Gas and Oil Home Heating Furnaces - mildew smell when forced air blower on

Since the weather has recently turned cold we have turned on our heating. The first thing I noticed was that it smelled like mildew and has been ever since. I have forced air heat and A/C that was installed after the house was built (home is ~40 years old). I checked for moisture or water in and around the accessible areas of the furnace, vacuumed all the vent covers and the smell remains. Where could this be coming from and what can I do about it. Should I have someone come in and clean my ductwork?

You need to try and clean the evaporator coil and drain pan. Some times the installer makes it impossible to get to without cutting an access hole to the area. Use a weak solution of water and bleach if you can get to it. If not it's best to call a pro because you need to be careful cutting this panel so you don't puncture the coil.

I have the same problem with a smell coming from the vents when the heat is on. I posted in this forum and received the same good advice...clean the coils and drain pan. This is also what a friend of my husband's said (he used to work in heating/cooling) to do. I put my husband to work last weekend and he sprayed the coils with half a bottle of disinfectant. We still get the smell sometimes, but not always.

Our house is only 5 years old...I never knew that we would have to clean the coils on the system in a "newer" house to keep our heating from "stinking up" the place. I would love to be rid of the "off" smell for good. Any other ideas? My husband is going to go back in there and try to clean things better. Hopefully this will help.

If you have the pan and coil clean now, You could look at putting in a ultraviolet air treatment system in the duct there. They get the airborn germs and prevent mold spore growth in the duct work. go www.honeywell.com/yourhome and look around
;) ED