Just checked my DW and yup, sure enough, it is connected to the hot line. I was thinking of the refer line. I’ll be honest I never really put much thought into it and now I feel silly.

I actually am American lol. I’m an electrician by trade, so I was thinking more in terms of the equipment on board of the DW itself, but this is much more logical now that I think about it. I let plumbers do their thing and avoid installing/servicing appliances for customers (although I did just pull a 24" hair snake out of my shower drain this morning, smelled wonderful).