E21 corresponds to drain time exceeded in Midea L11. Retained water and the outlet path guide the inspection, but the code does not confirm a failed pump.
The definition appears in the official technical manual for the L11 platform. It should not be equated with an E21 from another brand or carried over to another Midea model without confirming the platform.
Check the accessible assembly
With the appliance stopped, check whether the hose is bent and whether the outlet matches the dimensions in the user manual. A clear hose can still drain poorly if its connection is installed incorrectly.
Filter cleaning should only be done through user-authorized access and after the water has been safely drained. Disconnect power, let it cool, and prepare to collect the water; do not replicate pump disassembly steps from the technical manual.
If you hear the pump motor, note the sound without assuming the flow rate is correct. When E21 returns after checking the outlet and the permitted maintenance, request diagnosis instead of repeating cycles with retained water.
Indicate whether the level dropped partially or stayed the same; this helps distinguish slow draining from a completely blocked outlet.