The Potterton air pressure switch is a safety device which checks that the fan is fully operational. It ensures that if the boiler's fan fails, there will be no toxic fume build-up with no way to safely remove them.
Fits a number of Potterton appliances
Technical specification
TypeAir Pressure SwitchCompatible WithSuprima 80 HEManufacturer Model No5110393Brand NamePotterton