Scheduled hot water not turning on

Good morning. I’ve just installed my Tado heating system and the extension for the hot water. I scheduled my hot water via the app but this morning I woke up (1st day after the installation) and the water was not hot... maybe mild-ish but definitely not hot. Any suggestion? Thank you


  • I’m having issues with my hot water aswell. the hot water controle won’t actually work unless the room thermostat is turned up. I’m pretty sure it’s a fault with the extension kit but maybe the same on yours. Tado technical team are very slowly looking into it but no solution yet. try turn up the thermostat and see if the valve opens to heat hot water
  • I have the same issue

  • Jurian
    Jurian | Admin

    As far as we are aware, there are no known issues with the extension kit and the hot water control.

    How does tado control hot water and heating in the Extension Kit ?

    The Extension Kit uses the normal dual channel UK backplate.

    All tado does, to activate the hot water is to connect the number 3 wire with the live wire (L).

    All tado does, to activate the heating is to connected the number 4 wire with the live wire (L).

    In some cases, there might be an issue with the wiring or with the 3 port valve, and this could lead to issues where the hot water can only heat up when both the number 3 and 4 wire are connected to the live wire.

    If this is the case, there is something wrong with the wiring or 3 port valve.

    The best way to go forward: Get an experienced heating electrician to take the tado Extension Kit from the wall, to manually connect the number 3 and 4 wires with live. To see if the heating system is able to produce hot water by ONLY connecting the number 3 wire with the live wire.

    If that is not the case, he needs to do a full check of the system because something is not right with the heating system (tado has been excluded from the equation since the Extension Kit has been taken from the wall).