The Sime (80C to 100C) air pressure switch enables safety protocols to ensure the fan is fully operational. It ensures that, if the fan fails within the boiler, there will not be a build up of toxic fumes with no means of venting them. The printed circuit board closely monitors the air pressure switch to make sure it is fully operational before the unit is fired up, preventing the appliance from starting without one of its key safety mechanisms.

Brand Name	Sime