U11 indicates an inability to drain on Panasonic FR1 and other documented washers. Hose inspection changes depending on whether there is a drain pump or a gravity drain.
The Panasonic FR1 chart checks U11 for the NA-V10FR1 and NA-S106FR1. For other units, confirm the meaning and layout before making any changes to the installation.
Identify how the water drains
With a pump drain, follow the height and connection in the manual; lowering the hose without a clear reason can cause siphoning. With a gravity drain, raising it like a front-loader’s hose can prevent flow. Do not mix the two instructions.
With the appliance stopped, look for kinks, compression, and external blockages. If there is a filter that the manual allows you to clean, first prepare for controlled draining with the power disconnected and the water cold. The door staying locked may be a result of the water not draining out.
Do not force the door open or remove the filter while the water is hot. If U11 persists after the accessible checks, request service without assuming the code means the pump must be replaced, especially if your model does not even use one.
Provide support with the load type and a view of the exterior hose path; this helps confirm whether the installation matches that setup.