I noticed this while I was sitting in my office. There is an air return vent near the ceiling. I felt a draft, and when I looked up at the vent, because that was obviously where the cold air was coming from, I could see (it's time to vacuum the ducts for 1 thing) air blowing out because it was blowing a little 'dust cobweb' outward. It is VERY windy outside today and it is windy here often, hence our expensive heating bills last year. We have an electric heater, if that matters. Also, I went downstairs to take a look at the heater and to change the filter, and notice that there was cool air blowing out of where the filter goes as well. Again, the unit is OFF.

If anyone can tell me how to find where the air might be getting in to the system and/or house at, I would REALLY appreciate it!

This has some interest in the thinking pattern as to how someone would go about finding the source of a hole in a duct from not being in that house to look for it. It is also interesting to think about how to advise someone to find a hole in a duct in the many varieties of shapes and number of rooms there can be in so many different houses.

Perhaps cameras can be installed in all ducts to see every inch of the interior of ducts for future possibilities of holes in ducts that let air in. That would be a lot easier than sealing off all room registers, throwing a smoke bomb in the duct, then looking where the smoke comes out.

www.heatpro.us energy businessmen's knowledge

Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.