There are a variety of common signs that you have been exposed to Carbon Monoxide from unserviced Gas Ducted Heaters.
In small concentrations, there are few symptoms until the issue has become to the point that medical assistance is required.
The initial symptom encountered is general fatigue due to oxygen depletion in the heated space while the more severe symptoms include memories loss, convulsions, gasping for breath, or cardiac arrest.
Occupants can fall victim to CO (Carbon Monoxide) poisoning at any time without much warning.
The longer you are exposed, the more serious the impact will be due to the accumulative nature of Carbon Monoxide poisoning.
If you notice any of these signs, you must ensure that the gas ducted heater is checked by a licensed and trained professional like Dynamic Heating and Cooling right away.