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Error code reference

Frigidaire Refrigerator Error Code SH (FZ)

Shorted freezer (FZ) thermistor detected.

Frigidaire codesFrigidaire refrigerator codes

Shorted freezer (FZ) thermistor detected.

First step from the service manual

Check for pin back-outs, pinched or damaged wires before replacing components.

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

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What SH (FZ) means on a Frigidaire refrigerator

The SH (FZ) error code on a Frigidaire refrigerator indicates that the control board has detected a shorted condition in the freezer compartment thermistor circuit. A thermistor is a temperature-sensing resistor whose resistance changes predictably with temperature. When the control board reads an abnormally low resistance value from the freezer thermistor, it interprets this as a short circuit and triggers the SH (FZ) fault to alert the technician that temperature sensing in the freezer is compromised.

A shorted thermistor typically reads resistance values far below the expected range for the current ambient or compartment temperature. This prevents the refrigerator's control system from accurately monitoring freezer temperature, which can cause the compressor and evaporator fan to run erratically or continuously. Left unaddressed, this fault can lead to temperature instability, food spoilage, or component wear from uncontrolled run cycles.

Before condemning the thermistor itself, wiring integrity must be evaluated. Pin back-outs from connectors, pinched wire harnesses, and chafed or damaged insulation can all create a low-resistance path to ground that mimics a shorted thermistor at the control board. These wiring faults are common in freezer compartments due to ice buildup, door seal compression, and repeated thermal cycling. A thorough inspection of the wiring harness from the thermistor back to the control board connector is the required first diagnostic step.

Source: manufacturer service documentation.

Common causes of SH (FZ)

  1. 01

    Damaged or pinched wiring harness

    Wiring / connection

    The wire harness running to the freezer thermistor can become pinched by shelving, ice, or door components, creating a short to ground. Visually trace the harness from the thermistor connector to the control board and look for chafed insulation or compressed sections.

  2. 02

    Pin back-out at connector

    Wiring / connection

    Terminal pins inside the thermistor wiring connector can back out of their housing, causing unintended contact between terminals or with the connector housing itself. Inspect each connector in the thermistor circuit and reseat any pins that have shifted out of position.

  3. 03

    Failed freezer thermistor

    Part replacement

    The thermistor itself can fail internally, resulting in a shorted condition where resistance drops far below the expected range. If wiring and connectors check out, measure the thermistor resistance directly and compare it to the specification for the current freezer temperature.

  4. 04

    Moisture or ice intrusion at connector

    Wiring / connection

    Ice accumulation or condensation inside wiring connectors in the freezer compartment can create a conductive path between terminals, simulating a shorted thermistor. Inspect connectors for signs of corrosion, moisture, or ice and dry and clean them thoroughly before retesting.

  5. 05

    Faulty control board

    Part replacement

    In rare cases, the main control board itself may misread a normal thermistor circuit as shorted due to a defect on the board's input circuitry. This should only be considered after the thermistor and all wiring have been confirmed to be in good condition.

See the test procedure for each cause

Frequently asked questions about SH (FZ)

What does SH (FZ) mean on a Frigidaire refrigerator?
SH (FZ) means the control board has detected a shorted freezer thermistor circuit. The thermistor is the sensor that monitors temperature inside the freezer compartment. When the board reads an abnormally low resistance from that circuit, it logs this fault code to indicate that temperature sensing is unreliable. The issue may be in the thermistor itself or in the wiring connected to it.
Can I fix the SH (FZ) error code myself?
Some causes of this error are DIY-accessible, such as inspecting visible wiring for damage, reseating connector pins, and checking for ice buildup around the thermistor harness. However, accurately diagnosing a shorted thermistor versus a wiring fault requires a multimeter to measure resistance values. If you are not comfortable working with electrical components or accessing the freezer's internal wiring, a qualified technician should perform the diagnosis.
Is it safe to keep using my refrigerator while the SH (FZ) code is active?
Operating the refrigerator with an active SH (FZ) code is not recommended for extended periods. Because the control board cannot accurately read the freezer temperature, the compressor and fans may run incorrectly, leading to temperature swings that can compromise food safety. It is best to address the fault promptly and use a standalone thermometer to monitor freezer temperature in the meantime.
Will resetting the refrigerator clear the SH (FZ) error code?
A power reset may temporarily clear the displayed code, but if the underlying wiring fault or thermistor failure is still present, the SH (FZ) code will return once the control board re-evaluates the circuit. A reset is useful for confirming whether the fault is intermittent, but it does not repair the root cause and should not be treated as a fix.
How much does it cost to repair a Frigidaire refrigerator showing the SH (FZ) code?
Repair costs vary depending on what is causing the fault. If only a wiring repair or connector reseating is needed, labor costs may be relatively modest, typically in the range of $75 to $150 for a service call. Replacing the freezer thermistor is generally an inexpensive parts repair, with the part itself often ranging from $15 to $50 plus labor. A control board replacement, if required, can bring total repair costs to $200 to $400 or more depending on the model and service rates in your area.

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