Being Sued

I sold my home in late October and six weeks after the sale my buyer had to replace the furnace due to it being red tagged for a defective heat exchage. She had an FHA and a professional home inspection which both Okay'd the furnace. She is sueing me for the full cost of replacing her furnace. No warranties were given and no insurance policies were purchased by either of us. I lived in the home until the day of closing. HELP

I live in Ohio, I own a duplex. had an inspection of my furnance, and the furnance in the rental unit done in October 99.
In november, during an second inspection, my furnance was found to have cracked heat exchanger. And the rental furnance was still good, then in January 2000, the rental furnance, developed a cracked heat exchanger.
The whole point I'm trying to get across is
the furnance could pass one inspection, then fail one a week later.

I don't see how you could be held responsible.
But check into your local regulations.