Fridge
F2
The F2 error code on a Siemens fridge is a temperature sensor fault — specifically, it tells you that the appliance has detected a problem with the internal temperature sensor (NTC sensor) in the fridge compartment. It’s not a crisis, but it does mean your fridge may not be cooling properly, which is a food safety concern you should sort out promptly. In this article, we’ll walk you through exactly what F2 means, the most likely causes, what you can safely try at home, and when it’s time to call an engineer.
What does this error mean?
The F2 error code on Siemens fridge-freezers and upright fridges indicates a fault with the NTC (Negative Temperature Coefficient) temperature sensor located inside the fridge compartment. This small component is responsible for continuously monitoring the internal temperature and feeding that data back to the appliance’s control board. When the control board receives a reading that is out of range — either because the sensor has failed, developed a short circuit, or become disconnected — it throws the F2 fault code and may restrict or stop normal cooling cycles to protect the appliance and your food. In plain terms: your fridge’s thermometer is either broken or not being read correctly. Until this is resolved, your fridge cannot regulate its temperature accurately, meaning it could run too warm (spoiling food) or too cold (freezing fresh produce). Siemens fridges across their iQ range and KI/KG series commonly report this code.
Est. repair cost
£10–£25 for a DIY NTC sensor replacement; £80–£130 for a professional sensor repair including call-out; £150–£250 all-in if the main PCB requires replacement
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 – Do a hard reset first (no tools needed): Switch the fridge off at the wall socket, leave it unplugged for 5–10 minutes, then plug it back in and power it on. This clears temporary electronic faults caused by power glitches. If the F2 code disappears and does not return within 24 hours, no further action is needed — monitor it closely.
Step 2 – Check the door seal for damage (no tools needed): Run your fingers around the entire door gasket. Feel for cracks, tears, or sections that have gone stiff or flat. A quick test: close the door on a piece of paper — if you can pull it out easily with no resistance, the seal is failing. Replacement door seals for Siemens fridges are available online for £15–£35 and clip or press into the door channel without specialist tools.
Step 3 – Defrost the fridge completely to clear ice build-up (no tools, allow 4–6 hours): Empty the fridge, remove all shelving, and leave the door open for at least 4–6 hours to allow any ice build-up around the sensor or evaporator to melt fully. Place towels on the floor to catch water. Once fully defrosted, clean the interior, check the drain hole at the back is clear, and restart the fridge.
Step 4 – Locate and inspect the NTC sensor (no tools needed for visual check): The NTC temperature sensor is typically a small plastic probe clipped to the rear inner wall of the fridge compartment, sometimes near the top or behind a plastic cover panel. Without opening any sealed components, visually check whether it is physically in place, whether its wiring looks intact, and whether the connector to the wiring harness is firmly seated. If the connector is visibly loose, gently press it back into place.
Step 5 – Clean the condenser coils (soft brush or vacuum with brush attachment): Pull the fridge away from the wall. At the rear, you will see a grille or exposed coils. Using a soft brush or vacuum cleaner nozzle, gently remove dust and fluff from the coils and the surrounding area. A heavily blocked condenser is a common cause of erratic temperatures and sensor faults. This takes around 10–15 minutes and should be done at least once a year.
Step 6 – Check the fridge is level (spirit level or use your eye): An unlevel fridge can cause condensation and drainage issues that lead to ice build-up around the sensor. Adjust the fridge’s front feet (they screw in and out by hand or with a flat-head screwdriver) until it sits level side-to-side and has a very slight backward tilt to aid door closure.
Step 7 – Replace the NTC temperature sensor (DIY-possible but proceed with care): If the above steps have not cleared the fault, the NTC sensor itself has likely failed. Replacement Siemens-compatible NTC sensors are available from UK appliance parts suppliers (e.g. eSpares, 4ourhouse, Siemens genuine parts) for approximately £10–£25. Before attempting this: unplug the fridge from the mains. The sensor is accessed from inside the fridge compartment — you do not need to open the appliance’s back panel. Unclip the old sensor from its bracket, disconnect the wire connector, connect the new sensor, and clip it back into position. If in doubt about this step, skip to calling a professional.
Step 8 – STOP here if the fault persists after Step 7: If the F2 error code has returned or never cleared after completing all the above steps, the fault is likely with the main control board (PCB) or there is a wiring fault deeper in the appliance. Do not attempt to open the rear appliance panels or access the PCB yourself — this requires a qualified appliance engineer.
📞 When to call a professional
Call a professional appliance engineer if: the F2 error code returns after a full hard reset and defrost; you have replaced the NTC sensor and the fault persists; you notice the fridge is not cooling at all or is freezing everything solid; or you are uncomfortable with any of the DIY steps above. When you call, tell the engineer: ‘My Siemens fridge is displaying an F2 error code — this is a temperature sensor fault. I have already tried a hard reset and a full defrost [add anything else you have attempted]. The fridge is model [your model number, found on the label inside the door frame].’ This saves diagnostic time and may reduce your call-out cost. Look for a Domestic & General-approved engineer or a Which? Trusted Trader with experience in Siemens or BSH Group appliances (Siemens white goods are manufactured by BSH alongside Bosch and Neff, so engineers familiar with those brands will know Siemens fridges well).
⚖️ Repair or replace?
If your Siemens fridge is under 7 years old, repair is almost always the right call. A new NTC sensor is a cheap part and a straightforward job for an engineer, keeping repair costs well within a sensible threshold. If the fault turns out to be the main PCB, costs rise to £150–£250 all-in — at that point, consider the age of the appliance. Siemens fridges typically last 12–15 years with proper maintenance, and parts availability for most iQ and KG/KI series models is good through BSH’s UK parts network. If your fridge is over 10 years old and needs a PCB replacement, the repair-vs-replace calculation becomes tighter: a comparable Siemens or Bosch replacement fridge starts at around £400–£600 from UK retailers. As a rule of thumb, if the repair costs more than 50% of the replacement value, replacing is the wiser long-term investment. For most F2 faults — which are sensor-related — repair is likely to cost well under that threshold.