How To Test A Dishwasher Water Inlet Valve (The Right Way)

Hi, this is Ryan with Parts Dr and I am going to explain you how to test the water inlet valve on your dishwasher to see if it is good or bad. Other articles online explain to test the valve by measuring the resistance of the solenoids on the valve. This test is not very conclusive and doesn’t actually tell you if the valve is working properly.

The testing process I am going to explain you is the only conclusive way to determine if the water valve is working properly.

Water valves can fail in a variety of ways. They can start to leak which can cause water to fill up inside the dishwasher when it is not in use. They can also cause the dishwasher to not fill with enough water or not fill with water at all.

The first thing you will need to do is unplug or turn off the power to the dishwasher.

Next you will need to gain access to the water valve and look for a sticker or stamping in the metal on the side of the valve. What we will first need to know is if the water valve is powered by AC or DC voltage and what the voltage rating is. You should should see a sticker or stamping in the metal with information like this on the side of the valve.

To test the valve we are going to need to apply power to the valve to manually actuate the valve to see if it is working properly.

If your dishwasher has a AC voltage water valve, it is most likely powered by 110-120v AC power which is the standard power that comes from the power outlet in your house. We are going to first need to make a test cord to apply power to the water valve. To make a test cord you are going to need a power cord, two crimp on insulated terminals, and a crimping tool.

I will include links to the items we used to make the test cord in the description below. If the wires are your test cord are not already exposed you will need to strip the insulation from them so they look like this. On the power cord we are using here, the green is the ground wire and the white and black are the two power wires.

Other articles online explain to

If the power cord you are using is not color coded, you will need to test each wire with a multimeter for continuity to see which wire is ground, hot, and neutral. The green is the ground wire, the white is the neutral, and the black is the hot wire. We will not be using the ground wire on the test cord, so we are going to cut that off. Now we are going to crimp on an insulated 1/4” female spade terminal onto each of the white and black wires.

And now the test cord is done and ready to use.

If your dishwasher has a DC voltage water valve, it is most likely power by 12-14V DC power. We are going to use a 12V battery pack that uses 8 AA batteries for our power supply. This battery pack works nicely because it has wires coming out of it that we can crimp out spade terminals to and it also has an on/off switch that we can use to switch the power on and off.

You can also use any 12V DC battery that you can attach wires to.

To get the battery pack ready we are just going to need to crimp on a female spade terminal onto each of the two wires. I will include links to the items we used for our battery back in the description below. Next we need to inspect the valve to see what style wire terminals it has.

There are two common styles of terminals we see on most water inlet valves. Most either have two 1/4” male spade terminals, or two smaller pins that stick out of the valve. If your valve has the 1/4” spade terminals, we will be able to directly connect our test cord or battery pack directly to the valve.

We are going

If the valve has two pins, we will need to cut the wiring harness a few inches away from the valve.

Next we will strip all four wires using a wire stripper. On one side of the harness we will crimp on two male spade terminals. And on the other side of the harness we will crimp on two female spade terminals. This will allow us to connect our power source to the water valve and reconnect the harness back together when we are done.

To test the valve you will need to make sure the water is turned on to the dishwasher and the water supply to the dishwasher is flowing at a good rate.

Let the valve sit for little while and make sure no water leaks from the outlet of the valve. If the water valve leaks when there is no power supply to the valve then it is bad and should be replaced. Next connect the battery pack or test cord to the water valve. It does not matter which wire goes to which terminal.

Now turn on your power supply or plug in your test cord.

If the water valve is good, the water should flow out of the valve at a steady rate. If no water comes out of the valve or the water flow seems restricted or slow then you should replace the valve. The water flow rate should be about that same as the water supply line to the dishwasher.

You can also check your dishwashers owners manual or installation instructions for the manufactures recommended water supply specifications for the psi and flow rate. Do not apply power to the water valve for more than 1 minute at a time before letting it cool down for a few minutes as it can damage the valve. If the flow rate on your water valve is slow, it can be caused by sediment that has built up on the screen of the valve or inside the valve.

On most water inlet valves the screen is not removable. Do not try to disassemble the water valve to try to clean it. We often see people try to do this and it will almost always result in leaking afterwards which can flood and damage your house.

For the cost of replacing the water inlet valve it is not worth damaging your house. If you find that you have a bad water inlet valve and you need to purchase a new one, you can purchase one from our online store by clicking the link in the description below. Please be careful when shopping water inlet valves as many stores sell lower quality aftermarket water valves.

To get the battery pack

You can be assured when you purchase from Parts Dr that you will receive a new OEM water valve.

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