If you have a new account but are having problems posting or verifying your account, please email us on for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact

Eddi (hot water diverter) question. Tank 1 and Tank 2.

  • 05-10-2022 5:18pm
    Registered Users Posts: 1,237 ✭✭✭

    I only got panels and Eddi installed recently and notice today that when I went to boost the Tank 2 it says that it has reached its max temperature. I was always under the impression that Tank 1 was "sink" and Tank 2 was "bath" as per old switch removed.

    Does the above make sense? Is that normally that order when the Eddi gets wired to the element?

    I now prioritised Tank 2 over Tank 1. I had Tank 1 being priorised before.

    Post edited by Galego on


  • Moderators, Sports Moderators Posts: 18,906 Mod ✭✭✭✭slave1

    Normally 1 is Sink, 2 is Bath i.e. 1 top of tank, 2 bottom of tank.

    Sounds like installer mixed the cables up

    My stuff for sale on Adverts inc. EDDI, hot water cylinder, roof rails...

    Public Profile active ads for slave1 (

  • Registered Users Posts: 160 ✭✭vistaphotos

    My cylinder has Tank 1 as sink and Tank 2 as bath, you can confirm by checking power consumption in app, bath is about 2kW I think. In my case there’s no element at the bottom of the tank they both come in on top. Thought I saw someone mention (@unkel ?) that if top of tank is already warm from sink element Eddi won’t heat further with surplus but can be manually boosted.

  • Registered Users Posts: 2,508 ✭✭✭bullit_dodger

    Typically immersion heaters only have 1 thermostat near the top of the tank, so when the temp is reached you have to wait a bit for the tank to cool down by 2-3C and then you can use the other element.

    The Eddi has a "Priority" function though on the menus, so if they have wired it backwards (which also happened to me) I have the sink as the according to the eddi it's heating the top of the tank, but in's heating the bottom.

  • Registered Users Posts: 1,237 ✭✭✭Galego

    Ok my initial thoughts were somehow wrong.

    This is the case.

    Tank 1 (whatever coil that is, sink or batch) works with surplus from PV panels or via the app if I use the boost button.

    Tank 2. It always gives me the message max temperature reached although the water in the cylinder is cold.

    I read about the immersion thermostat tripping but if that was the case I guess tank 1 should give me the same max temp message?

    Another possibility is that it was wired incorrectly to tank 2 and isolater is off (if that makes any sense)?

    Any ideas?

  • Moderators, Sports Moderators Posts: 18,906 Mod ✭✭✭✭slave1

    Sounds like Immersion 2 has possible tripped, there should be a very small button to press under the metal cover on the outside of the tank, if you do this and hear a faint click then that was the issue.

    Immersion 1 is independent from Immersion 2 so will still work perfectly if 2 is faulty

    My stuff for sale on Adverts inc. EDDI, hot water cylinder, roof rails...

    Public Profile active ads for slave1 (

  • Advertisement
  • Registered Users Posts: 1,237 ✭✭✭Galego

    So it turned out that the immersion heater only has one element!!

    That means the sink/ bath I had before did nothing!