Do Gas Heaters Produce Carbon Monoxide? Melbourne Safety Guide

Yes — But Only When Something Is Wrong

All gas appliances produce carbon monoxide as a byproduct of combustion. Under normal operation, a correctly maintained gas heater vents these gases safely through a flue to the outside. The risk occurs when combustion is incomplete or when CO escapes into the living space rather than being vented out.

When Does a Gas Heater Become a CO Risk?

The two most common causes of CO leakage are a cracked heat exchanger — which allows combustion gases to mix with circulated air — and a blocked or damaged flue, which prevents exhaust gases from escaping the building. Both faults are undetectable without professional testing equipment. This is why annual servicing by a licensed Type A gas fitter is so important. A cracked heat exchanger produces no smell, no noise, and no error code. It is found during inspection — or not at all.

Symptoms of CO Exposure

Carbon monoxide poisoning symptoms include headaches, dizziness, nausea, shortness of breath, and confusion. Symptoms often improve when you leave the home — which is the key signal. If multiple people in the household experience these symptoms simultaneously, leave the building immediately, get fresh air, and call emergency services.

Should I Install a CO Detector?

Yes. A carbon monoxide detector is a worthwhile investment for any home with gas appliances. Install one on each floor, particularly near bedrooms and living areas. CO detectors are available from hardware stores for $30–80 and should be tested monthly. However, a CO detector is a last line of defence — not a substitute for annual servicing. Call ATC Plumbing on 1300 282 758 to book a gas heater safety inspection across Melbourne's south-east.