Description

The objective of this Standard is to provide uniform requirements, which regulatory authorities may apply in Australia, for basic safety and public health issues resulting from the use of water heaters and hot-water storage tanks.

The objective of this Standard is to provide uniform requirements, which regulatory authorities may apply in Australia, for basic safety and public health issues resulting from the use of water heaters and hot-water storage tanks.

This edition is a major revision of the superseded edition, and incorporates the following significant changes:

• (a) Specifies that all heaters comply with the requirements of AS/NZS 4020.
• (b) Creates a new classification for heaters that claim to deliver water not greater than 50°C. Such heaters are permanently marked with a warning label with internal temperature adjustment permanently disabled. To validate the performance of such heaters, new methods of tests to evaluate transient temperature spikes and to evaluate scalding are defined. Also included are a series of tests for proving the durability of such appliances.

Amendment No. 1 is issued to strengthen the intent of Section 7, Control and protection. The changes confirm hot water adjacent to any temperature and pressure relief valve (T&PRV) should not reach temperatures to cause the valve to operate thermally under normal operating conditions. The T&PRV is a safety device and should not be used as a control device.

Scope

This Standard specifies basic safety and public health related requirements for water heaters and hot-water storage tanks that are intended for connection to a potable water supply, such as water heaters designed for connection to cold-water supply mains, including-

• (a) storage water heaters;
• (b) heat-exchange water heaters;
• (c) hot-water storage tanks with an external energy source;
• (d) instantaneous water heaters; and
• (e) boiling-water dispensers.

The Standard applies to water heaters using any type of heating, irrespective of the source of the heat energy imparted to the water, including electric resistance, gas, liquid or solid fuels, heat pumps, waste-heat recovery systems, solar energy or any other means of heating potable water.

In addition to the requirements of this Standard, additional requirements may be applicable for early childhood centres, primary and secondary schools and nursing homes or similar facilities for young, aged, sick or disabled persons, as described in AS/NZS 3500.4.2.

The Standard does not include requirements affecting the durability of water heaters, except those applying to safety devices. It does not apply to steam generators, sterilizers, washing machines, wash boilers, urns, kettles, or hot-water supply systems intended solely for space heating, swimming pools, spa pools or industrial processes.

Note: The installation of water heaters and hot-water supply systems is covered by AS 3500.4.1, AS/NZS 3500.4.2 and AS/NZS 3500.5.