"Problem is in this type of weather if you don't really understand that one needs to be turned off because one's trying to produce heat and the one is trying to cool down so their constantly running. If there's a little bit of a blockage that air condition unit will start pulling air down and through the flue pipe and into the house and that's what we think happened." said Steve Gettemeier.
Fire officials suggest getting separate thermostats converted into one or make sure that one of them is always turned off. Homeowners are also advised to install a carbon monoxide detector.