Dishwasher versus handwashing for multiple small loads: efficiency pros and cons...

[Kaleva]

13. Dishwashers use tap water.

Residential dishwashers are supplied by the same hot water line that feeds the kitchen sink faucet.

I've installed many dishwashers and I've never had one where the instructions said to hook up the supply line directly to the output of the water heater and before the mixing valve (if one is installed).

To do what you say, one would have to have a dishwasher with a booster heater and those are very expensive and mostly used in commercial applications.

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