Central A/C turned on last night and within 5 minutes the entire house smelled like smoke - the kind of smoke that comes from an electrical fire. I immediately turned the system off and checked the unit. Found nothing amiss with the compressor/condenser outside the house. Checked the indoor component that sits atop the furnace in the basement and found nothing wrong or on fire. Incidentally, loud clicking sounds were coming from the furnace right before the smell of smoke was noticed.

This is the first time this happened. The A/C unit is only 2 years old and the furnace is about 6 years old.

Any help or advice would be appreciated!

Thanks,
MK

Does the blower fan run in the furnace?, the furnace/airhandler is what cycles the air out and back into the house

Sometimes dust collects in the system and the first time you fire it up for the season it "burns off" and gives a burning smell. It happens at our office nearly every year. Never hurts to have your system checked out each year. Many companies do a "tune up" for a reasonable price.

The fan blower does work. And it had been working fine thus far in the season. The unit is in the basement and the basement is ordinarily humid in the summer, and I did notice that there seems to be a lot of condensation around the joints of the ducts. Which means that there's probably condensation inside the ducts as well. As far as I know there is no "de-humidifier" feature. Could that moisture cause damage to the internal parts of the unit?

If you have condensation in the electrical side of your system its not good. You may have burnt out a blower motor or blower control from moister getting in it.