Bosch · Oven
Bosch Oven F31 Error Code
Oven temperature sensor short circuit
What this error means
F31 indicates a short circuit in the oven temperature sensor—the PT500 probe in the upper rear cavity sent resistance near zero, so the board disables bake and broil to prevent uncontrolled heating.
How F31 is detected
When F31 appears on a Bosch oven, the control board has confirmed that water did not leave the machine within the programmed drain window. On Bosch HBL8753UC, Bosch HBL8454UC, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most F31 calls are resolved without parts: turn off the breaker and allow the oven to cool completely. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If F31 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Sensor wire pinched against oven cavity metal during rack insertion
- Shorted RTD probe from grease fire or steam damage
- Moisture bridge across sensor terminals after cleaning
- Harness chafe at the door hinge pass-through
Step-by-step fixes
- 1Turn off the breaker and allow the oven to cool completely
- 2Locate the sensor rod entering the upper rear wall and follow wires to the rear harness
- 3Reseat the connector and inspect for bare wires touching chassis metal
- 4Allow twenty-four hours dry time if steam cleaning triggered F31 once
When to call a technician
Replace the oven temperature sensor if short persists with the probe unplugged from the board side.
Affected models
- Bosch HBL8753UC
- Bosch HBL8454UC
- Bosch HBE5451UC
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use ovens to prevent F31 from lint and food debris buildup.
- Record when F31 appears in the cycle and whether it clears after a 60-second power reset on your Bosch oven—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for F31; Bosch uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting F31; reversed plugs on pumps and valves cause immediate repeat faults.