Float switches

A float switch turns a pump on and off by water level. The same switch can work for filling (the pump runs until the tank is full) or emptying (dry-run protection, sump pumping) — it depends on which wires you connect.

Choose the model by pump current and cable length: the cable should reach the panel without tension. Sewage applications need special heavy-duty models. For a storage tank with automatic filling, see “A storage tank for a water reserve”.