How to Purchase & Use Gas Water Heaters Properly 

All domestic gas water heaters supplied or sold in Hong Kong must be approved by the Gas Authority of EMSD. All approved domestic gas appliances bear a GU mark for identification, so that consumers can make an informed choice. Non-domestic gas water heaters (for commercial or industrial use) are not subject to this requirement. However, all gas water heaters must comply with the requirements of the gas legislation.

Purchasing and Using Gas Water Heaters Properly and Safely Pursuant to the Gas Safety Regulations, all newly-installed gas water heaters must be the room-sealed (balanced flue) type water heaters (see diagram). The air intake and flue terminal of this type of heater are on the exterior wall of the flat, so fresh air for combustion is drawn from outside and combustion products are discharged outside the building as well. The heater does not consume or contaminate the air in the room. This can avoid the accumulation of carbon monoxide indoors, which can be very dangerous. Flats in general are provided with flue apertures suitable for the installation of room-sealed (balanced flue) type water heaters to serve their bathrooms. Please note that it is an offence to install new open-flued (natural draught) gas waters heaters or open-flued (fanned draught) gas water heaters [PDF format (5.51MB)] serving bathrooms or showers. Offenders are liable to prosecution.

For their own safety, users of domestic gas water heaters should pay attention to the following:

Users should
  • GU Mark purchase the domestic gas water heater that has been approved by EMSD and bears a GU Mark ;
  • read and follow the instructions in the user manual provided by the manufacturer of the gas water heater;
  • use the gas water heater only after it is installed and tested by a registered gas installer employed by a registered gas contractor;
  • If a gas water heater is being in used, it should be used in a well-ventilated area.
  • arrange for a registered gas contractor to conduct safety checks on the domestic gas water heater and its installation once every 18 months;
  • stop using the gas water heater immediately if defects or abnormalities are detected. Notify the appliance dealer for follow-up action;
  • turn off the gas main switch promptly under safe conditions if a gas leak is detected and notify the appliance dealer. Do not use the gas water heater again until it has been repaired.
Users should not
  • should not purchase domestic gas water heaters without the GU Mark or bring in or import non-approved domestic gas water heaters for use in Hong Kong; otherwise, they commit an offence and are liable to prosecution;
  • should not install gas water heater themselves or arrange for a non-registered gas contractor or non-registered gas installer to install or modify the gas water heater; otherwise, they commit an offence and are liable to prosecution;
  • should not use gas water heater models other than those specified in the Gas Safety (Installation and Use) Regulations (see appendix - Chinese version) to serve bathrooms or showers; otherwise, it may cause fatal danger;
  • should not continue to use the gas water heater if defects are detected or a gas leak is suspected; otherwise, it may cause fatal danger.
Safety Notice for Gas Users

(Chinese version only) [PDF format (185KB)]

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