Smart Thermostats Not Triggering Boiler

I have a recent problem with our Tado setup.

We have 4 wired Smart Thermostats and Extension Kit controlling Hot Water.

Recently, within the past week, the Smart Thermostats are not calling for heat from the Boiler. The Extension Kit is heating the hot water as per the Smart Schedule, and the entire setup is “connected” according to the App with all battery levels “good” and everything seeming in perfect working order.

The Smart Thermostat shows as calling for 1-2-3 bars of heat, but no response from the boiler.

I can only sometimes trigger a response from the boiler if I manually ask the Extension Kit to heat the hot water then it realised that some of the rooms also need heat.
Sometimes I can get a response out of 1 Smart Thermostat when I manually adjust the temperature, but when the temperature in that room is reached, the whole system will stop heating other rooms that still require heat.

I need help to understand what is wrong with the system.

It doesn’t seems to be a Wifi issue, but could be an RF issue, although all items in the setup show as functioning and communicating with each other, there’s clearly something wrong, perhaps with the Smart Thermostats ability to communicate with the Extension Kit?


  • Same issue. Did you find the problem
  • Same issue here too :(

  • MACH
    edited November 2020
    Same problem, 2 zone heating.
    Multiple Tado TRV are not triggering the boiler to fire up.
    Connection to bridge and app is all fine.
    I need to call for heat in zone 1 or zone 2 before heat will get to my TRV connected radiators.
    Has been working for the past 12 months +, has stopped working in the past 5 days
  • OK, so it may not work for all setups, but the situation seems to have been resolved with a systematic restart (long button press for 10+ sec) on all devices.

    One-by-one starting with each Smart Thermostat, then the Extension Kit, then the Tado Internet Bridge.

    I can only assume this re-establishes both the Wifi and RF connection between all devices, but for now, the system is re-communicating with each other correctly.
  • Similarly, I occasionally have the issue that the Tado is asking for heat, but the boiler isn't receiving the request (or is ignoring it) I have a smart thermostat which is wired into the main heating circuit (hot water separate so no extension kit)

    The only way I've found to fix it is to switch off the heating circuit via the main fuse spur for 10 seconds and then switch it back on again, and several minutes later the heating kicks in. Tado some time ago suggested it could be an issue with the 3 way valve jamming, but I'm not convinced. Since switching the heating circuit off and on shouldn't affect the Tado, it however does make me think it's an issue with the heating not receiving the message, rather than Tado not sending.

  • I have a similar issue with my wired thermostat. Occasionally the boiler won't fire up even though the system is calling for heat. Unclipping the smart thermostat from it's base and refitting it usually solves the problem. I suspect poor connections between the thermostat and the base but I'm by no means sure.
  • chris, check nothing has changed in your device config and that the thermostats are still calling for heat from the zone controller.

    in rooms & devices tab under room settings as what you are commenting sounds as if they are not assigned.

  • If you have a wired thermostat you will need to bridge this out and set up the new thermostat with wireless control and set it to call heat from the new extension kit to control heat.

    You will then need to setup all your TRV's to call heat from the new extension kit and not the wired thermostat which is what it would have been set for before you installed a extension kit. This can be done in setup.

    Heat cannot be called from both the wired thermostat and the extension kit. the extension kit has to do all the work.

    Tado extension kit cannot turn on the boiler due to the fact that the wired thermostat may be off.

    Each TRV or device needs to be assigned to the correct zone controller.

    Hope this helps

  • I have the same problem in a very simple setup: a wired thermostat controlling the boiler and a valve in one room, and 4 more valves in other rooms. Not sure how to diagnose it without replacing the thermostat.
  • Any updates on this?
  • As a starting point with any of this type of issue, I'd recommend turning off the power to the extenstion kit for 10 seconds then back on. I have had some issues with mine where it wouldn't trigger and a restart resolved it.

    Mine became much more reliable after a few months which was probably due to a firmware upgrade