Oven
F13
The F13 error code on a Bosch oven indicates a fault with the oven’s temperature sensor (NTC sensor) or its circuit — it’s a moderately serious fault that will prevent your oven from heating correctly or at all.
What does this error mean?
F13 tells you that your Bosch oven’s control board has detected an abnormal reading from the NTC (Negative Temperature Coefficient) temperature sensor inside the oven cavity. This sensor constantly monitors the internal temperature and feeds data back to the control board; when the signal falls outside the expected range — either a short circuit or an open circuit — the oven triggers F13 and shuts down heating as a safety precaution. In plain terms: the oven can’t trust its own temperature readings, so it stops rather than risk overheating.
Est. repair cost
£15–£35 DIY sensor replacement; £80–£150 professional repair (sensor or wiring); £200–£350 if PCB replacement is required
🔍 Likely causes
🛠️ Step-by-step fix
1. Power cycle the oven: switch it off at the wall socket (or trip the circuit breaker), wait 5 minutes, then restore power. If F13 clears and doesn’t return, it was a temporary glitch — monitor it closely.
2. Check the oven door seal: a damaged or missing door seal can cause heat to escape and damage nearby components. Inspect the rubber gasket around the door; if it’s cracked or loose, replace it yourself — seals cost £10–£25 and clip or screw into place without tools.
3. Locate and visually inspect the NTC sensor: on most Bosch built-in ovens the sensor is a small probe mounted on the back wall of the oven cavity, held by one or two screws. With the oven completely cold and unplugged, remove it and check for visible burn marks, corrosion, or physical damage.
4. Test the NTC sensor with a multimeter: a healthy Bosch NTC sensor reads approximately 990–1,010 ohms at room temperature (around 20°C). A reading of zero (short) or infinite resistance (open circuit) confirms the sensor has failed and needs replacing. Replacement sensors cost £15–£35 and are straightforward to fit — unplug the connector, unscrew the old sensor, screw in the new one.
5. Inspect the wiring harness: with the oven unplugged, gently tug each connector at the sensor end and at the control board end to check for loose plugs. Look along the wire run for any melted insulation or breaks. Reconnect any loose plugs firmly; if wiring is damaged, this repair should be handed to a professional.
6. If the sensor and wiring test fine but F13 persists, the control board (PCB) is the likely culprit. PCB replacement is a professional job — stop here and book an engineer.
📞 When to call a professional
Call a qualified appliance repair engineer if replacing the NTC sensor doesn’t clear the fault, or if you find damaged wiring inside the oven cavity. You should also call a professional if you’re not comfortable using a multimeter or removing oven components. When you call, tell the engineer: ‘My Bosch oven is showing error code F13 — I believe it’s the NTC temperature sensor or associated wiring, and the sensor has already been checked/replaced’ — this saves diagnostic time and money.
⚖️ Repair or replace?
A professional repair for F13 typically costs £80–£150 depending on whether it’s a sensor swap or a PCB replacement; a new mid-range Bosch oven costs £400–£900. If your oven is under 7 years old, repair is almost always the better value. If it’s over 10 years old and the PCB has failed, replacement becomes worth serious consideration — especially if other components are also showing wear.