Dishwashing: Cold Water, Hot Issue

It's positively humbling how complicated it is to check out a simple question about dishwashing.

Take, for instance, the comments we received from B.J.

``Water heaters are set at 120 degrees Fahrenheit by state law. Dishwasher soap dissolves at 140 degrees. As a result, it coats our dishes and the coating melts into the foods we eat and drink,'' B.J. wrote.

``My son had stomach problems until we discovered this and started washing dishes with high heat. Seems the public should be informed,'' she concluded.

Checking out that note sent us to two utilities, several public agencies and a trade association.

And in case you are new to this area, you need a brief historical note. In 1983, the Washington state Legislature passed a law, which requires that residential water heaters be preset by the manufacturer no higher than 120 degrees.

Advocates who helped bring about that change in the law made compelling arguments about the unnecessary risks of burns that are posed by hot water. The elderly, the disabled and children are especially vulnerable.

The statute also requires utilities to notify customers at least once a year that residential water heaters should not be set higher than 120 degrees. And water heaters sold or installed after July 24, 1983, must have a tag attached noting the risk of burns if the setting is above 120.

Dishwashers have changed since the early 1980s, too.

Many new dishwashers have their own heating systems so that consumers can have their dishes washed at temperatures higher than 120 degrees.

If you have an older dishwasher without its own heater, the Soap and Detergent Association recommends that you use a prewash or prerinse cycle to compensate for the lower water temperature of 120 degrees. Or hand-rinse the dishes to remove as much soil as possible before you put them in the dishwasher. You also may have to use more detergent.

The Soap and Detergent Association says dishwashing detergents should effectively dissolve at temperatures below 140 degrees.

Even at temperatures well below 140 degrees, ``there is no indication that the detergent would coat or stick to dishes,'' said Jane Meyer, director of consumer affairs for the association.

The folks in the conservation business have a few words on this subject, too.

``We recommend conservation, not sparkling dishes,'' said Connie Fevold, an energy planning supervisor for Seattle City Light.

If homeowners have trouble with spotted dishes, Fevold suggests they experiment with different brands of detergents and rinse and scrape their dishes in cold water before placing them in the dishwasher. Or wash badly soiled dishes and utensils by hand.

``I would hate to see people raise water temperatures just because of how the dishes look,'' Fevold added.

As an energy-saving device, City Light also recommends turning off the dishwasher's drying cycle. But that, too, can leave spots on dishes.

City Light sends its customers literature on ``Using Appliances Efficiently'' prepared by the Energy Extension Service of the Washington State Energy Office.

The literature notes that a dishwasher costs from $40 to $50 to operate annually, and is among the top 10 energy users in the home.

City Light says a dishwasher requires from 10 to 16 gallons to run a full load, depending on the model and brand.

You can reduce energy costs by:

-- Installing the dishwasher away from the refrigerator or freezer, to reduce the transfer of heat from the washer to the other appliance.

-- Washing only full loads of dishes.

-- Using cold water to prerinse.

-- Using short cycles for easy-to-clean loads, or using the ``air dry'' or ``power saver'' switches.

When buying a new dishwasher, compare the energy-savings labels of different brands.

If you'd like more information, write the Washington State Energy Office, 914 E. Jefferson St., No. 30, Seattle 98122, or Seattle City Light, 1015 Third Ave., Room 123, Seattle 98104.

To receive information from Puget Power, write the utility at 411 108th Ave. N.E., OBC8N, Bellevue 98009-9734.

Puget Power notes that washing dishes by hand takes about the same amount of energy as by machine.

``However, if you have a dishwasher, you can save energy by running full loads on a regular basis. In addition, you will also have cleaner, more sanitary dishes,'' according to Puget Power.

Shelby Gilje's Troubleshooter column appears Sunday through Thursday in the Scene section of The Times.