Bosch Oven E4 error code
E4 means the oven temperature sensor is shorted. The control sees near-zero resistance, reads it as extreme heat, and shuts the oven down.
Also shown as: E4, E:4
Last updated: October 6, 2026
What causes the E4 error?
- Shorted oven temperature sensor
- Pinched sensor wires touching each other or the chassis
- Melted wire insulation from extreme heat
- Corroded connector bridging the sensor terminals
- Control board misreading the sensor circuit
How to fix Bosch E4 — step by step
Work through these in order, from simplest and safest first. Stop as soon as the code clears.
- Power reset and cool-down
Turn off the breaker and let the oven cool completely. Restore power and try Bake. A shorted sensor will return the code right away. - Inspect the sensor wiring (technician)
A technician can check the sensor harness for pinched, melted, or touching wires — especially where it passes near hot surfaces. Separating or replacing damaged wire can fix it without a new sensor.Safety warning: Do not run the oven with damaged sensor wiring. - Test the sensor (technician)
A shorted sensor reads far below the normal ~1,080 ohms at room temperature. If it tests shorted, it needs replacement.Safety warning: Sensor testing requires pulling the oven out on most models. Call a technician. - Replace the sensor
If the wiring is intact but the sensor itself is shorted, replacement is the fix. If a new sensor does not clear E4, the control board is at fault.Safety warning: On gas models, leave burner-area work to a technician.
When to call a technician
- E4 returns immediately after a reset
- You see melted or pinched wiring
- The sensor needs testing or replacement
- It is a gas oven
Frequently asked questions
The oven shows E4 when it is stone cold. How?
A shorted sensor always reads as extremely hot, no matter the real temperature. The control believes the false reading and locks out.
What causes a sensor to short?
Melted insulation letting the two sensor wires touch, a crushed harness, or internal failure of the sensor element itself.
Is E4 urgent?
The oven protects itself by shutting down, but do not keep resetting and retrying — find and fix the short.
Sources
Every meaning and fix above was checked against official manufacturer documentation:
FixCode provides general troubleshooting information only — not professional repair advice. If you are unsure about any step, stop and call a qualified technician. Repairs done incorrectly can be dangerous and may void your warranty.