Display shows F9, oven may shut down or not start; sometimes associated with tripping the breaker.

Safety first: Isolate the cooker at the mains and verify with a tester that it is not live before opening the rear terminal cover.

• 1. Check mains supply: Confirm the cooker is connected to the correct voltage and phase as specified on the rating plate. If in doubt, have a qualified electrician test the supply.
• 2. Inspect terminal block: Remove the rear terminal cover and check that all live, neutral, and earth connections are tight and not heat-damaged. Tighten loose screws and replace any burnt terminals.
• 3. Look for signs of arcing: Inspect wiring around the terminal block and filter board for scorch marks or melted insulation. Replace damaged wiring.
• 4. Internal filter / power board: Some Rangemaster ovens use an EMI filter or separate power board. If this component is cracked, burnt, or smells of burnt electronics, it should be replaced.
• 5. Control board: If the supply and terminal block are sound, F9 may indicate an internal control board power fault. Replace the control board if confirmed.

Note: Mains supply issues can be hazardous; if breakers trip repeatedly, stop using the appliance and consult a qualified electrician or Rangemaster engineer.