Part B2 Heated water services

B2O1

Objective

2019: BO2

The Objective of this Part is to—

safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a heated water installation; and
ensure that a heated water installation is suitable; and
conserve water; and
safeguard the environment; and
reduce greenhouse gas emissions; and
safeguard public and private infrastructure; and
ensure that a heated water installation is designed and is capable of being maintained so that throughout its serviceable life it will continue to satisfy Objectives (a) to (f).

B2F1

Heated water supply

2019: BF2.1

Sanitary fixtures, sanitary appliances and supply outlets provided with heated water must have a safe and adequate piped heated water supply.

B2F2

Heated water installations

2019: BF2.2

The heated water supply must be conveyed through plumbing installations in a way that—

minimises any adverse impact on building occupants, the Network Utility Operator’s infrastructure, property and the environment; and
facilitates the conservation of water.

B2F3

Greenhouse gas emissions

2019: BF2.3

To reduce greenhouse gas emissions, to the degree necessary, a heated water service is to—

be capable of efficiently using energy; and
obtain its heating energy from—
1. a low greenhouse gas intensity energy source; or
2. an on-site renewable energy source; or
3. another process as reclaimed energy.

Explanatory information

The greenhouse gas intensity of energy sources vary. For example, natural gas has a low greenhouse gas intensity compared with electricity generated from coal.

For the purposes of B2F3(b), the renewable energy source must be on-site (not GreenPower) and includes, but is not limited to solar, wind, hydroelectric, wave action and geothermal.

B2P1

Heated water supply

2019: BP2.1

A heated water service must be connected to a drinking water supply.

Applications

B2P1 applies to a heated water service used for human consumption, food preparation, food utensil washing or personal hygiene.

B2P2

Scald prevention

2019: BP2.2

Heated water supplied by a heated water service must be delivered from the point of discharge of fixtures and appliances at a temperature which is unlikely to scald.

Applications

B2P2 applies to fixtures and appliances used primarily for personal hygiene.

B2P3

Velocity

2019: BP2.3

The water velocity in heated water service pipework up to 65 °C must not exceed—

3.0 m/s for more than 1% of the time that water is required during the peak hour in reticulated heated water systems; and
1.2 m/s for the flow and 1.0 m/s for the return of a copper circulatory heated water service for more than 1% of the time that water is required during the peak hour; and
1.0 m/s for the flow and return of a circulatory heated water service using other materials for more than 1% of the time that the water is required during the peak hour.

VIC B2P3 Velocity2019: BP2.3

Delete subclause B2P3(1) and insert B2P3(1) as follows:

The water velocity in heated water service pipework up to 65 °C must not exceed—

3 m/s for more than 1% of the time that water is required during the peak hour in non-circulatory heated water systems; and
1.2 m/s for the flow and 1.0 m/s for the return of a copper circulatory heated water service for more than 1% of the time that water is required during the peak hour; and
1.0 m/s for the flow and return of a circulatory heated water service using other materials for more than 1% of the time that the water is required during the peak hour.

Explanatory information

High velocities in heated water services can be a contributing factor to the erosion/corrosion of pipework. Consideration should be given to the appropriate velocities for the building based on water temperature, water chemistry and materials used.

B2P4

Access and isolation

2019: BP2.3

(1) Access must be available to heated water service pipework for maintenance of mechanical components and operational controls.

VIC B2P4 Access and isolation2019: BP2.3

Delete subclause B2P4(1) and insert B2P4(1) as follows:

(1) Access must be available to the heated water service for maintenance of mechanical components and operational controls.

(2) Heated water service pipework, appliances and devices must be capable of being isolated for testing and maintenance.

B2P5

Pressure relief and temperature limitation

2019: BP2.4

Containers used for producing and/or storing heated water are to relieve excessive pressure and avoid flash steam production by—

relieving pressure so that the maximum rated working pressure, or 1400 kPa, whichever is the lesser, is not exceeded; and
limiting water temperatures to a maximum of 99 °C; or
other suitable means providing an equivalent level of safety to (a) and (b).

Applications

B2P5(a) has a tolerance of +5% or 14 kPa whichever is the greater.

B2P6

Legionella control

2019: BP2.5

Heated water must be stored and delivered under conditions which avoid the likelihood of the growth of a Legionella bacteria count greater than or equal to 10 Legionella colony forming units (cfu) per millilitre.

Explanatory information

A risk assessment should be undertaken for the control and management of Legionella in heated water systems in aged care, health-care and other similar facilities with high risk occupants.

B2P7

Energy use and source

2019: BP2.6

NCC Title

Energy use and source

NCC State

QLD

NCC Variation Type

Deletion

NCC SPTC Current

Energy use and source

(1) A heated water service, including any associated distribution system and components, must ensure the efficient use of energy and water.

(2) Features in B2P7(1) must be appropriate to the following:

The heated water service and its usage.
The geographic location of the building.
The location of the heated water service.
The energy or water source.

VIC B2P7 Energy use and source2019: BP2.6

Insert VIC subclause B2P7(3) in clause B2P7 as follows:

(3) A solar water heater system installed in a new Class 1 building to comply with Part 2.6 and Part 3.12 of NCC 2019 Volume Two must comply with the Plumbing Regulations 2018.

Explanatory information

Excessive ‘dead water’ draw-off, i.e. where cooled water from the supply pipe is drained off prior to delivery of heated water, can result in water and energy wastage.

To improve the efficiency of heated water systems, the design should consider factors such as the number of outlets, their purpose and expected typical usage, and the distance between the water heater and each of the outlets. The water heater should be positioned nearest to the most used outlets, or installed to provide consistent coverage of the building. Where this is not viable, the use of multiple water heaters or a flow and return pipe loop may need to be considered.

B2P7(2) permits the energy source of the heated water service to be considered. This means that the net energy obtained from renewable energy sources such as solar, geothermal, wind, and biofuels may be considered as 'free' energy in calculating the energy consumption. Similarly, heat reclaimed from another 'free' source such as a by-product from co-generation type processes as well as other industrial processes, which could otherwise be rejected from the building, could be considered as 'free' energy in calculating the energy consumption.

B2P8

Temperature

2019: BP2.3

A heated water service must ensure that heated water is provided at appropriate temperatures for the correct functioning of the fixture or appliance.

B2P9

Pressure

2019: BP2.3

NCC Blurbs

The points of discharge for a heated water service must—

have—
1. a working pressure of not less than 50 kPa: and
2. a static pressure within the building of not more than 500 kPa; or
have water pressures suitable for the correct functioning of the fixture or appliance where water pressures outside of (a)(i) and (a)(ii) are required.

Exemptions

B2P9(a)(i) and B2P9(a)(ii) do not apply to existing low-pressure gravity only water services.

NCC Title

Pressure

NCC State

TAS

NCC Variation Type

Replacement

NCC SPTC Current

Pressure

The points of discharge for a heated water service must—

have—
1. a working pressure of not less than 50 kPa; and
2. a static pressure within the building of not more than 500 kPa; or
have water pressures suitable for the correct functioning of the fixture or appliance where water pressures are outside of (a)(i) and (a)(ii) are required.

B2P10

Uncontrolled discharge

2019: BP2.3

A heated water service must avoid failure or uncontrolled discharge.

B2P11

Water efficiency

New for 2022

A heated water service must ensure the efficient use of drinking water by limiting water use from a tap or outlet for a shower, basin, kitchen sink or laundry trough to a flow rate of not more than 9 l/m.

B2V1

Heated water storage temperature

2019: BV2.2

Compliance with B2P6 is verified for each heated water storage system when the water heater is designed such that all water is subjected to a temperature-dependent minimum exposure period as specified in Table B2V1 within 7 days before passing through the water-heating appliance's heated water outlet.

Table B2V1 Heated water storage minimum exposure period

Temperature	Minimum exposure period
70 °C or greater	1 second
66 °C	2 minutes
60 °C	32 minutes

B2D1

Deemed-to-Satisfy Provisions

2019: B2.1

(1) Performance Requirement B2P1 is satisfied if heated water is supplied by—

the Network Utility Operator’s drinking water supply; or
an alternative drinking water supply.

(2) Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements B2P2 to B2P11 are satisfied by complying with B2D2 to B2D11.

(3) Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable.

(4) Where it is proposed to use a warm water system, Performance Requirement B2P6 must be complied with.

Notes

There are no Deemed-to-Satisfy Provisions for warm water systems.

B2D2

Water heater in a heated water supply system

2019: B2.2

NCC Blurbs

(1) In an established Class 1 building connected to a reticulated gas supply or a new Class 1 or Class 10 building, a water heater must be one of the following types:

A natural gas or LPG water heater, either instantaneous, continuous flow or storage, that has an energy rating of 5 stars or more.
A natural gas or LPG boosted solar water heater, with a total tank volume of not more than 700 litres, that is eligible for any number (one or more) of STCs.
An electric boosted solar water heater or electric heat pump water heater (air source or solar boosted), with a single tank, that is eligible for the minimum small-scale technology certificates shown in SA Table B2D2.
A wood combustion water heater, with no additional heating mechanisms, with a total tank volume of not more than 700 litres.
A wood combustion boosted solar water heater, with no additional heating mechanisms, with a total tank volume of not more than 700 litres.

(2) In an established Class 1 building that is not connected to a reticulated gas supply, a water heater must be one of the following types:

A water heater complying with the requirements set out in (1).
An electric water heater with a rated hot water delivery of no greater than 250 litres.
An electric instantaneous water heater, having a water storage capacity no greater than one litre and total electrical input no greater than 15.0 kW.

(3) The requirements of (1) and (2) do not apply to any of the following:

Water heaters serving buildings other than Class 1.
Repairs to water heaters including:
1. Like for like replacements that are the result of manufacturer, supplier or installer warranty arrangements.
2. Replacement of a single major component of a solar or electric heat pump water heater (for example, a heat pump compressor/evaporator unit, a solar collector, or a storage tank).
Secondary electric water heaters of up to 55 litres rated delivery, which do not serve a shower or bath.
Temporary electric water heaters of up to 55 litres rated delivery, for a period not exceeding 60 days, pending installation of a complying water heater.
An electric or gas vented (gravity fed) water heater, located in a roof space of an established Class 1 building, of no greater than 250 litres rated hot water delivery.
A gas water heater installed entirely within a fully enclosed roof space, room or attached garage of an established Class 1 building, providing the water heater has an energy rating of 3 stars or more.

Insert SA table (B2D2) B2D2 as follows:

SA Table B2D2: Small-scale technology certificates

Year	Tank volume of 400 litres or more and not more than 700 litres	Tank volume of more than 220 litres and less than 400 litres	Tank volume of not more than 220 litres
2022	34 in zone 3* and/or 32 in zone 4	24 in zone 3 and/or 23 in zone 4	15 in zone 3 and/or 14 in zone 4
2023	30 in zone 3 and/or 28 in zone 4	21 in zone 3 and/or 20 in zone 4	13 in zone 3 and/or 12 in zone 4
2024	26 in zone 3 and/or 25 in zone 4	18 in zone 3 and/or 18 in zone 4	11 in zone 3 and/or 11 in zone 4
2025	22 in zone 3 and/or 21 in zone 4	16 in zone 3 and/or 15 in zone 4	10 in zone 3 and/or 9 in zone 4

Table Notes

* Zones are defined by the Clean Energy Regulator

Explanatory information: Connection to a reticulated gas supply

A property is connected to a reticulated gas supply if it has a piped connection to a gas distribution system and this connection is capable of supplying gas to gas equipment and/or appliances.

A property is not connected to a reticulated gas supply if:

It does not have a piped connection to a gas distribution system; or
It has a piped connection to a gas distribution system but this connection is not capable of supplying gas to gas equipment and/or appliances (for example, if the supply has been physically disconnected at the meter by the gas network operator).

Reticulated gas includes:

Reticulated natural gas; or
Reticulated compressed gas of some other type (including LPG, SNG or TLP gas).

Explanatory information: Gas water heaters

The energy ratings for natural gas and LPG water heaters are available at: http://www.aga.asn.au/product_directory

Explanatory information: Solar water heaters and electric heat pump water heaters

STCs are Small-scale Technology Certificates. References to Renewable Energy Certificates (RECs) refer equally to STCs. The number of STCs is provided for each eligible model of solar water heater and electric heat pump water heater at: https://www.cleanenergyregulator.gov.au/RET/Scheme-participants-and-industry/Agents-and-installers/Small-scale-systems-eligible-for-certificates/Register-of-solar-water-heaters

The STC values specified in Section SA B2D2 for either CER Zones 3 or 4 may be used to demonstrate compliance, regardless of the actual zone in which the water heater is to be installed.

NCC Title