Water heater requirements

South Australia has had energy efficiency requirements for installing water heaters in homes since 2008. These may affect water efficiency for showers.

The requirements are only for new or replacement water heaters. Working water heaters don’t need to be replaced.

For most homes, it means installing:

  • a low emission water heater, such as a high efficiency gas, solar or electric heat pump system
  • water efficient shower heads or flow restrictors.

These requirements don’t apply if the water heater installation is:

  • non-residential, eg for a commercial building, shop, school, or office
  • an electric or gas gravity-fed water heater of up to 250 litres installed in a roof space
  • a like-for-like replacement under warranty
  • only supplying a shed, garage or swimming pool
  • a temporary electric water heater of up to 55 litres that is providing water heating for up to 60 days while waiting for a new, compliant water heater to be installed
  • a secondary electric water heater of up to 55 litres that isn’t supplying a shower or bath
  • shared between multiple units, flats or apartments in a multi-storey building
  • repairing or replacing a single major component of a solar or electric heat pump.

Installing a water heater

Only licensed or registered plumbers can install water heaters. Use the licensing public register to check your installer has a license to do plumbing work.

Once the plumber has installed your water heater, they must provide a Certificate of Compliance (eCOC) to the household and the Office of the Technical Regulator.

Eligible solar or electric heat pump water heaters are entitled to small-scale technology certificates (STCs), which can assist with purchase costs.

Find out which water heater can be installed

There are different types of water heaters – including electrical, gas and solar hot water systems – which work in different ways and have different running costs.

The tool below will identify the type of water heater your home needs to meet the requirements.

Building classifications

Class 1A: Single detached dwelling or two or more attached dwellings separated by a fire-resistant wall, including a maisonette, row house, townhouse, and single-storey flats or units.

Class 1B: Boarding/guest house or hostel not exceeding 300m2 with no more than 12 residents.

Class 2: Multi-storey building containing two or more sole-occupancy units, where each is a separate dwelling.

Low emission water heaters

Type of water heaterRequirements

Solar - electric boosted (single tank)


Electric heat pump (single tank)

You can install a water heater meeting either zone requirement anywhere in South Australia.

220 litres or less rated hot water delivery:

220 litres and less than 400 litres rated hot water delivery:

  • 27 STCs or more for Zone 3
  • 26 STCs or more for Zone 4

400 litres or more and less than 700 litres rated hot water delivery:

  • 38 STCs or more for Zone 3
  • 36 STCs or more for Zone 4

Gas instantaneous, continuous flow or storage - bottled or mains

Must have an energy rating of 5 stars or more.

If you are installing a gas water heater entirely within a fully enclosed roof space, room or attached garage of an established home, it must have a 3-star or higher energy rating. This option is not available for water heaters installed as part of building work that requires development approval.

Solar - gas boosted

Eligible for 1 or more STC and total tank volume of 700 litres or less.

Solar - wood boosted

Any water heater can be installed, provided it has no additional heating mechanisms and a tank volume of 700 litres or less.

Wood combustion

Any water heater can be installed, provided it has no additional heating mechanisms and a tank volume of 700 litres or less.

How to determine if an electric boosted solar or heat pump water heater meets the requirements

Find out the number of STCs for a particular brand and model in zones 3 and 4 by:

Check the table above to find out the minimum number of STCs a water heater needs, based on tank volume, in Zone 3 and in Zone 4. You can then compare the water heater's STCs for Zone 3 and for Zone 4 with the minimum requirements. Only one of the two zone requirements needs to be met, ie either the Zone 3 or the Zone 4 requirement. It doesn’t matter which zone the water heater is installed in.


Question: does a 300-litre electric heat pump water heater that is eligible for 26 STCs in Zone 3 and 26 STCs in Zone 4 meet the requirements in this table?

Answer: while the electric heat pump water heater does not meet the Zone 3 requirement (27 STCs or more) it does meet the Zone 4 requirement (26 STCs or more) and can be installed anywhere in the state.

Water flow rate requirements

When installing a new or replacement water heater in a home, any shower outlets connected to the water heater must have a flow rate of nine litres per minute or less. This means you may also need to install water efficient shower heads or flow restrictors that have no less than a three star rating under the water efficiency labelling and standards (WELS) scheme.

If the shower outlets already have three star rated shower heads, no change is needed.

Most new water heaters are compatible with water efficient shower heads, but check with the manufacturer if you are unsure.

Gravity fed water heaters meet the water flow rate requirements, meaning water efficient shower heads or flow restrictor don’t need to be installed.

These water flow rate requirements do not apply if your water heater installation is exempt from the water heater requirements.

Electric storage water heaters supplied by photovoltaic solar

The National Construction Code Volume Three - Plumbing Code of Australia sets energy performance requirements for water heaters in new Class 1 or Class 10 Buildings. The NCC lists several water heater types that are 'deemed to satisfy' these performance requirements, however, Electric Resistive Storage (ERS) water heaters are not included.

Recently, a range of products have been released that use on-site renewable energy - for example, solar photovoltaics (PV) - to supply some or all of the energy for ERS water heaters.

There are two broad types of systems available; those that supply on-site PV energy directly to an electric resistive water heater and those that divert excess on-site PV from being exported to the grid to an electric resistive water heater.

A Verification Method (82.6 KB PDF) has been prepared to demonstrate compliance of these systems with Performance Requirement BP2.6.3(b) of the NCC Volume 3. If you are considering one of these systems for your new home, seek confirmation from your installer that the system complies with this verification method.

Plumbing contractors who install electric resistive water heaters on new homes supplied by PV panels must certify compliance with this verification method on the plumbing Certificate of Compliance (CoC) which is provided to the property owner and the Office of the Technical Regulator. To include this information on the plumbing CoC, simply click on the 'on-site renewables' box located below the 'heated water energy source' category.

Small-scale Technology Certificates (STCs)

Installing an eligible solar or electric heat pump water heater entitles you to STCs, which can be sold to registered agents or traded individually.

Each STC represents an amount of electricity displaced by your solar water heater or heat pump over the course of its lifetime of up to 10 years. One STC equals one megawatt hour (MWh) of electricity displaced.

You can either:

  • receive a point of sale discount by assigning your STCs to the retailer or installer when you buy your water heater – this is the most common option
  • register your STCs and sell them through the STC market or STC clearing house yourself.

The dollar value of the STC offered by retailers and installers varies day to day. If you choose to trade your STCs yourself through the STC clearing house the price is fixed at $40 per certificate.

For further information and to find out how many STCs you could receive see the Clean Energy Regulator's website

Detailed technical requirements

Details of the requirements for new homes and established homes are in the National Construction Code Volume Three - Plumbing Code of Australia.

Further assistance

Plumbers can contact the plumbers' water heater information line on 1300 883 019 (Monday to Friday 9.00 am to 5.00 pm) for assistance.

Householders can ask their licensed plumber or building contractor for assistance with code requirements or contact the Energy Advisory Service for more information.

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Page last updated 16 March 2021

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