I just looked on the wiktionary for a translation of reinvent the wheel and was given scoprire l'acqua calda. I do not agree. AFAIK, reinvent the wheel means to redo work that others have already done (cfr. also the wiktionary's definition of said idiom), whereas scoprire l'acqua calda (typically found in the nominal form "scoperta dell'acqua calda") means to discover something obvious, perhaps with lots of thought and/or effort. Do you agree that the Wiktionary is wrong about this or do you think something above is wrong, or that there is more to the issue than what I wrote?
There is at least one situation I can think of where I would use the English idiom but not the Italian one, and it is the situation I first saw the English idiom used in. If someone tries to recode something that has already been coded and made available by others via a class, library, or macro package (and that is the case I found it in on TeX SE), that is definitely reinventing the wheel, but (IMHO) definitely NOT scoperta dell'acqua calda.