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Solar PV + combi bolier

  • 29-04-2022 5:12pm
    Registered Users Posts: 2,216 ✭✭✭

    Just wondering if anyone here has this set up, I know it is possible as long as the boiler can accept hot water in from a tank and not expect just cold water in.

    Seems like even with 20kw worth of batteries still exporting a bit so I need to look into this setup.

    Have no hot water tank anymore and I need to find out if my Vokera boiler can take hot water in (I suspect that no) and then probably need an actual genius of a plumber to hook all these things up. An eddie would then make sense but as is if I need to get a tank/new boiler probably not.



  • Registered Users Posts: 2,216 ✭✭✭SD_DRACULA

    Was talking to vokera and apparently there is such a thing as a thermostatic valve that can be installed to a combi boiler to allow pre-heated water to be used so maybe I would only need that, the tank and the eddi.

    I assume the eddi can be configured to divert pv after the batteries are full?

  • Registered Users Posts: 121 ✭✭fael

    If I understand it correctly you can fit a 3way thermostatic valve after the boiler. You put in a tank that you heat with the Eddi, then the tank and the combi both have an input on the 3way valve. If the tank is too cold it will control the temperature using hot water from the boiler. Would be handy as well because you can disconnect the tank in the wintertime then, since there would be not solar excess.

    Not sure if you have an oil or gas combi. This system would work best with a properly modulating boiler, which oil combi boilers can't, they are just on/off (at least mine is). I think it's only feasible with a gas combi.

  • Registered Users Posts: 2,216 ✭✭✭SD_DRACULA

    It's a gas combi.

    I spoke to misummer about one of these and it looks like they can be wired to work with PV excess/grid and a combi boiler. They suggested the 9kwh one for my house size and it's funny they sell a pack with the eddi included.

    But they could not recommend any installers for them, probably since they are so new.

    Not sure if worth 3k + vat + installation to get hot water for what, about 4 months?

    Once gas unit overtakes the night tariff price of electricity, absolutely.

  • Registered Users Posts: 2,216 ✭✭✭SD_DRACULA

    Spoke with Sunamp the other day and they said at the end of the year they expect to release a module which will do hot water and also heat the water in the rads around the house, the ones connected to the gas boiler which is very interesting as you could heat the whole house either from night rate or PV without a heat pump.