mypros+
Error code reference

Miele Refrigerator Error Code F1

Refrigerator air NTC defective (short- or open-circuited); emergency operation

Miele codesMiele refrigerator codes

Refrigerator air NTC defective (short- or open-circuited); emergency operation: compressor switches on for 10 minutes, off for 40 minutes.

First step from the service manual

Check the NTC resistance per NTC resistance table; if defective, replace it.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for F1.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What F1 means on a Miele refrigerator

The F1 error code on a Miele refrigerator indicates that the refrigerator compartment air NTC (Negative Temperature Coefficient) sensor has been detected as either short-circuited or open-circuited. The NTC sensor is a thermistor whose electrical resistance changes predictably with temperature, allowing the control board to monitor the internal air temperature of the refrigerator compartment. When the control board reads a resistance value that falls outside the expected range defined in the NTC resistance table, it flags the sensor as defective and triggers the F1 fault.

In response to this fault, the unit enters an emergency operating mode to prevent food spoilage. In this mode, the compressor runs on a fixed cycle: 10 minutes on followed by 40 minutes off. This cycle repeats continuously regardless of actual compartment temperature, since the control board can no longer rely on sensor feedback to regulate cooling. While this emergency mode provides some basic cooling function, it is not efficient and cannot maintain precise temperature control.

The most common root causes include physical damage to the sensor, wiring harness failures such as broken conductors or corroded terminals, and moisture intrusion causing short circuits. The correct diagnostic procedure involves measuring the NTC sensor resistance with a multimeter and comparing the reading against the Miele NTC resistance table, which maps specific resistance values to specific temperatures. A sensor reading near zero ohms indicates a short circuit, while an infinite or open reading indicates a broken sensor element. If the resistance deviates from the table values at the current compartment temperature, the sensor should be replaced.

Source: manufacturer service documentation.

Common causes of F1

  1. 01

    Failed NTC temperature sensor

    Part replacement

    The thermistor element inside the NTC sensor can fail over time due to age or thermal stress, resulting in an open or short circuit. Resistance measured at the sensor will not match the values in the NTC resistance table for the given temperature.

  2. 02

    Broken or damaged wiring harness

    Wiring / connection

    The wiring between the NTC sensor and the control board can develop breaks, cuts, or pinched conductors, causing an open circuit reading even if the sensor itself is intact. Inspect the full length of the harness for visible damage.

  3. 03

    Corroded or loose connector terminals

    Wiring / connection

    Moisture inside the refrigerator compartment can cause corrosion at the sensor connector or control board plug, increasing resistance or breaking continuity. Clean and reseat connectors as part of the diagnostic process.

  4. 04

    Moisture-induced short circuit

    Wiring / connection

    Water or ice buildup near the sensor or along the wiring harness can cause adjacent conductors to short together, producing a near-zero resistance reading at the control board. Inspect for ice accumulation or signs of water ingress around the sensor mounting location.

  5. 05

    Faulty control board

    Part replacement

    In rare cases, the control board itself may misinterpret a valid sensor signal due to a failed input circuit. This should only be considered after the sensor and wiring have been confirmed good through resistance testing.

See the test procedure for each cause

Frequently asked questions about F1

What does F1 mean on a Miele refrigerator?
F1 on a Miele refrigerator means the refrigerator compartment air NTC temperature sensor has been detected as defective, either short-circuited or open-circuited. The control board uses this sensor to regulate cooling, and when it fails, the unit switches to an emergency compressor cycle of 10 minutes on and 40 minutes off. The refrigerator will continue to run in this limited mode but cannot maintain precise temperature control until the fault is resolved.
Can I fix the F1 error on my Miele refrigerator myself?
If you are comfortable using a multimeter, you can start by checking the resistance of the NTC sensor and comparing it to the NTC resistance table for your model. Inspect the wiring harness and connectors for visible damage or corrosion as well. If the sensor reads outside the expected resistance range, replacing the NTC sensor is a repair many experienced DIYers can handle. If the wiring and sensor both check out, the control board may be involved and a qualified technician should be consulted.
Is it safe to keep using my Miele refrigerator when F1 is displayed?
The refrigerator will operate in emergency mode with a fixed compressor cycle, which provides some level of cooling but not precise temperature regulation. Food safety can be at risk if the compartment temperature rises too high during the extended off cycles. It is advisable to check compartment temperatures with a thermometer and minimize the time before getting the fault repaired, especially if storing perishable items.
How much does it cost to repair a Miele F1 error?
Repair costs vary depending on what has failed. If only the NTC sensor requires replacement, parts and labor typically range from around $100 to $250. If the wiring harness needs repair or the control board is involved, costs can be higher, generally in the $200 to $500 range or more depending on parts availability and local labor rates. Getting a diagnostic from a Miele-authorized technician will give you a more accurate estimate for your specific situation.
Will resetting my Miele refrigerator clear the F1 error code?
Performing a reset may temporarily clear the F1 error code from the display, but the fault will return if the underlying cause has not been corrected. Since F1 is triggered by a measured sensor resistance that is out of range, the control board will detect the problem again as soon as it checks the sensor signal. A permanent fix requires testing the NTC sensor resistance, inspecting the wiring, and replacing any defective components.

Related Miele refrigerator codes

All Miele refrigerator codes
View all 68 Miele refrigerator codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass