Many storage-type electric water heaters are sub-standard, potentially explosive and should be checked immediately, the Consumer Council warned yesterday.
All but two out of 19 heaters tested by the watchdog body were found to be below safety standards set by the International Electrotechnical Commission.
Most electric water heaters in Hong Kong are of two types - single-outlet 'shower' models and unvented 'pressure' models which can supply multiple hot water taps.
The latter are particularly dangerous as they are enclosed with no outlets to relieve steam and water expansion. They use several safety devices, such as cutoff valves, to prevent overheating and pressure buildup.
But council spokesman Dr Michael Tsui Fook-sun said the devices were substandard in six of the eight unvented types sampled, while all eight failed general electrical safety regulations.
The systems tested came mainly from Europe, Hong Kong or the mainland.
'There have been cases of explosions,' Dr Tsui said.
