Oven
F24
The F24 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?
F24 tells you that your Bosch oven’s control board has detected an abnormal signal from the NTC (negative temperature coefficient) temperature sensor. This sensor monitors the internal oven temperature in real time and feeds that data back to the control board. When the signal falls outside the expected range — either too high, too low, or absent entirely — the oven throws F24 and typically locks out the heating function to prevent overheating or unsafe operation.
Est. repair cost
£15–£40 DIY (NTC sensor part only); £80–£150 professional repair (sensor + labour); £150–£280 if PCB replacement is needed
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 — Hard reset: Switch the oven off at the wall socket (or trip the circuit breaker), wait 5 minutes, then restore power. If F24 clears and doesn’t return, it was a temporary glitch. Monitor closely.
Step 2 — Check for obvious wiring damage: With the oven fully isolated from the mains, carefully remove the back panel inside the oven cavity (usually 2–4 screws). Inspect the wiring connector at the NTC sensor for loose, burnt, or corroded pins. Firmly reseat the connector.
Step 3 — Test the NTC sensor resistance: Using a multimeter set to Ohms, measure resistance across the sensor’s two terminals. At room temperature (~20°C), a standard Bosch NTC sensor should read approximately 4,000–6,000 Ohms. A reading of zero (short) or infinite (open circuit) confirms a failed sensor.
Step 4 — Replace the NTC sensor: A compatible Bosch oven NTC sensor costs £15–£40 from UK suppliers (e.g. eSpares, 4ourhouse). Unclip the old sensor from the oven cavity wall, disconnect the wiring plug, fit the new sensor, and reconnect. Reassemble and power on.
Step 5 — Trace and repair the wiring harness: If the sensor tests fine, inspect the full length of the wiring loom from sensor to control board for signs of chafing, burning, or pinching. Repair minor damage with heat-resistant appliance wire and proper crimp connectors — not standard electrical tape.
Step 6 — If steps 1–5 don’t resolve F24: The control board (PCB) is likely faulty. PCB replacement on a Bosch oven requires confident electrical knowledge — if you’re not comfortable working with appliance electronics, stop here and call a professional.
📞 When to call a professional
Call a qualified appliance engineer if the F24 fault persists after replacing the NTC sensor, or if you find burnt wiring or a visibly damaged PCB. Tell the engineer: ‘My Bosch oven is showing error code F24, I’ve already checked/replaced the NTC sensor, and the wiring appears intact.’ This will save diagnostic time and money.
⚖️ Repair or replace?
A professional repair for F24 — typically sensor replacement plus labour — costs £80–£150 in the UK. If the control board needs replacing, expect £150–£280 all in. For any Bosch oven over 8–10 years old where the repair quote exceeds £150, replacement is usually the smarter financial decision given that a decent new electric oven starts at around £350–£500. For a newer oven still under warranty, contact Bosch UK directly before spending anything.