Bosch Oven E303 Error: Relay Module Overheating
What Does Bosch Oven Error Code E303 Mean? Error code E303 indicates the electronic relay module has overheated. This component switches heating elements on and off. When it overheats, the oven shuts down for safety. Immediate Action Turn off at the breaker, especially if you smell burning electronics. Let everything cool for at least an […]
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. An overheating relay module is a fire risk. Do not use until professionally repaired.
Can I reset the code?
No. The underlying cause must be repaired. Resetting will just lead to re-overheating.
When to stop immediately?
Stop if you notice: Immediately if you smell burning electronics, Oven shuts off during normal cooking.
Symptoms You May Notice
Oven shuts off during use
The oven turns off mid-cook when the relay module reaches its thermal limit.
Electrical burning smell
A distinct electrical or plastic burning smell from behind the oven control panel.
Possible Causes
Failed cooling fan for electronics
The fan that cools the electronic relay module has failed.
Requires ProfessionalOverloaded relay
A relay is switching excessive current due to a partial short in a heating element.
Requires ProfessionalSafe Checks You Can Do
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1
Turn off and let cool
Turn off the oven at the breaker. Wait at least 1 hour for electronics to cool.
If you smell electrical burning, this is urgent — leave the breaker off.
When to Call a Professional
Contact a qualified technician if:
- Cooling fan is not running
- Relay module shows thermal damage
- Heating element draws excessive current
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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