Storage temperature (legionella control)
To minimise the risk of Legionella (legionellae) proliferation, this storage-type electric water heater is configured to maintain a tank/storage temperature of not less than 60 °C, in accordance with AS/NZS 3500.4 Clause 1.11.2 / 1.9.1.
Delivery temperature to personal-hygiene outlets (scald prevention)
Heated water delivered to fixtures used primarily for personal hygiene (showers, baths, vanity basins / bidets etc.) must not exceed:
- 50 °C for standard residential / general access situations; and
- 45 °C (often documented as 43.5 °C control target) for aged care, healthcare, early childhood, schools, nursing homes and similar facilities for vulnerable occupants, as required by AS/NZS 3500.4 and PCA/NCC provisions.
Because this appliance can store water at ≥60 °C, a compliant temperature-limiting device (TLD)—typically a Tempering Valve (domestic) or Thermostatic Mixing Valve (TMV) for higher-risk / commercial applications—MUST be installed on the heated water service to restrict outlet temperature at/near the point of delivery where required by the PCA and local plumbing regulations.
Kitchen / laundry outlets
Kitchen sinks and laundry tubs are not classified as sanitary fixtures used primarily for personal hygiene, so the ≤50 °C rule does notstrictly apply to those outlets. Nonetheless:
- The installing licensed plumber must still configure the system so that all personal-hygiene branches are tempering-protected; and
- Where higher temperatures are plumbed to kitchen/laundry (e.g. for washing performance), they must remain isolated from hygiene outlets and must not create a scald hazard to users.
Circulating / return lines (where fitted)
For systems with forced circulation/return loops: return water temperature to the storage vessel shall be maintained at not less than 55 °C to limit microbial growth in distribution piping, per AS/NZS 3500.4 guidance.