Hot water heaters in winter

After a number of serious incidents in the past two months involving hot water heaters, including injuries to home owners, the QBCC Plumbing Investigation Unit has produced a home owners guide to help minimise potential risks associated with hot water heaters.

The QBCC advises that the best way a home owner can mitigate any issues arising with a hot water heater is to contact an appropriately licensed contractor.

Below is a list of issues that could potentially occur, how home owners can identify these to better protect themselves, and who to contact if necessary.

  1. Rusty or discoloured hot water at hot water tap/s

    • Hot water storage heater may be rusted or corroded internally. This may be a telltale sign that the heater is about to fail (leak/burst).
    • Call a licensed plumber.
  2. Rusted or leaking hot water storage heater
    • A hot water storage heater that is leaking from the main cylinder casing generally means that the cylinder has failed and the heater should be replaced.
    • Call a licensed plumber.
  3. Pilot light on gas storage heater not lighting, or doesn’t say ‘lit’
    • Generally means there is an issue with the gas supply or gas components within the heater.
    • Call a licensed gas fitter.
    • Note: when relighting a pilot flame please refer to the manufactures instructions.
  4. No hot water supply, gas continuous flow or instantaneous hot water heater
    • There are several different makes and models with these units. These units have water, gas and electrical componentry. No hot water could be a result of a problem with one or more of these components.
    • Call specialist technician connected with the relevant make of the unit or a licensed plumber (plumber may need to refer the matter to a technician).
  5. Continuously dripping drain line
    • Generally means that the Temperature and Pressure Relief valve has failed and the valve requires replacement.
    • Call a licensed plumber.
  6. Electric storage hot water heater tripping power supply resulting in no hot water.
    • Generally means that one or more of the electrical components within the hot water heater have failed. This may be a result of a leaking cylinder dripping onto electrical components. (See ‘2. Rusted or leaking hot water storage’ above).
    • Call a licensed electrician or otherwise call a licensed plumber. Be sure to isolate the power to the hot water heater until a licensed electrician is able to assess the fault.   

Other handy information

Relevant information about your hot water is normally explained on the compliance plate of the hot water heater. For electric storage heaters the compliance plate is usually found on a sticker at the top or bottom of the heater.

For a gas storage hot water heater, the compliance plate is usually found on the back / internal side of the gas service panel which usually lifts and pulls out.

Importantly, property owners must take all reasonable attempts to ensure that plumbing and drainage on a premises is kept in good condition and operates properly. It is an offence under the Plumbing and Drainage Act for failing do to so and this may result in a penalty.

This extends to property owners maintaining an awareness of the condition of the hot water heater. Also, most manufacturers require that a major service on a hot water heater be conducted by a licensed plumber every five to six years. Refer to the manufacturer’s guidelines/instructions for further details.

In case of emergency

In the event of an incident with a hot water heater, the general isolating procedure is as follows:

  1. Stop, look and assess to prevent any safety risks.
  2. Isolate energy source:
    • Gas – Isolate gas at gas isolation valve (usually yellow in colour) at side of heater or underneath for continuous flow or instantaneous.
    • Electricity – Isolate at main switch board (Usually marked “(Hot Water or Mains Pressure Hot Water Heater or HWS”).
    • Isolate water supply
    • Gas continuous flow or instantaneous heaters – Sometimes a green or blue-handled valve underneath the unit – Should turn 90 degrees in a clockwise direction. (Older units may have an isolation valve similar to that mentioned below)
    • Electric or gas storage heaters - this can be done by using the water isolation valve at side of heater. Cold water isolation valves come in many shapes and sizes depending on the age, generally looking like either a T-Head (similar to a hose tap) or a black or brass-coloured circular handle. These need to be turned in a clockwise direction to close the valve. 
  3. Call a licensed plumber.

In addition to the information above, the QBCC notes that Master Plumbers Association of Queensland also recently issued a warning about hot water systems.