Vaillant is located around the flow switch section. The flow switch acts as a safety instrument. It is a switch with an in-built sensor that sits in the pipework for both the domestic hot water and central heating systems. When the pump is powered up, the flow switches sense this movement and feed the information back to the electronic control, allowing the ignition sequence to progress. The flow switch function is to make sure that the burner cannot switch on if the system is low on water or dr

Brand Name	Vaillant