Induction hob displays E3 and will not start heating on one or more zones.

Safety first: This fault can involve dangerous mains voltages. Only a qualified electrician or appliance engineer should perform internal tests.

User checks:

• Confirm the hob is connected according to the Caple installation diagram (single‑phase vs two‑phase) and that no DIY alterations have been made.
• If E3 appears during storms or grid issues, switch off the hob at the isolator and wait for the supply to stabilise.

Technician checks:

• Measure the supply voltage at the terminal block with a calibrated multimeter; verify it is within Caple’s specified range (typically 220–240 V AC for UK models).
• Check the mains terminal block for signs of overheating, loose screws, or bridging links incorrectly fitted.
• Inspect the EMI filter / power entry board for burnt components or cracked solder joints.
• Verify the voltage sensing circuit on the main control PCB (resistor divider, optocoupler) and replace the board if readings are incorrect.

Do not operate the hob until the supply and wiring are confirmed correct; overvoltage can permanently damage the induction modules.