Signs and symptoms of carbon monoxide CO poisoning and tips to stay safe this winter. Winter snows can create drifts that block exhaust vents, forcing carbon monoxide gas (CO) to back-up into your home. High efficiency appliances and those with power-vent blowers by definition waste less heat, so the exhaust air temperature is very low. Often it is too low to melt snow in a plugged exhaust pipe or vent. Keep sidewall and direct vents clear of obstructions, drifting snow and bushes to provide proper ventilation. Hundreds of people accidentally die each year from CO poisoning caused by malfunctioning or improperly used […]