Common Dishwasher Problems

A dishwasher is meant to save time and effort, but leaks, smells, or dirty dishes can quickly turn it into extra work. This comprehensive guide brings together the most common dishwasher problems in one place and shows you which issues you can safely fix yourself and when it’s time to call a professional. Always unplug the appliance or switch off the circuit breaker before working on it, and refer to your model’s user manual for part locations and safety instructions.

Problem / Symptom	Likely Causes	DIY Fixes (Difficulty: Low | Med | High)	Call Professional When
Dishwasher won’t start/run	No power, door not latched, Control Lock/Sleep/Delay active, software glitch	Low: Check power/breaker, latch door firmly, disable locks/delays, reset (power off 1-2 min)	Controls dead, flickering lights, non-clearing error codes, door switch failure
Cycle stops early	Software error, sensor fault, power interruption	Low: Reset appliance, run empty short cycle, check manual for model reset	Cycles repeatedly stop, panel freezes, persistent error codes
Not filling with water	Closed valve, kinked hose, stuck float, door not closed	Low: Open water valve fully, straighten hose, wiggle float, latch door properly	Inlet valve, float switch, or control board issues
Water won’t drain / standing water	Blocked filter, clogged sump/pump, kinked drain hose	Med: Clean filter/sump thoroughly, flush drain hose, verify high loop/air gap	Pump loud but ineffective, internal blockages
Dishes not clean	Overloading, blocked spray arms, wrong cycle/detergent, low temp	Low: Reload with space, clean spray arms/filters, correct cycle/detergent amount, verify hot water ~120°F	Circulation pump weak, heater faulty
Spray arms not spinning	Clogged nozzles, blocked by dishes, dirty bearings	Med: Remove/rinse arms, clear nozzles with toothpick, test spin by hand	Arms wobble/don’t seat, internal manifold damage
Dishes wet/cloudy/white film	No rinse aid, wrong dry setting, hard water minerals	Low: Fill rinse aid, use Heat Dry, vinegar cleaning cycle, angle dishes properly	Heating element stays cool, vent/fan failure
Leaking from door/bottom	Wrong detergent, overloading, worn gasket, loose hoses	Low: Use proper detergent, avoid overload, clean gasket, check visible hoses	Cracked tub, pump seal leak, internal joints
Bad smells/mildew	Trapped food, dirty filter/spray arms, standing water	Low: Weekly filter clean, monthly cleaner cycle, wipe seals, leave door ajar	Smells return fast, hidden mold/leaks
Strange noises (buzzing/grinding/rattling)	Dishes hitting arms, debris in pump, water supply issues	Low: Rearrange dishes, clean filter/sump, check inlet hose/valve	Grinding persists, screeching bearings, motor failure
Detergent not dispensing	Caked detergent, blocked dispenser, old detergent	Low: Clean dispenser, use fresh detergent, ensure nothing blocks door	Dispenser mechanism/spring broken
Detergent not dissolving	Old detergent, cool water, clogs reducing pressure	Low: Fresh detergent, hot water at sink, clean filters/arms	Pump/heater weak
Persistent error codes	Sensor faults, leaks, heat/motor issues	Low: Look up code, basic checks (filter/hose/door), reset appliance	Code returns immediately
Electrical/burning smell	Failing wiring, motor, heater, control board	High: Turn off power immediately	ELECTRICAL HAZARD – Always call professional

1. Dishwasher Won’t Start or Won’t Run a Cycle

When the dishwasher won’t start at all, it’s often a simple power, door, or setting issue not a failed control board.

What to check

1. Power supply
   • Make sure the dishwasher is firmly plugged in or hard-wired at the junction box.
   • Test the outlet with another appliance.
   • Check the circuit breaker and reset if tripped.
2. Door latch and seals
   • Confirm the door is fully closed and latched; push firmly until you hear a click.
   • Inspect the latch and strike for damage or misalignment.
   • Worn or warped door gaskets can prevent the door switch from engaging.
3. Control panel settings
   • Look for:
     • Control Lock / Child Lock
     • Sleep mode or “Demo” mode
     • Delay Start / Delay Wash
   • Turn these settings off following the instructions in your manual.
4. Quick reset
   • Unplug the dishwasher or turn off the breaker.
   • Wait 1–2 minutes.
   • Restore power and run a short cycle with no dishes to test.

If the unit still doesn’t respond or shows non‑clearing error codes, the issue may be with the control board, door switch, or wiring. At that point, call a qualified technician.

2. Dishwasher Not Cleaning Dishes Properly

If dishes come out dirty, greasy, or with food stuck on, focus on loading, water flow, and detergent.

Common causes

• Overloaded racks or poor loading
• Blocked spray arms or dirty filters
• Wrong cycle, water temperature, or detergent
• Low rinse aid or dishwasher salt (in hard water regions)

How to improve cleaning

1. Reload correctly
   • Don’t overload; leave space between items.
   • Face the dirtiest surfaces down or toward spray arms.
   • Keep tall items away from the spray arm paths.
   • Lay utensils in the basket with some handles up, some down to avoid nesting.
2. Choose the right cycle
   • Use “Normal” for everyday loads, “Heavy/Pots & Pans” for baked-on food.
   • For lightly soiled dishes, a quick cycle is fine avoid using it for heavy soil.
3. Check detergent and rinse aid
   • Use high‑quality dishwasher detergent (tabs or powder) made for automatic dishwashers.
   • Follow the manufacturer’s recommended amount; too much leaves residue, too little weakens cleaning.
   • Make sure the rinse aid reservoir is full; it helps water sheet off surfaces.
4. Clean filters and spray arms
   • Remove the lower rack to access the filter.
   • Take out the filter, rinse under warm water, and gently scrub with a soft brush.
   • Remove spray arms if your model allows:
     • Rinse under warm water.
     • Use a toothpick to clear blocked nozzles.
   • Reinstall everything securely and run a short cycle.
5. Check water temperature
   • Run the hot water at the sink before starting the dishwasher.
   • Ideally, incoming water should be around 120°F (49°C) to dissolve detergent.

If cleaning is still poor after these steps, there could be a failing circulation pump, partially blocked inlet valve, or sensor issue that needs professional diagnosis.

3. Dishwasher Won’t Drain or Water Is Left in the Bottom

It’s normal to see a small puddle (up to about an inch) after a cycle, but pooled or standing water indicates a drainage problem.

Quick checks

1. Confirm the cycle is finished
   • Make sure the machine has completed the full program and isn’t paused mid‑cycle.
2. Clean the filter area
   • Pull out the lower rack.
   • Remove any visible food scraps or broken glass at the bottom.
   • Take out the filter and wash it thoroughly.
3. Inspect the drain pump area
   • Shine a flashlight around the sump (where water collects).
   • Remove any debris you can see, using care not to damage the impeller.
4. Check the drain hose
   • Under the sink, locate the drain hose where it connects to the garbage disposal or sink drain.
   • Make sure it’s:
     • Not kinked, pinched, or crushed.
     • Not clogged (disconnect carefully with a towel or pan beneath, then flush with warm water).
     • Routed with a proper high loop or air gap to prevent backflow.
5. Check the garbage disposal (if fitted)
   • If the dishwasher is newly installed to a disposal, confirm the knockout plug in the disposal inlet was removed.
   • Run the disposal to clear any blockage before testing the dishwasher again.

If water still won’t drain after filter and hose checks, the drain pump or internal plumbing may be blocked or faulty and should be inspected by a technician.

4. Dishwasher Not Filling with Water

When the cycle starts but you don’t hear normal filling sounds or error lights blink there may be a water supply or sensor issue.

What to check

1. Door closure
   • Make sure the door is fully latched; an unlatched door stops filling.
2. Water supply valve
   • Locate the shutoff valve (usually under the sink or in a nearby cabinet).
   • Confirm it is fully open.
3. Inlet hose and valve
   • Check that the hose isn’t kinked or crushed behind the machine.
   • If comfortable, pull the dishwasher slightly forward and ensure hoses aren’t pinched.
4. Float and overfill protection
   • Inside the tub, locate the float (often a small dome or cylinder on the floor).
   • Move it gently up and down to ensure it isn’t stuck in the “up” (overfill) position.
   • Remove any debris around it.

If nothing improves, the inlet valve, float switch, or control board may require professional testing and replacement.

5. Dishwasher Won’t Empty the Water Completely

If there’s more than a shallow pool of water after the cycle, but the machine is otherwise running, focus on exit flow.

Steps to take

• Make sure the drain hose rises at least about 20 inches from the floor before looping back down to the drain to prevent siphoning issues.
• Recheck filters, pump intake, and hose for blockages.
• Ensure the hose isn’t sitting so low that sink water can backflow into the tub.

Persistent issues after these checks suggest a failing drain pump or control issue and call for service.

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6. Dishwasher Is Leaking Water

Leaks can come from something as simple as wrong detergent or loading, or from failing parts.

Common leak sources and fixes

1. Wrong detergent or too much detergent
   • Never use regular dish soap or hand soap; they create excess suds that overflow.
   • Use only dishwasher detergent (tabs, gel, or powder) and the correct amount.
2. Overloading and poor loading
   • If dishes press against the door or racks block sprays and drains, water can force its way out around seals.
   • Avoid stacking items so high that the door struggles to close.
3. Door gasket and hinges
   • Inspect the rubber seal around the door for cracks, splits, or debris.
   • Clean it with a damp cloth and mild soap.
   • If damaged or flattened, it may need replacement.
4. Hoses and connections
   • Check the inlet hose, drain hose, and internal connections (if accessible) for cracks or loose clamps.
   • Look for water pooling under or behind the unit.

If you can’t identify an obvious external cause, stop using the dishwasher and schedule professional service. Internal leaks can damage flooring and cabinets if ignored.

7. Dishes Coming Out Wet, Cloudy, or with White Film

Drying issues and cloudy glassware usually point to rinse aid, drying settings, or hard water.

How to improve drying

1. Adjust dry settings
   • Use “Heat Dry,” “Extended Heat Dry,” or a fan‑assisted dry if available.
   • Avoid opening the door immediately at the end of the cycle; let the heat work for a few minutes.
2. Use rinse aid
   • Keep the rinse aid dispenser filled.
   • Rinse aid helps water slide off surfaces instead of beading, promoting faster drying and fewer spots.
3. Load for drying
   • Place cups and bowls at an angle to avoid water pooling.
   • Avoid nesting items together.
   • Don’t block the vent or fan area.
4. Address hard water and white film
   • A white, chalky film usually indicates mineral deposits.
   • Use a dishwasher cleaner or a cycle with a cup of white vinegar on the lower rack (check your manual first).
   • Consider a water softener or specific detergents designed for hard water.

If the heating element is not working (feels cool right after a hot cycle), it may be faulty and needs professional replacement.

8. Strange Noises: Buzzing, Grinding, Rattling, or Thumping

Not all noises signal damage many are loading or water flow issues.

Normal vs. abnormal sounds

• Normal: Gentle humming, water sloshing, brief draining noises, soft fan noise after the cycle.
• Needs attention: Loud grinding, constant buzzing, knocking, or repeated thumping.

What to do

1. Rearrange dishes
   • Ensure tall utensils or pans aren’t hitting spray arms.
   • Space dishes to prevent them from clanging together.
2. Check spray arms
   • Spin them by hand; they should rotate freely.
   • Remove and clean if they feel stiff or obstructed.
3. Clean filter and sump
   • Debris in the filter or pump area can cause grinding.
   • Remove foreign objects like bone fragments, glass, or seeds.
4. Water supply noises
   • A loud buzzing at the start of the cycle can mean the water supply is off or restricted.
   • Check the inlet valve and ensure it’s fully open; verify hoses aren’t kinked.

If the noise persists after basic cleaning and reloading, internal pump, bearing, or motor issues may be developing and should be checked by a technician.

9. Dishwasher Smells Bad or Has Mold and Mildew

Musty or rotten smells come from trapped food, grease, and standing moisture.

How to eliminate odors

1. Clean interior surfaces
   • Wipe the door, walls, and especially corners where grime collects.
   • Clean the door gasket and around the edges thoroughly.
2. Clean or replace filters regularly
   • Rinse filters weekly in busy households.
   • Remove all loose food after each cycle to prevent rot.
3. Run cleaning cycles
   • Use a dishwasher cleaner tablet every 1–3 months.
   • Alternatively, run an empty hot cycle with a cup of white vinegar on the lower rack if your manufacturer allows it.
4. Improve ventilation
   • Leave the door slightly open between loads to allow the interior to dry.
   • Don’t leave dirty dishes sitting for days; use a rinse or pre‑wash cycle if needed.

Persistent mold despite cleaning may point to chronic drainage issues or internal leaks.

10. Detergent Not Dispensing or Not Dissolving

If detergent remains in the cup or clumps on the door, dishes won’t get fully clean.

Troubleshooting steps

1. Check the dispenser
   • Clean dried or caked detergent from the cup and lid.
   • Make sure the lid opens freely and isn’t blocked by tall dishes or pans in the upper rack.
2. Use fresh detergent
   • Old or moisture‑exposed detergent can harden and fail to dissolve.
   • Store detergent in a cool, dry place in an airtight container.
3. Confirm proper water temperature and pressure
   • Water that’s too cool won’t dissolve detergent properly.
   • Ensure your hot water is around 120°F (49°C).

If the dispenser door consistently fails to open despite being clear, the dispenser mechanism or control may be faulty and requires service.

11. Common Blockages and How to Clear Them Safely

Blockages can appear at several points in your dishwasher’s system.

Key areas to inspect

• Filter and sump (bottom of the tub)
• Spray arm nozzles
• Drain hose (behind the unit and under the sink)
• Garbage disposal connection or sink drain

General clearing steps

1. Turn off power at the plug or breaker.
2. Remove the lower rack for clear access.
3. Clear visible debris around the filter and sump.
4. Remove and clean filters and spray arms.
5. Disconnect and flush the drain hose if you suspect a clog.
6. Reassemble everything and run a short cycle to verify drainage.

If you’re not comfortable removing hoses or interior parts, stop at filter and spray arm cleaning and call a professional for deeper inspection.

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12. Monthly and Seasonal Maintenance Checklist

Regular maintenance helps prevent most of the problems above and extends your dishwasher’s lifespan.

Every week

• Empty and rinse the filter.
• Remove large food scraps from the tub after runs.
• Check racks and tines for damage or rust.

Every month

• Run a hot, empty cleaning cycle with a dishwasher cleaner or approved method.
• Wipe door seals, hinges, and corners.
• Verify that spray arms spin freely and aren’t clogged.

Every 3–6 months

• Inspect and flush the drain hose if you notice slow draining or odors.
• Check the inlet hose and valve for leaks or corrosion.
• Inspect the door gasket for wear and replace if needed.

13. When to Call a Professional

DIY fixes are great for clogs, filter cleaning, basic resets, and loading adjustments. Stop and call a licensed technician if you notice:

• Persistent leaks or water pooling beneath or behind the unit
• Error codes that do not clear after a reset and basic checks
• Repeated tripping of breakers or signs of electrical burning/smell
• No heat during wash or dry despite correct settings
• Loud grinding from the pump or motor that continues after cleaning
• Cracked tubs, damaged wiring, or parts you can’t safely access

A professional can test electrical components, pumps, valves, and control boards safely and help you decide whether repair or replacement makes more sense for the age and condition of your dishwasher.

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By following these troubleshooting steps and adopting a simple maintenance routine, you can solve most dishwasher problems yourself, keep your machine running efficiently for years, and reserve service calls only for issues that truly require an expert.