Options are - buy a reconditioned piano from a dealer, you pay more that buying privately but you get some form of warrenty.
Just to amplify this: make sure you understand the the various definitions of 'reconditioned, rebuilt, renewed" etc. They mean different things to different people.
Also, buying a recently built, but used piano from a dealer may present the best of all possible worlds, it certainly was the case for me. You get the piece of mind of buying from a dealer, but the piano is new enough that you do not have to be concerned about age related problems, or understanding the issues I raised in my first paragraph.
I have become friends with a few dealers and I can tell you that there are certain pianos that they take on a trade-in in order to accomodate a sale, that they do not want around their showrooms. It might be a competing line to their main seller, it might be a line they've previously sold, and have a bad relationship with the distributor or something. There are variety of reasons why a dealer may be motivated to sell a
used piano to a
used piano shopper at a good price. The main reason being that the used piano may take a new piano sale away from them. So get to know the dealers around you and let them know what you may be interested in.
Oh, and get Larry Fine's The Piano Book. There's lots of questions in my mind about the objectivity of the ratings, but as a far as sound advice on how to go about shopping it is a great read.