Last year, we replaced the dishwasher that came with our house. It had stopped cleaning dishes altogether and was too costly to repair. Then, just last week, our new dishwasher began malfunctioning. When the repairman came out, he said the problem was...drum roll, please....I was putting dirty dishes in the machine. (Yes, I'm serious. More on this later.)

With these things in mind, here's what I've learned in recent years about how to (and not to) run a dishwasher.

Why Use a Dishwasher?
Whenever I have dishwasher problems, I feel slightly guilty. After all, one can't actually say a dishwasher is a necessity. On the other hand, a dishwasher does lighten my workload, shortening the amount of time I spend doing dishes. It also saves us money on water and energy bills.

There are a number of studies proving dishwashers use less water and energy (to heat the water), but the most recent was conducted by the University of Bonn. It showed that even among those who took great pains to use as little water and energy as possible while hand washing dishes, dishwashers still did a more efficient job. On average, dishwashers used about 4 gallons of water and used1-2 kWh of total energy. Hand washing used an average of 27 gallons of water and 2.5 kWh of energy.

Not surprisingly, the Environmental Protection Agency (EPA) has something to say on the topic, too. They claim a post-1994 dishwasher saves 1,300 gallons of water over its lifetime. So yes; there are good reasons for using a dishwasher.


The Problem with Older Dishwashers
I like old dishwashers. As long as they are in good repair, I believe they do a much better job of cleaning dishes. However, they do use more water and energy than modern Energy Saver dishwashers. And now that the EPA has scared dishwashing detergent makers into removing phosphates from detergents, old dishwashers don't clean dishes nearly as well. So many Americans are now finding they must buy new dishwashers, or begin hand washing.

The Problem with New Dishwashers
However, new dishwashers come with their own set of problems. Yes, they use less water and energy - but at a price. Dishes that go into new dishwashers must be well rinsed before they go into the dishwasher. Water pressure is lower in new machines, and sensors that indicate dirtiness may make the washing cycle considerably longer if dishes go in dirty. 

But your dishwasher has a food grater, you say? According to my repairman, they are chintzy and don't work well - so count on them to only get rid of very small, very soft, accidentally-left behind pieces of food.

In addition, new machines are liable to plug up or leak if you ignore these new rules.

When I expressed amazement at all this, our repair man - who has been in the business for over 20 years - said, "They don't make a really good dishwasher anymore. They just don't do the job well. The best brand is Bosch, but they aren't that much better than anything else, and they cost a whole lot more." 

Tips for More Efficient Dishwasher Use:

* Clean the dishwasher at least every two months. Most manufacturers recommend buying special cleaner for this, but our repairman says a cup of white vinegar works just as well. Just pour it into the machine and run it through a wash cycle.

* Inspect the machine before every use and remove any bits of food. Look especially along the seal and the drain.

* Rinse dishes right away; don't let them sit in the sink or dishwasher while they still look dirty. This simple step saves time, water, and energy because you won't have to really wash or scrub dishes before putting them in the dishwasher.

* Run the dishwasher only when it's full - but don't overfill, block nozzle sprayers, or overlap dishes so water can't get between them.

* To save more energy, stop the machine after dishes are clean but before the dry setting kicks in. Either use a dishcloth to dry the dishes or air dry the dishes in the dishwasher. (If you feel you must let the dishwasher dry the dishes, be sure to use Jet Dry or a similar product or the sensors in new dishwashers will make the dry cycle last much longer.)

* Use the right amount of detergent. Using too much leaves a film on dishes. Using too little can result in dirty dishes. Consult your dishwasher manual for details.

*  Read your dishwasher manual for tips on the most efficient loading and maintenance techniques for your particular machine. If you don't have the manual, check for it online. Often, they are available as a free download from the manufacturer.