Safety: Isolate the appliance from mains and close the water tap.

E10 is associated with the heat exchanger and its water level control.

Inspect heat exchanger: Remove the left side panel to access the heat exchanger / water matrix. Look for heavy limescale, sludge, or standing dirty water.
Flush channels: Disconnect the hoses to the heat exchanger and flush with hot water and a descaling solution until water flows freely.
Check level sensor: Some models use a float or optical sensor in the heat exchanger. Inspect for stuck floats or dirty optical windows. Clean gently with warm water and mild detergent.
Check valves: Verify that any small solenoid valves controlling flow to/from the heat exchanger operate freely and are not blocked.
Replace components: If the level sensor is defective or the heat exchanger is heavily scaled beyond cleaning, replace the Neff heat exchanger assembly or the heat exchanger level sensor as applicable.

After repair, run a hot cycle with dishwasher cleaner to help prevent future buildup.

Dishwasher shows E10; often related to drying or heat exchanger water level issues.

Possible Causes