worcester bosch greenstar 30i with greenstar comfort i rf

Hi, I don't have a wall plate as my current controller is mounted on the boiler itself (see pic)

so will I have to run a cable from the boiler to the Tado extension kit? If so

will the cable come with the purchase?

Is this a simple job? (I have basic diy skills)

Any help please


  • Michael
    Michael | Moderator


    You have to run a cable to the Extension Kit. You will get this cable from tado°

    It's a simple job with our step-by-step installation instructions. After you received your devices, just register these online on your account. After answering the question about your heating system you will receive step by step instructions.

    Kind regards,


  • Gashman
    edited November 2019
    Just done my worcester today. Similar model. Really easy. Remember to remove the interior panel behind the drop down control panel to access the wiring. The ST19 box is at the right rear. Not obvious which slot the wires go into - black at rear B and grey at second rear B. Remove the existing controller from the exterior - screw above. Remove wire control and then replace with blanking plate.

    Edit. The tado instructions are pretty good but not 100% intuitive in places, hence my tips above ;)
  • Novice_001
    edited January 2020
    @Gashman, @Michael my heating engineer was cautious in following the instructions from Tado for my Greenstar boiler (older than this one above).

    He said the ST19 was only a switch? And he couldn’t see where the power would be going into the extension kit. I had the the Tado team create custom instructions for my boiler and in it, they say to run the grey and black wires from ST19 into the extension box. That’s it.

    In your experience, is that all you had to do? Or does the power have to run into the extension kit separately?

    Thanks for taking the time to read my lengthy question, I really appreciate it. Hope you can help!
  • @Novice_001 did you get your set up resolved? I can't get my heating to work, even by following the Tado instructions. I put my black and grey cable into my EMS (Orange block) and the grey in the + on the Tado extension box and the black cable in the - block.

    Nothing seems to turn the heating on.

    Thanks in advance

  • Hi. In the end I got a plumber to instal ( he had experience with Hive, etc) so can’t comment on your installation but it’s probably something minor
  • Just done mine. Connected B B on the top right of the board to +and - on the Tado. Worked perfectly. I didn't have the unit in tge boiler though, just a blank plate in mine.

    Mine is a 38CDi
  • Zulfi
    edited December 2020
    Hi i have the worcester bosch greenstar 34cdi. Im having the trouble where the boiler doesnt switch off. Had an electrcian come and install it but he wasnt sure which way round the black and grey wires go. @Gashman thanks for the advice i had my black and grey wires the wrong way round

    Switched them over after reading this post. Yet still cant switch the boiler off. Another night with the boiler constantly on. Tado instructions are awful. The support guy from tado says its all fine from his end but iv told him repeatedly the boiler doesnt switch off. The bathroom rads where there is no TRV is constantly on even in 'away' mode.

    Im at my wits end with this. Starting to think just repackage the whole lot and send it all back for a refund. Any advice to the fix would be greatly appreciated. Thank you
  • What ports on the boiler are you connecting is this the EMS ports
    I recall my boiler constantly staying in and this was that factor I didn’t have Live connected to LR for the heating
    Maybe worth posting a screenshot up
  • benpb1
    edited January 2021
    @zulfi - did you get yours sorted?

    I’ve got an extension kit to fit on my greenstar 34 cdi. The instructions on the tado app are saying I only need to connect to the B terminals on ST19.


    Links to photos of the connections and installation guide for the boiler.

    I currently have a comfort 1 rf. does this have to be disconnected or can it just be set to CH always on then leaving the tado schedule to do the rest?