New Legislation For Mandatory Cylinder Trays

Monday, October 2nd, 2017

Amendments to the G12 Water Supplies section of the New Zealand Building Code have recently come into effect, among other changes there is now a legislative requirement for all newly installed hot water cylinders to have Safe Trays fitted (See G12/AS1 clause 5.2.3 of the New Zealand Building Code).

The concept of hot water cylinder Safe Trays or Drip Trays as they are sometimes called is not new, in fact some of the major hot water cylinder brands in New Zealand including Rheem and Rinnai have been recommending the installation of Safe Trays for quite some time. Australian regulations, namely standard AS/NZS 3500 (also an acceptable standard in NZ) have also been in place since 1996 making their installation across the ditch mandatory.

Hot Water Cylinder Safe Trays – What Are They?

Made from plastic or galvanised steel, Safe Trays are designed to fit snugly underneath the hot water cylinder and contain any water leakage. They come in a range of sizes to suit any brand or size of cylinder with custom built designs available if necessary.

Safe Trays are available in either smooth or raised surface styles, the raised kind will usually have dimples or some kind of patterned bottom surface allowing air circulation underneath the cylinder in order to reduce ‘sweating’ against the tray.

The New G12 Building Code Amendments 2017

As well as setting out the mandatory provisions for building work in New Zealand the Building Code and its associated regulations also sets out the requirements for the installation of water heating systems. These include but are not limited to; solar water heating and electric hot water heating systems. The section that relates to these two is the G12 clause for Water Supplies.

Primary Objectives

The primary objectives of the G12 Clause are to safeguard people from water supply related issues arising from contamination, water heating and water temperatures essentially ensuring the building has safe and adequate water supplies.


The G12 clause covers all of the components of the water supply system including water tanks, water pipes, hot water heaters and supply systems, safety and relief valves, temperature control devices, vent pipes, water heater insulation, seismic restraints and drainage as well as installation requirements. There is also an entire section covering the installation of solar water heating systems (G12/AS2 Solar Water Heaters).

Safe Trays

The amendments to the G12 Water Supplies clause (Acceptable Solution G12/AS1) in relation to hot water cylinder Safe Trays comes under Section 6.11.3 which states “Storage water heaters shall have: a) Safe trays complying with Paragraph 5.2.3…”

The Water Tank Installation section 5.2.3 goes into more detail and applies specifically to Safe Trays. Stating any accidental leakage must be taken care of in a way that avoids and damage to the building. Safe Trays are offered as an acceptable method for meeting this requirement. Safe Tray installation will also require connection to an approved point of discharge (via a drain of at least 40mm in diameter), this enables the water to escape and prevents overflow.

It is unclear whether a Safe Tray must be installed in replacement situations as the Building Code states when a repair or ‘like for like replacement’ takes place the current state of affairs can be maintained. However it stands to reason that all good hot water cylinder installers would now include a Safe Tray as standard practice however it is up to the home owner to investigate this prior to the installation process.

The Benefits Of A Drip Tray

10 Hot Water Conservation Tips

Reducing hot water usage can result in some impressive yearly savings, take a look below for 10 quick tips on conserving your hot water.

  1. Replace existing shower heads with ones with more efficient flow rate.
  2. Fix dripping hot taps (or cold) as soon as possible. 
  3. Choose water efficient products when purchasing things like shower heads, taps, dishwashers, toilets and washing machines.
  4. Test the temperature of your hot water, it should be 60°C at the cylinder (preventing the potential growth of legionella bacteria) and 55°C at the tap.
  5. Schedule regular hot water system maintenance, using only qualified, and professional hot water system specialists.
  6. Where possible wash clothes in cold water.
  7. Turn off the tap or fill the sink when brushing your teeth or shaving.
  8. Choose a short shower over a bath.
  9. Rinse dishes in cold water before loading the dishwasher.
  10. Only run the dishwasher and washing machine when fully loaded and choose eco-wash or cold settings if available.

Alternative Hot Water Heating Systems

Looking for an alternative to the traditional hot water cylinder based water heating system? Many people prefer instant hot water systems like gas hot water heating. Some of the benefits of continuous flow Gas Water Heating Systems are:

See here for a handy water heating tool provided by the Energy Efficiency and Conservation Authority (EECA) to compare upfront and ongoing costs of different water heating systems.

It should be noted that it is the responsibility of the home owner and installers/plumbers to ensure any hot water cylinder installation complies with the new G12 Water Supplies updated amendments. Any non-compliance may result in a dispute over who is liable for the associated costs of hot water cylinder repair or replacement and water damage.

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