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Translating high quality research specific to better design and building practice

Regulatory Requirements for Controlling Water Temperature in Bathrooms

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Authors Bridge, C., Carnemolla, P.
Illustrators/Contributors Svenger, M.
Audience Consumers, Government/NGOs/Peaks, Industry, Librarians/Researchers/Students
ISBN 978-0-7334-3662-8
DOI 10.4227/169/5a8b5ec912dce

This Summary Bulletin relates to the safe provision of heated water in the people’s bathrooms for washing and bathing through the installation of temperature limiting devices. A number of regulations and requirements are in place around the storage and delivery of heated water in a residential setting because of two public health concerns: the risk of scald burns in water delivered too hot and the risk of microbial presence (particularly legionella) in heated water stored at temperatures too low. An analysis of Australian Standards and regulations indicate that temperature limiting device options for use in people’s homes include: thermo-static mixing valve, tempering valve, or a hot water system compliant with AS 3498.

Publication History

1st edition Thermostatic Mixing Valves by Julie Cameron and Catherine Bridge, 2004.

This is the Second Edition of the Summary Bulletin: Temperature Limiting Devices in Hot Water, replacing the original publication, titled Thermostatic Mixing Valves. This edition updates compliance regulations which have been superseded since first publication. In the twelve years since this first edition there have been considerable changes and additions to relevant codes. The First edition was authored by Julie Cameron and Catherine Bridge (2004), for the Home Modification Information Clearinghouse, UNSW Australia.

In this 2nd edition, Phillippa Carnemolla updated all references to regulatory codes, restructured the report and added information about maintenance and assessment. Catherine Bridge contributed to the draft report .

Product illustrations have been drawn by Michelle Svenger and diagrams by Phillippa Carnemolla.

Table of Contents


  • Glossary
  • Background
    • The need for temperature regulation in household water storage and delivery
    • Risks of low temperatures in water delivery
    • Microbial risk of low temperatures in water storage
  • Regulatory Requirements for Temperature Limiting Devices in the Home
    • Temperature Limiting Devices
    • Thermostatic Mixing Valve (TMV)
    • Tempering Valve
    • Thermostatic Mixer (Thermostatic ‘Point of Use’ Mixer)
    • Water heater (AS 3498 compliant)
    • Risk of Malfunction
    • Overview of Installation and Maintenance Requirements
  • Relevant Australian Codes and Standards
    • Assessing Your System
  • Summary
  • Approaches for Compliant Water Temperature Regulation – Comparison
  • Questions to Ask the Supplier
  • References
  • Appendix 1: Standards Relevant to Temperature Control Devices for storage and delivery of heated water.


  • Figure 1. Example of a Thermostatic Mixing Valve (TMV)
  • Figure 2. Example of a Tempering Valve
  • Figure 3. Example of a Thermostatic Mixer
  • Figure 4: National and State regulatory envivironment.


  • Table 1: Relationship between water temperature and time to develop full thickness burn
  • Table 2. Maintenance and installation requirements for temperature regulation devices as per AS 4032.3.
  • Table 3: Australian Standards
  • Table 4: State legislation and state regulations (NSW example)
  • Table 5. Advantages and disadvantages of devices for limiting water delivery temperature

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