Gas appliances and conversions

The conversion of a gas appliance requires a specialised level of understanding.

The incorrect conversion of an appliance, especially an open flued or flueless gas appliance, can lead to serious injury or death. Appliances shall only be converted if they are certified for use on the type of gas required, and a manufacturer's conversion kit or procedure is available. When converting appliances, the manufacturer's conversion procedure must be applied and the appliance tested when complete.

The gas-fitter may need to perform several tasks to convert the appliance, such as:

  • replace the main burner and/or injector
  • replace surface combustion tiles (some flueless room heaters may need burner tile replacement)
  • replace pilot burners and/or injectors (Oxygen Depletion Pilots (ODP) must be fitted in accordance with conversion procedures)
  • replace gas valves
  • set air to gas ratios
  • fit regulators and install springs
  • set appliance operating pressures with a correct calibrated instrument
  • adjust the thermostat bypass rates to burners
  • adjust turndown gas rates to burners
  • re-program or replace microprocessor units
  • check for gas leaks
  • analyse combustion products with a correctly calibrated instrument

Testing the appliance is part of the conversion procedure.

Combustion levels for open flued appliances

A flueless appliance does not have a dedicated flue and expels its combustion products directly into the surrounding air space.

A critical part of testing an appliance after conversion is carrying out a quantitative analysis of the combustion products. This may not be included as part of the conversion procedure; however, the gas-fitter is responsible for ensuring combustion levels comply wth the relevant Australian Standards.

Conversion or commissioning of a flueless appliance must only be performed if you can ensure combustion levels are with Australian Standards for that class of appliance.

Example: AS/NZS 5263.0  Gas appliances, Clause 5.13.4 - the CO/CO2 ratio for indoor flueless space heaters shall not exceed 0.002 when operating on available gas at manufacturer's specified test point pressure.

Stand by gas systems

To reduce substantial interruptions and subsequent operational risks, a business or gas installation owner may elect to install ready-to-use alternative gas supplies. In such instances, the Director of Gas Safety can accept alternative gas supplies and conversion procedures in accordance with Section 54 of the Gas Safety Act 2021 prior to a supply emergency. This will allow timely conversion of the gas installation to ‘stand by’ gas should the situation arise.

To provide acceptable conversions using standby gas systems, specific technical and operational information needs to be considered. Read the Fact Sheet -  Construction and approval Standard for stand by gas systems for NG installations (PDF, 295.8 KB).

Updated: 25 Jul 2022

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