Bosch EV home charger shows E103 and does not energize the relay; no charging current flows.

Safety first: Turn OFF the dedicated breaker and verify no voltage is present at the charger input before opening any covers. High voltage inside can cause serious injury.

• Listen for relay click: With the cover closed, turn the breaker ON and plug in the vehicle. Listen closely for a distinct click from inside the Bosch unit when charging should start. No click suggests a failed coil or driver; repeated clicking with E103 suggests welded or sticking contacts.
• Check line connections (electrician only): A licensed electrician can remove the front cover and verify that the line and load terminals on the internal contactor are tight and show no signs of overheating (discoloration, melted insulation).
• Do not tap or strike the unit: Hitting the charger to free a stuck relay is unsafe and can worsen the damage.
• Replace contactor if needed: If the contactor shows pitting, discoloration, or mechanical binding, it must be replaced with the Bosch-specified power contactor model. This requires disconnection from mains and should be done by a qualified technician.