This fan is a genuine Ariston part for use in Intesa, microGenus, microGenus II, microTEC, One, Excalibur, microCombi, Modula, Next and T2 boilers. The fan introduces fresh air into a boiler's combustion chamber, ensuring that gas is burnt correctly and extracting burnt gas at the end of the combustion process. Your boiler's safety parameters ensure that no gas passes through to the main burner if the fan is not functioning correctly.