Display shows E16 and the unit will not allow spray or brush operation; only standby is possible.

Safety: Unplug the unit before working on the control panel.

• Toggle child lock: Press and hold the child lock button (or the combination specified in the manual) for 5–10 seconds to toggle the lock state.
• Clean keypad: If buttons feel sticky, wipe the control panel with a slightly damp cloth and mild detergent. Do not allow liquid to enter the panel.
• Inspect lock switch: Open the control panel and test the lock button switch with a multimeter for proper operation. Replace the switch or keypad assembly if faulty.
• Reset control board: Unplug for 5 minutes and reconnect to clear any temporary firmware glitch.