Why do new dishwashers take so long to complete a normal cycle?

That's the downside of lower water and energy use

Published: April 23, 2014 04:15 PM

Dishwasher cycle of 3 hours, 20 minutes

Between federal energy standards and the Energy Star program, dishwasher manufacturers face myriad restrictions—some mandatory, some voluntary—that require them to make dishwashers that use less water. and energy But when they do, something has to give and that something is time. Some of today's dishwashers take more than three hours to complete a normal cycle.

Think of it like the food you buy. To appeal to consumers who want less fat, salt, or sugar, food makers alter the amount of other ingredients as well. Look closely at the label, and you'll often see that when the amount of one undesired ingredient is reduced, the amount of one or two others goes up. If it didn't, you may decide the food tastes awful. Making the food taste good enough for you to buy it again is the bottom line.

In the case of dishwashers, both water and energy are needed for a model to do its minimum job—spraying hot, soapy water at the dishes and rinsing them afterwards. But to qualify a model for Energy Star, manufacturers have to limit the water and energy the machine uses for its normal cycle even more than the federal standard requires. No matter how miserly they are, though, the bottom line remains: Dishes have to get clean, or the machine doesn't sell.

It's a simplification, but no regulation addresses how long a cycle can run. So don't expect normal cycles to drop anytime soon from their 2- to 3-hour mark. Fortunately, there's some good news: While dishwasher makers are limiting the water and energy their normal cycle uses, no regulation blocks them from also offering quicker cycles that claim to wash either a fully soiled load or, more commonly, a lightly soiled one.

We don't recommend you pre-rinse dishes; today's better dishwashers can get off even the grungiest stains. But if a quick pre-rinse turns your load into a "lightly soiled" one you can complete in a half hour, go for it. Models that include such cycles include most of our top dishwasher picks, including the Bosch Ascenta SHX3AR7[5]UC, $730; Kenmore Elite 12783, $1,200; Kenmore Elite 12793, $1,350; and KitchenAid KDFE454CSS, $1,500. Of these, the Bosch has the shortest normal cycle at 95 minutes.

In the market for a new dishwasher? Check our buying guide for dishwashers before viewing our Ratings of almost 170 models.

—Ed Perratore
(on Twitter, follow @EdPerratore)

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