Hot water in home often dangerous

More than 40 per cent of domestic hotwater cylinders deliver water at unsafe temperatures, research shows.

An analysis of water temperatures and systems by the Building Research Association shows 43 per cent of measured temperatures were above 60C and 13 per cent over 70C.

The findings are contained in the seventh year of Branz's household energy end-use project.

"The analysis of the hot water temperatures and systems raises a number of energy, safety and health issues about the provision of hot water in homes," the report says.

One-third of cylinders tested had inaccurate thermostat control.

One out of seven houses with a tempering valve delivered hot water over 60C, but only 12 per cent of the total number of cylinders tested had a tempering valve.

"These results help to identify potentially important hot water health and safety issues in New Zealand homes," the report said.

The project would develop ways to help identify hot water systems likely to be too hot and tools to lessen the dangers.

Hot water continued to be the biggest use of household electricity and gas, at close to 30 per cent. Space conditioning (heating or cooling) was second on 22 per cent, followed by lighting (11 per cent) and refrigeration (10 per cent).

The research found a significant difference in the average daily start and finish times of indoor heating, from northern to southern parts of the country. Heating in Auckland started around 5.50pm, while in Christchurch it started around 4.20pm.

Of the 280 houses tested in Auckland, Hamilton, Wellington and Christchurch, 42 per cent of occupants reported the main heating source was electricity, 33 per cent said solid fuel, 14 per cent said LPG and 11 per cent natural gas.

- NZPA