Center article. The Wireless Receiver/Extension Kit controls the central heating boiler (and, in some cases, hot water). On each floor, there is a wired Smart Thermostat controlling a heating zone. In addition, the radiators are equipped with Smart Radiator Thermostats. 

    In such a case, your radiators will only get heated when both the Smart Thermostat of that heating zone and the Wireless Receiver/Extension Kit call for heat. This means that in your tado° system, the Smart Radiator Thermostats have to ask for heat from both the Smart Thermostat and the Wireless Receiver/Extension Kit.

    The Smart Radiator Thermostat, however, is designed to only ask a single tado° device for heat. It can’t, unfortunately, inform both these devices. As a result, the radiators with the Smart Radiator Thermostats might not receive heat when asking for it. Therefore, tado° can’t replace all devices in your setup. 

    You can still use tado° Smart Thermostats with the Smart Radiator Thermostats for individual room control. We recommend that you reinstall your old programmer and not use the Wireless Receiver/Extension Kit. If you had bought the Wireless Receiver/Extension Kit from the tado° webshop in the last 30 days, we’re happy to provide you with a free return voucher.

    We’re sorry for the inconvenience and thank you for your patience.


    But you said that after speaking to someone at TADO you were able to "now call for heat by individual room without having to set the Smart thermostats first". Do you by any chance know any more about what they did?


  • @Marsh and all .... this thread was very useful to me but I've got some more information which may help some now or in the future.

    I have 2 central heating zones in my house (1 for the Lounge and 1 for the rest of the house).

    I bought 2 Smart Thermostats (Wired) to replace the old wired ones, an Extension Kit and several Smart Radiator Thermostats (TRV's).

    What I wanted was to be able to replace the existing system with the Smart system, connecting the TRV's to the main Smart Thermostat that controlled the majority of the house. That way, if one room gets too cold, it triggers the heating to come on.

    Issues I'm now aware of:

    --> My old control unit controlled both Central Heating and Hot Water, so the Extension Kit needed to do the same - makes sense but this is where the problem started for me.

    --> TRV's can only talk to (connect to) 1 Zone Controller device. This is an issue in my setup because the (Wired) Smart Thermostat and the CH controller (the Extension Kit) would both need to be signalled that the CH needed to come on. So turned out I can't use this setup (anyone want to buy a hardly used Extension Kit?).

    Fix --> Remove the Extension Kit from the setup, set the CH to be on constant (then it's controlled by the thermostats), and use the old "dumb" unit to run the Hot Water cycle. Thinking about it, I won't really miss the remote HW control.... never really changed it anyway apart from the odd boost, now and again.

    By removing the Extension Kit, it allows the Smart Radiator Thermostats (TRV's) to then connect to the Smart Thermostats and, when needed, call for heating in that zone to come on. You may, or may not, need help setting up these zones to connect things up.

  • ChrisJohnston
    edited December 2021
    Hi all,

    My setup is pretty much the same as RonGs, where there’s 2 wired zones and a master timer for both hot water and central heating.

    I had a long and relatively productive dialogue with Tado support on this last year and the conclusion was to either remove the extension kit as per RonG’s solution (and not have hot water control) or wire up a bypass on the radiator control of the extension kit (so hot water control remains), thus allowing the two wired thermostats to control the 2 zones and the smart TRVs to call for heat via the thermostats.

    Its taken me almost a year to decide what I want to do about this but one thing that frustrates me is why they can’t make it so the extension kit can be set up such that the heating relay is permanently closed so as not to require a hard bypass.
  • To add to my comment above, the setup that RonG and I are describing is a standard UK S-Plan setup.

    I found these videos extremely useful in understanding how my system (and Centra Heating systems in general) work:

    Central Heating Electrical Wiring - Part 1 - Fundamentals:

    Central Heating Electrical Wiring - Part 2 - S Plan:

    Central Heating Electrical Wiring - Part 3 - Y Plan:

  • Hi all, I have been reading this thread with interest as I ahve a similar problem.

    I have hard wired my two CH heating zones upstairs and downstairs to the extension kit. the Extension kit only has space for one CH zone and hot water. I got round this by wiring both central heating zones into one zone on the extension kit, and then it left the hot water to be conneted up as normal. Tado said that this couldnt be done but the upstairs and downstairs work independantly calling for heat from the boiler when required and then the mecanical zones on the tank switch on and off independantly.

    My issue is that I also have 2 TRV's upstairs both of which will control the radiators as long as the upstairs zone is switched on. if the upstairs thermostat is switched off because the room is at the desired temp the trv's cant switch the boiler on. Does anyone else have or has had this issue?

    Any help appreciated

  • Hi,

    I had a 3 channel heating system, 2 heating zones and hot water. I installed a 2 channel Tado wireless receiver, wired into the boiler. I already have a wired thermostat, but I wanted individual room control, so I fitted 10 TRV's and just turned up the thermostat up high.

    I connected the Hot Water and then connected the 2 heating zones into the 2nd channel. This works fine for me, having the 2 heating zones as 1, because each individual rooms TRV calls for heat as required. A wireless Temperature Sensor came as part of the kit, I have it connected, but turned off, as I haven't found a purpose for yet. It can control the Hot Water and the heating from it, and can be fitted to a stand bracket, totally portable, and placed in any room.

    The new setup works fabulous, very easy installed, very simple to use. It will be even easier when I connect to Google Home in a few days. It's a little expensive, but seems to be very good product.