Like what exactly? I am curious. Is this happening because if everybody was buying industrial dish washers an entire industry was going down or there are legitimate problems?
"One of the things about commercial equipment is the lack of insulation. So there could be issues with the booster heater affecting the counters around it. The moisture that comes with a high temp machine are also an issue. Maintenance can be a problem if he doesn't have a softener. EDIT: probably the worst thing though, which is mentioned by someone else below, is that if a commercial appliance causes a fire or other damage, you might be S.O.L. when it comes to your homeowners insurance."
That said, who doesn’t want a big gas griddle, serious fume hood exhaust, and a giant three door stainless fridge in their kitchen?! I’m so tired of smoke detectors going off when I try to cook a steak indoors, or filling the whole house with burger grease smoke.
A real set of commercial kitchen gear, in a room designed for the purpose, to me is the ultimate luxury kitchen. Beats the hell out of those pot-filler arms and silly islands that pass for such these days in residences.
Follow the clearances, supply the 240V 50 amp power, install a catch pan under it, soften the water if needed, etc. None of it rocket science if you are mechanically-minded, but requires to educate yourself and pay attention.
My friend is from a large family, and they had a proper commercial kitchen in their house growing up, so no big deal for him.