Why won’t the dishwasher drain water? A serviceman can name you several causes for that. Drainage of dirty water is the final moment of the next stage of a washing program. If dirty water does not drain, the dishwasher will not be able to proceed to the next wash stage. And in some types of dishwashers, the issue with draining might not reveal itself until the end of the wash. Only when the program is complete and the owner opens the door, they see that the dishwasher has not drained the water: dirty water is still in the tub and the dishes are not clean enough.
Poor drainage may be caused various factors:
- Drain hose is positioned incorrectly.
- The filter is covered with grease.
- Other parts of the drainage system are clogged.
- Drain pump is out of order.
- Faulty water level sensor (pressure switch).
- The control unit has failed.
Drain hose issues
If the hose is incorrectly positioned, you may not notice the problem right away. If the hose is kinked, the water will not flow at all. But if the hose is slightly bent, then you will not be able to detect the problem until there will be a clog.
Primary filter clogging
Primary filter is located at the bottom of the tub. Remove the filter by simply unscrewing it. It has to be removed and rinsed well. If necessary, rinse the filter housing as well. Now you only need to remove all deposits from it.
Other parts of the drainage system are clogged
The debris could go down the pipes and could get stuck there. In order to do cleaning, you will need to remove the cover of the dishwasher, and twist the elastic pipes a little. The debris will liquefy and leave after you first wash.
Drain pump is out of order
If you cleaned the entire drain system, but the water does not drain, then it is quite possible that the pump itself is broken. You can hear it right away, since when the drain starts the pump makes a specific clicking sound. If you hear no sound then the pump is most likely broken. In some cases it can be repaired. It often happens that it simply gets stuck due to the lack of lubrication. It also happens that the dirt gets onto the impeller and it stops spinning.
Faulty water level sensor
The failure of the water level sensor may often be the cause of poor water drainage. This device works on the principle of communicating vessels. The pressure switch tube is connected to the tub so that the water in it is always at the same level as the water level in the tube during filling. Water in the tube compresses the air in its upper part. Pressure switch measures the pressure and determines the amount of water in the tub.
If the sensor is faulty, or there is a crack in the tube, the sensor will send wrong data to the control board. The system will assume that the water has been drained and will refuse to pump it out.