Charger displays E104 and refuses to charge; app may show 'Line voltage out of range'.

Danger: This involves live 240 V circuits. If you are not qualified, do not open the charger or panel. Turn OFF the breaker and call a licensed electrician.

• Verify breaker and supply: Confirm the Enphase charger is on a dedicated 2-pole breaker of the correct rating per the installation manual (commonly 40–60 A depending on model).
• Check for obvious issues: With power OFF, remove the charger front cover only if the manual allows homeowner access. Look for burned insulation, discoloration, or loose wires at the line terminals. Do not touch any components.
• Tighten connections (electrician only): A qualified electrician should verify torque on line lugs and confirm 240 V (or specified voltage) at the charger input with a multimeter.
• Monitor utility voltage: If E104 occurs during brownouts or storms, the charger may be correctly rejecting unstable power. Wait until grid conditions stabilize and try again.
• If voltage is normal but error persists: The internal voltage sensing circuit on the control board may be defective and will require board replacement by a service technician.