Remeha iSense not compatible with Tado?

edited August 22 in Technical Questions
Since our move in October 2020, I have transferred our entire Tado installation, and invested significantly more in it.

Old situation, in the new house:

* Remeha Calenta 40c
* iSenseRF Control

In terms of Tado we now have:
* 5 radiator knobs scattered throughout the house
* the Tado Thermostat in the living room
* One knob installed on the the underfloor heating system at 400 euros to gain control over the underfloor heating
* The Wireless Upgrade Kit
* The installation back in October was a mega pain in the *butt*. But after 2 weeks of messing around with customer support everything seemed to work. In the end situation I replaced all "iSense" parts, so I connected the Wireless Extension Kit directly to the OpenTherm plug in the boiler and used the Tado Thermostat purely as a temperature sensor.

What was striking is that the bathroom always remained very warm, the only room where I couldn't make room for a radiator knob. Well a warm bathroom is not really a problem so I was happy.

But in June the boiler broke down. The repairman indicated that a number of parts were exhausted, but even more worrisome, that the boiler was 100% on (with of course faster wear).

So we have been firing full-time since October, with worn parts and high gas costs. However, every room had Tado control, so only the bathroom was continuously heated.

After the repairman established this, I started experimenting, and indeed, after some time, without a heat demand (all radiators off in Tado), the boiler turns on anyway.

Support asked me to go through the entire installation again. Well done, without effect.

And now they suddenly come up with this message!

 "After some additional checks on your system, unfortunately we must communicate that tado° is not compatible with your heating system at the moment. We are continuously enhancing tado°'s compatibility with different heating systems, but we cannot say when your system will be compatible"


"We will update our database soon, but unfortunately your boiler uses an opentherm module which" is not compatible with tado°.

 :( :( :(

The website in all documentation states that Tado is fully compatible with Remeha OpenTherm.

Does anyone have any advice? Anyone got this working?


  • Jurian
    Jurian | Admin
    edited August 23

    @DiederickLA The Remeha Calenta is fully compatible with tado (because tado is compatible with OpenTherm and the boiler supports OpenTherm)

    I think what went wrong is that your current thermostat is "RF" (Radio Frequency). In other words, it is wireless.

    This means that you need the tado wireless starter kit, or buy the "Wireless Receiver" that is available on the webshop.

    However, having looked at your specific case it seems that your boiler+thermostat combination has a special dependency. This is not allowing tado to control your boiler via OpenTherm. There are currently no known workarounds for your issue. If you still want to pursue installing tado, please contact a Remeha Specialist and ask them if they can install tado on the RELAY ON/OFF ports (you will lose modulating control).

  • Hi Jurian,

    Thank you for responding.

    I have installed the Wireless Receiver. And the entire installation that I did twice was using the Wireless Receiver.

    " it seems that your boiler+thermostat combination has a special dependency" --> What do you mean by this? Why is OpenTherm different for iSense?? OpenTherm is an open protocol right? I don't understand how an open protocol be different when using iSense vs a wired thermostat?

  • Jurian
    Jurian | Admin

    Even though OpenTherm is a on open standard, implementations vary hugely from manufacturer to manufacturer. And even from boiler PCB to boiler PCB.

    In your specific case, our engineers have looked into the system and for some reason the digital connection was never made between the boiler and the tado devices. This means that your specific setup won't support tado as you have been made aware of by our technicians.

    Alternatively, you could try to install by using the on/off (relay) interface by following the professional installer manuals:

    Or get a remeha technician to check out your system, maybe there is a hidden setting that does not allow 3rd party OpenTherm thermostats to be connected in your specific setup.