Strong chemical/solvent/petroleum smell in the ductwork. Some describe it as a new carpet smell, others think fresh paint, and some say it smells like the wood floors have been refinished. It might be in my head.., but it seems to give me a headache and my son frequently clears his throat when the smell is present. We've lived in the house two years without the smell and we have not done any recent remodeling and or touch-ups.

Here's some potentially important info. It rained a lot in May. One morning after a hard rain we opened the door to the basement and could smell the smell. There is no moisture in the basement or on the outside wall. I aired out the house, ran the fan, the furnace, and today I turned on the AC. I've done this both with and without the electronic air filter. All produce the smell from the vents. When the system is off you can only smell a faint odor from the air return-- this persisted during the last month and a half of no system with windows open.

We wondered if the furnace was not burning properly and had a pro take a look at it. He said it was clean and burning properly.

The utility room houses a gas furnace, gas water heater and shares a wall with a gas fireplace.

Any ideas on what to do next? What kind of professional do I call?

Thank you for your thoughts.