A MAJOR liquefied petroleum gas (LPG) supplier is stepping up the inspection of bathroom water heaters at a large private residential estate after one unit caught fire. The small blaze broke out in a Heng Fa Chuen home when the heater was left on. The Chai Wan development is believed to be one of several estates installed with a central LPG system. Most recent developments use Towngas. Shell Gas director Robert Young Man-kim said an initial investigation showed that the fire was a result of damage to a filter. ''The automatic valve was jammed by some rusty and sandy particles and could not be closed properly. ''Its main burner could not be turned off, even though the water tap was closed, and the heater caught fire,'' he said. Mr Young said it was an individual case but they would conduct random checks at the building where the incident happened, and later extend inspections to other buildings on the estate. Jebsen and Co is the water heater dealer in Hong Kong. Project manager Siu Sai-choi said the heater was German-made and had been distributed in Hong Kong for more than five years. ''We will present our views to the manufacturer, which will conduct an investigation and examination. ''One proposal we suggest is to have the plastic filter replaced with a metal one to avoid damage,'' he said. ''But the final action will depend on the result of the investigation in Germany. It's too early to say.'' Mr Siu said there was no need to ban the type of heater from the local market as it met Hong Kong and international safety standard. He said all 6,000 households at Heng Fa Chuen and some in Mei Foo Sun Chuen were installed with the same model of heater. The chairman of Heng Fa Chuen Owners' Committee, Chao Shing-kie, said: ''I was shocked when I heard the news. There was a problem in one water heater and the others may suffer the same problem.'' He said the potential danger should not be underestimated. ''We'll meet the estate management to discuss the problem and then contact the gas supplier,'' said Mr Chao. He had also asked for free inspection and the replacement of defective parts if necessary. A spokesman for the estate management, the Mass Transit Railway Corporation, said residents who wished to have their water heaters inspected should contact it. Resident Connie Chak hoped the supplier could identify the problem as soon as possible and would take necessary steps to rectify it. ''If they need to have the water heater replaced with new spares, I'm willing to pay any charge for it. Life is more important than everything,'' she said.