DeLonghi has not merged or started a joint venture with btc in mind
I think about them every time I come home to my toasty apartment heated by an A1 Dragon instead of a DeLonghi Dragon. The kicker for oil-cooled miners as space heaters is probably access to internet, and reduced returns. Sure almost everyone has wifi these days, but what's the overhead cost of adding a wifi-enabled computer and enough interfacing to actually configure it? Additionally, how much money is there in a gimmick heater that'll return bitcoins during the season but when you plug it in the next year the returns are about 10% what they were the winter before?
I do know some folks using immersion miners to heat industrial space by patching into existing in-floor heat piping, but I'm not sure how "off the shelf" feasible it is for average folks.