||01-22-2013 04:00 PM
Originally Posted by dbaird
We have a normal gas furnace system. This past weekend I noticed a exhaust smell when entering the house. Is it possible the exhaust is backed up? It is not a constant odor. I checked the unit itself and smell nothing there or at the hot water hearter. Those are the only 2 gas appliances
That depends, doers your furnace and/or water heater have a vent motor, or do they use natural draft?
Systems with a vent motor have a proving switch, if your flue is backed up it won't allow the unit to run. Older systems however can allow exhaust to back up into the house. For instance I looked at a house the other day with an older furnace/water heater venting through a chimney. The chimney was clogged and whenever the furnace would run the only place the exhaust had to go was the water heater flue. So all the furnace exhaust was leaking out of the water heater flue. The entire top of the water heater was covered in soot. Fortunately the house was vacant.
So yes that can happen. If you think that's the case I'd recommend having a pro look at it. Carbon Monoxide is not something to fool around with.