When buying a gas appliance, it must be certified by an industry body prior to sale. There are five national gas certification bodies:

• Australian Gas Association (AGA)
• SAI Global
• International Association of Plumbing and Mechanical Officials (IAPMO)
• Global-Mark
• BSI

Your gas appliance must also carry a certification label and meet the approved standards of the Australian Gas Association (AGA) or Standards Australia International Global. Appliances must carry a compliance plate with an AGA approval number.

You can check what certification labels to look out for at Australian Gas Association.

Appliances must carry a compliance plate with an AGA approval number. This confirms they are designed to run specifically on natural gas. If you buy a second-hand gas appliance, always check the compliance plate and have it installed by a licensed gasfitter.

Never connect liquid petroleum or LP gas to a natural gas appliance, unless it’s been converted by a licensed gasfitter or the appliance manufacturer. Likewise, only use your gas appliances for the jobs they're designed to do. It's dangerous to use a gas stove to heat a room, or to try to cook on a heater.

Always use a licenced gas professional fitter and make sure you receive a compliance certificate once the job is done. Licenced gas professionals can only install or repair certified products. These licenced professionals carry an identity card with a photograph, stating what work they are qualified to perform.

Your state’s regulator can help you find a licenced gas professional.

Regularly clean your gas appliances and pay attention to service records, making sure you only have work done by a licensed professional.

How do you know if your gas appliance is working properly? Check if the flame burns blue. If the flame continuously burns yellow, it's time to get it serviced by a licensed gasfitter. If you experience headaches, drowsiness, sore eyes or throat when using a gas appliance, turn it off immediately and ventilate the area. Do not use the appliance again until it has been checked by a licensed gasfitter.

Regularly servicing your gas heater reduces the risk of it releasing carbon monoxide, an odourless gas that can cause chronic illness or even death.

Symptoms of carbon monoxide poisoning can include:

• tiredness
• shortness of breath
• headaches
• nausea and vomiting
• weakness and sleepiness.

Extreme cases can cause confusion, loss of consciousness or death.

To help with a diagnosis, let your medical professional know if you feel better when in the fresh air or if other members of the house - including pets - have similar symptoms. The elderly, children, unborn babies and people with heart disease and anaemia can be particularly susceptible to carbon monoxide poisoning.

Unflued gas heaters (those without a chimney) need proper permanent ventilation and can only be used in rooms that are a certain size. Before you buy, check with the appliance retailer or a licensed gasfitter to make sure they’re suitable for your home.