Support current and more recent Vaillant eBus controllers



  • Hello all,

    After reading through this thread (thanks to all who contributed) I have provided solutions and problems below:

    My Set up: EcoTec 938 1 year old. Installed Tado V3 wireless. It works perfect on analogue/relay without any problems for a week. Followed instructions via tado app, but connected the power directly to boiler instead of to a UK plug outlet as the instructions suggested. The Vaillant + / - connected to COM and NO on the Tado EK. The first time I fired it up it took about 3 minutes for the relay to 'click'. But subsequently is takes only a few seconds.

    Setup then says: change wireless controller to D.07. When I try, wireless controller flashes FAIL.

    I called TADO technical support who informed me that because my Receiver is UK version it doesn't have the digital module. Can anyone confirm this?

    They also said if I can get the EU Receiver I can enable the digital eBUS connection D.07. Can anyone confirm this is true before I spend £90 on another piece of kit?

    Also, is the digital connection worth it? what advantages/controls does it have?

    Thank you all for your help.


  • Uk wireless receivers don’t have digital connections. Eu versions do. Might help to make that a pinned post because it gets asked so often on here!

    If the app was telling you to connect relay connections to digital there’s something very wrong. Good job you didn’t end up putting 240v through the low voltage connections and blowing the circuit board.

    If Tado support say your boiler will work with ebus then I would hope they’re right.

    Digital connections, which modulate the heat output of the boiler, will usually lead to less energy being used and less wear and tear on the components.

    On relay connections Tado simulates modulation by cycling the boiler on and off so it doesn’t overshoot its target temperature, so you get some of the benefits of modulation.

    For my money I’d say digital connections are worth the extra, but it depends if you want the time and expense of reinstalling.
  • The original UK extension kit does have D07 functionality so you could source one from eBay. I have still got mine since I replaced Tado with vSmart and will be listing the whole kit in eBay.
  • Thanks for the quick reply @johnnyp78 To clarify the app was asking for a connection from a UK socket to the EK. Not the digital.

    Can the digital connection control the Vaillant heating curve? I cannot access that even at installer level. Only on Vsmart.

    @Bakshish how much you selling for ;)

  • I PM'ed you @JediSid

  • Tado now sell the eBus/OpenTherm supporting model in the UK again at last!

  • @AndrewN

    The original Tado Extension kit for the UK and EU did both eBus/OpenTherm and Y/S-plan aka 'call for heat'. They then launched two versions, one did eBus/OpenTherm only the other I believe did Y/S-plan only.

    I believe what Tado have done is restore UK availability of both the newer versions so you can once more get the eBus/OpenTherm only model as well as the Y/S-plan version but still not one that does both.

    Arguably the reason the UK take up of OpenTherm is so low is that the two biggest brands - Vaillant and Worcester Bosch do not support OpenTherm in the UK and only support their proprietary eBus standards. (Each is slightly different as well.) In the Netherlands where support for OpenTherm is compulsory everyone uses it and both Vaillant and Worcester Bosch have had no choice also but to provide OpenTherm support. They do this by providing their own modules to translate their proprietary eBus to OpenTherm.

    Outrageously, even though those modules are official products and even if you get a certified Vaillant or Worcester Bosch engineer to fit them the manufacturers will regard this as invalidating their UK warranties.

    I still have an older boiler which does not support eBus or OpenTherm but had originally considered replacing it with a gas boiler with either eBus or OpenTherm support, I then considered a similar boiler with future support for Hydrogen as well. However I get the impression that whilst boiler makers have been proactive and made new models future proof with the ability to use Hydrogen the chances of the UK gas network switching to Hydrogen are becoming less and less likely. This is because the gas network would need significant upgrading to supply gas to consumers and I also get the impression that the plans are/were to actually 'cheat' and use a mixture of methane and hydrogen rather than pure hydrogen - making this only a partial step to a zero emission solution.

    I have therefore more recently been looking at moving to an Air Source Heat Pump. I do not yet feel I have as good an understanding of these as gas boilers but it does seem clear that whereas gas boilers can rapidly supply heat to rapidly warm your house ASHP take much longer to do so and therefore counterintuitive though it might seem, it sounds like you would more likely have the ASHP running almost all the time. It is not clear to me if ASHP use a modulated control and how effective a 'smart' thermostat would be with an ASHP. I do know that Tado claim compatibility with ASHP systems although again it is not clear whether this uses modulating control or not. Things would be a lot easier if boiler and ASHP makers themselves provided smart home solutions instead of persisting with their own proprietary products. Maybe a significant take up of 'Matter' will help these dinosaurs wake up and smell the roses.

    As a curiosity, does anyone know if any brands of ASHP support OpenTherm or provide a non-proprietary smart home solution?

    I will be making any changes as part of a major house renovation - not yet scheduled and as my house is about 140 years old and has no cavity walls I will also have to do major work to fit internal wall insulation. (My choice over external wall insulation.) I am planning on using a likely more expensive choice of a combined plasterboard/aerogel solution as the thinnest option. Aerogel has many magical properties one of which is unmatched insulation capability hence being able to achieve a similar performance with a thinner solution. As ASHP run on electricity and as they need to run most of the time even though they are genuinely more efficient from a physics point of view with electricity costing so much currently and also illogically bearing all the green taxes unlike gas I am also planning on fitting solar panels to as much as possible use 'free' electricity. Whilst like up to 45% of the country I have no off-street parking for an EV I do have the fortune to have an east-west orientated roof meaning that I have a large 45 degree pitched roof facing south and therefore ideal for solar panels which I will of course link to Tesla Powerwall batteries.

  • @jelockwood take a look at early days but retrofits into a central heating system. Combine with an overnight EV tariff & solar.
  • @JediSid Tado should in theory use its own heating curve, rather than vaillant’s. I’m afraid there’s no end user control of it though.
  • @JediSid, If you want fine user control then you should really consider vSmart over Tado. Being an early adopter of Tado (since Jan 2015), moving to vSmart has been an eye opener. There is something good to be said for using Vaillants own controls with their own boilers. Tado have tried to create a smart system but after 7 years of using it I cannot say it is that smart where it counts. These days the word smart is be applied to any gadget that has internet connectivity and a phone app! If you have a Vaillant boiler I would seriously recommend vSmart as it has both load compensation and weather compensation built in and it will modulate the boiler perfectly whilst giving you the level of heating curve control you seek. The Tado support has been lacking also in my opinion.

  • @Bakshish Does vSmart have auto geofencing? The number 1 feature of Tado for me (given I have an irregular work schedule) is that it turns down/off my heating when I leave the house and turns it back on when I return. It would be a HUGE backward step if I had to manually select whether I was home or away.

  • vSmart does not have geofencing. To be honest I didn’t find the Tado geofencing that useful but more of an annoyance. For example, I would travel 30mins away and the heating would turn off or reduce to a set back temperature. Then on my drive back home it would notice me only as I was almost down the road and so turn the heating on too late for the house to be at the correct temperature for my return. You may have a better experience but I didn’t.
  • My experience has been great - there are settings you can change. Firstly you decide how big your home area is, you decide what happens when you are outside that area - you can have your effectively switched off, or the temperature reduced by a few degrees - then you decide whether your heatings turns back on as you approach home or when you actually return. I have my heating turned to the minimum temperature when I leave home and it only switches back to normal when I actually reach my house on my return. I've found that the house doesn't lose much heat while I'm away. The lack of auto geofencing would be an absolute deal-breaker for me.

    I have a friend with Hive and it always amused me that when we went anywhere together her phone would ping to tell her she'd left the house and to ask her if she'd like to turn her heating down/off. It really amused me that she had to go through this process every time she went anywhere.

    I like it that Tado really is a 'set and forget' system. Once it is functioning to your satisfaction you never need to touch it again.

  • Sid, I also have a EcoTec 938 and do indeed have it wired via eBUS (using a wired thermostat as the controller). I've had it setup this way for 2-3 years. Before this I have EvoHome.

    Would I say it's worth the extra, not for me it isn't but as i already have all the equipment there's no point changing it to relay mode.

    I cap the flow temperature using the Vaillant control panel. (45oC unless it's very cold outside and then move it to 50oC) although I did fit bigger radiators than needed.

  • @scgf sorry old thread but another thread said that the TADO does have control in a combi boiler!!