Air Pressure Switches
Also referred to as a pressure differential switch, it is designed to act as a safety instrument which checks if the fan is running correctly, the air pressure switch connects to the Fan via heat resistant tubes which go directly onto the fan Venturies. Through these, it enables the boiler to detect when the fan is running to ensure that if the fan fails there would not be a build-up of toxic fumes with no way of venting them, A signal would then be sent to the printed circuit board telling the boiler to stop sending gas to the burner and preventing the boiler from turning on.
