Support current and more recent Vaillant eBus controllers



  • @scgf

    I think it will be a matter of visually inspecting it. Obviously ideally done by your fitter.

    I don't have a Vaillant boiler myself. I did some Googling and found the following link which is (apparently) for a VR66 manual.

    The following is for the VR65.


    According to a now old response from Tado they were compatible with the VR65 but not the VR66. It could be your boiler has something else altogether.

  • @jelockwood Thank you, but I am still none the wiser. All I know is that my boiler was sourced by my installer within the last week or so.

  • @scgf

    I would presume that some on the VR65 or VR66 would indicate which it is, this might be a sticker or printing on the back or inside.

  • I wouldn’t know where to look. I’ve heard people mention the VR65 and VR66 but I have no idea what they are. I’m just pleased my new boiler works with Tado.
  • @jelockwood I've been looking through those manuals you sent. To me it looks like the VR 6x is a control unit, similar to the Tado extension box, and is installed on near the boiler. I am now even more confused. I have nothing like this and my Tado extension box is simply wired to the + and - terminals on the eBus inside the boiler.

  • @scgf. I have the same boiler as yourself and my Tado was connected to the ebus initially. I was amazed how easily it was and that it seemed to work.

    Until I noticed that the boiler was firing up randomly.

    When I entered into the installer level on the boilers controller and looked at diagnostic code D.009 eBus controller target value. I could see the value was changing every few seconds from 0° to 30°.

    So I believe the boiler heat mode was turning on and off constantly. It was only being saved by the S.08 Heating mode: Anti cycling time.

    Even though it wasn't firing up every few seconds I'm sure firing up and stopping every 15 minutes is not good for the boiler and would probably shorten the life of the boiler, especially the water pump.

    My Tado is now fitted like an old style thermostat and simply switches the heating on and off. (Even that was not simple as I've had to leave the Vailliant VRT 350f connected and heating switched on permanently otherwise the D.005 heating target flow temperature will not go above 50° and my target temperature is set to 70° in the boiler controller setting)

    Does your boiler do the same?
  • Thank you for your comments @Ajh. My new boiler fires exactly like the old one did (Vaillant TurboMAX) , much of it due to having comfort mode set, and occasional random firings. The temperature set on my thermostat is being maintained, the schedule works and the home/away mode is reliable, as always. Everything works from my point of view as a user. To be honest that's all I'm bothered about. If the life of the boiler is shortened, so be it. I'll probably have moved house by then. What is the firmware on your extension box?

  • @scgf thanks for getting back to me.
    Yes I've found that Tado does all those other things well too. And works better than my Valliant thermostat that would lose signal constantly which seemed to turn the boiler into heat mode until it re-established connection. Not good in the summer!!!

    My extension kit. Firmware 71.2
  • @Ajh I have the same firmware. I'll leave things as they are and see how it goes long term.

  • scgf
    scgf ✭✭
    edited November 2020

    @Ajh Did you go into the thermostat installer menu and change it from R01 (relay mode) to D07 (Vaillant eBus mode)? I noticed that the basic Vaillant user installation instructions do not mention this step, but the professional installer instructions do.

  • @scgf.

    Yes I did. Thinking about it the firmware version has probably updated since then. I fitted it back in August (anyone know if this is the case?)

    Im reluctant to rewire it and try again as my boiler is in the Attic and it's all a bit of a faff.

    Which is why I was so interested to see if yours was doing the same.

    I'd like it to work properly with ebus then I wouldn't have to go in the attic to increase the target temperature when it gets really cold.
  • scgf
    scgf ✭✭
    edited November 2020

    @Ajh My Vaillant engineer warned me that the boiler would do all sorts of strange things for a few days after installation. He said it would be learning about the system to which it is connected. I could imagine there might be situations where Tado and the boiler's onboard computer might be in a minor conflict until it all settles down. Did you allow for this when you connected your Tado? As i said before, I'm happy that from my point of view as a user everything works and my home is always almost exactly at the temperature I have set. The system doesn't under or overshoot in the way it did when I had my old boiler and Todo was in call-for-heat mode.

  • Hello, I have a Vaillant eco tech pro 28 I've paired all devices and ready to go but there is no heat to the radiators.

    The wiring seems fine maybe it is the firmwire I have seen someone mention?

    Any ideas?
  • Hello, I have a Vaillant eco tech pro 28 I've paired all devices and ready to go but there is no heat to the radiators.

    The wiring seems fine maybe it is the firmwire I have seen someone mention?

    Any ideas?
  • scgf
    scgf ✭✭
    edited December 2020

    @RV93 Have you configured the thermostat? It needs to be set to D07 rather than the default of R01. 'D' is for digital interfaces, 'R' for relay interfaces. I have attached the relevant installation manual. The thermostat configuration is the only thing you'll need to do. I have HW x (ie. hot water off) since the ecoTEC Pro is a combi boiler. Running through the thermostat configuration options it should be TS, HC01, HW X, EK ✓, D07.

    Only two wires need to be connected. + and - from the Vailant eBUS to + and - on the right side of the Tado extension box backplate. No other connections should be made.

    My extension kit firmware is 71.2. Bear in mind there is often an intentional delay after Tado calls for heat until the boiler fires. It could be two minutes or so,

  • Thank you for responding, I've just configured this into the thermostat, but nothing yet?

    What does it mean by EK X ?
  • scgf
    scgf ✭✭
    edited December 2020
    Extension kit. You must chose the tick for it to work - x would mean you do not have an extension box and the thermostat is connected directly to the boiler.
  • @jelockwood

    I thought a small update on my experience with an apparent Vaillant-boiler (a Protherm Gepard, CZ model) and the Tado since installed one year and a half ago would be well deserved after venting my frustration on this forum last time.

    In short, it works!

    It seems as if the water-temperature on the radiators is being modulated after demand, same goes for hot-water temperature. Had a technician over for the annual check-up and he stated that the Czech company's lower ranged products are being build with their own parts, although I do not know how to confirm that without taking the whole boiler apart.

    The ability to modulate must have been implemented some time a few months after the installation, either Tado just had to be tweaked locally or the coders twisted and twirled some buttons on their side, I can not know for sure.

    Either way, I m still happy with the investment, as long as the system stays online, it has proven reliable and convenient. Apparently, we have have also saved a few bucks when not at home, although 2020 will probably be on the more costly side when it comes to heating.

    Only thing that worries me now with this system, is the the lack of any fallback routines if internet fails or if there is some power-outage that disconnects any remote controls.

  • Glad to hear it is working well for you. It sounds like from your and other comments that the Tado system takes a while - weeks to learn the system adequately.

    The Tado will work to some extent without Internet access - obviously remote control stops. You could consider a small UPS. In my own case my longterm plan is to get solar roof tiles and Tesla Powerwall so my entire house can run 'off grid'.

  • @scgf unfortunately nothing has happened yet even after configuring as you mentioned earlier.

    Not sure what else to try.
  • scgf
    scgf ✭✭
    edited December 2020

    So, to recap, you have the latest firmware on your extension box. You have connected the + and - connections from the Vaillant boiler eBus to the + and - connections on the right side of the extension backplate. Just two wires. You have correctly configured the thermostat (including selecting the tick for 'EK". Everything is shown as 'connected' in the Tado app and the white LED on the extension kit is slowly pulsing.

    You manually turn up the thermostat temperature, wait a few minutes and nothing happens? I'm not sure what else to suggest - I did all those things and my System works perfectly.

  • @RV93. Are your 24v link and burner off link in on your boiler PCB?
  • @RV93. Have you seen this?
  • @RV93

    Reading the link I attached.

    I think you need to have the 230v burner off link in place.

    And the 24v link pulled out.
  • For information my Vaillant boiler installer was not at all familiar with Tado when he installed my ecoTEC Pro 28 so I did the research and told him how to connect it up. It was a brand new boiler without controls and he just connected the Vaillant eBus to the Extension box using two wires and did nothing else to the electrics in the boiler and once I had configured the thermostat it worked.

  • Hi all, thanks your help regarding my issue.

    Update is that I spoke to someone called Nacho at Tado this morning, under his instructions I opened up the boiler and took a picture, he highlighted I needed to add a bridging wire to RT24 (next to BUS) thankfully I had some spare wire and was able to cut it to size etc.

    The bridging wire seems to have done the trick for my Vaillant boiler!

    Radiators now warming up after a cold night :#
  • I'd add a picture if I knew how too! But otherwise its simple to do.
  • Also it's seems I had to make sure HW is ticked on the thermostat during configuration.

    HW was not working otherwise.
  • @RV93

    So do you have a hot water cylinder?
  • scgf
    scgf ✭✭
    edited December 2020

    @RV93 I'm glad you've got it working. My installer was used to connecting Vaillant controls to the eBus so I suppose he knew about the bridging wire. When he showed me the connections inside the boiler there was a bridging wire in place.

    The HW bit is confusing -Tado has no control of hot water on a combi boiler. Ticking HW on the thermostat will give you a Hot Water tile in the Tado app, but it will do nothing. I did HW X and it all works perfectly.