AS NZS 3500.4-2025

AS NZS 3500.4 – 2025 Edition – Plumbing and drainage, Part 4: Heated water services

AS NZS 3500 Part 4 specifies the requirements for the design, installation, and commissioning of heated water services using drinking water, rainwater, or a combination of both.

The Standard covers heated water service installations from and including:

• Valves on the cold-water inlet to any cold-water storage tank or water heater, and

• All downstream fixtures and fittings.

This document applies to:

• New installations, and

• Alterations, additions, and repairs to existing heated water service installations.

Scope of AS/NZS 3500.4

AS/NZS 3500.4:2025 applies to the installation of the following types of water heaters:

1. Storage water heaters

   • With a rated delivery or storage capacity of up to 700 L per heater

2. Heat exchange water heaters

   • Electric heat exchange water heaters are covered by AS 1361

   • Other fuel sources are covered by applicable Standards, including AS/NZS 2712 and AS/NZS 5263.1.2

3. Instantaneous (continuous flow) water heaters

Additional Information

• Appendix M provides guidance on the operation and maintenance of heated water services (informative appendix within AS/NZS 3500.4:2025).

Application

Australia

• AS/NZS 3500.4:2025 shall be read in conjunction with the mandatory requirements for heated water services under the:

  • National Construction Code (NCC)

  • Volume Three — Plumbing Code of Australia (PCA)

• Where alternative Australian or New Zealand Standards are referenced:

  • The Australian Standard shall apply in Australia only

New Zealand

• AS/NZS 3500.4:2025 shall be read in conjunction with the New Zealand Building Code

• This Standard may be used to demonstrate compliance with:

  • New Zealand Building Code, Clause G12 — Water Supplies

• Where alternative New Zealand Standards are referenced:

  • The New Zealand Standard shall apply in New Zealand only

General Product Information: