Why Is My Dishwasher Not Getting Hot?

If your dishes have been coming out of the dishwasher looking less-than-clean and feeling cold to the touch, you may be wondering why is my dishwasher not getting hot? Here’s a look at the potential causes and how to get your dishwasher up and running again. 

1. Busted Thermostat

Your dishwasher's thermostat tells it whether or not the water coming in is at the right temperature. However, if the thermostat needs repairs, it could measure the water temperature as hotter than it is, causing the machine to run with colder water and leaving you with grimy dishes.

How to Fix It

Determining whether or not your thermostat is to blame requires the use of special tools. Your best bet is to hire a local dishwasher repair pro to test the thermostat and replace it, if needed.

2. Faulty Heating Element

While the thermostat tells your dishwasher if the water is at the appropriate temperature or not, the heating element is responsible for actually warming the water up. When there's a problem with the heating element, it can't get the water hot enough. 

The heating element is typically located on the bottom of the dishwasher. Depending on the problem, you may be able to see visible signs of damage, such as cracks. 

How to Fix It

If your heating element is to blame, your best bet is usually to replace it with a new one. A dishwasher repair pro can test your machine's heating element and visually inspect it to determine if there are obvious signs of damage. They'll then swap out the broken part for a new one.

3. Your Hot Water Heater Is Broken

While modern dishwashers heat water themselves, they aren't starting from room temperature. Typically, your dishwasher is connected to your home's hot water heater, so that water that's at least 120 degrees Fahrenheit flows into the machine when you switch it on.

But if your water heater is failing and doesn't heat your home's water sufficiently, that can affect your dishwasher. The machine may have trouble heating colder water up, leading to lackluster dishes. 

Usually, if your home's water heater is having troubles, you'll notice it throughout the house, not only with your dishwasher.

How to Fix It

Fixing a problem with your water heater could be simple. For example, you may have turned down the thermostat on the heater to "vacation" mode before a trip and forgotten to turn it back up. In that case, adjusting the thermostat may be enough to solve your cold water woes.

But if you can’t easily pinpoint the issue, your best bet is to have a plumber who fixes water heaters come out and take a look at it. They'll be able to troubleshoot the problem and either repair or replace the water heater.

Signs of Hot Water Problems With Your Dishwasher

When a dishwasher doesn't get hot enough, the proof will be in the dishes. The machine needs hot water to clean away grease, grime, and bits of food. Your dishes will emerge from a too-cold dishwasher looking almost as dirty as when you put them in. 

If you use dishwasher tablets or powder, you may also notice that they don't thoroughly dissolve when the dishwasher's water doesn't get hot enough.

When to Call a Pro

Since fixing a dishwasher's thermostat or heating element typically involves using specialized tools and doing electrical work, your best bet is to call a pro. 

It's also a good idea to call a plumber if you suspect that your dishwasher's water troubles can be traced back to your water heater. A professional plumber will inspect your heater and perform maintenance on it to improve its performance. Depending on the age of the heater and the problem, they may recommend replacing it.