Building Code consultation – Temperature limited water heaters

Have your say on options

About this consultation

This consultation is seeking feedback on a proposal to modify a reference to an Australian water heater safety standard. This will provide Aotearoa New Zealand suppliers and installers of instantaneous water heaters more flexibility to comply with Aotearoa New Zealand hot water delivery temperature safety provisions without the need for setting maximum temperature adjustments in the factory.

In November 2023, MBIE amended the acceptable solutions and verification methods to improve the safety and reliability of new plumbing systems.

One of the changes made was to reduce the risk of tap water scald injuries for all New Zealanders, including the most vulnerable. These changes came into effect on 1 November, with a 1-year transition period ending on 2 November 2024. 

We’ve received feedback from some manufacturers and suppliers that a sub-clause within the acceptable solution (AS3498) limits flexibility for how certain ranges of instantaneous (continuous flow) water heaters available on the Aotearoa New Zealand market can be used and therefore, limits their ability to comply with G12/AS1.

Proposed changes

MBIE are proposing to modify the G12/AS1 table 8B reference to AS3498 to exclude sub-clause 7.3.2.1(a) of this standard. This sub-clause limits the maximum temperature adjustment for a temperature limited water heater.

This change would mean that a temperature limited water heater set to deliver water that does not exceed 50°C could be subsequently adjusted by an authorised installer to deliver water above 50°C, if required.

In these situations, the authorised installer (e.g., licenced plumber) would be responsible for providing additional temperature control device(s) as needed to ensure the maximum temperature of hot water delivered at the outlets of sanitary fixtures used for personal hygiene does not exceed 50°C.

It is proposed that this change would come into effect on 2 November 2024, with no transition period.

Related documents

What’s next?

The proposed timing of this amendment is expected to provide greater flexibility of product suppliers to provide compliant products from the date that the new hot water temperature requirements come fully into force. It ensures a compliance pathway remains available after this date for TLWHs that do not meet the requirements of AS3498 without stopping the supply or use of those which do.