AGA electric oven displays F5 and will not heat; fans and lights may still operate.

Safety first: Isolate the oven at the mains. Heating circuits carry high current; only work on them if you are competent with electrical repairs.

• Check thermal cut-outs: Locate the high-limit thermostats or thermal cut-outs on the top of the oven cavity or rear panel. Test for continuity. A blown cut-out will read open and must be replaced with the correct AGA-rated part.
• Inspect element wiring: Remove the rear panel and check wiring to the top, bottom, and grill elements for burns, loose spade connectors, or melted insulation. Repair or replace damaged wires.
• Listen for relay click: With power restored and extreme caution, start a heating cycle and listen for a click from the control board. No click may indicate a failed relay or control PCB.
• Test element resistance: With power off, measure each element's resistance. An open circuit indicates a failed element, which can also trigger F5 on some models.
• Replace faulty parts: Replace any open thermal cut-outs, failed elements, or the main control PCB if the relay is not energizing despite correct inputs.

Warning: If you are unsure how to safely test live circuits, contact an AGA service engineer.