The Worcester Bosch flow switch acts as a safety device. It is a switch with an in-built sensor that sits in the pipework for both the central heating and domestic hot water systems. When the pump is switched on, the flow switches sense this movement and feed the information back to the printed circuit board, allowing the ignition sequence to progress. The flow switch function is to make sure that the burner cannot switch on whilst the system is low on water or dry.

Brand Name	Worcester Bosch