Gas heater safety: the carbon monoxide check your heater needs

Carbon monoxide gives you no warning. It has no smell, no colour and no taste, and a gas heater can produce it while looking and sounding completely normal. That is why the safety check matters more for heaters than for any other gas appliance in the house.

The two-year rule

Gas heaters should be serviced and checked every 2 years by a licensed gas fitter. A proper service is not a dust and wipe-down: it includes inspecting the burner and heat exchanger, testing for carbon monoxide spillage, confirming the flue is drawing properly on flued models, and checking room ventilation on unflued models. If the heater has not been touched in years, or it came with the house when you bought it, book the check before the next winter rather than after.

Warning signs of carbon monoxide exposure

CO poisoning is regularly mistaken for a virus. The pattern to watch for:

• Headaches, dizziness or nausea that appear when the heater is running
• Tiredness, confusion or shortness of breath indoors
• Symptoms that improve when you leave the house and return when you come home
• More than one person, or even the family pet, unwell at the same time

If that pattern fits, stop using the heater, get everyone into fresh air, and see a doctor. Do not run the heater again until a licensed gas fitter has tested it.

Flued vs unflued heaters

A flued heater sends its combustion products outside through a flue, so the key check is that the flue is intact, unblocked and drawing. An unflued heater releases combustion products into the room itself, which is why the rules are stricter: the room must meet minimum size and fixed ventilation requirements, and unflued heaters are not permitted in bedrooms or bathrooms in NSW. Old unflued units, and any heater not designed for indoor use, are the highest-risk appliances Terry sees. Outdoor patio heaters and camping heaters must never be used inside, even briefly, even in a garage.

Physical red flags on the heater itself

• A yellow, lazy or wavering flame instead of a crisp blue one
• Soot stains or discolouration around the heater or flue
• A pilot light that keeps going out
• Heavy condensation on windows whenever the heater runs

Any one of these is reason enough to switch the heater off and have it checked before it runs again.

Never DIY gas repairs

There is no safe version of a home gas repair. Gas work in NSW must be done by a licensed gas fitter working to AS/NZS 5601, and every job must come with a compliance certificate. Terry holds NSW gas licence L10959 and has serviced heaters across Berala, Western Sydney and the inner west since 1986. A heater safety check is quick and inexpensive; a carbon monoxide incident is neither. If yours is overdue, book a check on 0415 274 542 before the cold sets in.

If you smell gas right now

Skip the reading and act: turn the gas off at the meter, open windows and doors, do not use flames or touch electrical switches, get everyone out of the house, and call a licensed gas fitter or your gas distributor emergency line from outside.