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Why Does a Dishwasher Smell Like Sewage or Burning Plastic?

Gaya Chudnovski

Technically Reviewed by Gaya Chudnovski on Apr 09, 2024 | Written by Olga Larina

Authorized repair service for most home appliance manufacturers

Why does a dishwasher smell like sewage or burning plastic, and what to do to fix it? Dishwasher smells of burning plastic or raw sewage are dangerous signs. Burning smells could be due to friction or electrical shortages that could cause a fire. The smell of rotten eggs or a fishy smell and a dishwasher that smells like a sewer could be due to mould buildup in the dishwasher or blockages in the drainage system, causing wastewater to accumulate and emit foul smells. It’s crucial to address these issues promptly to ensure the safety and proper functioning of your dishwasher.

Please read our article to learn more about why my dishwasher smells like sewage or burning plastic and what you can do about it.


Suppose you’re wondering what to do when your dishwasher smells because you are sick of fish smells. In that case, there are several different issues that you need to take into consideration.

You may be able to clean a dishwasher that smells bad on your own, or you could face more difficult repair or replacement. Identify the symptoms before doing any work, and you will be ready to fix that burning or mouldy smell.

Why Does a Dishwasher Smell Like Sewage or Burning Plastic and What to Do To Fix It

Why Does it Smell Very Bad?

For a dishwasher that smells like sewage or burns, there are signs that you can check for to make a quality repair. No one wants a dishwasher that always smells. Take the time to review this list of common problems facing your dishwasher before deciding which action to take.

Reason 1: Dirty Filter

The filter at the bottom of the dishwasher basin filters out large food particles from entering the drain pipe. Filtering those and other organic matter is important because it stops the drain from clogging.

However, a drain filter on a dishwasher will get filled with old and decaying particles after several washes. The dirty filter on your dishwasher can begin to mildew and cause the dishwasher to smell bad between washes.

Reason 2: Bent Drain Hose

The drain hose from your dishwasher into the plumbing under your sink needs proper flow. If the hose is bent or turned, it causes the dishwasher’s wastewater enter the dishwasher basin. A bent drain hose may even cause a new dishwasher to smell bad. Dirty backflow water may sit in your dishwasher basin and begin to mould or mildew.

Reason 3: Drain Hose Too Low

The drain hose for your dishwasher has an uphill climb into the plumbing under your sink. The pressure of the water can force most wastewater out of the appliance. If the hose is positioned too low under the sink, there will be backflow into the dishwasher basin.

This water may contain food particles that rot or mildew. If the drain hose under your sink is too low, you will surely get bad smells.

Reason 4: Clogged Sprayer Arm

The sprayer arm is where water comes from the water inlet and sprays onto your dishes. The sprayer arm also spins on an axis at high speeds as it sprays. This rotation can cause a dishwasher to smell burnt if the sprayer arm is clogged.

Without the free motion to spin, the plastic around the sprayer arm gets put under immense pressure. This pressure and friction cause the dishwasher to smell like burning plastic.

A burning plastic smell is a bad sign that your sprayer arm is causing too much friction and may fail soon.

Most Common Steps to Do When Dishwasher Smells Bad

If you’ve pinpointed the potential cause of the foul odour emanating from your dishwasher and are seeking solutions for how to address it, this section provides actionable steps you can take. Many of these remedies are straightforward and don’t necessitate any tools or specialised chemicals. However, if you use household cleaners in conjunction with the suggestions below, make sure to adhere to the instructions on the bottles.

Step1: Clean Filter

The water filter at the bottom of the dishwasher collects all of the solid food particles and waste from your dishes during washing cycles. It would help if you started with the filter to clean a dishwasher that smells bad when running.

Make sure you remove a dishwasher filter from the bottom of the unit. Use a brush or cloth to remove excess food particles from the filter inside and outside. Run under warm water in your sink. Replace the filter by screwing it into place at the bottom of the basin.

Step2: Use Vinegar

Another way to clean out the basin, filter, and drain hose of your dishwasher is by using household vinegar. You want to use vinegar if the bad wet dog smell is coming out of the vent in the dishwasher, which means it is more than just the filter that smells.

Make sure to empty the dishwasher and clean any detergent residue from the basin and filter. The chlorine in detergent can mix with vinegar and create a toxic gas.

Let the vinegar sit for several minutes, and then run a rinse cycle on your dishwasher.

Step3: Straighten the Drain Hose

The drain hose is probably attached to the underside of the sink or countertop. However, it usually comes from a hole in the cabinet from the dishwasher machine and into the plumbing. This drain hose may be too long and can have an excess length that gets bent or kinked.

Visually and physically check the hose while the machine is running when watering is flowing, and when it is empty. Loosen and secure any section of the nose that is bent.

Step4: Attach Drain Hose Higher Up

The drain hose must be about ten inches above the pipe entrance to drain correctly from the dishwasher into the plumbing. It attaches the drain hose above the drain pipe, and plumbing limits dirty water’s backflow into the dishwasher.

Ensure hooks or ties are on the ceiling under your sink. Tie or secure the hose onto these places so that it is up and above the drainage pipe and garbage disposal a minimum of ten inches.

Step5: Clean or Replace the Sprayer Arm

If the dishwasher smells hot, it could be the sprayer arm you must investigate and clean or replace.

The sprayer arm will tend to heat the connection where it spins if it is dirty or old. Make sure there is no debris in the way of the spinning arm. If the arm connection place is clean, buy a replacement and install it by locking it into place. This action is most likely going to fix a dishwasher that smells burnt.

Best Reasons To Choose Fix Appliances CA

As an appliance repair company, our technicians work tirelessly to put your appliances back in working condition and get your life back to normal. We understand the hassle that appliance repair and replacement cause and will work with you every step of the way to ensure that you get provided with the best dishwasher repair services.

Some of the best reasons to choose Fix Appliances CA for your next appliance repair are listed below:

  • Same-day service for all major appliances
  • 18+ years of experience providing excellent service
  • 9-times Winner of the HomeStars Award
  • A TSSA-certified gas appliance contractor
  • 90 days satisfaction guarantee
  • FREE house calls with any repair

Don’t live with the hassle of a broken dishwasher another day. We service all major appliance brands, including Whirlpool, LG, Miele, Electrolux, Samsung, Maytag, Kitchenaid, Kenmore, Fisher & Paykel, Bosch, Frigidaire, GE, and many more! Take the time to give us a call at 1-888-242-0777 for a same-day dishwasher repair service in Toronto and the GTA surrounding areas.

Date of page creation: May 11, 2021

Page update date: April 09, 2024


What Our Customers Say About Us

Discover how Fix Appliances maintains a 5-star service record since day one.

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rating twales, Brampton
twales, Brampton
March 12, 2024

The serviceman, Danny, was very efficient at repairing our dishwasher and did a great job ensure the space was clean before he left. I would recommend Danny and use him again for future repairs.

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colin, Toronto
February 12, 2024

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FAQ: Top Frequently Asked Questions

A dishwasher smelling like burning plastic may indicate a clogged sprayer arm causing friction. Sewage-like smells could be due to mould build-up in the dishwasher or bent drain hoses leading to backflow. These issues pose potential risks and require attention.
Common reasons include a dirty filter collecting decaying particles, a bent or low-positioned drain hose causing mould or mildew, and a clogged sprayer arm leading to a burnt plastic smell. Identifying these issues is crucial for effective repair.
Start by cleaning the filter at the bottom of the dishwasher, removing excess food particles. Using household vinegar to clean the basin, filter, and drain hose is effective, but be cautious of detergent residue. Straightening or adjusting the drain hose and cleaning or replacing the sprayer arm are also recommended steps.
Yes, many issues causing a bad smell can be addressed without professional help. Cleaning the filter, using vinegar, straightening the drain hose, and cleaning or replacing the sprayer arm are steps you can take. However, if problems persist, it's advisable to seek professional assistance.
Yes, a burning plastic smell is a serious concern as it may indicate excessive friction or pressure on the sprayer arm. This issue can lead to potential electrical shortages and even fire hazards. Immediate attention and corrective measures are essential to ensure the safety of your dishwasher and home.

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