Oven selector knob is loose, slips, or does not change functions reliably

Safety first: Disconnect power before removing the control panel or selector switch.

Step-by-step checks:

• 1. Inspect knob: Pull off the knob and check for cracks or a rounded inner spline. Replace the knob if damaged.
• 2. Check shaft: Inspect the selector switch shaft for wear or play.
• 3. Test switch: With the panel removed, test continuity across the switch contacts in each position. Replace the Zanussi function selector switch if contacts are unreliable.
• 4. Refit knob: Push the new or existing knob fully onto the shaft, aligning any flat or keyed sections.

Warning: Do not force a knob onto a misaligned shaft; this can break the switch.