Water heating – water temperature is too high

Causes

Thermostat setting is too high

Thermostat is faulty

Tempering valve (if installed) is faulty

Common

Listed under: water heating, Services

Cause

Thermostat setting is too high

Repair

  • reset the thermostat
  • stored hot water should reach no less than 60°C to avoid the growth of Legionella bacteria. However, the delivery temperature of hot water to sanitary fixtures used for personal hygiene in housing such as baths, showers and hand basins must be no more than 55°C. (The maximum was reduced from 55°C to 50°C when G12/AS1 was amended in November 2023, with a 12-month transition period.)

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Cause

Thermostat is faulty

Repair

  • call a registered electrician to check and replace the thermostat
  • stored hot water should reach no less than 60°C to avoid the growth of Legionella bacteria. However, the delivery temperature of hot water to sanitary fixtures used for personal hygiene in housing such as baths, showers and hand basins must be no more than 55°C. (The maximum was reduced from 55°C to 50°C when G12/AS1 was amended in November 2023, with a 12-month transition period.)

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Cause

Tempering valve (if installed) is faulty

Repair

  • call a registered plumber to replace the tempering valve
  • stored hot water should reach no less than 60°C to avoid the growth of Legionella bacteria. However, the delivery temperature of hot water to sanitary fixtures used for personal hygiene in housing such as baths, showers and hand basins must be no more than 55°C. (The maximum was reduced from 55°C to 50°C when G12/AS1 was amended in November 2023, with a 12-month transition period.)

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