Combi boiler hot water control


Hello everyone.

A bit of pickle here with hot water control and i can't seem to find an answer to it. I have a vaillant ecotec pro (vcw 289 i believe) hooked up to tado via ebus. Works like a charm when it comes to heating, no issues here. But i have a problem with hot water control as it seems to have overtaken the control from the boiler and no matter the settings hot water allways heats up to 60°. What i've tested so far:

HW control disabled (with the pro app), temp on boiler set to 45°, water goes to 60°

HW off, water goes to 60°, can set any temp i want on the boiler, water goes to 60° anyways

HW set to 46° in the app, water goes to 60° BUT the boiler also shows 46° in the settings, this means the app actually changes this parameter

My dad has the same boiler at his place, once we hooked up tado to it it exibits the same problem.

Am i missing something?


  • martini
    martini ✭✭

    Sounds to me like either tado is not quite sending the right commands to your boiler to fix the temp at 46° or that there is an issue at the receiving end…

    That being said: I am aware that some regulations (at least in Germany) stipulate that hot water tanks need to heat the contents at least once daily to 60°C… While this might be a long shot: The boiler is not by any chance just doing that 60° heating cycle to then fall back down to 46°?

    I know, not quite the best thing to say in a community-driven context - but I have a feeling that this might be something that someone at tado support with insights into the data transmitted on your boiler's bus might be better suited to answer…

  • Glasofruix

    There is no water tank, it heats water on demand. But without tado the hot water temperature is respected by the boiler.