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Error code reference

Bosch Refrigerator Error Code F31

Ice rod sensor is interrupted (open circuit).

Bosch codesBosch refrigerator codes

Ice rod sensor is interrupted (open circuit).

First step from the service manual

Check the sensor and the supply cable to the electronics module.

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

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What F31 means on a Bosch refrigerator

The F31 error code on a Bosch refrigerator indicates an open circuit condition in the ice rod sensor circuit. The ice rod sensor is a thermistor or resistive sensor used to monitor temperature or ice formation status within the ice-making system. When the electronics module detects that the signal from this sensor has been interrupted rather than reading a valid resistance value, it logs F31 and may halt ice production to prevent damage or unsafe operation.

An open circuit in this context means the electrical path between the sensor and the electronics module has been broken completely. This differs from a short circuit, where resistance drops to near zero. With an open circuit, resistance reads as infinite, meaning no current can flow through the sensor line. The electronics module interprets this absence of signal as a fault. Common points of failure include the sensor element itself, the wiring harness connecting the sensor to the module, and the connector terminals at either end of that cable run.

The first diagnostic step is to inspect both the ice rod sensor and its supply cable leading to the electronics module. This involves checking for visible wire damage, corrosion at connector pins, and loose or disconnected plugs. If the wiring appears intact, resistance testing of the sensor element with a multimeter will confirm whether the sensor itself has failed internally. A working sensor will show a measurable resistance value, while a failed open-circuit sensor will show no continuity.

Source: manufacturer service documentation.

Common causes of F31

  1. 01

    Damaged or broken sensor wiring

    Part replacement

    The cable running from the ice rod sensor to the electronics module may have a break or cut in it, especially near flex points or clip mounts. Visually trace the entire wire run and look for fraying, pinch points, or separation.

  2. 02

    Disconnected or corroded connector

    Wiring / connection

    The plug connecting the sensor cable to the electronics module or to the sensor itself may have worked loose or developed corrosion on the terminals. Unplug and re-seat the connectors, and inspect the pins for oxidation or damage.

  3. 03

    Failed ice rod sensor

    Part replacement

    The sensor element itself may have failed internally, resulting in an open circuit even when the wiring is intact. Testing with a multimeter across the sensor terminals will show no continuity if the sensor has failed.

  4. 04

    Ice or frost buildup causing wire strain

    Wiring / connection

    Excessive ice accumulation around the ice maker assembly can physically stress or displace sensor wiring over time. Inspect the area for heavy frost buildup that may be pulling on the cable.

  5. 05

    Faulty electronics module

    Part replacement

    If the sensor and all wiring check out correctly, the electronics module itself may have a failed input circuit that is incorrectly reading the sensor line as open. This is the least common cause and should only be considered after ruling out all wiring and sensor issues.

See the test procedure for each cause

Frequently asked questions about F31

What does F31 mean on a Bosch refrigerator?
F31 on a Bosch refrigerator means the ice rod sensor circuit is interrupted, specifically an open circuit condition. The electronics module is not receiving any signal from the ice rod sensor, which monitors the ice-making system. This could be caused by a broken wire, a disconnected connector, or a failed sensor element.
Can I fix F31 on my Bosch refrigerator myself?
Some causes of F31 are DIY-accessible, such as reconnecting a loose plug or clearing frost buildup from the ice maker area. However, testing sensor resistance with a multimeter and replacing the ice rod sensor or wiring harness requires basic electrical knowledge and comfort working inside the appliance. If you are not confident working around appliance wiring, a qualified technician is the safer option.
Is it safe to keep using my Bosch refrigerator with an F31 error?
The refrigerator itself will typically continue cooling food with an F31 error, but the ice maker may be disabled or operating incorrectly. There is no immediate safety risk to food or household safety in most cases. However, leaving the fault unresolved may prevent ice production entirely, and underlying wiring issues should be addressed promptly to avoid further damage.
Will resetting my Bosch refrigerator clear the F31 error?
A reset may temporarily clear the F31 code from the display, but the error will return if the underlying fault has not been corrected. The electronics module will re-detect the open circuit in the ice rod sensor on its next diagnostic cycle. A permanent fix requires identifying and repairing the broken wiring, connector, or failed sensor.
How much does it cost to repair a Bosch refrigerator F31 error?
Repair costs vary depending on the cause. If the issue is simply a disconnected connector, there may be no parts cost at all, though a service call will typically run between $75 and $150. Replacing the ice rod sensor or wiring harness adds parts costs that generally range from $20 to $80 depending on the specific model. If the electronics module itself needs replacement, total costs including labor could range from $200 to $450 or more.

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