Are DualSun panels compatible with Daikin ECH2O split thermodynamic water heater?


Yes, the DualSun SPRING hybrid panels can be coupled with the Daikin split ECH2O thermodynamic water heater (only the model EKHHP500A2V3).


For optimal coupling, it is recommended to schedule heating time slots by the thermodynamic group compatible with the customer's consumption habits and solar heating hours.

  • Showers in the evening: 4 p.m. to 11 p.m.

  • Showers in the morning: 2 a.m. to 8 a.m.


If necessary to ensure a better hot water comfort by programming heating time slots between 8 a.m. and 4 p.m. (solar hours):

  • It is then possible to inform the intelligence of the thermodynamic water heater by an electric signal to always give priority to free solar heating and avoid simultaneous heating.

  • The DualSun solar controller must be connected to the electronic board of the water heater.


Option to control the solar/thermodynamic water heater coupling

The communication between the DualSun SLL solar controller and the Daikin EKHHP thermodynamic water heater controller is possible to intelligently activate the compressor according to the solar energy.

For this purpose, the relay R4 of the SLL controller must be wired to terminal block IN 1 and GND of the X2M box of the Daikin EKHHP  water heater dedicated to the external source:



If the potential-free contact is closed by an external heat generator, the DAIKIN EKHHP reduces its own heat output to support the external heat generator.


Setting R4

In DualSun SLL controller, set R4 using the parallel relay option : 

  • OPARR = ON

  • Parallel relay: REL = R4

  • Reference relay: RELR = R1



See also the compatibility of our solar panels with the DAIKIN compact thermodynamic water heater EKHH2.