Bosch Oven Error E05 — What It Means & How to Fix It

What Does This Error Mean?

E05 on a Bosch oven means the cooling fan has stopped working or has been detected as faulty. The cooling fan protects the oven's electronics and the surrounding kitchen cabinetry from heat damage — it runs during and after cooking. When the fan fails, the oven shuts down to prevent overheating.

Affected Models

Bosch HBG Series
Bosch HBA Series
Bosch Series 4, 6 and 8 Built-In Ovens
Bosch HBN Series
Bosch HBS573BS0B

Common Causes

Cooling fan motor has failed — bearings seized or motor winding burnt out
Fan blade jammed by debris — grease or a food particle preventing the fan from spinning
Cooling fan wiring fault — connector loose or wire broken
Control board not sending power to the fan — board fault rather than fan fault
Fan speed sensor fault — fan is running but the speed sensor is not confirming it

How to Fix It

Switch the oven off at the wall for 5 minutes, then restart.

A fan that temporarily seized due to a food particle may free itself after a reset. Listen for the fan running when you restart — it should be audible as a gentle hum.
Note whether the fan was running before E05 appeared.

Bosch ovens run the cooling fan during and after cooking. If the fan was not running or made a grinding noise before stopping, the motor or bearings have failed.
Do not continue using the oven until E05 is repaired.

Without the cooling fan, the electronics above the oven cavity will overheat within minutes of operation, causing secondary damage to the control board.
Call Bosch service for cooling fan replacement.

A cooling fan motor typically costs £20–50 for the part. Total repair with labour is usually £100–200.

When to Call a Professional

Cooling fan replacement requires a technician — the fan is located behind the oven cavity and requires partial removal of the oven from its housing. Do not continue using the oven with E05 — without cooling, the electronics will overheat and be damaged. Contact Bosch service on 0344 892 8979 (UK).

Frequently Asked Questions

How do I know if my Bosch oven cooling fan is running?

When you turn on the oven, you should hear a gentle whirring sound from the top or rear of the oven. The fan continues running for 15–30 minutes after the oven is switched off — this is normal. If you notice complete silence where the fan sound used to be, the fan has likely stopped.