Induction or ceramic hob zone will not heat and the display shows E04 when that zone is selected.

Safety first: Disconnect the cooker or hob from the mains. Induction hobs contain high-voltage capacitors that can retain charge; do not touch electronic components unless you are trained and have discharged capacitors safely.

• Surface inspection: Check the glass-ceramic surface for cracks or signs of impact above the affected zone. If the glass is cracked, discontinue use and arrange replacement of the glass and inspection of the coil.
• Check for spills: Remove any large spills or moisture around the control area. Some Zanussi hobs will show error codes if liquid is detected. Dry the surface thoroughly and leave the hob powered off for at least 30 minutes before retesting.
• Internal inspection (advanced users): Remove the hob from the worktop and take off the bottom cover. Inspect the induction coil and wiring for burn marks or melted insulation. If the coil is visibly damaged, it must be replaced.
• Power module check: Look for obvious damage on the power module PCB (burnt components, cracked solder joints). Component-level repair is not recommended for untrained users; usually the entire power module is replaced.

Recommendation: Due to the high voltages and complex electronics, E04 faults on induction hobs should generally be handled by a qualified Zanussi technician. Do not attempt to bypass safety circuits.