Worcester Air Pressure Switches
The air pressure switch is designed to discover whether the fan within the boiler is rotating and can be closely connected to the fan via heat resistant pressure differential tubes on to the fan venturies. This permits the pcb to discover whether the fan is operating since air flow from the fan closes the air pressure switch that then sends a signal to the pcb confirming the fan is functioning, Gas is then sent to the burner together with the initialising of the in depth ignition process.
If the fan stops operating or jams, there'll be too small air flow across the pressure switch that would create the air pressure switch to opperate. This information is then relayed into the printed circuit board instructing that the Worcester Bosch boiler to stop supplying gas to the burner and also to halt the boiler from working. This Worcester Bosch air pressure switch is a safety device and ensures the safe and secure functioning of the boiler.