Gas water heaters that have not been properly maintained have been responsible for deaths and serious injuries. If you have a gas bath heater or flued instantaneous water heater in your bathroom or a flueless water heater in your kitchen like any of the appliances shown here (see diagram) it could be a source of danger. 

The following advice applies to both natural gas and LPG water heaters.

Flued water heaters

Flued water heaters, using natural or LPG gas, were often installed in bathrooms. They were designed to operate with a flue that vented harmful fumes outside – just like a chimney. If the flue pipe leaks or becomes blocked problems can occur. 

Bathrooms are particularly tough on water heaters. The moist environment speeds up corrosion, which causes leaks. Lint, hair, fluff from towels, talcum powder, shampoo and aerosol residue can accumulate within the heater. This can block the airflow needed for the gas burner to operate safely. 

Flueless water heaters

Flueless water heaters, also using natural or LPG gas, were designed to work without a flue pipe. However, they still need permanent unobstructed ventilation to operate safely. They were sometimes installed in the kitchen, often in cupboards below the kitchen sink.

If you are uncertain about the type of water heater you have in your home contact the NSW Master Plumbers Association on 1800 424 181 (toll free).

The potential risk

If ventilation is obstructed in either a flued or flueless water heater, poisonous fumes such as carbon monoxide can be forced back into the room contaminating the air you breathe. As carbon monoxide is colourless, odourless and tasteless, you will be unaware of its presence.

If you are renting your home, it is important to bring this safety message to the attention of the property owner, real estate agent or the landlord.

Reducing the risk

The easiest way to reduce the risk is to replace the heater with a new, safer and more energy efficient heater, located outside the building. If you decide to do this, use an authorised gas service agent to carry out the work.

Make sure your water heater (indoor or outdoor) is serviced once a year by a licensed gas fitter.

If you have a water heater in your bathroom disconnect the exhaust fans to avoid circulating poisonous fumes.

Important safety tips

Here are some important safety tips to remember:

• Make sure your water heater is serviced once a year by an authorised gas service agent.
• Make sure your bathroom and kitchen heaters have unobstructed ventilation.
• Keep a written report of any maintenance work undertaken and be sure you receive a Certificate of Compliance from the authorised gas service agent.
• Look out for any signs of discolouration of the water heater or the walls near the heater, as this can indicate dangerous problems with the heater or its flue.
• Make sure heater flue pipes are free from all restrictions and holes.
• Disconnect exhaust fans in bathrooms with gas water heaters.
• Make sure that all new and replacement gas water heaters are installed outside the building.

Need more information?

For further information contact your gas retailer or the NSW Master Plumbers Association on 1800 424 181 (toll free) or the Office of Fair Trading.

This information was produced in conjunction with the Australian Gas Association and NSW Master Plumbers Association.