Why Is My Dishwasher Leaking From Underneath? Troubleshooting and How to Fix It

Dishwashers are supposed to make your life easier, but when they start leaking, they can cause more frustration and headaches than anything else. If you’ve noticed water leaking out during the wash cycle or see evidence of water damage around your appliance, use this guide to learn why your dishwasher is leaking from underneath and how to fix the issue.

1. Damaged Door Gasket

One of the most common reasons a dishwasher leaks from underneath is a damaged door gasket. This gasket sits around the interior perimeter of the door and creates a watertight seal to prevent leaking. Over time, the gasket can dry out, crack, or get damaged, and any of these problems could lead to leaks that seem to be coming from under your dishwasher.

How to Fix It

Your best option is to replace the door gasket. Purchase a new one from your dishwasher manufacturer, remove the old one, and seat the new one into place. This is easily DIYable and requires no special tools.

2. Leaking Supply Line

Another common culprit of a dishwasher leak is the supply line. This is the water line that runs from behind your wall to the bottom of the dishwasher. If the gasket inside is broken or the supply line isn’t connected properly, it will leak water under your dishwasher.

How to Fix It

Remove the bottom front panel of the dishwasher and locate the supply line. It connects to a brass elbow that’s screwed onto the inlet valve. With the supply line shut off, remove the supply line and install a new one, being careful not to cross-thread the connections and to tighten them properly.

3. Damaged Inlet Valve

The plastic inlet valve that your supply line connects to is another common area where things go awry, especially if the connecting is cross-threaded. These can leak from the connections on either end if the gaskets dry out or get cracked with changes in temperature over time.

How to Fix It

Buy a new inlet valve from your dishwasher manufacturer. Shut off the water to the appliance and then disconnect the supply line and the inlet valve. Install the new inlet valve. Make sure to tighten all connections and avoid cross-threading when installing.

4. Loose Hose Clamp on the Drain Line

The drain line runs from the bottom of your dishwasher up to a drain pipe. In most cases, it connects to the drain pipe under your kitchen sink. The hose clamps that keep the line in place can get damaged or fail over time, which can leak water under your dishwasher.

How to Fix It

With the appliance off, uninstall the drain line and reinstall a new line with new hose clamps.

5. Faulty Float Switch

Your dishwasher has a float switch inside that regulates the amount of water in your appliance during a wash cycle. If the switch isn’t functioning properly, your dishwasher can overfill and leak out the bottom.

How to Fix It

The only way to fix a faulty float switch in a dishwasher is to replace it. The switches are affordable, but they do require wiring the new switch, so it’s best to call in a professional. You can test the float switch by pulling up on the float connected to the bottom of your dishwasher. If you don’t hear a click, the switch hasn’t turned on, and you’ll need a replacement.

When to Call In a Pro

Dishwashers use both water and electricity, which makes some maintenance and repairs inherently dangerous. If your issue involves replacing plumbing or electrical components, it’s a good idea to call in a professional unless you have experience working with these types of repairs.

Plus, mistakes can lead to ongoing water damage that can quickly get expensive, so unless it’s a simple repair, like replacing the door gasket, hiring a dishwasher repair specialist near you is well worth the money.