Problems installing extension kit, smart thermostat / Worcester Bosch Greenstar 34cdi classic

Afternoon all,


Looking for any advice or assistance available to get my system fully and properly operational.

For a few months I've only had the smart rad valves installed and they seemed to be doing their job. I had bought the starter kit and never got around to fitting the smart thermostat or extension kit.

I've added the devices to my app and upon adding the EK all other devices were then showing "no connection". So this forced my hand and jump started me into installing the EK. I diligently followed the instructions via the app for my boiler and programmer (Worcester Bosch greenstar 34 Cdi Classic with Comfort 1 rf). This is until the instruction to "remove the wiring for your old device"as there is no evident wiring. The programmer simply slots in to the front plate of the boiler.

Instructions are to connect the -ve and +ve of the EK to the 'B' terminals of the ST19 connector on the board... Done. As per a previous topic on here is was advised that black goes in the rear terminal and grey in second rear.


When powering the boiler back on, the EK has booted up and I have successfully been able to pair this to my system. Result, all of my other devices are now showing connected again and seem to be operational.Thats where the god news ends...none of the Tado devices appear to be calling for heat. I don't have a HW tank and previously had that setting turned to 'Off' on my old programmer, it is simply produced when a hot tap is opened. This does seem to still be functioning correctly.

The Worcester Bosch literature suggests that with a third party controller installed that the jumper pin between Lr & Ls should be removed.


Given that a go...same result. Ive now tried and tested the following arrangements;

EK installed to B terminals, Lr/Ls jumper in, Comfort programmer removed = HW works, no call for heat on CH

Ek installed to B terminals, Lr/Ls jumper removed, Comfort programmer removed = HW works, no call for heat on CH

EK installed to B terminals, Lr/Ls jumper in, Comfort programmer in and CH set to 'off', HW set to 'off' = HW works, no call for heat on CH

Ek installed to B terminals, Lr/Ls jumper removed, Comfort programmer in and CH set to 'off', HW set to 'off = HW works, no call for heat on CH

EK installed to B terminals, Lr/Ls jumper in, Comfort programmer in and CH set to 'on', HW set to 'off' = CH works but its the Comfort thermostat that's calling for heat, not the Tado. The radiator valves are working to the schedule/manual setting though. HW works.

Ek installed to B terminals, Lr/Ls jumper removed, Comfort programmer in and CH set to 'on', HW set to 'off' = CH works but its the Comfort thermostat that's calling for heat, not the Tado. The radiator valves are working to the schedule/manual setting though. HW works.

I've also tried to amend settings in the smart thermostat config page too. This is what comes up as I go through;

D17 / HC02 / HW (y) / EK (x) / Save

I understand that D17 is only necessary when using the HW facility, which I won't be but when I change this to D18 I get a fail message when saving. Attempt to set the HX to X and get a fail message, try to set EK to yes and get a fail message. Try and do all setting at the same save and still fails.

I can't think of any other configurations to try. Tried to completely remove the EK and smart room thermostat but they don't appear to be removable from the system.

This is a photo of the connections on my boiler. If anybody can think of anything that I need to do differently to get this to properly work, I would be SO grateful. I am no adverse to the possibility of hardwiring the EK on the 230v connection but can't locate a guide for that which clearly sets out which terminals on the board go to which terminals on the EK.

Best Answer

  • Pete
    Pete ✭✭
    Answer ✓

    @benpb1

    I think the advice from Worcester Bosch is wrong. I have extension kit wired to my 30cdi boiler using electronic bus (BB terminals). Works fine.


    I think that I left in the link to maintain the 230V demand (got that from the Worcester Bosch Wave installation instructions I think).

    I remember when I wired mine up I had to contact Tado to tell them to configure the back end to work with the electronic Bus. Once the system knew it was wired to the electronic bus it all worked fine.

Answers

  • Hi, I have exactly the same issue. With the same boiler. Have wired in the EK today, replacing a BG WR1. Initially followed the e-instructions to replace the WR1 but resulted in no heating, so went back and rewired from scratch to B-B. Water all good, no heating.

    Have you resolved your problem? if I get a result will let you know!

  • benpb1
    benpb1
    edited February 6
    Worcester Bosch have said that the BB terminals are for Worcester low voltage kit only and that the Tado should be wired to the 230v ST10 (green block in the second photo of my original post).

    Still waiting for a response from Tado having been asked for photos and further information from them.

    Will update as and when I get a response from Tado and a working solution.
  • benpb1
    benpb1
    edited February 6

    With regards to the above, my best understanding is...

    EK connections to ST10;

    N = Ns

    L = Bridge to EK 1

    1 = Ls

    4 = Lr

    Earth = Earth

  • Thanks, I’ll try and push Tado on this.

    So far it’s been almost 2 weeks and they haven’t actually given me any solution or even a hint at one!
  • Have you got anywhere with this. I have same issue.

  • @JulianMeck - Not as yet. From my experience the response from Tado is usually 2 days after I email/reply to them and I don't think they cover weekends. I'm not expecting anything until Monday now...at the earliest 😥

  • benpb1
    benpb1
    edited February 18

    @JulianMeck - everything seems to be fully operational now. After much too and fro with Tado I've got it all set up as per the setup guide on the app (and as per post earlier from @Pete). I've only had it set up and 'working' for about an hour. Cant foresee any issues as I've tested the boiler firing by turning all rooms off, then calling for heat from an individual smart radiator valve or the smart thermostat.

    I can only deduce that the settings on the Smart Thermostat were incorrect as this is the only thing that I managed to since change that I couldn't seem to get a successful save of when I made my first post.

    Whilst Tado haven't explicitly stated what the settings should be and only commenting "Please avoid changing any setting on your system, it is already configured correctly" I have got them as;

    TS / HC01 / HW (x) / EK (y) / D17 / Save successful

    Previously I was not able to get the settings to save with a tick against the EK (which I understand is 'Extension Kit') and I presume necessary for the system to properly operate.

    Connections as per the photo in my first post, original controller removed, link piece in position between Ls & Lr;

    Black from the rear BB terminal to -ve on the EK

    Grey from the second rear BB terminal to +ve on the EK

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