If you are fortunate to have a dishwasher in your kitchen, this practical appliance will save you countless hours of your valuable time washing-up and drying pots, pans, cutlery and dishware in your kitchen. This can be a real time-saver especially on those days when you invite guests for dinner and can leave all the work to your trusty dishwasher “robot” so you can enjoy the evening without having to worry about that mountain of work waiting for you in the kitchen the moment your guests leave to go home. We all know what a dishwasher is and all the benefits that it brings you by relieving you of the routine cleaning chores after each mealtime, but have you ever stopped to really ask yourself how this marvelous invention actually works its wonder? In this short article, I would like to explain this in layman’s language that anyone can understand. While dishwashers may differ slightly from model to model, they all work according to the same basic principles. Below I will deal with the four basic stages of the dishwasher operation as well as the most common problems you may encounter in the process.
The Filling Operation
The filling cycle normally commences when draining the water from the appliance, although some of this water is retained in the sump housing in order to prevent the seals from drying out and cracking when the dishwasher is not in use. The majority of dishwashers have a time-filling cycle, which will not allow more than 7.5 liters of water to enter during operation. This water is connected to the water inlet valve on the dishwasher via the water supply line of your home.
Once you have selected a wash cycle, the controller sends 120 volts of alternating current to the inlet valve’s solenoid, which opens the valve and allows the right amount of water into the dishwasher. The voltage sent by the controller then keeps the valve open between 90 and 120 seconds, depending on the model you have. If the controller fails and does not shut off the voltage to the valve, a float then actuates a switch that shuts off the water immediately. It is important to bear in mind that the purpose of a float is only to prevent overfilling, but it will not actually monitor or control the quantity of water entering the tub. A crucial factor determining the performance of the dishwasher is that it has the right quantity of water. If the dishwasher does not have sufficient water, the dishware will not be cleaned properly, which is normally caused by a restricted water inlet valve. If you want to find out whether or not the water inlet valve is restricted, you should pour between 1 and 2 liters of water into the bottom of the tub and then run the dishwasher. Should the dish performance improve after doing so, this indicates that the valve is probably restricted and should be replaced. Should this be the case, is not advisable that you clean out an old valve owing to the risk of part failure after repair.
The Washing Operation
Once the right quantity of water has flowed into the tub, the washing stage will then start. Water circulation, detergent and water temperature are the three factors affecting the wash cycle. To circulate water within the dishwasher, the controller sends voltage to a circulation motor. The motor drives a pump, which uses an impeller for forcing the water up through the wash-arms. The arms are driven by the water jetting out from the holes. If the arms do not rotate or you experience poor wash performance, the cause could be attributable to a worn or damaged impeller. As the food debris is being cleaned from the dishware, it collects in the sump that filters and retains the larger particles. bosch dishwasher sms46ki03i This filter prevents larger food particles from being circulated through the wash-arms. During the course of time, some particles might still reach the wash-arms, clog the holes and thus reduce wash-performance. For this reason, you might need to clean out the holes at regular intervals. In addition, you should note that it is normal for the arms to feel a little loose when they are not in operation. As the water circulates through the arms, a wax motor or solenoid then causes the dispenser to open thereby releasing detergent that mixes with the water. Since dishwasher detergent does not create suds like other detergents or soaps, you should only use detergents stipulated for use with dishwashers. You should also bear in mind that too much detergent may cause pitting or etching on glassware. For this reason, you should always follow the manufacturer’s recommendations. Depending on the setting, the dishwasher might use a heating element during the wash cycle. The controller will send voltage to the element at regular time intervals in order to maintain a water temperature between 120 to 160 degrees F. If a problem should develop, a high-limit thermostat will then switch off the voltage in order to prevent damage to the dishwasher. If you think that a heating element is not working properly, you can test this element for continuity to determine whether or not a continuous electrical path is present. Upon completion of each wash cycle, the dishwasher will drain the dirty water from the tub. The controller sends voltage to a drain pump that uses an impeller to force water through the drain hose to a disposal pipe or drain pipe. To ensure proper drainage and to prevent water from flowing back into the tub, you should make sure that the drain hose has a loop that goes above the drain. If the water does not drain, you should first check the drain hose for any obstructions. If the hose is unobstructed, the drain pump might be faulty and need replacing.
The Rinsing Operation
The dishwasher will go through several rinse cycles similar to the wash cycles, and might also use the heating element. During the final rinse cycle, rinse aid is introduced from the dispenser instead of detergent. This helps to dry the dishware and prevent streaking caused by hard water. The harder the water, the more rinse aid will be needed. Always refer to your user’s manual to determine the optimum rinse aid setting for your use. After the rinse cycles have finished, there will be a final drain cycle. As mentioned above, some water will remain in the tub in order to preserve the seals and prevent cracking.
The Drying Operation
Once the dishware has been washed and rinsed, and the water has been drained from the dishwasher, the drying process will then begin. Two things are needed to dry the dishware efficiently, namely heating and venting. Some dishwashers will use a heating element to heat the area inside the tub, whereas other models will rely solely on heat generated by the final rinse cycle. The hot, moist air will either exit through the permanent vent or be emitted through a vent in the door opened by a wax motor or solenoid. Without proper venting, the moisture or water vapor would condense back into liquid and then collect on the dishware.
So there you have it in a nutshell. Understanding how a dishwasher works is not rocket science requiring a degree in physics. Its basic operations are really quite simple to comprehend. And even if you do not intend doing any repair work yourself, it is still well worth taking the time to understand these basic principles so you have a good grasp of what is actually happening “underneath the hood” during the wash cycles. And in the event that a malfunction should occur, you will be in a much better position to give an intelligible account to the service technician of what you think the problem might be when you call him in based on the rudimentary knowledge in this article.