Pressure switches within your appliance help to control different aspects of the internal pressure of closed systems and boilers. Pressure switches can relate to gas, air or water and are used to restrict or allow the flow of certain material dependent on the pressure variables.
![Vaillant 0020059717 Water Pressure Sensor [8548]](http://allgasltd.com/cdn/shop/files/Screenshot2023-05-10at15.05.49.png?v=1683727591&width=1445)