So a while ago I designed my own with a little cistern float and a broken circuit that will connect when the water gets too low. This was flawed in that the circuit connectors were exposed and it malfunctioned. So I built a new one with better parts. Check it! Parts List Mounting Bracket: Measure 25mm off one side Bent Bracket: Place in oven to soften PVC to bend Drill Hole: Drill Hole for attachment of float switch Float Switch: Screw Float switch to bracket Wiring: Split Wiring and connect into strip connector Neaten Wiring: Wrap wiring with insulation tape Mount ATO: Hang or Glue Bracket to Return Chamber of Sump Tah Dah!