getting an 'OE' error code at the end of every cycle, what causes that?

Diagnosis

The 'OE' error code on your Samsung DW80CG4021SR indicates a "Drain Error," meaning the control board has detected that water is still present in the sump area after the drain pump has completed its timed cycle. This is typically triggered by a pressure sensor or a timeout mechanism that realizes the water level hasn't dropped sufficiently within the allotted window. If this happens at the end of every cycle, you have a partial restriction rather than a total failure, allowing some water to exit but not enough to satisfy the sensor's requirements. The root cause is almost always a physical blockage located in the drainage path. This usually manifests as a "slug" of food debris, a piece of broken glass, or a buildup of solidified grease trapped in the filter assembly, the drain pump impeller, or the corrugated drain hose. In some cases, if you recently installed a new garbage disposal, a plastic knockout plug may still be blocking the dishwasher's inlet port, causing a backup that triggers the OE code. You can confirm this by opening the door after the cycle and seeing a pool of standing water (usually 1-2 inches) at the bottom of the tub.

How to Fix It

1. Clear the Sump Filter: Rotate the cylindrical filter at the bottom of the tub counter-clockwise to unlock it. Lift it out and rinse it under hot water using a soft brush to remove the biofilm and food particles. Reach into the sump area and feel for any hard debris like popcorn kernels or glass shards that may be blocking the impeller intake.
2. Inspect the Air Gap: If your sink has a small chrome cylinder (air gap) between the faucet and the sink, pop the chrome cover off and remove the plastic cap. Use a bottle brush or a pipe cleaner to clear any debris from the interior of the gap. If water is backing up into this gap, the blockage is further down the line.
3. Check the Garbage Disposal Port: If you have a disposal, disconnect the dishwasher drain hose from the disposal nipple. Insert a finger or a screwdriver into the disposal port to ensure the rubber knockout plug was fully removed during installation. If the plug is still there, the water cannot exit, triggering the OE code.
4. Flush the Drain Hose: Disconnect the hose from the sink/disposal end and place the end into a 5-gallon bucket. Run a "Cancel" or "Drain" cycle. If the water flows out in a strong, steady stream, the hose is clear. If it trickles, there is a clog in the corrugated line. Use a wet/dry vac to suck the blockage out from the sink end of the hose.
5. Inspect for Kinks: Pull the dishwasher out a few inches from the cabinetry. Ensure the drain hose isn't pinched against the wall or crushed by the unit being pushed too far back. Even a slight kink can restrict flow enough to trigger the OE sensor.

If That Didn't Work

• Clean the Drain Pump Impeller: If the filters are clean but water remains, the impeller may be jammed. Access the pump from the bottom of the unit. Remove the pump cover and check if a small object (like a toothpick or piece of plastic) is wedged in the impeller blades, preventing them from spinning at full RPM.
• Test the Drain Pump Motor: Use a multimeter to check the continuity of the drain pump motor. If the motor windings are open or showing infinite resistance, the pump has failed electrically and the entire pump assembly must be replaced.
• Clear the Check Valve: There is a small rubber check valve (one-way valve) located where the hose connects to the pump. If this valve is stuck closed or warped, water will be pushed out and then immediately flow back into the tub, causing the sensor to detect water at the end of the cycle.
• Reset the Control Board: In rare instances, a glitch in the sensor logic occurs. Perform a hard reset by disconnecting the power from the circuit breaker for 10 full minutes, then restart the unit to clear the cached error.

Heads Up

• High-Loop Installation: Always ensure your drain hose is installed in a "high loop" (fastened to the underside of the countertop) before it drops into the disposal. Without this, dirty sink water can siphon back into the dishwasher, causing odors and OE errors.
• Avoid Pre-Rinsing: Do not rinse plates completely clean before loading. Modern detergents require a certain amount of food soil to work effectively; without it, the detergent can create excessive suds that confuse the drain sensors.
• Monthly Maintenance: Run a dedicated dishwasher cleaner or a bowl of white vinegar on the hottest cycle once a month to dissolve grease buildup in the internal pump housing.
• Avoid Heavy Greasy Pots: Never put pots with solidified fat or grease into the machine. This grease cools inside the drain hose and acts like glue, trapping other debris and leading directly to the OE error.