The code names the symptom, not the cause
A Samsung dishwasher will tell you it could not drain, which is useful but incomplete: a drain code means water did not leave in time, not that the pump has failed. On this platform the usual reason is the filter in the tub floor, which twists out by hand and is meant to be rinsed regularly. After that come the drain hose, the disposer connection and something hard jammed in the pump - and only then the pump itself.
What you are seeing
- A drain code appears and water is left in the tub.
- Dirty water appears in the tub between cycles.
- Water backs up into the sink when the machine drains.
- A rattle or grinding sound during the drain.
- Not this fault: A small pool of clean water in the sump is normal.
- Not this fault: Water on the floor rather than in the tub is a leak, and a different page.
Most likely causes, in order
- Tub filter clogged — Why ranked: First because it is the usual meaning of a drain code on this platform, it is reachable by hand, and it is free to correct.
- Drain hose kinked, or with no high loop — Why ranked: Second because it explains water siphoning back into a tub that had already emptied - the version that comes and goes.
- Disposer knockout plug never removed, or the air gap blocked — Why ranked: Ranked here because it explains a machine that has never drained since a disposer was fitted.
- Something hard jammed in the pump — Why ranked: It announces itself with a rattle or a grind and will damage the pump if the machine keeps running.
- Drain pump failed — Why ranked: Last. It is what owners read into the code and the least likely of the five in practice.
What to check, in order
- Twist out the tub filter and look at what is in it. — Because: Rank one is the usual meaning of the code and needs no tools at all.
- Follow the drain hose under the sink and look for a kink or a missing high loop. — Because: Rank two is visible and explains water returning after the machine has emptied.
- Ask whether a disposer was fitted recently, and lift the air gap cap. — Because: Rank three is settled by history and a cap that lifts off by hand.
- Listen during the drain for a rattle or grind. — Because: Rank four is identified by sound alone, before any panel comes off.
Checks you can do safely
- Bail the standing water out with a jug and a sponge until the sump is nearly dry. — N: 1 — Tools: Jug, sponge, towels — Time: moderate
- Twist out the filter under the lower spray arm, rinse it and clear the sump opening by hand. — N: 2 — Tools: Gloves — Time: moderate
- Look under the sink and confirm the drain hose rises into a high loop or an air gap and is not kinked. — N: 3 — Tools: Torch — Time: moderate
- Lift the air gap cap on the sink top and clear any debris inside it. — N: 4 — Tools: Gloves — Time: quick
- Stop rule: Stop here. Removing the pump cover, disconnecting the drain line or clearing the disposer inlet is plumbing or service work.
Before you reach into the tub
Safety
Switch off the dishwasher breaker before reaching into the sump, and never put a hand into a disposer. A capacitor can hold a charge after the power is off. The water in a tub can still be hot at the end of a cycle. Broken glass in the sump is common; use gloves and a torch, not bare fingers. Never run the machine to test while the pump cover is off.
When this becomes a service call
The code returns with the filter clean and the hose confirmed clear. A rattle or grind comes from the pump. Water backs up into the sink with the sink drain confirmed clear. The machine has never drained since a disposer was fitted.
Nearest pages
What this page does not cover
This is generalized information for Samsung dishwashers as a group. It does not decode codes or name parts. Where a family- or model-specific page exists it supersedes this one.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
