Carbon Monoxide From Your Gas Heater: The Silent Risk Adelaide Homeowners Don’t Think About
Every winter, Australians die from carbon monoxide poisoning in their own homes. Not from the dramatic gas leaks they could smell. Not from the obvious malfunctions they could see. They die from colourless, odourless gas produced by heaters that appear to be working normally.
Carbon monoxide is called the silent killer for good reason. You cannot see it, smell it or taste it. By the time you realise something is wrong, you may already be too drowsy and confused to get help. It happens in Adelaide homes every year, and it is almost always preventable.
This is not the same as a gas leak. Natural gas has a distinctive rotten egg smell added specifically so you will notice a leak. Carbon monoxide is different. It is a byproduct of incomplete combustion, produced when your gas heater is not burning fuel properly. A heater can produce dangerous levels of carbon monoxide while appearing to work perfectly fine.
This guide explains how carbon monoxide builds up, which heaters are most at risk, the warning signs you need to watch for, and why a professional safety check before winter could save your family’s life.
How Carbon Monoxide Builds Up in Your Home
When a gas heater burns fuel completely, it produces carbon dioxide and water vapour, both harmless in normal amounts. But when combustion is incomplete, the heater produces carbon monoxide instead. This happens when there is not enough oxygen, when the burner is dirty or damaged, or when exhaust gases cannot escape properly.
Blocked or Damaged Flues
Flued gas heaters are designed to vent combustion gases outside through a flue pipe. If that flue becomes blocked by bird nests, debris, rust or damage, the gases have nowhere to go. They spill back into your living space instead. This is one of the most common causes of carbon monoxide incidents in Australian homes.
Dirty or Malfunctioning Burners
Over time, dust, lint and debris accumulate on gas heater burners. This affects the air-to-gas mixture needed for clean combustion. A dirty burner does not burn fuel completely and produces carbon monoxide as a result. You might notice the flame looks different, yellow or orange instead of blue, but not always.
Inadequate Ventilation
Gas heaters need oxygen to burn fuel. Unflued heaters, which vent directly into the room, need adequate ventilation to bring in fresh air and dilute any combustion byproducts. In tightly sealed modern homes or older homes where ventilation has been reduced for energy efficiency, this can become a serious problem.
Adelaide winters are cold enough that people close up their homes to keep warm. Windows stay shut. Doors stay closed. Draft stoppers block gaps. This is exactly the environment where carbon monoxide can accumulate to dangerous levels.
Which Gas Heaters Are Most at Risk
Not all gas heaters carry the same level of risk. Understanding which types need the most attention helps you prioritise safety checks.
Older Flued Heaters (Highest Risk)
Gas heaters manufactured before 2000 are the highest risk for carbon monoxide production. They were built to less stringent standards and have now been operating for 20 to 30 years or more. Many Adelaide homes, especially in established suburbs like Unley, Norwood, Burnside and Mitcham, still have these older heaters in use.
The age of the heater means more wear on components, more time for flues to deteriorate, and more opportunity for problems to develop. If your gas heater is more than 20 years old, it needs a professional inspection every winter without exception.
Unflued Gas Heaters
Unflued heaters, sometimes called portable gas heaters or cabinet heaters, vent combustion gases directly into the room. They rely on adequate ventilation to dilute any carbon monoxide produced. When used in poorly ventilated spaces or when they malfunction, the risk is immediate.
South Australia has regulations about where unflued heaters can be used. They should never be used in bedrooms, bathrooms or small enclosed spaces. They require permanent ventilation openings in the room. Unfortunately, many homeowners are not aware of these requirements or ignore them on cold nights.
Ducted Gas Heating Systems
Central ducted heating systems burn gas in a furnace, usually located in the roof space, and distribute warm air through ducts. If the heat exchanger in the furnace cracks or corrodes, combustion gases can mix with the air being circulated through your home. This can affect every room connected to the system.
Heat exchanger failures are more common in systems over 15 years old. Because the furnace is out of sight in the roof, problems can go unnoticed until they become serious.
When Did You Last Have Your Gas Heater Checked?
A professional safety inspection checks for carbon monoxide risks, flue blockages, burner problems and ventilation issues. Book before winter while appointments are available.
Call 0484 600 095 to Book a Gas Heater Safety Check
Warning Signs Your Heater May Be Producing Carbon Monoxide
Carbon monoxide itself is undetectable without a monitor. But there are warning signs that your heater may not be operating safely.
Signs From the Heater
Yellow or orange flames instead of blue – A properly burning gas flame should be mostly blue with perhaps a small yellow tip. Predominantly yellow or orange flames indicate incomplete combustion.
Soot or discolouration around the heater – Black marks, soot deposits or staining around the heater, on walls or on the ceiling above indicate combustion problems.
The pilot light keeps going out – A pilot light that repeatedly extinguishes may indicate oxygen starvation or exhaust spillage.
Unusual smells when operating – While carbon monoxide is odourless, incomplete combustion can produce other byproducts with noticeable smells.
Excessive condensation on windows – More moisture than usual on windows when the heater runs can indicate combustion gases spilling into the room.
Physical Symptoms of Carbon Monoxide Exposure
The early symptoms of carbon monoxide poisoning are easily mistaken for the flu or general illness. This is part of what makes it so dangerous. Symptoms include headaches, dizziness, nausea, tiredness, confusion, shortness of breath and difficulty concentrating.
A key warning sign is that symptoms improve when you leave the house and return when you come back. If everyone in the household feels unwell when at home but better when out, consider carbon monoxide as a possible cause.
Pets may be affected before humans, as they are smaller and closer to ground level, where carbon monoxide accumulates. Unusual lethargy or illness in pets can be an early warning.
If you suspect carbon monoxide exposure, get everyone out of the house immediately, including pets. Open windows and doors if safe to do so. Call 000 if anyone has symptoms. Do not re-enter until the property has been checked by a licensed gas fitter.
What a Professional Gas Heater Safety Check Involves
A proper gas heater service is more than just turning it on and checking that it heats. A licensed gas fitter will inspect multiple components and test for safety issues.
Combustion analysis – Using specialised equipment, we measure the gases produced by your heater. This tells us whether combustion is complete and safe, or whether carbon monoxide is being produced.
Flue inspection – We check the entire flue system from the heater to where it exits the building. We look for blockages, corrosion, damage, disconnections and proper sealing. A blocked or damaged flue is one of the most common causes of carbon monoxide spillage.
Spillage testing – We test whether combustion gases are being properly drawn up the flue or spilling back into the room. Even a properly connected flue can spill if there are ventilation or pressure problems in the building.
Burner inspection and cleaning – We inspect the burner for damage, corrosion or blockage and clean away accumulated dust and debris that affects combustion quality.
Safety control testing – We check that flame failure devices, thermocouples and other safety controls are working correctly. These components shut down the heater if something goes wrong.
Ventilation assessment – We check that the room has adequate ventilation for the type of heater installed, especially important for unflued heaters.
A full safety check typically takes 30 to 60 minutes, depending on the heater type and any issues found. We provide a report on the heater’s condition and any recommended repairs or replacements.
When and How Often to Service Your Gas Heater
The recommendation from Energy Safe Victoria and gas industry bodies across Australia is clear. Gas heaters should be professionally serviced at least every two years. Heaters more than 10 years old should be serviced every year.
The best time to book a service is in autumn, before you need the heater for winter. This gives you time to address any issues found before cold weather arrives. It also avoids the rush period when gas fitters are busy with emergency calls from people whose heaters have failed on the first cold night.
Many Adelaide homeowners have never had their gas heater serviced. The heater came with the house; it turns on when needed, and they assume it is fine. This is exactly how carbon monoxide incidents happen. A heater can deteriorate gradually over the years, producing increasingly dangerous levels of carbon monoxide while appearing to work normally.
Should You Install a Carbon Monoxide Alarm?
Carbon monoxide alarms are mandatory in some countries and states, but not currently required in South Australian homes. However, they are highly recommended, especially if you have gas heating or other gas appliances.
A carbon monoxide alarm provides an additional layer of protection. It will alert you if CO levels rise, giving you time to ventilate, evacuate and investigate before levels become dangerous. Alarms cost between $40 and $150 and are available from hardware stores.
Install alarms according to manufacturer instructions, typically at head height in rooms with gas appliances and in sleeping areas. Test alarms regularly and replace batteries as needed. An alarm is not a substitute for professional servicing, but it provides valuable backup protection.
Protect Your Family This Winter
A gas heater safety check takes less than an hour and could prevent a tragedy. Our licensed gas fitters service all types of gas heaters across Adelaide. Book now before winter.
Call 0484 600 095 for Gas Heater Servicing
Frequently Asked Questions
- Can I smell carbon monoxide like I can smell a gas leak?
No. Carbon monoxide is completely odourless. Natural gas has a distinctive smell added to it so you notice leaks, but carbon monoxide has no smell at all. This is why it is called the silent killer. You cannot detect it without a carbon monoxide alarm or professional testing equipment.
- How old is too old for a gas heater?
Gas heaters generally have a lifespan of 15 to 20 years with proper maintenance. Heaters over 20 years old are at higher risk of problems and may not be repairable if parts are no longer available. If your heater is more than 20 years old, have it inspected annually and consider replacement, especially if issues are found.
- Is a blue flame always safe?
A blue flame indicates better combustion than a yellow or orange flame, but it does not guarantee the heater is completely safe. Flue blockages, spillage problems and other issues can cause carbon monoxide buildup even with a blue flame. Flame colour is one indicator, but professional testing is needed to confirm the heater is operating safely.
- Do new gas heaters produce carbon monoxide?
All gas heaters produce some carbon monoxide as a normal byproduct of combustion. New heaters are designed to produce minimal amounts and vent them safely. The risk comes when heaters malfunction, are poorly installed, have blocked flues, or lack adequate ventilation. Even new heaters need correct installation and regular servicing.
- Can I service my gas heater myself?
No. Gas heater servicing must be performed by a licensed gas fitter. This is a legal requirement in South Australia. Working on gas appliances without the proper licence is illegal and dangerous. You can clean dust from external surfaces, but internal components, burners, flues and safety controls must only be serviced by a licensed professional.
- Are portable gas heaters safe to use indoors?
Portable unflued gas heaters can be used indoors, but only in well-ventilated spaces that meet specific requirements. They should never be used in bedrooms, bathrooms or small enclosed rooms. Permanent ventilation openings are required. If in doubt about whether your space is suitable, consult a licensed gas fitter. Many carbon monoxide incidents involve portable heaters used in inappropriate spaces.
- How much does a gas heater safety check cost?
A professional gas heater service typically costs between $150 and $250, depending on the heater type and any additional work required. This includes combustion analysis, flue inspection, spillage testing and safety control checks. Given that a service can prevent carbon monoxide poisoning and identify issues before they become expensive repairs, it is a worthwhile investment.
- What should I do if I suspect carbon monoxide in my home?
Get everyone out of the house immediately, including pets. If possible, open windows and doors on your way out. Once outside, call 000 if anyone has symptoms like headache, dizziness or nausea. Do not go back inside. Call a licensed gas fitter to inspect the property before anyone re-enters. If you smell gas as well, turn off the gas at the meter if safe to do so.
Do Not Wait Until Something Goes Wrong
Carbon monoxide poisoning is almost always preventable. The heaters that kill people are usually ones that have not been serviced in years. The flues that spill deadly gas into living rooms are ones that no one has checked since the house was built. The warning signs are there, but no one is looking for them.
A gas heater safety check is a small investment that provides enormous peace of mind. You will know your heater is operating safely. You will know your family is protected. And you will avoid the kind of tragedy that devastates families every winter.
If you have not had your gas heater serviced in the last two years, or if you cannot remember when it was last checked, now is the time to book. Do it before winter arrives, and the cold nights make your heater essential.
Wills Plumbing Adelaide provides gas heater safety checks and servicing across all metro suburbs. Our licensed gas fitters service all types of gas heaters, including flued, unflued and ducted systems. We can also advise on replacement options if your heater is past its safe operating life. Call 0484 600 095 to book your gas heater safety check before winter.
