try this test first. open water without turning on power,if it start filling water there is dirt inside inlet solenoid valve preventing valve to shut off. if water overflow only after power switched on it could be the water level indicator,normally a small brown/white unit with 3 wires and pipe connected to it. if you know how to use a multimeter the centre and r/h conector is open circuit and centre and l/h close circuit
johan, November 2011
