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Prohibition on the sale of open flued gas heaters

Due to safety concerns, Tasmania’s Director of Gas Safety (the Director), intends to prohibit the supply and sale of a specific class of open flued gas heaters within Tasmania from 1 December 2022.

The Director has published and distributed the CBOS Gas Safety Compliance Guide - Open flued heater prohibition (PDF, 251.6 KB) to provide forewarning to the gas industry.

This action has been undertaken following an assessment of the risks posed by old open flued gas heaters that lack contemporary safety features. In assessing these risks, the Director regarded the deaths experienced in Victoria.

The Director has determined that open flued gas space heaters that are lacking the safety features specified in Amendment 1 of AS/NZS 5263.1.3:2021 Gas Appliances Part 1.3 Gas space heating appliances, are unsafe to use, or are likely to become unsafe to use for the following reasons:

  • As open flued gas heaters draw their air from the room or space in which they are installed, they
    are susceptible to the effects of negative pressure in buildings caused by insufficient ventilation.
    This negative pressure is exasperated by the operation of air extraction systems such as bathroom
    exhaust fans or kitchen range hoods. Negative pressure in a building can cause the products of
    combustion such as carbon monoxide (CO) to be drawn into the building.
  • If ventilation is insufficient and the negative pressure is sufficiently high, airflow through the flue
    may become restricted or in some cases even reversed. This restriction will result in a diminished
    supply of fresh air to the burner resulting in high levels of CO, which in turn could be drawn into
    the building.
  • The usage patterns of open flued gas heaters indicate that these appliances are operated for
    significant periods of time and as a result, allow for a build-up of dangerous levels of CO in houses
    when the appliance is operated in a negative pressure environment resulting in the heater
    becoming unsafe to use.
  • Modern homes are more energy efficient. Air extraction systems such as bathroom exhaust fans and kitchen rangehoods are becoming more powerful. As a result, there is an increased risk of negative pressure environments in new housing stock.

Subsequently, open flued gas heaters should not be supplied or sold in Tasmania unless they have the following features:

  • A fan-assisted combustion system, where the burner only operates while the fan functions.
  • A fail-safe interlock that will shut down within 15 minutes if spillage occurs. This shutdown will apply under any negative pressure condition.
  • An inability to be automatically reset if shut down. That means the appliance requires the use of a tool for access to reset the appliance manually.
  • The carbon monoxide/carbon dioxide ratio of combustion products does not exceed 0⋅02 after 10 minutes operation under any operating conditions.
  • Concentration of CO in the combustion products does not exceed 90 ppm when the fail-safe interlock is tested in a test room under negative pressure conditions

To determine if an open flued gas heater complies with the requirements of Amendment 1, check the following;

  • The appliances data plate must show that it was manufactured on or after the 1st January 2022; and
  • The appliance is certified as compliant with contemporary standards by an external authority (AGA, IAPMO, SAI Global, BSI, Global Mark).

Gas Standards and Safety recommend consumers research and verify the age and certification status before purchasing any gas appliance.

This prohibition does not affect open flued heaters that are already installed. These open flued gas heaters are safe if they are serviced in line with manufacturer’s recommendations, typically at least once every two years by a licensed gasfitter.

The Director also recommends that when operating an open flued gas heater;

  • They are not operated in conjunction with extraction fans such as your kitchen rangehood or bathroom fan if possible. When there is a lack of ventilation this can cause a negative pressure environment where CO or other poisonous gasses can be drawn out of your flue and into living areas; and
  • Allow for adequate ventilation when operating the heater.

For further advice read the the CBOS Gas Safety Compliance Guide - Open flued heater prohibition (PDF, 251.6 KB), or contact us.

Updated: 01 Sep 2022

This page has been produced and published by the Consumer Building and Occupational Services Division of the Department of Justice. Although every care has been taken in production, no responsibility is accepted for the accuracy, completeness, or relevance to the user's purpose of the information. Those using it for whatever purpose are advised to verify it with the relevant government department, local government body or other source and to obtain any appropriate professional advice. The Crown, its officers, employees and agents do not accept liability however arising, including liability for negligence, for any loss resulting from the use of or reliance upon the information and/or reliance on its availability at any time.