Oven
F23
The F23 error code on a Bosch oven indicates a fault with the cooling fan or its temperature monitoring circuit — it’s a moderately serious fault that will prevent the oven from operating safely until resolved.
What does this error mean?
F23 signals that the oven’s control board has detected either a failure in the cooling fan motor or an issue with the fan’s temperature sensor circuit. The cooling fan protects the oven’s electronics and external casing from overheating during and after cooking. When the control board can’t confirm the fan is working correctly, it locks the oven out as a safety precaution.
Est. repair cost
£80–£150 professional repair; £20–£50 DIY fan motor replacement (part only)
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 – Power cycle the oven: Switch the oven off at the wall socket, wait 5 minutes, then switch it back on. A one-off software glitch can occasionally trigger F23; a reset clears it. If the code returns immediately, move to the next steps.
Step 2 – Let the oven cool fully: If the error appeared during or after cooking, allow the appliance to cool for at least 30 minutes before inspecting anything. The cooling fan runs after the oven shuts off — if you hear it struggling or not running at all, that confirms a fan fault.
Step 3 – Inspect the fan vent for obstructions: Locate the cooling fan vent, usually at the rear or top of the oven casing. With the oven fully off and unplugged, check for visible blockages such as accumulated grease, dust, or debris. Clear any obstruction carefully with a dry cloth or soft brush.
Step 4 – Check for error recurrence after cleaning: Plug the oven back in and run it at a low temperature (e.g. 150°C) for 10 minutes. If F23 does not return, a blocked fan was the culprit. If it returns, the fault is mechanical or electrical.
Step 5 – Replace the cooling fan motor (confident DIYers only): Bosch cooling fan motors are widely available from UK parts suppliers (e.g. eSpares, 4ourhouse) for £20–£50. With the oven unplugged and cooled, the rear panel can typically be removed with a Torx screwdriver to access the fan. Match the part number from your model label before ordering. If you are not confident working inside the appliance, stop here and call a technician.
Step 6 – Do not attempt PCB repairs yourself: If replacing the fan does not clear the fault, the control board or sensor wiring is likely at fault. These repairs involve live electrical components and should only be carried out by a qualified appliance engineer.
📞 When to call a professional
Call a qualified appliance engineer if the F23 code returns after a power reset and the fan vent is clear, or if you are not comfortable removing the oven’s rear panel. When booking, tell the engineer: ‘My Bosch oven is showing error code F23 — I believe it’s a cooling fan fault.’ This helps them bring the correct parts. Do not attempt to bypass the fault or tape over the error — this safety lockout exists for good reason.
⚖️ Repair or replace?
A professional repair for a cooling fan fault typically costs £80–£150 in the UK including parts and labour. If your Bosch oven is under 7 years old and in otherwise good condition, repair is almost always the better value choice. For ovens over 10 years old or where the control board is also faulty (pushing repair costs above £200), replacing the oven becomes more cost-effective.