Gas appliance flue terminal requirements for recreational vehicles (RV) with annexes

The purpose of this Safety Alert is to highlight the risk of CO poisoning if flue terminals for gas appliances are incorrectly installed in recreational vehicles with annexes.


AS/NZS5601.2:2013 (the Standard) specifies the minimum safety requirements for fluing gas appliances installed within recreational vehicles. These requirements must be considered by the recreational vehicle and aftermarket annex industries to ensure compliance with the Standard is not compromised.

Examples of flued gas appliances:

  • Refrigerators
  • Hot water heaters
  • Room heaters

It should be noted the ventilation openings and fluing requirements of the Standard are not new. These minimum safety requirements have been within the Standard (in various forms), since 1992.

Examples of gas appliance flue terminals

Image shows the refrigerator flue terminal on an RV

Image show a water heater flue terminal on an RV

Gas appliance flue terminals must terminate and discharge their products of combustion outdoors. The reason a flue terminal cannot be terminated indoors (inside an annexe) is to prevent excessive build-up from products of combustion, condensation, or other toxic conditions, such as carbon monoxide (CO) build-up, from eventuating.

Gas appliances are a potential source of CO poisoning. RVs and their annexes pose an increased risk of CO poisoning due to the small area within which gas appliances operate. As a result, faulty or incorrectly flued appliances can rapidly increase the CO concentration in RVs and associated cover areas such as annexes to potentially dangerous levels. The risk of CO poisoning is well demonstrated by inappropriate use of gas appliances in enclosed vehicles which led to the deaths of two men in separate incidents in Queensland in 2007 and 2009.

Contributing factors

  • Consideration of appliance ventilation must be given when fitting an annex to any RV (motorhome, campervan, camper trailer, or caravan).
  • Are there any gas appliance flue terminals on the side of the RV where the annex is going to be fitted?
  • The Standard requires the flue terminal to be located in an outdoor position that allows the products of combustion to readily disperse and not cause a nuisance.

A typical three sided annex shown below does not meet this requirement.

The image shows an RV awning

If the area is covered, such as an awning or within an annex:

  1. the area must be open on two sides and the flue terminal located to ensure free flow of air across it is achieved
  2. in the case of a fan assisted flue the area can be open on one side, if the terminal is within 500mm of the opening and the direction of discharge is towards the open side.

If in doubt consult a holder of a gas work licence or this department before proceeding.

Diagram showing an example of an awning open on two sides


Ventilation for gas appliances and the use of ‘outdoor’ gas appliances is a separate issue to the location of the flue under a covered area. These requirements can be found elsewhere within the standard.

Action required

  1. Caravan designer/manufacturers should:
    • modify caravan design to ensure gas appliance flue terminals are located to allow for the addition of aftermarket annexes without compromising existing gas system compliance. The majority of new RVs are manufactured with all flued gas appliances on the off (or driver) side of the vehicle which eliminates this issue as annexes are normally located on the passenger side where the door is located
    • educate caravan purchasers about the flue terminal requirement and advise on appropriate annex/awning design.
  2. Annex/awning manufacturers/suppliers should:
    • ensure the design and placement of any proposed enclosed annex does not compromise the compliance of an existing gas system
    • not provide annexes that are known to cause a non-complaint system
    • education caravan users about the requirement.
  3. Owners of RVs need to:
    • be aware of the requirement when purchasing or using RVs and annexes to ensure safety and compliance of the gas system is not compromised understand that alterations to flue terminals or their locations cannot be undertaken by unlicensed persons and would require further approvals
    • contact a licensed gas installer or this department if they need any further advice.
  4. Licensed gas installers must:
    • ensure when certifying the gas system of an RV that there is no existing stored annex or awning, that when installed would compromise the compliance of the gas system
    • clarify on any certificate issued the circumstances of the approval. E.g. RV with no annexe or with compliant annexe.

Note: The Northern Territory Dangerous Goods Regulation 177 specifies the installation shall conform to the requirements specified in AS5601 “Gas Installations – General installations” and therefore makes it an offence for a person to cause an existing gas system to not comply with the Standard.

Further information



The information in this Safety Alert contains safety information published by the Queensland Department of Natural Resources and Mines. NT WorkSafe does not warrant the information in this Safety Alert is complete or up to date and does not accept any liability to any person for the information in this report or as to its use.