Product Information: The air pressure switch acts as a safety device which ensures the fan is in full working order. It ensures that, if the fan fails within the boiler, there would not be a build up of toxic fumes with no means of venting them. The PCB closely monitors the air pressure switch to make sure it is fully functional before the unit is fired up, preventing the appliance from starting without one of its key safety devices.
We only have this part as fitting one appliance, The Glowworm MICRON 50 FF .