AS/NZS 3500.4:2003


Plumbing and drainage, Part 4: Heated water services

Included in NCC Primary References Historical Editions, Supplements and Amendments Set
This Standard sets out the requirements for the design and installation of heated water services. It includes aspects of the installation from, and including, the valve(s) on the cold water inlet to any cold water storage tank or water heater and the downstream fixtures and fittings.
Published: 15/12/2003
Pages: 132
Table of contents
Cited references
Content history
Table of contents
About this publication
1 Scope and general
1.1 Scope
1.2 Application
1.2.1 Plumbing Code of Australia reference
1.2.2 Building Code of Australia
1.2.3 New Zealand Building Code reference
1.3 Normative references
1.4 Definitions
1.5 Plastics abbreviations
1.6 Water quality
1.7 Equivalent pipe sizes
1.8 Velocity requirements
1.9 Water temperature
1.9.1 Storage temperature
1.9.2 Sanitary fixtures delivery temperature
1.9.3 Acceptable solutions for control of delivery temperatures
2 Materials and products
2.1 Scope of Section
2.2 Authorization
2.3  Selection and use of materials and products
2.4 Pipes and fittings
2.4.1 General
2.4.2 Metallic pipes and fittings
2.4.3 Plastics pipes and fittings
2.5  ‘Text deleted’
2.6 Safe tray and safe waste materials
2.6.1 Safe tray
2.6.2 Safe wastes
2.7 Joints
2.7.1 Flanged joints
2.7.2 Elastomeric seals
2.7.3 Shouldered or grooved joints
2.7.4 Silver brazing alloy Copper and copper alloys Stainless steels
2.7.5 Soft solders
2.7.6 Filler rods for stainless steel joints
2.8 Concrete and mortar
2.8.1 Concrete mix
2.8.2 Cement mortar
2.8.3 Chemical admixtures
2.8.4 Water for concrete and mortar
2.8.5 Steel reinforcement
2.9 Miscellaneous materials
2.9.1 Timber
2.9.2 External protective coatings
3 Cross-connection and backflow prevention and thermostatic mixing valves
3.1 Scope of Section
3.2 Cross‑connection control and backflow prevention
3.3 Thermostatic mixing valves
4 Installation of cold and heated water piping and controls
4.1 Scope of Section
4.2 Electrical safety precautions and earthing
4.3 Proximity to electrical cables and gas pipes
4.3.1 General
4.3.2 Electrical cables, gas pipes and other services Above- and below-ground pipework Above-ground pipework Below ground—Electrical cables and gas pipes Below ground—Communications services Below ground—Crossover
4.4 Methods of jointing
4.4.1 General
4.4.2 Threading
4.4.3 Compression-type fittings
4.4.4 Capillary fittings
4.4.5 Silver brazing Joints Taps and valves
4.4.6 Soft soldering
4.4.7 Flanged joints
4.4.8 Shouldered or grooved joints
4.4.9 Jointing of stainless steel pipe and fittings Jointing of piping, up to and including DN25 Jointing of piping larger than DN 25
4.5 Support and fixing above-ground
4.5.1 General
4.5.2 Brackets, clips and hangers
4.5.3 Prohibited supports
4.5.4 Spacing
4.5.5 Securing of pipes and fittings
4.6 Location of piping
4.6.1 Concealed piping Walls Chases, ducts or conduits Under concrete slabs
4.6.2 Protection during building construction
4.6.3 Floor or roof penetrations
4.6.4 Provision for movement of encased piping
4.7 Bedding and backfill
4.8 Contaminated areas
4.8.1 General
4.8.2 Installation
4.9 Corrosive areas
4.10 Depth of cover in public areas
4.11 Depth of cover in private areas
4.12 Protection against freezing
4.12.1 Requirement for protection
4.12.2 Piping located outside buildings
4.12.3 Pipes located on metal roofs
4.12.4 Pipes located inside buildings General Pipes in unheated roof spaces Pipes adjacent to external walls
4.12.5 Insulation of piping and fittings
4.13 Cold water piping and storage tanks
4.13.1 General
4.13.2 Cold water storage tank (see Figures 5.1 and 5.2) General Water storage tank capacity Flow capacity Cold water storage tank overflow Position of cold water storage tanks
4.13.3 Safe tray for cold water storage tanks
4.13.4 Support for separately mounted cold water storage tanks Platform Spacing between cold water storage tank and safe tray
4.14 Installation of heated water services
4.14.1 Design and installation
4.14.2 Identification
4.14.3 Provision for expansion General Expansion of fixed offsets U-bends, coiled loops, offsets and lyre bends Placement of bends and offsets
4.14.4 Gradient
4.14.5 Maximum rise of heated water supply pipes
4.14.6 Shower assemblies
4.14.7 Venting of secondary circuit
4.14.8 Terminal fittings
4.14.9  Recirculation of cold water
5 Installation of water heaters—General requirements
5.1 Scope of Section
5.2 Water heaters
5.2.1 Water heaters
5.2.2 Selection of anode
5.2.3 Working pressure
5.2.4 Auxiliary controls
5.3 Location
5.3.1 Placement
5.3.2 Accessibility and clearances
5.3.3 Ventilation and fluing
5.4 Protection against damage from leaking water
5.4.1 Concealed water storage tanks
5.4.2 Unconcealed water storage tanks
5.4.3 Safe tray construction
5.4.4 Safe wastes Sizes of safe wastes Safe waste construction Safe waste installation
5.4.5 Placement of water heater or cold water storage tank on a safe tray
5.5 Support
5.5.1 Support of water storage tanks installed in a roof
5.5.2 Support of water heaters or water storage tanks installed above a roof
5.5.3 Support of water heaters or water storage tanks installed other than in a roof space or above a roof
5.5.4 Seismic restraints
5.6 Corrosion prevention and weather protection
5.6.1 Water heater base—Corrosion avoidance
5.6.2 Weather protection of externally installed water heaters
5.7 Connections to water heaters
5.8 Pressure relief and venting of water heaters and containers
5.9 Valves
5.9.1 General
5.9.2 Required set pressure of valves (for unvented water heaters)
5.9.3 Installation of valves
5.10 Multiple installations of pressure-type storage water heaters
5.10.1 General
5.10.2 Balanced flow conditions
5.10.3 Positioning and sizing of pressure-control valves
5.11 Multiple instantaneous water heaters
5.12 Temperature/pressure-relief and expansion-control valve drain lines
5.12.1 Size and material
5.12.2 Interconnection of drain lines Individual water heaters Multiple relief valves
5.12.3 Installation
5.12.4 Common stack discharge
5.12.5 Tundish drain lines
5.12.6 Areas subject to freezing
5.13 Vent pipes
5.13.1 Installation Storage water heaters Heat exchange water heaters and boiling water units
5.13.2 Termination of vent pipe
5.13.3 Cold water storage tank‑fed water heaters (other than side‑fed types)
5.13.4 Vented storage water heaters, inlet pressure-controlled
6 Installation of solar water heaters
6.1 Scope of Section
6.2 Application of Section (New Zealand only)
6.3 General
6.3.1 Performance
6.3.2 Solar water heater
6.3.3 Location
6.3.4 Sizing
6.4 Installation of solar water heater container
6.4.1 Solar water heater containers
6.4.2 Containers installed on or above a roof Support Protection of externally mounted containers Containers installed in a roof Protection against damage from leaking water Connection to containers Pressure relief and venting of containers
6.4.3 Valves
6.4.4 Relief and expansion valve drain lines
6.4.5 Vent pipes
6.4.6 Supplementary heating connections
6.5 Installation of collectors
6.5.1 Positioning Shade Relative to container Orientation Inclination Provision for removal of collector
6.5.2 Mountings Manufacturer’s instructions Method of mounting
6.5.3 Precautions Frost-prone areas Water salinity Water hardness Cyclonic areas Hail-prone areas
6.6 Installation of close-coupled and integral solar water heaters
6.6.1 General
6.6.2 Roof mountings and supports
6.7 Thermosiphon flow solar water heaters with remote containers
6.7.1 General
6.7.2 Primary circuit flow and return pipes—Pipes and fittings
6.8 Solar water heaters with forced primary circulation
6.8.1 General
6.8.2 Primary circulation pump Construction Capacity Pump and controller installation
6.9 Solar water heaters used as preheaters
6.9.1 General
6.9.2 Installation of solar preheaters— Cold water storage tank-fed water heaters
6.9.3 Installation of solar preheaters—Mains pressure and reduced‑pressure water heaters New buildings installation Existing systems installation Suitable types of existing heaters
6.10 Multiple solar water heaters installations
6.10.1 General
6.10.2 Thermosiphon systems—Series connection
6.11 Supplementary heating
6.11.1 Thermal capacity
6.11.2 Drain connection
7 Energy sources
7.1 Scope of Section
7.2 Controlled energy sources
7.3 Water heaters with uncontrolled energy source
7.3.1 Installation
7.3.2 Supplementary external heating
7.3.3 Provision for drainage
8 Water and energy efficiency
8.1 Scope of Section
8.2 Thermal insulation
8.2.1 Piping associated with storage water heaters
8.2.2 Other piping for heated water systems
8.3 Protection of insulation
8.3.1 Insulation exposed to the weather
8.3.2 Protection of thermal insulation on buried piping
8.4 Heat traps
8.5 Container for storage of heated water
8.6 R-value calculations
8.7 Water efficiency
9 Heated water below 60°C
10 Heated water services for people with disablilities
10.1 Scope of Section
10.2 General
11 Testing and commissioning
11.1 Scope of Section
11.2 Flushing
11.3 Testing
11.4 Commissioning
11.5 Operating instructions
12 Operation and maintenance
12.1 Scope of Section
12.2 General
12.3 Maintenance of heated water services
Appendix A
Appendix B
B1 Water analysis
B2 Total dissolved solids (TDS)
B3 Scaling properties
B4 Water pH
Appendix C
Appendix D
Appendix E
Appendix F
F1 General
F2 Volumetric storage capacity
F3 Recommended operating temperature
F4 Temperature/pressure-relief valve
F5 Collector/container size ratio
F5.1 Normal conditions
F5.2 Non-optimum conditions
F6 Components
F7 Claimed performance
Appendix G
G1 General
G2 Support
G2.1 ‘With pitch’ installations
G2.2 ‘Against pitch’ installations
G2.3 ‘Cross-pitch’ installations
G3 Points to note
Appendix H
H1 General
H2 Anticipated solar fraction
H3 Solar radiation data
Appendix I
I1 General
I2 Sun locater
I3 Approximate method of determining solar altitude
Appendix J
Appendix K
Appendix L
L1 Scope
L2 Climate zones
Appendix M
M1 Scope
M2 Climate regions
M3 Frost areas
Amendment control sheet
Cited references in this standard
Specification and Supply of concrete
Elastomeric seals for waterworks purposes
Timber — Preservative-treated — Sawn and round
Stainless steel tubes and tube fittings for food processing and hygienic applications, Part 1: Tubes
Chemical admixtures for concrete, mortar and grout, Part 1: Admixtures for concrete
Content history
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