Filter clogged. Solution: (“bi bi” sound twice per minute) Clean the filter.
Pump clogged. Solution: (“bi bi” sound twice per minute) Unblock the water pump.
Dripper clogged. Solution: (Green light steady on) Clean the dripper, restart the system.
Insufficient power. Solution: (Red light flashes for 30s and then turns off) Place the solar panel in direct sunlight.