Is there a device that i can install on my pump/filter circuit to stop the pump starting if the circuit has lost prime. Unfortunately the Hurlcon BX 1.0 is 1.4 m above waterline. It has one way valves pre pump and post filter and holds prime most of the time. But very occasionally the prime is lost ?debris under valve flaps or seals in valves need lube. Whilst primed there is a constant negative pressure in the suction line when the pump is off, Perhaps some sort of sensor here to a relay to control power to he pump?