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by 15457345234 931 days ago
This must be a US-centric thing, having had many dishwashers in my time and having never seen one with anything other than a cold water inlet.

I assume this is related to the availability of 230v/15A for the heater element.
2 comments
crazygringo 931 days ago
If you have hot water, why wouldn't you use that for the water connection?

My dishwasher has a heating element, but the colder the water is, the more it has to work.

So if it's cheaper to use gas-powered hot water from the boiler than to heat it electrically, why wouldn't you? And it's there in the kitchen right next to the sink which has hot water available anyways, so it's kind of a no-brainer.

Yes, I'm in the US -- you can see on a kind of average dishwasher installation manual [1], it specifically instructs you to connect it to a hot water line.

[1] https://www.whirlpool.com/content/dam/global/documents/20101...

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adrianN 931 days ago
My dishwasher uses sufficiently little water that it would get mostly cold water from the hot water pipe.
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crazygringo 931 days ago
Yeah, the standard advice is actually to run your kitchen faucet on hot until you get hot water, before you start the dishwasher.

I'm always rinsing off the bigger gunks of food with hot water anyways as I load the dishwasher, so it's hot already.

At the end of the day it doesn't matter that much. The main point is just, if you have hot water available, it's hard to see why you wouldn't take advantage of that.

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adrianN 931 days ago
I’d assume that wasting a lot of hot water before running the dishwasher negates any price benefits from heating the water with gas instead of electricity. Not to mention the CO2.
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nemetroid 930 days ago
> If you have hot water, why wouldn't you use that for the water connection?

Two protein related reasons: hot water can denature detergent enzymes making them less effective, and hot water can cause food proteins on the dishes to harden and set.

European manufacturers claim that detergents work better when starting the program with cold water, and recommend doing so. The situation might be different in the US, where using the hot water seems to be the norm.

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wkipling 931 days ago
Must be. I'd say most dishwashers are connected to the mains supply and not pre heated.
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