Legislative Council Panel on Economic Services



This paper informs Members about the safety of gas water heaters in the light of a recent incident involving a flueless sink gas water heater.


2. In Hong Kong, gas water heaters can be broadly divided into four types, namely, room-sealed, open-flued (fanned draught), open flue and flueless. The last two types might be hazardous if insufficient ventilation is provided for combustion. Use of the open flue and flueless types was prohibited after enactment of the Gas Safety Ordinance (the Ordinance) in 1991, except that the Ordinance allows the flueless type to be used other than serving bathroom or shower; and that they are well ventilated and the heater is affixed with a warning label to advise not to be used for more than five minutes continuously.


3. An incident involving the use of an old Towngas flueless sink gas water heater and two fatalities occurred on 17 January 1999 in Shek Kip Mei Estate. The water heater involved supplied hot water to a shower room. Investigations into the cause of the incident are continuing.


Towngas flueless water heaters

4. HKCG maintain comprehensive customer records and also carry out safety inspections every 18 months. Following the incident, the Hong Kong & China Gas Co. Ltd. (HKCG) announced an immediate programme to inspect within one week some 15,800 shower installations recorded by the company as using flueless sink water heaters. The objectives of the inspection programme were to ensure that the 15,800 water heaters were being operated safely, to emphasise the importance of opening windows while using these water heaters and to encourage customers to upgrade to a open-flued and fanned draught model, which does not require an open window for safe operation. The Housing Department and the Gas Standards Office (GasSO) of the Electrical and Mechanical Services Department have assisted HKCG in gaining access to premises with this type of water heater.

LPG flueless water heaters

5. The Ordinance provides for the registration of gas supply companies and for these companies, if they supply LPG, to monitor their distributors' activities. These activities including staff training, safety inspection, emergency response, awareness of current gas safety regulations etc. They are governed by operating manuals which have been examined by GasSO. The maintaining of customer records is a matter between the gas supply companies and their distributors.

6. Customer records in respect of LPG flueless water heaters are generally not immediately available from LPG supply companies, except in respect of piped LPG installations, because the water heater may not have been bought and installed through their LPG distributors. However, the regular safety checks by the LPG distributors enable them to record such installations.

7. GasSO has met with the LPG supply companies and requested them to provide to GasSO customer records of those using flueless sink water heaters. GasSO also urged them to arrange advertisements to encourage their customers to arrange for a safety check of their flueless water heaters and step up the safety inspection of these water heaters from the customary 18 months to about one month.

8. Subsequently, GasSO has again met with LPG supply companies together with their distributors to impress upon both of them the importance of making available to GasSO their records of flueless water heaters and of doing a survey of the safety of installation and use of these water heaters. For piped LPG installations, the distributors are known to have such records and were urged to supply a report on their inspections within 10 days. In respect of users of LPG cylinders, the distributors were urged to gather data on these gas installations at the next delivery of cylinder supply with a view to performing a subsequent safety inspection. It is expected that the data will be available within a month. The distributors will continue to do the regular safety checks in future.


9. Government issues from time to time safety messages concerning the need to open windows wide when using a room-sealed water heater and to use registered gas contractors/registered gas installers for carrying out gas works. These are backed up by issue of safety leaflets and safety talks given to the public. Similarly, gas supply companies, including HKCG and oil companies, are active in a wide range of safety promotions which also include safety messages issued with gas bills.

10. Publicity campaigns have been arranged by HKCG and the LPG supply companies to remind users of flueless gas water heaters to contact HKCG or their LPG distributor, as appropriate, to arrange safety inspections. Distribution of safety leaflets to customers through the gas supply companies is in progress.


11. At the Gas Safety Advisory Committee (GSAC) held on 17 November 1998, members considered a proposal to strengthen the regulation of the activities of LPG distributors, in relation to, among other things, maintaining proper customer records. GSAC agreed that a new code of practice detailing the duties and responsibilities of LPG cylinder suppliers should be prepared. This is now in hand.

12. As regards flueless gas water heaters, the GSAC's advice will be sought on whether it is necessary to prohibit the use of such water heaters.


13. The Gas Safety (Installation and Use) Regulations ("the Regulations") regulate the installation and use of gas appliances, including flueless sink gas water heaters. The Regulations, which came into operation in 1991 and do not have retrospective effect, provide that no person shall install a flueless sink gas water heater to serve a bathroom or shower. It is against the Regulations for anyone to use a gas appliance if he has reason to suspect that the space in which the appliance in use is not adequately ventilated. Under the Regulations, the gas supply may be shut off to enable repair work in such circumstances. The Regulations allow the installation of flueless sink gas water heaters for kitchen use provided that a warning label is affixed advising that the maximum continuous period of use should not be more than five minutes. All gas water heaters must be installed by registered gas contractors employing registered gas installers.

14. Comprehensive codes of practice have been drawn up to ensure safety in utilization of gas. These include -

    (a)GU03 -
    Installation Requirements for Domestic Instantaneous
    Gas Water Heaters (up to 60 kW Input) in Hong Kong;

    (b)GU05 -Approval of Domestic Gas Appliances;

    (c)GU06 - LPG Installations for Catering Purposes in Commercial Premises;

    (d)GU09 - Low Pressure Regulators for Supplying Gas from LPG

    Cylinders Having Less Than 40 Litres Water Capacity.

15. EMSD undertakes random inspections of the work carried out by the registered gas contractors to ensure that high standards are maintained.

Electrical & Mechanical Services Department
January 1999