Gas cooktop burners do not spark, F21 or a similar ignition error appears on electronic models.

Safety: Turn off power and close the gas supply before servicing. Avoid creating sparks if gas smell is present.

• Dry electrodes: If the hob has recently been cleaned, moisture may be shorting the electrodes. Allow the hob to dry completely or use a hair dryer on a low setting (power off) to dry around the burners.
• Check spark: Restore power, turn a burner knob to the ignition position, and look for sparks at each electrode. If none spark, suspect the spark generator. If only one does not spark, suspect that electrode or its wiring.
• Inspect electrodes: Remove burner caps and heads. Clean the electrode tips and ensure they are not cracked or loose. Replace any damaged electrodes with Ariston-specific parts.
• Test ignition switches: Under the control panel, each knob has a small switch that triggers the igniter. Check that the switch clicks and is not stuck. Replace faulty switches.
• Replace spark generator: If no electrodes spark and power is present, replace the ignition transformer/spark generator module.