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.

This Standard was prepared by the Joint Standards Australia/Standards New Zealand Committee WS-014, Plumbing and Drainage, to supersede AS/NZS 3500.4:2015.

This Standard incorporates Amendment No. 1 (June 2018) and Amendment No. 2 (June 2020). The changes required by the Amendment are indicated in the text by a marginal bar and amendment number against the clause, note, table, figure or part thereof affected.

The objective of this Standard is to provide Deemed to Satisfy solutions to comply with—

(a) the National Construction Code (NCC), Volume Three—Plumbing Code of Australia (PCA), and
(b) the New Zealand Building Code (Clause G12 Water Supplies).

Amendment No. 1 includes an option for installation of solar collectors, which is reliant on certificates issued by a third party (the Clean Energy Regulator). The use of third party certificates has been specifically approved by Standards Australia and the Australian Building Codes Board for this Standard.

The objective of this revision is to update requirements relating to plastics pipes in direct sunlight, circulatory heated water, thermostatically controlled taps and clarification for jointing methods. Some materials and products used in a heated water service are provided with instructions for installation and use. While not a requirement of this Standard, or acceptable as an alternative to the requirements of this Standard, conformance with these instructions generally ensures that—

(i) the material or product is fit for the application;
(ii) the performance of the system is not degraded;
(iii) the durability of the material or product is not impaired; and
(iv) the manufacturer’s warranty remains valid.

Contents:

Section 1: Scope And General
Section 2: Materials And Products
Section 3: Cross-Connection And Backflow Prevention And Thermostatic Mixing Valves
Section 4: Installation Of Cold And Heated Water Piping And Controls
Section 5: Installation Of Water Heaters- General Requirements
Section 6: Installation Of Solar Water Heaters
Section 7: Uncontrolled Heat Sources
Section 8: Energy Efficiency
Section 9: Testing And Commissioning
Section 10: Sizing And Installation  Of  Circulatory  Heated  Water Reticulation
Appendix A: Water Analysis
Appendix B: Acceptable Pipes And Fittings
Appendix C: Internal Pipe Diameters
Appendix D: Preferred Sizes Of Pipe For Non-Circulatory Typical Single-Storey Household Installations
Appendix E: Recommendations For The Installation Of Unrated Solar Heated Water Supply Systems
Appendix F: Recommendations For The Installation Of Close-Coupled And Integral Solar Heated Water Supply Systems On Roofs
Appendix G: Solar Heated Water Supply Systems—Suggested Component Sizes (Custom-Built Systems)
Appendix H: Estimation Of Shading Of Collectors
Appendix I: Effect Of Inclination And Orientation On System Performance  
Appendix J: Map Of Regional Basic Design Wind Speeds
Appendix K: Australian Climate Regions
Appendix L: New Zealand Climate Regions
Appendix M: Operation And Maintenance
Appendix N: Provision For Expansion And Contraction
Appendix O: Estimation Of Probable Simultaneous Demand For Residential Buildings From The Total Of Loading Units
Appendix P: Sizing Of Expansion Vessels In Mains Pressure Systems