We have a solar system that heats our water in the spring and summer.

In our airing cupboard is a Resol ES10 box which until recently has been fine, however it has started clicking constantly like it is switching on and off, while it does this, the pump in the loft switches on and off and the display on the ES10 cycles through various readouts.

In your experience, do these panels have known issues? Any thoughts what might be causing it?