Samsung Dishwasher Not Draining — 5 Causes & How to Fix It

You open your Samsung dishwasher after the cycle finishes, and there's a pool of murky water sitting at the bottom. The dishes are still dirty, and that standing water isn't going anywhere. This drainage problem affects models across Samsung's DMR and DMT series — from the DMR57LFB to the DMT400RHS — and it's one of the most common service calls for these machines.

Before you schedule an expensive repair visit, let's walk through the five most likely causes. Most drainage issues come down to clogs or a failed pump, and you can diagnose many of them yourself in under 30 minutes.

Quick Symptom Check

Your Samsung dishwasher likely has a drainage problem if you notice:

• Standing water at the bottom after the cycle completes
• Dishes still wet or dirty because rinse water didn't evacuate
• Gurgling sounds during the drain cycle but no water movement
• Error codes like 5E, SE, or 5C on the display panel
• Water backing up into the tub during or after washing

Cause #1: Clogged Filter Assembly (50% of Cases)

The filter at the bottom of your Samsung dishwasher catches food particles before they reach the drain pump. When it gets packed with debris, water can't pass through to drain properly. This is the single most common reason for standing water.

How to diagnose:

1. Pull out the bottom rack completely
2. Locate the cylindrical filter assembly in the tub floor (usually in the back corner)
3. Turn the filter counterclockwise and lift it out
4. Check for buildup — food particles, grease, small bones, stickers from dishes
5. Inspect the mesh screen below the filter for blockages

The fix: Rinse the filter under hot running water. Use an old toothbrush to scrub away stuck-on debris. Check the sump area where the filter sits — sometimes food gets trapped there too. Reinstall everything and run a rinse cycle.

Cost: $0 (cleaning) or $15–$25 if you need a replacement filter
Time: 10 minutes
Difficulty: Easy — no tools required

Cause #2: Failed Drain Pump (30% of Cases)

The drain pump (part DD31-00005A) is what actually pushes water out of the dishwasher through the drain hose. These pumps use an impeller motor that can fail from wear, debris damage, or electrical issues. If you hear the pump trying to run but no water moves, or if it's completely silent during the drain cycle, the pump's likely dead.

How to diagnose:

1. Start a drain cycle and listen carefully at the bottom left front of the dishwasher
2. If you hear humming but no water movement, the impeller might be jammed
3. If it's completely silent, check for power to the pump (requires multimeter)
4. Spin the impeller by hand (access through the sump) — it should rotate freely
5. Check for continuity across the pump motor terminals (should read 20–40 ohms)

The fix: The DD31-00005A pump isn't repairable — you'll need to replace the entire assembly. It's compatible with Samsung DMR and DMT series models including DMR57LFB, DMR57LFS, DMR57LFW, DMR77LHB, DMR77LHS, DMR77LHW, DMR78AHB, DMT300RFB, DMT300RFS, DMT300RFW, DMT400RHB, DMT400RHS, and DMT400RHW.

Replacement steps:

1. Disconnect power and water supply
2. Remove the lower spray arm and filter assembly
3. Tip the dishwasher on its back (have a helper)
4. Remove the bottom panel to access the pump
5. Disconnect the wire harness and drain hose clamps
6. Remove mounting screws and pull out the old pump
7. Install DD31-00005A in reverse order, ensuring gasket seals properly

Cost: $117 for the DD31-00005A pump assembly
Time: 45–90 minutes
Difficulty: Moderate — requires tilting the machine and working underneath

Cause #3: Kinked or Clogged Drain Hose (15% of Cases)

The drain hose runs from your pump to either the garbage disposal or a drain pipe under the sink. If it's kinked, you'll get a slow drain. If it's completely clogged with grease or food buildup, nothing drains at all.

How to diagnose:

1. Pull the dishwasher forward slightly to inspect the drain hose
2. Follow the hose from the pump to the sink connection
3. Look for obvious kinks or sharp bends (especially where it connects to disposal)
4. Disconnect the hose at the sink end and blow through it — should be clear
5. Check for a high loop (hose should rise above the connection point to prevent backflow)

The fix: Straighten any kinks. If the hose is clogged, disconnect both ends and flush it with hot water and vinegar. Snake it with a drain auger if needed. If the hose is cracked or permanently kinked, replace it ($10–$20).

Cost: $0–$20
Time: 20 minutes
Difficulty: Easy

Cause #4: Garbage Disposal Knockout Plug (3% of New Installations)

If your drainage problem started right after installing a new garbage disposal, there's a 90% chance you forgot to knock out the drain plug. All disposals come with a solid plastic plug blocking the dishwasher drain port. You have to physically punch it out with a screwdriver and hammer before connecting the drain hose.

How to diagnose:

1. Think back — was the disposal recently replaced?
2. Disconnect the drain hose from the disposal inlet
3. Shine a flashlight into the disposal drain port
4. Look for a solid plastic plug blocking the opening

The fix: From inside the disposal (with power OFF and unplugged), use a screwdriver and hammer to punch out the knockout plug. Make sure you retrieve the plug piece from inside the disposal — don't let it stay in there. Reconnect the drain hose.

Cost: $0
Time: 5 minutes
Difficulty: Easy

Cause #5: Defective Check Valve (2% of Cases)

The check valve prevents dirty drain water from flowing back into the clean dishwasher. It's a one-way flapper valve, usually made of rubber. When it fails or gets stuck, water either won't drain out or flows back in after draining.

How to diagnose:

1. Access the check valve (it's typically built into the pump housing on Samsung models)
2. Inspect the rubber flapper for cracks, warping, or debris
3. Make sure it moves freely and seals when closed
4. Look for calcium buildup that might prevent proper sealing

The fix: Clean the valve thoroughly. If the rubber is damaged, you'll need to replace the check valve assembly or, in some cases, the entire pump assembly that includes it.

Cost: $20–$117 depending on whether it's a separate part
Time: 30–60 minutes
Difficulty: Moderate

When to Call a Pro

Most drainage issues are DIY-friendly, but call a technician if:

• You've replaced the pump and it still won't drain (possible control board issue)
• You're uncomfortable tipping the dishwasher to access components
• There's an electrical fault you can't diagnose with a multimeter
• The drain line is shared with other plumbing that's backing up (main drain problem)
• You see water leaking from places other than the obvious drain connections

Professional diagnosis runs $75–$125. A drain pump replacement by a tech costs $250–$350 including the part, so you'll save about $130 doing it yourself with the DD31-00005A pump.

Frequently Asked Questions

How do I force my Samsung dishwasher to drain?

Press and hold the "Start/Pause" button for about 3 seconds until you hear a beep. This cancels the current cycle. Then press "Start" again — many Samsung models will automatically attempt to drain before starting a new cycle. If that doesn't work, you can manually bail out the water with a cup and sponge, then address the underlying drainage problem.

Why does my Samsung dishwasher drain pump keep failing?

Repeated pump failures usually mean debris is getting past the filter and damaging the impeller. Always scrape dishes before loading and clean your filter every 2–3 weeks. Hard water can also shorten pump life — if you have hard water, run a dishwasher cleaner monthly and consider a whole-house water softener. Finally, make sure you're using the right detergent amount; too many suds can overwork the pump.

Can I use my dishwasher if the drain pump is broken?

No. Running the dishwasher with a failed drain pump will leave standing water in the tub, which becomes a breeding ground for bacteria and creates a foul smell. The water won't evacuate between cycles, so your dishes will just be sitting in dirty water. You'll also risk water damage if the tub overflows because the pump can't keep up with the fill valve. Wait until you've replaced the DD31-00005A pump before running another cycle.