Welcome to Wikipedia in action.
If you go back to the older versions of the article, such as this one, you'll see that the operation of the device was explained as thermal siphoning. Then someone copied a press story into the article (complete with headline and subhead, notice). Someone else tried to tidy up the resultant mess. A third person copied another press story into the article wholesale. A fourth person tried to tidy that up. And thus we are where we are now, with an article that is the result of well-intentioned copy editors tidying up after plagiarists: one that is in large part lightly revised copies of uncritical news coverage rather than original and neutral encyclopaedic writing that presents known facts.
It's also worth observing that the article by Ovidiu Sandru, a partial copy of which forms much of Wikipedia's article right now, goes on to say, in the part not quoted in Wikipedia, that "[s]ome scientists say the device works by transforming thermal energy into mechanical work", but the museum director disagrees with them. Sandru very clearly sides with the museum director rather than the scientists.
The proper target for skepticism here is Wikipedia. You've got an article that has been built by a succession of plagiarists who cannot themselves write copying sensationalist snippets from news articles. Those snippets have usually been the first couple of paragraphs, which of course will contain the attention-grabbing speculative sensation rather than the boring old facts about what scientists who've looked at the thing say, that were buried 10 paragraphs in. As a result of this plagiarize-tidy-plagiarize-tidy cycle the article is biased towards sensation and speculation and low on the boring old facts of the matter.
Beware taking as factual encyclopaedia articles created by people who cannot write.