OE, E03, and E21 indicate a drain problem on LG front-loaders, which are grouped together in the documentation. Before opening the filter, check for any trapped water and the external hose.
The LG front panel groups these three codes together. Use that equivalence only if it applies to your machine; SideKick draining has different access points and controls.
Watch what happens when it tries to drain
- If water remains and the hose is bent or crushed behind the cabinet, that restriction should be addressed before blaming a part.
- If you hear the pump but no water comes out, the sound only confirms activity: it does not prove it can move enough flow.
- If water comes out and the alert returns, note whether the draining stops or is slow. Do not assume the circuit is clear because it drained only partially.
With the machine stopped, inspect the visible path and the house outlet. To open an accessible filter, follow the manual’s residual-drain procedure, with power disconnected, cold water, and containers ready. Unscrewing it suddenly can release the water from the drum.
The drain hose placement must match the height and connection for your model. If it still will not drain after the external check and approved cleaning, request a diagnosis for no drain.
Let us know if there was water, whether the pump could be heard, and what restriction or residue you found; that information is more useful than requesting a new pump based on the code.