Setting TRV to only open/close radiator valve (and not call for heat)


Okay. This seems like an odd request, but I want to know if I can set the TRVs to only open/close radiator valves and not call for heat to the boiler.

There is some method to the madness. I currently have a three-zone heating system (two central heating and 1 hot water). I have tried multiple ways to make it work with just Tado with no luck. My current configuration is as follows:

1. A wireless extension Kit to manage the hot water and underfloor heating zone via the wireless thermostat. There is only one Room (“Kitchen”).

2. A Honeywell THR827 thermostat to control the second zone, which provides heat to the rest of the house. I have put Tado TRVs on several radiators and created about 6 rooms, depending on the location of the TRV and radiators. The Honeywell basically switches on the circuit at fixed times during the day and then the TRVs should manage each room independently. My goal is to replace the Honeywell with a wired tado thermostat so everything is integrated.

The other day, I noticed that my underfloor heating was on even though the temperature in the room (in my system is it 'Kitchen') was higher than the wireless thermo settings. Specifically, I have set to 19 degrees in the room settings in the app but the actual temperature on the wireless thermos showed 22 degrees. The underfloor heating should be off.

I think what is happening is that the TRVs are making a call to the wireless extension kit, thereby turning on the underfloor heating. I noticed that the temperature on the TRV on the radiator in the room called ‘Hall’  was 17 degrees when the setting on the app for ‘Hall’ was 18 degrees. Remember, Hall is on a separate heating zone to the underfloor heating zone.

I *think* what is happening is that the Hall TRV opens the radiator valve and *also* making a call to the Extension Kit for heat. This turns on the heating zone that manages the underfloor heating, which is why the underfloor heating was on when it shouldn’t.

Anyone get any insight into this and how to overcome it?

Is there any way to stop a TRV from making a call to the extension kit but ONLY open / close the radiator valves themselves?


  • Found the answer (well - Jurian answered it)

    Go to (only via browser, not app)

    Go to settings

    Go to rooms/devices

    Click on room names.

    Under 'Heating Zones' you can see to what heat controller they request heat.

  • Interesting. I've got a two zone system, I've got upstairs sorted out and I've ordered the TRVs and thermostat for downstairs. Previously it seemed to be the case that the heat controller for a two zone system had to be set by Tado remotely, but does this mean now that I can assign the downstairs valves to the downstairs thermostat myself? Good if so ...

  • I dont know. I asked the question from technical support and they told me about above. If they made a change, then it was not obvious to me.