Improve the Performance of Your Automatic Dishwasher

The first symptom demonstrated by an aging, automatic, dishwasher is a noticeable increase in the number of dishes and glassware that having completed the washing cycle appear less than sparkling clean. Dishes will appear with food residue clinging to the surface of plates and saucers. Coffee cups and glasses will contain traces of lipstick or dark stains remaining in the bottom of cups or the center of saucers.

Most homeowners are at a loss to explain to the change in performance of the once reliable dishwasher. The first reaction in an attempt to improve dish washing performance is to buy and use more expensive automatic dish washing detergents, but these seldom correct the situation.

Studies have shown that as automatic dishwashers age two factors become critical in the performance of these older machines. When the quality of washing begins to deteriorate investigating and correcting, if necessary, either or both of these two factors can return the performance of the older dishwasher to its' original level of performance.

The first and easiest condition to check is the temperature of incoming "hot" water. Manufacturers of dishwashers state that the minimum water temperature for dish washing be at 120 F. degrees. To ensure food deposit removal 140 F. is required, and to sanitize dishes the water temperature must be 155 f. degrees or above. It is significant to note that the requirement for water temperature in the automatic dishwashers employed in public restaurants be measured at 180 F. degrees or higher to meet the requirements of most health departments.

Many of the failures of automatic dishwashers to provide an acceptable level of dish and glassware cleaning can be traced back to insufficient water temperature. Often this can be the result of the dishwasher being located at the opposite end of the house from the water heater. This requires the water to travel through several feet of non-insulated pipe. As a result water leaving the water heater at 120 F, degrees arrives at the dishwasher at 110 F. degrees.

To compensate for the above water heater temperature must be set at a level sufficient of offset the loss in temperature due to distance traveled.

Another factor affecting water temperature is the recent attention given to conserving energy. Many homeowners have reduced the water temperature set on water heaters in an effort to reduce energy and reduce high energy bills. Water temperatures set at 110-115 F. degrees may provide a comfortable shower or bath, but are insufficient for effective dish washing.

After investigation the failure of dishwashers to clean effectively has been traced back to the day temperatures on water heaters were reduced (without realizing the effect this might have on dishwashing and sanitation) .

If after investigation water temperature is found to be sufficiently hot (as defined above) the second most likely cause of loss of cleaning effectiveness can be found in the dishwasher spray arm. These spray arms contain many small (pore-like) holes(nozzles) through which water is pumped under pressure as the spray arm rotates. After many years of service these holes can get clogged with tiny particles suspended in the water. The effectiveness of cleaning deteriorates in proportion to the number of holes (nozzles) clogged as the quantity of water available for spraying is decreased.

To correct this problem the homeowner can clean the spray arm holes using a thin wire. The cleaning is done by starting at one end of the spray arm and plunging the thin wire into the hole nearest the end of the arm. Plunge the wire in and out of each subsequent hole three times each until every hole in the spray arm has been cleaned. In instances of severe blockage colored deposits will be visible on the wire or on the surface of the washer bottom. The wire should be wiped clean of deposits after every fifth hole (more often if an accumulation on the wire is observed).

After cleaning all spray holes wipe clean any debris or dirt remaining in the washer bottom.

To complete the cleaning, set the washer while empty to run on a short wash cycle. Once the washer has added all of the wash water add two cups of white vinegar and allow the cycle to complete. The white vinegar will further clean the spray nozzles and will serve a secondary purpose of freeing up any brittle rubber fittings.

After addressing the water temperature and correcting it to the required level and after cleaning the spray arm nozzles your washer's cleaning performance will improve dramatically and may well return to the performance of its' early years.