Cancelling a Controlled Load boost. On my Mk7A I activated the Controlled Load boost as described - easy. I confirmed the CL was in boost by long-pressing the clear-coloured lower button until the voltage and current values appeared. The first value is the grid voltage - around 230-255v. Another brief press of the same button scrolls up the Main Load current (MLI) - either a positive value if there is an appliance or lights on inside the installation - or a negative value if the solar is produci ...