Giusi wrote
Rod Speed wrote
Giusi wrote
Bob F wrote

How can that be true, no hot water is wasted in a cold fill dishwasher.

But heating it may cost more, if the water heater is gas, for instance.

No,

Yes, he did say MAY.

because a tank water heater works 24/7 no matter how cheap

Plenty of the water heaters dont store the hot water.

I have that type of water heater,

And not everyone does.

but it takes a lot of water running before the water is hot.

Yes, that is one of the real downsides of that type of hot water system.

The dishwasher fills with a couple of liters of water, rinses, drains, then 3 liters that it heats.

Yes, but a dishwasher that uses piped hot water doesnt have to use hot water all the time.

Nor does mine use all hot. There is a prewash rinse that is cold, and maybe the first rinse is cold.

With mine its only the last rinse that is hot and that appears
to be so the dishes will dry without hot air drying, like yours.

How would I know?

Open the dishwasher at the end of each rinse cycle, just after you
heat it start to pump out for that rinse and check the water temp.

We are encouraged to use our dishwashers in Italy because it uses less water and energy than handwashing.

The energy claim is very dubious, particularly with drying.

We do not have heated drying in our DWs.

Yes you do with some of them.

It dries using reserved heat from a superhot rinse cycle.

Yes, mine operates the same way, but that isnt universal.

You can hear silence for a period followed by the sound of the drain opening. The dishes are very hot. On occasion I
have opened it right away to get something I wanted and burned my fingers,

Yeah, me too, when I was trying to clean some old beer bottles I got
at a yard sale and was trying to check how well they had been cleaned.

Didnt actually get burnt, but I certainly had to let go quickly.

but there is not hot air period that follows that rinse.

Yes, but that isnt anything like universal with all dishwashers.