[Jean recalls what he overheard (he was definitely no eavesdropping, he just happened to be close by).]

Levi just said that hot water's run out again, so it's not the first time. Apparently Eren had just been to the shower before that. Most likely he's been trying to help his condition with hot water in silence.

[Because of course he can't just tell others he's feeling bad. At least Reiner was upfront about being in a shitty situation.]

Later I encountered Levi arguing with the roomba which struck me as weird...