October 20th, 2012 10:58 PM by Dan Howard
See the video for explanation
This furnace has a defect that could be in your home. You need to know the mistake that pulls carbon monoxide from other gas appliances back into the building.
The venter fan of the furnace can pull air from the hot water tank back down the chimney and into the interior air. If you smell the odor of gas from time to time, this is a likely cause.