This part of IEC 60730 applies to automatic electrical air flow, water flow and water level sensing controls for use in, or in association with, boilers with a maximum pressure rating of 2 000 kPA (20 bar) and equipment for general household and similar use including controls for heating, air- conditioning and similar applications. This second edition cancels and replaces the first edition published in 1994 and its Amendment 1 (1997), the first edition of IEC 60730-2-16 published in 1995 and its Amendments 1 (1997) and 2 (2001) and the first edition of IEC 60730-2-18 published in 1997. This second edition constitutes a technical revision. This second edition is a consolidation of three standards IEC 60725-2-15, IEC 60730-2-16 and IEC 60730-2-18. The title and scope were revised to reflect the additional topics covered by the standard.