Ideas for troubleshooting dishwasher problems will be particularly useful in the event that your appliance fails to fill with water. Inspecting your dishwasher to find the cause will help you to identify problem areas and find a suitable remedy. Before you begin investigating other options make sure the water beneath the sink did not get turned off, which would keep the dishwasher from filling.
1. Door Switch
Troubleshooting dishwasher problems should always begin with the door switch. This component controls the 'On' and 'Off' functions of the dishwasher switches, and prevents the door from being opened if there is still water in the appliance. Also, the switch will only allow the dishwasher to start the cycle once the door is closed. Most dishwashers will have a door switch about an inch in size with metal prongs and these can be affected in damp conditions. Although the door may appear to close normally, the dishwasher will not fill if the switch is incorrectly detecting that the door is open.
2. Drain Valve
A faulty drain valve on a dishwasher can prevent the appliance from filling as the solenoid will detect that there is nowhere for the water to drain. You will need to examine the drain valve and all adjacent components to determine whether it is faulty or clogged. After the drain valve has been replaced or rectified, test the dishwasher to find out whether this has solved the problem.
The drain valve is controlled by a component known as a drain valve solenoid and this can prevent the dishwasher from filling properly if it is malfunctioning. Test the component to determine whether it is working properly using a multimeter and replace it if it is found to be faulty.
3. Float Switch
The float switch should be examined as part of your troubleshooting plans as this controls the amount of water that enters the dishwasher. As the water fills the appliance, it triggers the float switch and once it reaches a certain level, a signal is sent to stop the flow of water. Accordingly, if the switch is faulty, the dishwasher will incorrectly read that it is already full and will not allow any more water to enter.
4. Water Inlet Valve
The water inlet valve is the point at which water enters the dishwasher and can often be the reason behind an appliance failing to fill with water. Check the filter screens inside the water inlet valve for any signs of debris that may have built up over time. If debris is present, clean the filter screens and the inlet valve cavity thoroughly before testing the dishwasher to see if this rectifies the problem.
If there are any defects to the water inlet valve itself, it will be necessary to replace the component in order to allow an effective flow of water.
When troubleshooting dishwashers, you may need to check the overflow pipes to ensure that water is able to drain from the appliance properly. If the pipe becomes clogged with debris or mineral deposits, water will back up into the system until the dishwasher stops filling at the start of a new cycle. There are a number of cleaning agents that can be purchased and used like normal dishwasher detergent, but they will actually clean the appliance and connected pipework instead.