Keeping outdoor gas furnace vents clear of snow and debris is important to a working and efficient heating system.

That according to local furnace and ventilation technician Trev Esau who says, if the vent is obstructed, it won't cause carbon monoxide poisoning but may cause the furnace to stop operating, making for a very cold home.

"The furnace itself is a self-contained unit that uses air from outside and then it's exhausted outside. If those vents get plugged the furnace is very fussy about having enough air - it's kind of like me underwater - the furnace likes to have enough air, and if it doesn't, it will just shut itself down and all of a sudden you're going to find yourself very cold."

Esau adds there are other outdoor vents which should be kept clear as well such as a fresh air exchange vent or dryer vent. "It's just going to help your house to operate better, it's going to help it operate like it's designed to operate."

As for electric furnaces, he says they have an element which heats up and then heats the air so they're 100% efficient and have no risk of vent obstruction or carbon monoxide poisoning.

He notes it's also advantageous to clear the snow away from basement windows to prevent basement flooding in spring and also in the event of an emergency it's easier to use as an escape, if necessary.