Types of Dishwashers
Built-in dishwashers are permanently installed (with water and electrical hook-ups) under a kitchen countertop and typically are 34" high and 34" deep or smaller. Built-in 24" dishwashers fit into a standard 24"-wide opening between kitchen cabinets, while the more compact 18" built-in dishwasher are designed to fit in smaller kitchens with narrower openings. Experts recommend buying new hoses and hardware (about $10-$30+) when replacing an old built-in dishwasher.
Portable wheeled dishwashers are similar to built-ins but they roll on casters and hook up to a sink with two hoses, one attached to the faucet as a water source and one to drain the unit into the sink. (Hoses and a power cord are usually included with the dishwasher, and are typically 3'-6' long; buying a longer hose and/or an appliance extension cord can cost $10-$30.) Portable dishwashers are typically 18" wide, although some are 24".
Countertop dishwashers are short and compact -- about the size of a microwave oven -- and designed to fit between a kitchen countertop and standard-height overhead cabinets. Like portables, countertops have two hoses that connect to the kitchen sink when the unit is being used. (Hoses and a power cord are usually attached to the back of the unit, and are typically 3'-6' long.)
Each manufacturer estimates the decibel levels for its dishwashers. In general, a decibel level of 60 or more may disrupt conversation in the kitchen. The American Speech Hearing Association estimates that 30 dB is extremely quiet, like in a library; 60 dB is typical conversation; and 80dB-90dB equates to a loud blow-dryer or food processor.
The way that dishwashers function has fundamentally changed in the last decade or so. In order to use less water and energy, the internal structure of these machines is different and wash cycles take much longer -- in some cases up to two to three hours (although many have a "quick wash" option) -- and not all models have heated drying, so the dishes might still be damp at the end of the cycle. Some dishwashers now have a sensor system controlling the water levels, temperatures and/or detergent dispensing based on the soil levels in the water. Every new dishwasher is required to display an EnergyGuide label listing estimated yearly energy use (in kilowatt hours for households with an electric water heater and in therms for gas water heaters) and estimated annual operating costs (calculated using official national average utility rates that are updated every five years). Actual operating costs vary based on usage and local utility rates, but the EnergyGuide estimates are useful for comparing the efficiency of similar models.
An Energy Star logo means the dishwasher meets specific Environmental Protection Agency efficiency standards, and if the dishwasher is classified as CEE Tier I, CEE Tier II or CEE Tier III, it meets additional (and stricter) efficiency criteria by the nonprofit Consortium for Energy Efficiency, with Tier III models being the most energy-efficient.
Most dishwashers have at least three cycles -- light, normal and heavy -- and Consumer Reports estimates these should be enough for most cleaning chores.
However, there can be an automatic wash cycle for just about everything, from delicate stemware to food-encrusted pots and pans. Additional cycles might include quickly cleaning lightly-soiled dishes and extra scrubbing for heavily soiled dishes loaded in a specific section.
Dishwasher capacity is based on the number of five-piece place settings that fit in a single load. Built-in dishwashers with a standard-height tub (with a front access panel below the door) typically hold up to 12 place settings, although a few may hold more, while tall-tub dishwashers (with no front access panel) may have a capacity of 10-16 place settings, although 12-14 is typical. Countertop dishwashers are typically rated at six place settings, although many users find it challenging to fit that many items inside these compact machines. Wheeled portable dishwashers can be estimated at eight to 16 place settings, although 10-12 is common.
Most racks are made of nylon- or vinyl-coated wires, although stainless steel racks are available on some high-end dishwashers. Some dishwashers have racks that can be adjusted in height (typically two up-down positions) and fold-down tines to accommodate tall or bulky objects, but less expensive machines usually don't have this flexibility. Some units include additional baskets, hooks and special trays to hold knives, cooking utensils or small plastic items.
Generally found on less-expensive dishwashers, plastic tubs are relatively durable and are usually covered by a 10- to 20-year full-replacement warranty; Consumer Reports estimates that a typical plastic tub will last as long as most consumers own the dishwasher. A stainless-steel tub is durable; somewhat quieter than plastic (in part because of more insulation); resists rust, stains and odors; dries dishes more efficiently because metal retains heat; and withstands high-temperature rinses better than plastic. Dishwashers with a stainless steel tub usually cost about $100 more than a similar model with a plastic tub, but check whether the interior of the door is also stainless steel.
Controls can be positioned on a wide console on the top of the door panel, often with dials or other protrusions; hidden ("integrated") on the top edge of the door, creating a sleeker exterior but making it difficult or impossible to see cycle and progress indicators; or wrapped around the top of the door ("partially integrated"), with some controls hidden on the edge and a narrow console (typically 2"-3" wide) of lights and controls barely visible along the top front of the door.
Filters and Food Disposers
A filter prevents food particles from clogging the lines or leaving specks on dishes, and is essential for those who want to load dirty dishes in the dishwasher without scraping off all food particles. Machines at all price levels may have either a manual or a self-cleaning filter. A manual filter must be periodically cleaned by hand, while a self-cleaning filter typically includes a food disposer that grinds up any food debris and flushes it away -- a process that is often the noisiest part of the wash cycle. Some consumers prefer a manual filter (even in a high-end machine with all the bells and whistles) because the dishwasher is significantly quieter.