This part detects if water is moving through the Saunier Duval boiler. If these switches are detecting water flow they can either be a pump proving flow switches or a domestic hot water flow switch which detects if a hot tap has been opened. All these Saunier Duval flow switches send signals to the printed circuit board within the boiler ensuring they are being monitored all of the time.
Saunier Duval S801189 SD30E Flow Switch

Part: S801189

Price: £32.43