According to a press release issued by the city of Elgin, these types of incidents are a common problem when there are high snow drifts that block furnace vents and air intakes in some homes — predominantly homes that have newer, high-efficiency furnaces. These systems typically vent through the sill plate of a home, close to ground level through white PVC piping.
Drifting snow has the potential to block these vents, causing the furnace or water heater to stop operating. Some newer high-efficiency furnaces have automatic shutoffs that shut down a furnace when the vents are blocked, but many furnaces don’t. If they fail to shut down, carbon monoxide may back up in a home.
Click on the following for more details: Carbon monoxide problems increase along with snowfall - Courier News