Dad’s short answer: Yes, and it's the feature I'd prioritize after cleaning performance. Hot water in the dock's self-clean cycle is what actually gets the roller clean instead of just wet, and a genuinely clean roller is what keeps the machine from smelling.

Two different hot water features, often confused

Hot water washing is the dock cleaning the roller with heated water after you're done — usually somewhere around 90°C on the better machines. That's the one that matters most, because it's what strips the grime out of the roller fibers rather than rinsing the surface.

Hot water mopping is different: heated water going down onto the floor while you clean. It helps on grease and sticky residue. One flagship I tested handles this in an unusual way — the dock pulls the water back out of the machine, heats it, and refills the tank hot before you start. Effective, but you have to remember to press the refill button or you're mopping with room-temperature water without realizing it.

Neither of these is steam. That's a separate thing and I've written about it.

Why a cold rinse isn't enough

A roller rinsed in cold water holds onto a surprising amount of what it just picked up. It looks clean and it isn't. Over a few weeks that residue is what turns into the smell people complain about, and it's also why a neglected machine starts leaving streaks — you're mopping with a dirty roller.

If you're choosing between two machines and one has a hot wash cycle, that's a meaningful difference in how the machine ages, not a spec-sheet nicety.

Dad’s Take: Cold rinse machines are the ones that end up smelling in month three. Pay for the hot wash.