Electric water heater safety instructions

Electric water heaters are commonly used electrical products in general households. The electric water heaters available in the market mainly include instant type, shower type electric water heaters (also known as low-pressure type storage type or open type electric water heaters) and non-exhaust pipe storage type. (also known as high pressure type) electric water heater. Although the electric water heaters supplied in the market have appropriate protection devices, accidents involving electric water heaters have occasionally occurred in the past. According to the investigation results, the causes of these accidents are mainly improper installation and lack of maintenance.

When using electric water heaters, the public should pay attention to the following matters:

  •  Employ registered electrical contractors and licensed plumbers for installation or modification of electric water heaters.
  •  Adhere to the instructions given in user manual of an electric water heater.
  •  Switch off the power source of an electric water heater after use.

  •  Arrange an experienced technician to inspect and maintain an electric water heater regularly.
  •  If an electric water heater has an abnormality while in use (such as circuit breaker tripping), stop using it immediately and contact the supplier for inspection and repair.
  •  Ensure that shower head with on/off valve is not installed for “Shower Type” electric water heater to prevent excessive pressure from building up inside the water storage tank, causing an explosion.

Trade members should note the following during installation or modification and maintenance of an electric water heater:

  •  For new installation of electric water heater, the fixed electrical installations and water pipes shall be installed by a Registered Electrical Contractor (REC) and a designated person# as required by Water Supplies Department (WSD) respectively.

    (Remarks: # For the details of designated person, please visit WSD website: Employ a Licensed Plumber.)

  •  The outlet pipework of a shower type electric water heater must not be connected with any on/off control valve and must not be connected to basin or bath tub, to prevent excessive pressure from building up inside the water storage tank, casing an explosion.

  •  The manufacturer’s instructions should be followed to carry out maintenance work on an electric water heater. Advice should be sought from related agent or manufacturer if necessary.
  •  In case the outlet pipework or ben pipe (if any) is not properly installed, the trade member should advise the user to fix the problem immediately.