Weird issue with Tado integration: TRV target temp is set to current temp when heating is off, causing unwanted boiler triggering

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1

After years of working fine, this heating season something constantly started triggering my boiler and the cause was not showing up either in HA or Tado app. No device would show heat demand, but my wall thermostat kept clicking on, triggering the boiler and heating the house. This chart shows heating demand on top for all my tado devices, and gas usage below:

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The tado app essentially shows the same.

After a lot of searching I found something weird may begin to explain it. This is bedroom TRV target temperature:

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The " curved" parts are when heating is supposed to be OFF, and shown as OFF in the tado app, and the values are exactly current temperature as measured by that very tado TRV.

At first I thought this was just a graphing error, showing current temp when there is no target temp (because heating is OFF), but this seems to explain what Ive seen perfectly: The bedroom TRV is not mounted to a radiator. I use it basically like a wall thermostat (there is another zigbee TRV on the radiator) . So when the living room requested a little heat, the bedroom warmed up as well. And if its true that for some weird reason the target temp is the current temp, thats going to keep going up and keep (silently) triggering the boiler.

Ive now disconnected the bedroom trv from the " zone controller" so it can no longer trigger the boiler and so far that seems to have solved the problem. Except of course, now I can no longer start the boiler and heat up my house if the bedroom starts freezing.

Ive been talking to Tado, I think an AI chatbot and Im not getting anything useful. Anyone have an idea whats going on?

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I have a similar issue for a couple of days now with my tado trvs. They were working really well up until now.

In my case, I have a zigbee window sensor and an automation that triggers when the window in my bedroom is open. When that happens, the automation turns off the Tado trv. As soon as the TRV goes off - the target temp becomes equal to the current temp and then they start going down to together as the room cools down.

When I close the window in couple of hours - the automation sets the hvac mode back to Heat. Up until few days ago - as soon as the TRV goes back to Heat hvac mode - the original target temperature used to be set and heating started.

But recently what started happening with this trv is that when hvac gets set back to Heat - the target temp continues to follow the current one, effectively never heating the room.
Quite odd issue

3

I have since found a few other users with almost identical problem. All HA or Homekit users. Here is one:
https://www.reddit.com/r/tado/comments/1gfjixe/boiler_firing_when_heat_isnt_being_called_for/

Contact tado support. Dont expect them to understand, let alone explain the cause, just insist on them refreshing or resetting the configuration for the device. It took me 7 mails of useless “advice” to get that through to them, but once the finally did it, it solved the issue.