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Has anyone wired their Thermostat to utilise the modulation feature on an Alpha Boiler? Alpha isn’t listed for a Bus code in the Tado instructions, I’ve used the contact us feature to Tado but so far no news.


  • Did you get a response Griffiths?. I am waiting for the worst of winter to pass before connect the extension kit to my Alpha Etec33 boiler. Reading the instructions, it seemed to me Tado can control this boiler via Opentherm??
  • No I haven’t heard back from them yet. You’d think they would have a drop down box on the website for every conceivable boiler to save asking them.
  • I do not know any more details than the website for the Alpha boilers. They do advertise compatibly with OpenTherm so you should be fine to use that for modulation control. As I live in the Netherlands and all boilers have OpenTherm I was able to use the D01 configuration code with a "2-wire bus" wired connection to my boiler and it works much better than the "potential free contact" thermostat that I replaced. Good luck

  • They came back to me yesterday to say Alpha doesn’t support modulation with Tado which is really annoying given the reason I chose Tado over Hive was the modulation facility.

  • rizsherrizsher
    edited January 12
    So. i raised a support ticket with Tado asking :-1:

    " I have an extension kit that I was looking to connect to my boiler. I currently have a Nest 3rd Gen controlling my Alpha Etec plus 33 boiler thru OpenTherm configution and the system works very well, including modulation. I recently came across this post on the Tado community form which states that Tado could controller on Alpha boilers cannot do modulation
    https://community.tado.com/en-gb/discussion/comment/20265#Comment_20265 "Geraint_Griffiths1
    January 8
    They came back to me yesterday to say Alpha doesn’t support modulation with Tado which is really annoying given the reason I chose Tado over Hive was the modulation facility."

    Can you please confirm if this indeed the case?. Regards.

    After 3 days, and a bit of back and froth, here is the following:

    Thank you for contacting us.
    If your Nest thermostat is the Heat link 3rd generation, tado can certainly replace that to control the Opentherm interface.
    Please do let us know if you have any further question. We are happy to help.
    Kind regards,

    And finally...

    Me: So, the community Forum posting is incorrect??

    And response:

    Hi Rizwan,
    The post is not incorrect.
    The fact is that the Alpha Etec plus 33 boiler does support two digital interfaces: 1) Opentherm 2) Alpha-BUS. tado° is compatible with Opentherm but not with Alpha-Bus. Since you are currently using the opentherm with Nest, you can use the same wires to connect tado to opentherm and replace your current room thermostat.
    What I can assume is that the person only asked if the Alpha Etec plus 33 was compatible and probably has no current thermostat. Since we replace the thermostat in place (in order to avoid the customer opening the boiler), we normally ask if there is a thermostat.
    Kind regards,



    So, if your boiler has OpenTherm control as an option, Tado should be able to control it fully including modulation. Looks like Alpha has two modes of control...Opentherm, is an open l, manufacturer agnostic standard and Tado should be able to work with it.
  • So I’m an I get a separate open theme controller and connect it to the Boiler the. Connect Tado to the open them controller?
  • No, you need to.check if your boiler supports OpenTherm, and if it does, then Tado would do modulating control on it.
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