Me? I'd have given her all the money back.....and felt bad about the situation. I sell a lot of stuff used - on ebay and elsewhere. I usually sell it all as-is, but say "it works fine - and look at my feedback". I don't worry about the law. If you do as you would want others to do to you, the solution will become more clear...... Just like most here, I'm not a lawyer either - but there is such a thing as "implied fitness for merchantability", which basically means that something you sell to accomplish a task should do that task.... Each situation is different....when I have something which is REALLY beat, maybe like this furnace.....I would have probably noted in the sale ad AND in the bill of sale that it was being sold as scrap......or something to that effect. For instance, I sold some slightly defective chimney extensions I had and clearly told the people I was selling them a piece of "non-combustible decorative building material", not a chimney extension. Time is money. Court sucks. If she does not show up the first time, she might have a good excuse....and then you have to go twice! If you don't show, she probably gets the award, but still has to go though trouble to collect it (they can't force money from your pocket in most places without a lot of documents!)..... Sometimes you have to eat one...... Other than all the advice here, I would present this on one of the many legal forums around or talk to a friend who is a lawyer (if you have one)...don't pay a dime, because the whole case is too small to hire anyone!