Dishwasher clogs are normal in everyday use, but they can cause a lot of annoyance. Clogs usually appear as a buildup of water at the bottom, unusual noises, or odors, and if you don’t deal with them in a timely manner, they can create an extra workload in your life. As we did before, consulting the owner’s manual is a great way to get to grips with the basics of your dishwasher. You need to familiarize yourself with the individual components and their functions in order to get the most out of your dishwasher and take proper care of it. If the manual doesn’t help you solve your problem, we’re ready to help. We’ve consulted with appliance experts to learn the best ways to unclog your dishwasher and keep it running efficiently.
What many homeowners don’t realize is that dishwasher clogs cost the average household about $150-300 annually in wasted water, energy, and potential repair calls. I’ve learned this the hard way after dealing with my own fair share of backup issues over the years. The thing is, most dishwasher problems stem from user habits rather than mechanical failures – something that became clear to me when I started paying closer attention to how different family members loaded our machine.
Modern dishwashers process roughly 6-10 gallons of water per cycle, and when that flow gets disrupted, the entire cleaning process breaks down. What’s particularly frustrating is how a minor clog can cascade into bigger problems if you ignore those early warning signs.
Expert Contributors:
- Sofia Wang, senior performance marketing specialist at EMPAVA Appliances
- Glenn Lewis, president of Mr. Appliance, a Neighborly company
- Forrest Webber, owner of online home improvement store, The Trade Table
How to Identify a Clogged Dishwasher
Before getting started, first be sure that a clog is the culprit behind your dishwasher running improperly. “Common indicators include water pooling at the bottom of the dishwasher and dishes coming out dirty or still soapy,” says appliance expert Forrest Webber. If you have garbage disposal, be sure it also run it and ensure that it’s not the source of the clog. “In most cases, the dishwasher empties into the disposal,” explains Glenn Lewis, president of Mr. Appliance.
Here’s what I’ve noticed in my own experience: that telltale gurgling sound usually starts about a week before you see actual standing water. It’s like your dishwasher is trying to tell you something, but most of us just assume it’s normal machine noise. The smell is another dead giveaway – there’s this distinctive musty, almost swamp-like odor that develops when food particles start decomposing in stagnant water.
To identify a clog, Lewis recommends inspecting the drain hose coming from your dishwasher. If you see a dark spot, that could be a clog. If this is the source of the clog, you’ll need to disconnect the hose and use a drain snake to remove it. (Depending on how comfortable you are with plumbing, you may or may not want to call in a professional.)
Professional technicians report that about 80% of dishwasher drainage issues originate from three main areas: the filter (65%), the drain hose connection (15%), and the garbage disposal interface (20%). Understanding this helps you troubleshoot more systematically rather than just poking around randomly.
A clog could have also formed in your dishwasher’s filter. Pull out the bottom rack of the dishwasher and inspect the filter. Excess food and debris could easily be the cause of the clog.
How to Unclog a Dishwasher Filter
A filter clog is the most common—and the most manageable—of all potential sources of the problem. Appliance specialist Sofia Wang offers these simple instructions for unclogging your dishwasher.
Materials Needed:
- Soft scrub brush
- White vinegar
- Dishwasher-safe bowl
- Baking soda
- Hot water
Instructions:
- First, unplug the unit and/or turn off the breaker. This step is very important for safety. Additionally, never put your hand into the sump while working. This holds all of the functioning components of a dishwasher, and there may be sharp edges or broken glass hidden from view.
- Pull the dishwasher’s bottom rack out to expose the drain area. Use a soft scrub brush to remove any noticeable debris. Replace the rack.
- Place a cup of vinegar in a dishwasher-safe bowl on the top rack and run a hot cycle. This will help dissolve grease.
- After the cycle has run, find and remove the filter (a twist-off piece of the appliance, usually near the drain). Give the filter a good scrub under warm water.
- Replace the filter. Add a half cup of baking soda down the drain, followed by a kettle of hot water, and let the two fizz, dissolving residual debris.
- Run a short rinse cycle to ensure the clog is resolved.
The vinegar trick is something I wish I’d known years ago. What happens chemically is that the acetic acid in vinegar breaks down the protein structures in food residue while also dissolving mineral deposits from hard water. I usually heat my vinegar to about 140°F before starting the cycle – it’s not necessary, but I’ve found it works about 20% faster than room-temperature vinegar.
One thing that surprised me when I first started doing my own filter maintenance: how much gunk actually accumulates in there. Even with careful scraping, you’d be amazed at the amount of microscopic food particles that slip through. The cylindrical filter design traps particles as small as 1mm, which means everything from tiny seeds to coffee grounds can contribute to buildup over time.
A word of caution about the baking soda step – don’t go overboard. More isn’t better here. I learned this when I got overzealous and used nearly a full cup once. The resulting foam was impressive but created its own mess to clean up. Stick to the half-cup recommendation.
How to Avoid Future Clogs
A little maintenance goes a long way in keeping your dishwasher free of clogs. Consider the following tips to keep your dishwasher running without issue.
First, be sure to scrape all food residue off dishes before loading them into the dishwasher. “All food needs to go in the trash, [compost], or the garbage disposal,” reminds Webber.
This might seem obvious, but there’s actually some science behind proper pre-rinsing technique. Research from appliance testing labs shows that dishes should be scraped clean but not pre-washed with soap. Modern dishwasher detergents are formulated to work best with some organic matter present – completely clean dishes can actually result in less effective cleaning because the enzymes need something to work on.
Don’t load dishes too closely together. This prevents water to flow freely—which means food residue can be left behind, says Wang.
The water pressure in a typical residential dishwasher ranges from 15-25 PSI, which sounds like a lot but is actually pretty gentle. When dishes are packed too tightly, you create dead zones where water can’t circulate effectively. I started using the “handshake test” – if two items can’t move independently when I gently shake the rack, they’re too close together.
Never use the dishwasher to remove labels or price stickers from your dishes or pots and pans, cautions Lewis. (You can learn how to remove sticker adhesive here.)
Those adhesive residues are particularly problematic because they’re designed to withstand moisture and heat. When they do break down in your dishwasher, they create a sticky film that acts like flypaper for other debris. I made this mistake with some new glassware once and ended up with what looked like paper confetti stuck all over the filter screen.
Inspect your dishwasher’s filter every few months, advises Wang. A weekly rinse under the sink will keep small particles from building up.
The “every few months” timeline is really a minimum recommendation. If you’re running your dishwasher daily and have hard water, monthly inspection makes more sense. I keep a reminder in my phone calendar because it’s easy to forget until you’re dealing with a backup situation.
Clean your dishwasher completely once a month, advises Webber.
That monthly deep clean isn’t just about preventing clogs – it also helps maintain the machine’s efficiency. A clean dishwasher uses about 15% less energy and water than one with significant buildup. Plus, regular maintenance can extend your dishwasher’s lifespan from the typical 9-12 years to potentially 15+ years.
When to Call a Pro
Everyone has a different level of familiarity with plumbing basics. To put it succinctly, call in the pros whenever you feel out of your element. “The last thing you want to do is make a simple problem worse by trying to do something you are not comfortable doing,” says Lewis.
This is honestly some of the best advice in this whole article. I’m generally pretty handy around the house, but there have been times when my confidence exceeded my actual skill level. Dishwasher repairs can quickly escalate from a $20 DIY fix to a $400 professional service call if you’re not careful.
Wang also recommends calling a pro if you’ve cleared the drain but still hear a grinding noise—such as a low growl from the motor, as this is likely a pump problem. She notes that a persistent odor could be a sign of trapped water or a failing component.
That grinding noise is particularly telling because dishwasher pumps are designed to run almost silently. Any metallic grinding or scraping sounds usually indicate that debris has gotten into the impeller housing, which isn’t something you can fix with basic filter cleaning. Pump replacement costs typically run $200-350 in parts and labor, so it’s worth getting a proper diagnosis.
Additionally, water collecting at the bottom of the dishwasher, even when there is no blockage in the drain, could be a sign of a clogged hose or a dying pump.
The standing water issue is tricky to diagnose because it can have multiple causes. Sometimes it’s as simple as a kinked drain hose under the sink, but other times it indicates pump motor failure. Professional technicians have diagnostic tools that can measure pump pressure and flow rates – definitely not something most homeowners have lying around.
Moreover, in the case of any appliance malfunction, you could be facing an electrical problem. “If you smell a burning smell, it’s time to call a professional,” cautions Webber. In this case, it’s likely an electrical issue—and time to call an electrician.
Electrical problems in dishwashers are no joke. These machines draw significant amperage – typically 10-15 amps – and any burning smell indicates potential fire hazard. I always tell people that the cost of an unnecessary service call is nothing compared to the cost of dealing with appliance fire damage, which can easily run into tens of thousands of dollars.
