Three temperatures, and why they differ
50°C at the tap. The Plumbing Code of Australia’s performance requirement is that heated water is delivered at a temperature unlikely to scald, from fixtures used mainly for personal hygiene. NSW’s deemed-to-satisfy provisions set a maximum delivery temperature at the outlet of each sanitary fixture: 50°C in all cases other than the care settings below, so including homes.
45°C in care settings. The lower limit applies in the residential parts of aged care buildings, patient care areas in health-care buildings, the parts of early childhood centres and schools used by children, and facilities designated for people with a disability.
60°C in the tank. Your Home, a guide to designing and building homes that is authorised by the Australian Government, says residential storage systems must be heated to at least 60°C once every 7 days to stop the growth of bacteria such as Legionella. It also says water at 60°C will burn skin within 5 seconds.
The valve that brings 60 down to 50
Your Home puts the two numbers together: the best way to prevent hot water burns is to bring the delivery temperature down to 50°C, with a tempering valve or a thermostatic mixing valve set to deliver water at a precise, safe temperature. For settings, Your Home advises a storage thermostat at 60°C, not lower because of Legionella and not higher because it wastes energy, and an instantaneous system at no more than 50°C.
NSW’s rules name the devices that can do the job:
- Thermostatic mixing valve 45°C or 50°C
- Allowed for both limits.
- Thermostatically controlled tap 45°C or 50°C
- Allowed for both limits.
- Tempering valve 50°C
- Allowed where the limit is 50°C.
- Temperature limited water heater 50°C
- Allowed where the limit is 50°C, if its maximum delivery temperature of 50°C is marked in line with AS 3498.
Which jobs trigger the rule
The rule applies to all new heated water services, and to any replacement of a hot water heater, whatever type of heater it is and wherever it is located. Building Commission NSW’s note sets out common jobs and whether each needs a temperature control device:
| Heated water work | Device required |
|---|---|
| Installing a water heater for premises for the first time | Yes |
| Replacing an existing heater with a like-for-like water heater | Yes |
| Replacing an existing heater with a different model, size or heat source | Yes |
| Moving an existing heater to a new location | Yes |
| Replacing associated valves, elements or thermostats (not an existing temperature control device) | No |
| Replacing a basin tap, where there is no existing temperature control device | No |
| Replacing all the fixtures in an existing bathroom that has no temperature control device (only the replaced fixtures need tempered water) | Yes |
| Replacing a solar collection panel only | No |
One exemption is written into the rule: a device need not be installed when one or more, but not all, of the heating units in a manifold water heater are replaced. The note’s full table has twelve cases.
Hot water is plumbing work
NSW’s definition of water plumbing covers installing, altering, repairing and maintaining the pipes, tanks, fixtures and appliances that convey, store, mix or regulate water, including hot water, and you need a licence or certificate to do any plumbing work in NSW.
Building Commission NSW says licensed plumbers are responsible for making sure any heated water service they install, replace, repair or alter complies with the code, and that non-compliant work can expose the people in a building to serious risks, including life-threatening injuries.
The note was issued in July 2026 and replaces an earlier one from 2013. It explains that the delivery temperature clauses now sit in the Plumbing Code of Australia 2022, as NSW variations B2D5 and B2D6, and no longer appear in the AS/NZS 3500.4:2021 standard.
Pit 06 shows how to check a licence before the work starts.