Well I encountered another one just last week. The infamous recalled horizontal attic furnace (isolated to California from what I've read). Here's the issue (in a nutshell):

The Torrance Fire Department noticed they were going to fires that seemed to start in attics. They then realized that certain furnaces were located in the houses with these fires. The investigated it and sent their information to the Consumer Product Safety Commission (CPSC). The CPSC reviewed it and announced an official recall of certain horizontal attic furnaces. The furnaces have NOx rods that are problematic and can catch fire, obviously a serious concern.
The list the Consumer Product Safety Commission gives for the recall is much more limited than that on the Torrance Fire Department's website. I'll stick with the Torrance Fire Department to stay on the safe side (after all, they are a fire department).
Of course the companies involved in these recalled furnaces are mostly bankrupt at this point. The Torrance Fire Department advises replacement of these furnaces and not repair.
Now keep in mind that in Southern California attic furnaces are very common and many have no problems at all. Please click on the following links to get the date, brand names and serial numbers of the furnaces involved as given by the Torrance Fire Department and the CPSC. The furnaces were made between 1983 and 1994 but might be in houses a few years after 1994 if they sat in a warehouse before they were installed.
And by the way, the first house my wife and I bought had a recalled attic furnace and the home inspector didn't even know about the recall (part of the reason I got in the business).
Click on any of the underlined words above to go to a website with further information.
I hope this gives you a little more information about a home inspection and its value. Be safe out there.

I remember seeing this issue on the news a couple of years ago. Because of it I mention to buyers of any homes (very few of them here in Yucca Valley) that I've heard of potential problems with certain attic furnaces.