Is your gas heater safe?

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You can’t see it or smell it. But while your gas heater is running, carbon monoxide could be spilling into your home.

 All gas heaters can spill carbon monoxide (CO) – a gas that you can’t see or smell but can make you seriously sick or kill you.

To be sure your gas heater is safe, you should:

  • have it serviced at least once every two years, by a qualified gasfitter.
  • check for safety advice – some heaters need fresh air flow to operate safely.

Service your gas heater for winter

Because you can’t see or smell carbon monoxide you won’t be able to tell if your heater is spilling carbon monoxide into your home. The first warning signs are often headaches, nausea and fatigue. To avoid carbon monoxide leaking into your home and making you sick, adequate ventilation and maintenance are vital.

Manufacturers recommend service periods for their appliances and these should be observed.

Building and Energy recommended that appliances are serviced as per the manufacturer’s instructions or at least every two years by a qualified gas fitter or service agent.  If the appliance is more than 10 years old, they should be serviced annually.

Check the ventilation requirements

Ventilation is also vital to ensure fresh air enters the room, diluting any carbon monoxide and other products of combustion that may spill into the room.

If you have an open flue heater, let fresh air flow through the room when the heater is on.

Open-flued heaters use air from inside the house. The heater pulls the air through an opening, to feed a gas flame. This creates CO and other dangerous gases that can spill back into the room, via the opening, and make you very sick or even kill you.

To find out if your heater is open-flued, call the supplier or ask a qualified gasfitter next time you have your heater serviced.

Flueless heaters can be extremely dangerous. They consume air and release combustion products, such as carbon monoxide and other deadly gases into the room and the air you breathe. This can cause the room to become stuffy if there is inadequate ventilation. Ensure there is adequate ventilation to dilute these products of combustion.

By law, If the room is fitted with a gas bayonet to allow the connection of a flue-less gas heater, two permanent ventilation openings must be installed.  The vents must connect to the outside of the building and one vent must be installed at low level and the other vent at high level.

Open flued and room sealed heater diagram
Open flued and room sealed heater diagram, by Gas

Use your gas heater safely

  • Check if a safety alert or recall has been issued for your gas heater.
  • Check the service sticker on the appliance, is it due for a service? Call a licensed gas fitter or service agent.
  • Check that the room is adequately ventilated and that permanent ventilation openings are not blocked.
  • Check flues are not blocked or obstructed.
  • Check the outer case of your heater. Is it discoloured? Discolouration is an indication of a faulty flue and that it is time to have it checked by a licensed gas fitter.
  • Check the heater - a yellow flame can indicate that your heater is not running correctly and needs servicing.
  • Don’t use kitchen rangehoods or exhaust fans at the same time as your heater. This can create a negative pressure environment, where carbon monoxide is drawn into living spaces.
  • Don’t leave your gas heater on for extended periods. Ensure you turn your heater off when you don’t need it.
  • Install a carbon monoxide alarm as a back-up measure.
  • If your heater is very old, consider replacing it.
  • Never bring portable outdoor gas appliances indoors.

How to tell if carbon monoxide is making you sick

Carbon monoxide building up inside your home can make you sick for a short period of time, have long-term health effects or even kill you and your family quickly. You may not know you have been exposed to potentially fatal levels of carbon monoxide until the symptoms become severe.

If you notice any of the following symptoms, they could be caused by carbon monoxide leaking from your heater:

  • Dizziness.
  • Feeling sick or nauseous.
  • Weakness.
  • Fatigue.
  • Headaches.
  • Rapid or irregular heartbeat.
  • Vomiting.
  • People and/or pets getting sick at the same time.
  • Feeling unwell only when you’re at home.

Act quickly if you think your heater could be making people sick

  • Call Health Direct, see your doctor or dial 000 in an emergency
  • Turn off all gas appliances straight away, open windows and doors to let fresh air into the house.
  • Leave the house immediately and get into the fresh air.
  • Do not use your heater until you’ve had it checked by a qualified gasfitter of service agent.


Energy Safe Victoria have produced videos highlighting the dangers of Carbon Monoxide and the need to service gas appliances every two years.

Be Sure - Carbon Monoxide Awareness Edit

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