This Standard sets out requirements for the design, installation and commissioning of heated water services using drinking water or rainwater or a combination thereof. It includes aspects of the installation from, and including, the valve(s) on the cold water inlet to any cold water storage tank or water heater and the downstream fixtures and fittings. It applies to new installations as well as alterations, additions and repairs to existing installations.This Standard applies to the installation of the following types of water heaters:(a) Storage water heaters with a rated delivery or capacity of up to 700 L per heater.(b) Heat exchange water heaters.NOTE: Electric heat exchange water heaters are defined in AS 1361. Other fuel sources are covered in the applicable Standards, e.g. AS/NZS 2712, AS/NZS 5263.1.2.(c) Instantaneous (continuous flow) water heaters.Illustrations used in this Standard are diagrammatic only and have been chosen without prejudice.NOTE: Appendix M provides guidelines for the operation and maintenance of heated water services.

First published as AS CA51—1968.Revised and redesignated as AS 1529—1974.AS 2002 first published 1979.Third edition 1987.AS 1529—1974 and AS 2002—1987 revised, amalgamated and redesignated AS 3500.4—1990.Second edition 1994.AS 3500.4—1990 jointly revised and redesignated AS/NZS 3500.4.2:1997.AS/NZS 3500.4.2:1997 jointly revised and redesignated as AS/NZS 3500.4:2003.Third edition 2018. First published as AS CA51-1968. Revised and redesignated as AS 1529-1974. AS 2002 first published 1979. Third edition 1987. AS 1529-1974 and AS 2002-1987 revised, amalgamated and redesignated AS 3500.4-1990. Second edition 1994. AS 3500.4-1990 jointly revised and redesignated AS/NZS 3500.4.2:1997. AS/NZS 3500.4.2:1997 jointly revised and redesignated as AS/NZS 3500.4:2003. Third edition 2018. Reissued incorporating Amendment No. 1 (June 2018). Reissued incorporating Amendment No. 2 (June 2020).