Worcester Bosch part is located around the flow switch section. The flow switch acts as a safety mechanism. It is a switch with an in-built sensor that sits in the pipework for both the domestic hot water and CH systems. When the pump is powered up, the flow switches senses this movement and feeds the information back to the electronic control, allowing the ignition sequence to progress. The flow switches function is to make sure that the burner cannot switch on whilst the system is dry or low o

Brand Name	Worcester Bosch