On my B36(2002) there is a small black rubber covered push button just below the edge of the worktop surrounding the wash basin, it has to be pressed continuously for the sump pump to run. Additionally there is a separate switch on the main switchboard which has to be in the on position for current to be supplied as far as that push button. Suggest you check with an avometer or with a wired light bulb that you have current at the pump motor when the switch is in the on position and the button depressed. If current is present but the pump does not run, it may be that the pump itself is faulty or has a problem. If the pump does run but does not pump, that may be due to a blockage or a leaking diaphragm. If your test reveals no electricity getting to the pump, you will need to check back to the switchboard to find out why. Good luck.