Vaillant ebus and hot water control

Currently have Extension Kit (3+) and 8 SRTs installed last week and working nicely in 'relay mode' ie just replacing control of the heating and hot water switched lives to each 2-port valve on my S-Plan system. I want to take advantage of boiler modulation via ebus and my 10-year old Vaillant EcoTEC 428 is compatible (confirmed by Tado). I now understand that if the boiler control is via ebus, the switched live circuits are replaced by ebus low voltage control, rather than having both as I'd earlier imagined (ie switched live to turn on and ebus to tell it what temp). Given this, what are my options for hot water control? Can I have my cake and eat it, with heating and hot water on the Tado interface and still get meaningful ebus modular control of boiler temp?


  • Joey
    Joey | Admin

    Hello DaveNotThePlumber,

    Thank you for your question,

    The Extension Kit can only be with one thing. It cannot be both or multiple. There is no option to control a (digi) combi in an S-Plan.

    Kind regards,


  • Hi @Joey

    Yes I realise it cannot be wired to do switched lives and EBUS at the same time. If I now want to go the EBUS route, can I have my S-Plan system rewired into a Vaillant VR65 Control Centre and hook up the EBUS into the +/- terminals on the Tado Extension Kit where the Vaillant instructions would show one of their VRC controllers? My boiler EcoTEC plus 428 supports VR65 connection according to the manual.


  • I'm not sure about S-Plan as I've had my system for about 5 years now. But I have a Vaillent EcoTec combination boiler connected via ebus and I can control the hot water temperature via Tado as well as heating demands. I am very happy with the system as it controls the heating water temperature based on the demand and seems very efficient.
  • Hi @Joey i have a question regarding the starter kit I got from OVO. I was told that it was compatible with my Vaillant system boiler which is already connected to a VR 65 controller and is currently controlled by a VRT392f controller with receiver mounted in the boiler facia (so will be controlling everything via the eBus).

    But every choice I make in trying to use the installation wizard results in “not compatible”

    I have seen an article on enabling Tado ebus control, but can’t see how you select it when it doesn’t tell you how to go about connecting the receiver to the boiler/control centre in the first place!