The experiments with the e-cat were measuring temperatures and estimating heat flow of the hot air flowing arround the device. That's too difficult to do acurately.
If you see a report of a groundbreaking experiment that only measure the heat of the air, you can safely press the "meh" button.
https://en.wikipedia.org/wiki/Energy_Catalyzer
nothing happened, of course, but the idea of an elegant energy source was so seductive.