The amount of water heated up in each cycle is small enough that 1500W is not the limiting factor. Maytag recommends connecting to the hot water outlet and recommends a minimum temperature of 120F [1].

The Miele user manual for their USA models recommends connecting to the cold water inlet unless the hot water is known to be heated by a very efficient source [2].

[1] https://producthelp.maytag.com/Dishwashers/Product_Info/Dish...

[2] https://media.miele.com/downloads/05/c4/00_96106053F20B1EDDB...