Worried that your ducted gas heater is leaking carbon monoxide? If so, there are a number of ways you can investigate the problem. Consider working through these troubleshooting tips:

1. Is the pilot light out?

If your gas heater has a pilot light, you may smell a faint odour of gas at times. Natural gas is actually odourless and colourless, but for safety, most gas companies add a slight smell to their gas to make it easier to detect leaks.

If the odour is relatively faint and the pilot light is out, you probably do not have a leak. You simply need to relight the pilot light. If the odour is strong and the pilot light is burning, that is a big sign that you need to call your natural gas provider or the 24-hour emergency line for your state or territory.

2. Is the pilot light yellow?

Before calling emergency services, check out the colour of the pilot light. Ideally, it should be blueish green or bright blue with a bit of yellow at the tip of the flame. If the flame is primarily yellow, you may have an issue with carbon monoxide, due to a lack of oxygen in the system.

To explain, natural gas consists mostly of methane, which features one carbon and three oxygen molecules. If there is not enough oxygen present in the system, the molecules floating around won't stay in their relatively safe methane format. Instead, due to the lack of oxygen, they will reform as carbon monoxide (one carbon and one oxygen molecule).

If you see a yellow flame, it doesn't necessarily mean you have a leak at the moment, but one could easily occur. Turn off the gas coming to the heater and attempt to remove any debris from the area around the pilot light with a piece of metal wire. The debris may be blocking the flow of oxygen.

3. Is the thermocouple well attached?

If the pilot light looks fine but you still smell gas, look at the thermocouple. It is a truncated metal tube typically next to the pilot light. If this piece is not attached correctly or if there are any holes in the metal surrounding it, gas could be leaking out of that area.

4. Does your monitor detect carbon monoxide?

If you have a gas ducted furnace, you should have a carbon monoxide detector in your home. This should beep if the carbon monoxide levels in your house are elevated. If your monitor goes off, leave the house and call for the proper help as soon as possible. However, if your detector has not gone off but you see some of the other issues explained above, there may be something wrong with your monitor. To be safe, take the precautions of calling for help as well.