How to check and change the controller of a SLL solar station?

1- Diagnosis of control operation

a) Checking the power supply to the circulator

The green LED on the side of the pump indicates the presence of 230V when it is flashing.

If the LED is off, check the voltage at the output terminals of relay R1 of the regulation when it is powered (see figure below).

  • If V = 230V => check the connection of the power cable to the pump, if it is correct then the pump must be replaced.
  • If V = 0 V => Replacement of the regulation is necessary.


b) Checking the PWM signal

The regulation sends a DC voltage of about 10 V when the PWM signal is sent to the pump.

To check that the PWM output is functional, the voltage at the PWM terminals of the regulation must be measured when the relay has been forced on (MAN1 = Max)* and one of the 2 cables has been removed from the regulation (see figure 2 below).

  • If V = 10 V => replacement of the pump is necessary.
  • If V = 0 V => replacement of the regulation required.

* NB : To switch to forced operation, use the Mode_manuel_r_gulation_DualSun_SLL.PNG.png button then validate MAN1, change the value with the knob to the desired value and then validate again with the Touche_valid_.PNG.png button.


(A) = Disconnect this strand before measuring


2- Regulation replacement

Before any operation of unwiring of the regulation in place, remember to take one or more photos of the existing wiring to be able to redo it identically.


Before switching the power supply of the existing regulation off, remember to note the following information in order to re-parameterise it identically in the new regulation: 

  • System number
  • Tank heater (number and mode)
  • Relay control type (number and mode)
  • Minimum and maximum relay speed (number and value)
  • Auxiliary heating (CA O; CA F; t1 O; t1 F; t2 O; t2 F)
  • Manual mode (number and mode)
  • Parallel relay option (REL; REL R; inverted mode ON or OFF)
  • Calorimeter option (if ON: VART; DMAX; GELT; GELT%; SDCAL; SRCAL)

To help you navigate through the menu please use the control manual supplied with the solar station. (Also available on request at


Once these 2 steps have been completed, it is possible to unwire everything and then remove the controller from the solar station. To do this please follow the steps below: 

  • Remove the front cover of the controller held by a cruciform screw.
  • Unclip the upper part by pulling on the upper corners.
  • Unscrew the retaining screw at the bottom 
  • Slightly pull the electronic board out of its slot to unscrew the high retaining screw.
  • Take it off


Proceed in reverse order to install the new control.

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