If your dishwasher is no longer starting, it could have a defective component that is preventing it from functioning properly.
Let’s look at some of the main reasons behind a faulty dishwasher and what you can do to remedy them.
While there are many different components that make up a dishwasher, only a select few affect its ability to start. These are often directly related to the washing cycle, such as the door latch assembly and main control board.
Keep in mind, that some issues applied to the dishwasher when it has power and when is hasn’t.
If Dishwasher Has Power
Failed Door Latch Assembly
What is it: The door latch assembly functions very much like that of a microwave’s door switch. This device lets the dishwasher know that it is safe to turn on and begin its washing cycles.
Why it fails: The microswitch can become defective or short out, resulting in the dishwasher thinking that the door is open, and thus, won’t start.
How to fix: Many door latch assemblies come equipped with a micro switch. This can be tested for continuity using a multimeter.
Touch the probes of the multimeter to the switch’s terminals. If you see continuous continuity, your door latch should be working correctly.
If, however, there is no continuity, you will need to purchase a new micro switch or door latch assembly.
What is it: A dishwasher’s touchpad allows you to set wash cycles and change settings.
An easy way to tell if the touchpad is responsible for the dishwasher not starting is if only some of its buttons work.
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Why it fails: Since this is an electronic device, the touchpad’s ribbon connection can become dirty, causing poor communication between the buttons and the control board.
How to fix: You can try cleaning the ribbon cable using a soft pencil eraser.
If this doesn’t remedy your power issue, you may need to replace the entire touchpad assembly with a new unit.
Failed Main Control Board
What is it: The main control board is responsible for providing power to nearly every major component within the dishwasher.
If this board becomes defective, it can prevent the dishwasher from starting.
Why it fails: There are many wires and connections attached to the main control board.
If any of these becomes loose or frayed, it can result in the dishwasher not functioning properly, including problems with starting.
Or control board software has been corrupted, this is common for Samsung dishwashers.
How to fix: Although it is difficult to test the board itself, you can look for signs of damage.
Begin by disconnecting the main control board. Using a flashlight closely examine the board for scorched areas or corrosion.
These can be signs that the unit is defective and needs to be replaced.
What is it: Some dishwasher models use a timer instead of the main control board. With that being said, it, too, can become defective and result in the dishwasher not starting.
Why it fails: If there is a bad connection or short in the timer assembly, it can cause the dishwasher to not want to start its washing cycle.
How to fix: Remove the timer assembly and look for any bad connection. Furthermore, check for corrosion or scorching, as this means that the assembly is defective and needs to be replaced with an entirely new timer.
If Dishwasher Has No Power
What happens if your dishwasher doesn’t have power? Fortunately, there is some troubleshooting you can employ to track down the root cause of your power issue.
To help get your dishwasher working again, start with the easiest solution, and work your way up.
Failed Thermal Fuse
What is it: Depending on the type of dishwasher you own, your unit may be equipped with a thermal fuse. This fuse is typically located near the bottom of the tub or by the control board.
Thermal fuses are important features, as they serve as a safety device that cuts power to the main controls in the event of a short in the wire harness.
Why it fails: The thermal fuse can blow if the dishwasher overheats for any reason.
Additionally, this fuse can blow if there is a failure to a major part, such as the dishwasher’s pump or heating element.
How to fix: This small device can be easily tested using a multimeter. Touch the probes to the thermal fuse’s terminals to check for continuity.
If there isn’t any, you’ll know that the thermal fuse needs to be replaced.
Check Your Switches
What is it: Many dishwashers won’t turn on unless a light switch is flipped. These are often located next to your sink’s garbage disposal switch.
Why it fails: While a simple flip of the switch is easy enough to forget, there may be more extensive issues involved.
If the switch is in the “on” position but you’re still not getting power to your dishwasher, move on to your home’s circuit breaker.
How to fix: Check to ensure that none of the breakers have been tripped. If you’re unsure, turn the dishwasher’s breaker off and back on.
Head back to the kitchen and make sure that the wall switch is in the “on” position.
Finally, try starting your dishwasher to see if it turns on. Hopefully, you don’t have to do any more troubleshooting.
But if you still aren’t having any luck, head on down to the next step.
Check the Power Source
What is it: Some dishwashing units come equipped with a power cord that connects to an electrical outlet via a plug under your kitchen sink.
Conversely, some units have a direct connection that features a power cord that’s tied to a junction box.
Why it fails: Either the power cord itself or the junction box is faulty. Although it is easy enough to check if they are working correctly, you should hire an electrician to make any needed repairs.
If you have sufficient experience, however, you can safely proceed to the following steps.
How to fix: First, make sure that the power cord is plugged in if your dishwasher connects to a power outlet. Next, test the outlet to ensure that it is delivering electricity.
A quick and easy way to do this is by plugging a small lamp into the outlet. If it doesn’t come on, you’ll know that the outlet is faulty and needs to be replaced.
If your dishwasher doesn’t plug into a power outlet, this means that it is tied directly to the junction box.
To safely test this, first switch off the main circuit breaker to your home to ensure that there isn’t electricity going to the junction box.
With the power off, locate the junction box and remove its access panels. You’re looking for a black wire and a white wire.
If either wire is disconnected or loose, tighten them snugly back in place.
Replace the access panels to the junction box and switch back on the circuit breaker. Head back to the dishwasher and switch it on.
If there still isn’t power, you may need to examine the wire harness on the control panel.
Check the Control Panel Wire Harness
What is it: This part is responsible for delivering power to the main interface control panel.
If you can’t access the control panel, you won’t be able to select settings, including the main power.
Why it fails: The wire harness may have a short or be defective. If it isn’t getting electricity, it won’t be able to power on the dishwasher.
This should be a fairly straightforward fix if you need to hire a professional to change them out.
How to fix: Begin by making sure that the power to the dishwasher is off. Inside the door of the dishwasher is an inner door panel that houses the control interface and wire harness.
You will likely need a Torx screwdriver to remove this inner panel. After successfully removing the panel, lay the control panel and outer door panel on the floor for easy access.
If you notice that the wire harness has become unplugged from the control panel, you’ve likely identified your problem.
Simply reconnect the harness and reassemble the panels. Restore power to the dishwasher and turn it on.
If this didn’t correct the power issue, you may be looking at a defective interface control.
It’s also possible that one or more of the wires has become damaged. Instead of buying a whole new interface, have an expert examine the control unit to determine if new wires will fix your power issue.
This is far less costly and may resolve your problem without having to sink a lot of money into your dishwasher repair.
Unless you are well-versed in the diagnostics required to test your control interface, it is recommended that you hire a professional to do it for you.
However, once the actual cause has been identified, you may be able to follow some online DIY guides and make the necessary repairs yourself.
Always remember to use extra caution when dealing with electricity. Take the time to ensure that there isn’t power going to your dishwasher before attempting any troubleshooting or repairs.