How To Get Cockroaches Out of Your Dishwasher

If you keep the rest of your house clean, roaches may seek out other hiding places. If they can’t find leftover food on kitchen countertops or in the sink, cockroaches may live in your dishwasher.

To get roaches out of your dishwasher, you must first take out every dish and disassemble the entire dishwasher. Check the air gap, drain hose, and seals for any damage, and then replace them if they are faulty. Disassemble the front and side panels of the dishwasher and clear out any roaches from the hardware. The inside of the dishwasher should be cleaned out with bleach. Once that’s done, add dishwasher detergent to the dispenser and run a full washing cycle on the maximum heat settings.

Next, you must ensure the roaches can’t get back in. A thin layer of boric acid should be spread under the dishwasher. Natural cockroach repellents, like oregano oil, should be used on the sink and countertops around the dishwasher. Be sure to avoid using traps or baits with poison, as these may contaminate your dishes.

Do Dishwashers Attract Cockroaches?

Roaches do not favor dishwashers. They prefer the rest of your kitchen as a source of food, moisture, and hiding places. For the average home, a garbage can, spilled foods, and leftovers are easy to find.

However, if these are absent, cockroaches will seek out other venues, such as your dishwasher. After all, you’ve inadvertently created the perfect environment for roaches to thrive. Dishwashers have everything cockroaches need, including:


Inside dishwashers, there will be leftover food on dirty plates. Any that’s washed off will gather inside the drain. This provides an ample source of nutrients for a roach infestation.

Cockroaches don’t like to scavenge too far from their colony. As such, they may nest inside or behind a dishwasher. This gives them easy access to any scraps, as well as mildew or condensation that builds up around poorly maintained dishwashers.


Cockroaches need water more than they need food. They can survive a month without food, but die within a week if they have no water. Because of this, dishwashers serve as an ideal source of moisture and condensation. They can even get juices, syrups, and water from the dishes you place inside the machine.

Even if roaches can’t get inside the dishwasher, they may colonize around it. After all, the sink is close to the machine. That makes it nearly impossible for any cockroach to die of thirst in this area.

roaches in the dishwasher door panel


Old dishwashers are more likely to have cockroaches in them. That’s because of faulty ventilation. Without a proper air vent, the heating function at the end of the washing cycle won’t dry out the dishwasher. Instead, it will create a damp space that cockroaches love.


Dishwashers provide cover and darkness. When the machine is open or running through a cycle, roaches can hide away toward the back of the appliance. This spot will be dark, warm, and cozy. If the dishwasher is closed or isn’t in use, they can enjoy darkness from the inside.


German cockroaches are the most common species to terrorize households. They are a lot smaller than other types, so they have an easier time getting into tight spaces. That means they can easily creep inside the machine’s actual hardware, like the control panel. A single dishwasher will then grant them access to many areas where they can nest comfortably.

How Do Cockroaches Get Inside a Dishwasher?

After encountering roaches in your dishwasher, it’s not enough to clean the inside and spray insecticide around your home. Cockroaches will always find a way back inside the machine as long as there is an opening.

The first step is to check these openings. Otherwise, any lingering roaches that avoid your pesticides will only congregate elsewhere. They will return to the dishwasher once they think it’s safe. Of course, the question is: where to start?

Roaches can enter a dishwasher from multiple spots. Some of these can only be checked after disassembling the machine. This could mean hiring a plumber, but there are plenty of videos online explaining how to do it.

Cockroaches in Dishwasher Drain

The machine’s drain is located at the bottom of the appliance. This is where all the water and food go after a washing cycle is done. Depending on how the machine was installed, there will be a hose. This connects the drain to the:

  • Garbage disposal
  • Sink

This hose can be found at the back of your dishwasher or under the sink. Cockroaches prefer to loiter about dishwasher drains, since they’re packed with food and water. They will enter through the sink pipes or the sink drain.

Roaches are also attracted to any food in the garbage disposal. They can gain access through this pipe. From there, they will travel through the drain hose right to your dishwasher.

If those two options aren’t available, roaches will use loose pipes. This doesn’t require them to use the sink drain. Instead, small species will sneak through tiny openings.

Some openings might be too small for adult cockroaches to enter. However, nymphs can easily get through and form a nest.

Cockroaches in Dishwasher Door Panel

A door panel can be found on the exterior part of the dishwasher. They are usually attached to the dishwasher with multiple screws. They can even be customized to blend in with the rest of the kitchen’s cabinets.

Even when the door panel is securely attached, the distance between the machine’s door and the actual panel is not water-tight. Cockroaches can easily climb through, especially when the panel is a bit loose.

Cockroaches Behind Dishwasher

The back part of the dishwasher is the easiest place for roaches to access. They can get there through:

  • The pipes
  • The underside of the dishwasher
  • The sides of the dishwasher
  • By gaining access to the back of the cabinet first

Much like the door panel, cockroaches will have no problem accessing the back. This is true even if the actual dishwasher is secured in place. There will still be a slight crevice that’s formed between the dishwasher and the cabinet or wall.

A crevice is also formed if the dishwasher has an insulation blanket. Insulation blankets are foamy, soft blankets that cover the top and sides of the dishwasher. They stand between the actual appliance and the countertop. However, they make it easy for roaches to reach the back of the dishwasher.

Aside from that, watch out for:

  • The holes in the back of the cabinet for the power supply
  • The drain hose

These are also spaces cockroaches use to get into the back of the dishwasher.

Cockroaches in Dishwasher Air Gap

During the washing cycle, an air gap prevents the dirty water from draining back into the dishwasher. Otherwise, this would contaminate the dishes.

Depending on where you live, plumbing codes may require you to have an air gap installed. Others only require you to have your drain hose in what’s called a “high loop.” This happens when the middle of the drain hose is curved to make an upside-down U-shape.

Air gapes have holes in them that connect to the drain hose and garbage disposal. Once the cockroaches have access to those places, it’s easy for them to get inside the dishwasher.

Why Are There Cockroaches in My Dishwasher?

Unintentionally, dishwashers are areas for roaches to live. Even if it’s only for a short period of time, they can thrive on the food and water there. Worse yet, unless you’re extremely thorough with your cleaning, dishwashers are rarely ever moved. That makes it an undisturbed place where roaches can hide.

Cockroaches do not like to stray far from their nest in search of food. As such, even if you never use the dishwasher, and there’s no food or water to be found, cockroaches will still use it. The machine will serve as a perfect hideout. They can easily access other areas with food, such as in:

  • Cabinets
  • Countertops
  • Fruit bowls

Do Dirty Dishes Attract Roaches?

Dirty dishes are a perfect lure for roaches. It’s common for people to leave dirty dishes inside their dishwasher overnight. This allows roaches to seek out the trace bits of food that are left behind. Even if the dishwasher is closed, they have many ways to get inside.

Remember, cockroaches don’t need much to survive. Even a small bit of food on a single dirty dish is enough to keep them going for weeks on end.

With that in mind, a single dirty plate inside a dishwasher could feed a whole colony. It’s best never to leave unclean dishes lying around. Cleaning away leftover food, rinsing the dish off, or running the dishwasher immediately can help prevent this.

Can I Spray Raid in My Dishwasher?

When spotting a roach, your gut reaction might be to get some insecticide and spray it. However, there is a time and place for everything. Just as you should not spray insecticide on your pillow or your toothbrush, you should not spray insecticide in your dishwasher.

Spraying Raid or any other kind of poison in your dishwasher never advised. That’s because:

Ineffective Against Roaches Long-Term

Commercial-grade insecticides have a low concentration of toxicity. That’s because it’s too dangerous for people to have such poisonous materials in their homes. The only insecticides with high levels of toxicity are those used by exterminators.

Due to their adaptability, cockroaches have actually grown resistant to store-bought insecticides. That’s according to the journal Scientific Reports. Spraying a dishwasher with insecticide won’t get rid of your cockroach problem long-term. Instead, it’s a waste of time and money.

Dangerous for Humans

Despite the low levels of concentration, insecticides such as Raid are still very dangerous for humans. Every single insecticide label will warn you not to use the spray near areas:

  • Where food is prepared
  • Where eating utensils are placed

This includes the inside of dishwashers. Even if you clean the dishwasher after using the spray, traces of poison will remain. According to North Carolina State University, insecticide residue can still be found in homes an entire month after being used.

How to Get Rid of Cockroaches in Dishwasher

Properly removing cockroaches from your dishwasher is hard. Dishwashers have many parts to them, and cleaning these machines isn’t as straightforward as other appliances.

However, it’s worth it in the long run. With these steps, you can ensure your dishwasher returns to being clean, safe, and sanitary.

Drain, Pipes, And Sink

Your first step is to check:

  • The pipes under your sink
  • The drain hose connected to the drain

Make sure there are no holes or leaky spots. If there are, be sure to replace them. After that, you’ll want to flush out any roaches in the hose and pipes. Do this by pouring baking soda and vinegar down the sink’s drain.

Wait for 5 to 10 minutes, and then pour boiling water. Cockroaches cannot stand extreme heat. Anything over 120 degrees Fahrenheit will have them running for the hills.

Dishwasher Door and Door Panel

Unplug the dishwasher and then remove the door panel. You can clean the door and the door panel with:

  • Soap and water
  • Bleach
  • A mix of baking soda and white vinegar

Check the seal around the door and make sure it’s in good condition all around. The dishwasher seal is a rubber lining. This ensures that water does not flow out of the dishwasher while it’s running its cycle.

A damaged seal needs to be replaced. This not only helps avoid a leaky dishwasher. It also seals off common entry points that roaches use to get inside.

Inside and Outside the Dishwasher

Pull out the dishwasher and clean out its space. If you want, you can place some baits or a thin layer of boric acid on the floor before you move it back. This will deter any stragglers and kill off roaches that try to re-infest the machine.

Remove as many components inside the dishwasher as you can, including the racks and the filter. Unlike the door panel, the contents inside the dishwasher come into contact with the plates that you use to eat. You should use a strong cleaner to sanitize them, such as bleach, and thoroughly scrub the inside components.

Once you’ve manually cleaned all the removable parts, put them all back where they belong. Now, pour some detergent into the dispenser. Let the machine run on the hottest cycle to sanitize the interior.

how do cockroaches get inside a dishwasher?

Roach Proof Dishwasher

There are many things you can do to roach-proof a dishwasher. It all comes down to:

  • Knowing which spots to clean
  • Knowing which roach products to use
  • Sealing off all the entryways

This will ensure the roaches have no chance of getting inside the dishwasher ever again.


There is an easy way to limit roach access to the dishwasher. Just use a sink strainer with tiny holes. Make sure to leave the strainer in the drain at night when the cockroaches are most active.

It’s also important for the strainer to be entirely clean. This will prevent roaches from being attracted to the leftover food on it.

Under the Dishwasher

The underside of a dishwasher can’t be neglected. Get in the habit of pouring a thin layer of boric acid down there.

Boric acid may be dangerous to pets if eaten. If you have small enough animals to get under the dishwasher, do not let them wander near the kitchen.

Dirty Dishes

Never leave dirty dishes inside the machine overnight. This will prevent roaches from infesting your dishwasher and keep them away from the kitchen as a whole. Instead, wash the dinner utensils by hand or run a full washing cycle before bed.

Natural Repellents

Insecticides and repellents have harmful substances that are not safe to use in areas where food is made. Instead, use natural oils with scents that cockroaches hate. Popular options include:

  • Oregano oil
  • Eucalyptus oil

Spread the oils around the countertops. You can also place small, open containers filled with the oils in a few corners around the kitchen.

Clean Frequently

Clean the garbage disposal and the drain once a week. Keep the countertop clean and entirely free of food, especially at night. If you live in an area where cockroaches run rampant, you might need to be more thorough. Clean the interior and exterior of the dishwasher every 2 weeks.

Roaches can take over your dishwasher. By thoroughly inspecting and cleaning them, you can remove cockroaches long before they cause any lasting damage.