Why Is My Gas Heater Smelling? Common Causes & What To Do

A smell from your gas heater should never be dismissed. Some smells are harmless — a brief mustiness at the start of winter is normal. Others are a sign of a serious fault that needs immediate attention.

The "Dusty" Smell When You First Turn It On If your heater smells dusty or like something burning when you first turn it on for the season, this is almost always harmless. Dust has settled on the heat exchanger and burner over summer and is simply burning off. The smell should disappear within 15–30 minutes of first use. If it doesn't, call a technician.

Musty or Mouldy Smell A musty smell usually means mould or mildew has grown in your ductwork or filter during the warmer months. The heater itself is fine, but you should: • Replace or clean the return air filter immediately • Have the ductwork inspected and cleaned • Consider a UV filter or ducted air purifier for ongoing protection

This is common in Blue Mountains homes where humidity is higher — especially after a wet spring.

Rotten Egg or Sulphur Smell This is the one to take seriously. Natural gas and LPG have a sulphur compound (mercaptan) added specifically so you can detect a leak. If you smell rotten eggs or sulphur: 1. Do NOT turn any light switches or appliances on or off 2. Do NOT use your phone inside the building 3. Open windows and doors immediately 4. Leave the building 5. Call your gas supplier from outside (Jemena: 131 909, AGL: 131 245) 6. Do not re-enter until the all-clear is given

Do not attempt to locate the leak yourself.

Burning Plastic or Chemical Smell This indicates an electrical fault — usually a failing motor, melting wiring insulation, or a failing control board. Turn the system off at the power switch immediately and call a technician. Do not use the system again until it's been inspected.

Exhaust or Combustion Fume Smell If you can smell what seems like exhaust fumes or combustion gases, this is a potential carbon monoxide warning. A cracked heat exchanger can allow combustion gases to leak into your living space — this is odourless in the case of CO, but you may detect an exhaust-like smell if there are other byproducts.

Signs of carbon monoxide exposure: headaches, dizziness, nausea, fatigue, especially when the heater is running. If anyone in the household experiences these symptoms: • Turn the heater off immediately • Open all windows • Leave the building • Call 000 if symptoms are severe

Install a carbon monoxide detector near your heater — they're inexpensive and potentially life-saving.

When Was Your Last Service? Most gas heater smell problems can be prevented with an annual service. Betar Air's gas heater service includes heat exchanger inspection, burner check, carbon monoxide test, and a full safety assessment.

For Blue Mountains and Western Sydney gas heater servicing, call Betar Air on 0438 944 224.