Three occupants of home exposed to low levels of carbon monoxide

Location: Taylor

Regulated industry sector: Gas - Propane system

Incident overview

A large deck was built on one side of a house near gas appliance vents. The occupants of the house awoke to their carbon monoxide detector at 2:30am. When the fire department arrived, they measured 45 ppm CO in the home’s boiler room and 24 ppm on the main floor of the house. It is highly likely that the deck over top of the gas appliance exhaust vents prevented exhausted gases from dissipating outside. Exhaust was trapped under the deck and the HRV air intake drew the exhaust inside, which distributed exhaust with carbon monoxide throughout the house.