Dishwasher Not Heating Water: How to Fix It

Picture this: you run your dishwasher, expecting to unload clean, sparkling dishes, but instead, they come out greasy and grimy. Something’s off. Then it hits you—your dishwasher isn’t heating the water. I’ve been there, and it can be so frustrating! But the good news is that this isn’t the end of your dishwasher’s life. In fact, with some troubleshooting and a little DIY spirit, you can probably fix this issue yourself. Trust me, I’ve fixed this same problem a couple of times, and I’ll walk you through how to do it step by step.

Let’s dig in and figure out what’s going on. By the time we’re done, you’ll have your dishwasher back to cleaning your dishes the way it should—hot water and all!

Step 1: Test If the Dishwasher Is Getting Hot Water

The very first thing you need to do is confirm whether your dishwasher is actually getting hot water from the start. Sometimes the issue isn’t the dishwasher itself but the water supply.

Here’s a trick I learned after dealing with lukewarm washes. I used to run the dishwasher and walk away, but now I always test the water temperature.

• Run the hot water tap: Before starting your dishwasher, turn on the hot water at your kitchen sink. Let it run until the water is as hot as it gets. This will ensure that the dishwasher starts with hot water from the get-go. Sometimes, the dishwasher just takes in cold water, especially if you’ve been using cold water elsewhere in the house.
• Feel the dishwasher door: During a wash cycle, touch the dishwasher door to see if it feels warm. You should notice the door heating up if the water is hot. If it’s still cold or lukewarm after running for a while, there’s likely an internal heating issue.

This tip saved me once when I realized my water heater was set too low, which was affecting the dishwasher’s performance. After turning up the temperature on the heater, the dishes came out much cleaner.

Step 2: Check the Dishwasher’s Heating Element

One of the most common reasons a dishwasher isn’t heating water is a faulty heating element. The heating element is responsible for boosting the water temperature during the wash and dry cycles. I had this exact issue a few years ago—the dishes were coming out dirty, and after some investigation, I realized the heating element was shot.

• Locate the heating element: The heating element is usually a thick metal coil located at the bottom of your dishwasher. It heats up the water and also helps dry your dishes at the end of the cycle.
• Test for visible damage: Open the dishwasher and take a good look at the heating element. Look for any visible signs of damage, like cracks, burn marks, or breaks. In my case, I noticed a slight crack in the element, which explained why it wasn’t heating the water.
• Test with a multimeter: If you can’t see any damage, you can use a multimeter to test the heating element. Set the multimeter to the ohms setting and touch the probes to the terminals on the element. A functioning element should give you a reading between 10-50 ohms. If it reads zero or shows no reading, the heating element is likely broken and will need replacing.

I had never used a multimeter before this, but once I did, I felt like a total DIY pro! It’s actually pretty straightforward and can save you from guessing whether or not the heating element is the problem.

• Replace the heating element: If your heating element is broken, you’ll need to replace it. You can order a new one based on your dishwasher’s model number. The replacement process is pretty simple—just unplug the dishwasher, disconnect the old element, and install the new one.

I remember the satisfaction I felt after replacing the heating element myself. It wasn’t nearly as complicated as I thought it would be, and after the swap, my dishwasher was back to heating water like a champ!

Step 3: Inspect the Thermostat or Thermal Fuse

If the heating element looks fine, the next thing to check is the thermostat or thermal fuse. These components control the temperature of the water, and if either one is faulty, your dishwasher won’t heat the water properly.

• Check the high-limit thermostat: The high-limit thermostat is a safety feature that prevents the water from getting too hot. If it malfunctions, it might prevent the dishwasher from heating water at all. This part is usually located near the heating element or under the dishwasher.
• Test the thermostat: You can use a multimeter to test the thermostat the same way you tested the heating element. If the thermostat is faulty, it will need to be replaced. I had to replace the thermostat on my dishwasher once after realizing it wasn’t letting the water heat up enough. It was a quick fix that made a huge difference!
• Check the thermal fuse: The thermal fuse is another safety feature that cuts power to the heating element if the dishwasher gets too hot. If the thermal fuse blows, the heating element won’t work. You’ll need to check the thermal fuse for continuity using a multimeter. If the fuse has blown, you’ll need to replace it.

The first time I replaced a thermal fuse, I was a bit nervous, but it was surprisingly easy to swap out. And once it was replaced, the water was heating perfectly again.

Step 4: Inspect the Control Board

If everything else checks out but your dishwasher still isn’t heating the water, there may be an issue with the control board. The control board acts as the brain of your dishwasher, telling it when to heat the water and run each cycle.

• Check for any signs of damage: The control board is usually located behind the control panel on the front of the dishwasher. Open up the control panel and inspect the board for any burn marks, loose wires, or signs of damage.
• Reset or replace the control board: Sometimes, a simple reset can fix a glitch in the control board. Unplug your dishwasher or turn off the circuit breaker for a few minutes, then plug it back in and try running a cycle. If resetting doesn’t work and the board is visibly damaged, it might need to be replaced.

Replacing a control board is a bit more advanced, but it’s definitely doable with the right instructions. I’ve had to do this once with an old dishwasher, and while it took a bit of time, it saved me from buying a whole new machine.

Step 5: Run a Diagnostic Test

Some dishwashers come with a diagnostic mode that can help you identify exactly what’s wrong. If your model has this feature, it’s worth running the diagnostic test to see if it can pinpoint the problem.

• Refer to your user manual: Your dishwasher’s user manual will have instructions on how to run the diagnostic test. It usually involves pressing a sequence of buttons to enter the diagnostic mode.
• Read the error codes: Once the test runs, the dishwasher will display an error code that corresponds to the issue. Look up the code in the manual or online to figure out what’s causing the problem.

I’ve used this feature before when I wasn’t sure what was wrong, and it’s helped me save time by pointing me directly to the issue.

Why Fixing It Yourself Is Worth It

I know that the idea of tackling a dishwasher that won’t heat water might sound intimidating, but trust me—if I can do it, so can you. From testing the heating element to checking the thermostat, these steps are totally doable with a little patience and some basic tools. Plus, once you’ve fixed it yourself, you’ll feel like a total DIY hero (and you’ll save some serious cash).

The first time I fixed my own dishwasher’s heating problem, I was so proud of myself. There’s something incredibly satisfying about figuring out what’s wrong and fixing it with your own two hands. Not only did I avoid a repair bill, but I also learned a lot about how my dishwasher works—knowledge that’s come in handy again and again.

So go ahead, give it a shot! You’ve got this. With these steps, you’ll be able to troubleshoot and fix the problem, and your dishes will be back to sparkling clean in no time.