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Error code reference

GE Refrigerator Error Code F516

Hot Water Thermistor Fault

GE codesGE refrigerator codes

Hot Water Thermistor Fault - thermistor values more than 10°F different after 60 seconds of heating.

First step from the service manual

Check both hot water thermistors and their wiring.

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

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
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What F516 means on a GE refrigerator

The F516 error code on a GE refrigerator indicates a Hot Water Thermistor Fault. This code triggers when the two hot water thermistors in the appliance's hot water dispensing system read temperatures that differ by more than 10°F from each other after 60 seconds of active heating. The control board monitors both sensors simultaneously, and when the readings diverge beyond this threshold, it interprets the discrepancy as a sensor or wiring failure rather than a legitimate temperature difference.

The hot water system relies on a matched pair of thermistors to confirm accurate temperature readings throughout the heating cycle. If one thermistor has failed, drifted out of calibration, or is receiving incorrect voltage due to a wiring fault, the two sensors will report conflicting data. The control board cannot determine which sensor is providing the accurate reading, so it shuts down normal operation and flags the fault to prevent potential overheating or unsafe water temperatures at the dispenser.

Common causes include a thermistor that has failed internally and is reading outside its expected resistance curve, corroded or damaged connector pins at the thermistor harness, or a wiring break that causes one sensor circuit to read an incorrect value. Physical damage to the thermistor probe itself, such as from water intrusion or heat stress, can also produce the out-of-range differential that triggers F516. Diagnosis should begin with a visual inspection of both thermistors and their associated wiring harnesses before moving to resistance testing of each sensor.

Source: manufacturer service documentation.

Common causes of F516

  1. 01

    Failed Hot Water Thermistor

    Part replacement

    One of the two hot water thermistors has failed internally and is producing an incorrect resistance reading, causing the temperature differential to exceed the 10°F threshold. Resistance testing of each thermistor individually will confirm which one is out of spec.

  2. 02

    Corroded or Loose Wiring Connector

    Wiring / connection

    Corrosion, moisture, or a loose connector at the thermistor wiring harness can cause a high-resistance connection that skews the sensor reading reported to the control board. Inspect the connector pins and harness terminals for discoloration, oxidation, or poor seating.

  3. 03

    Damaged Wiring Harness

    Part replacement

    A chafed, pinched, or broken wire in the thermistor circuit can cause one sensor to read an incorrect value, creating the temperature discrepancy that triggers F516. A visual inspection along the full length of the wiring harness can identify physical damage.

  4. 04

    Water or Moisture Intrusion at the Thermistor

    Part replacement

    Water intrusion at the thermistor probe or its connector can cause erratic resistance values and short the sensor circuit. Look for signs of moisture, mineral deposits, or water staining near the thermistor mounting location.

  5. 05

    Control Board Fault

    Part replacement

    In rare cases, the main control board may be incorrectly interpreting thermistor signals due to a board-level failure. This should only be considered after both thermistors and all associated wiring have been tested and confirmed good.

See the test procedure for each cause

Frequently asked questions about F516

What does F516 mean on a GE refrigerator?
F516 is a Hot Water Thermistor Fault code. It means the two thermistors monitoring the hot water system have reported temperatures that differ by more than 10°F after 60 seconds of heating. The refrigerator's control board detects this discrepancy and flags the error because it cannot confirm which sensor is accurate. The fault points to a problem with one of the thermistors, its wiring, or its connectors.
Can I fix the F516 error myself?
A knowledgeable DIYer can perform the initial diagnostic steps, including visually inspecting both hot water thermistors and checking the wiring harness for damage or loose connectors. If the problem is a corroded connector or a loose wire, that repair may be straightforward. Replacing a thermistor is also a manageable repair for someone comfortable working with appliance wiring, but if the control board is at fault, that replacement is more involved and may be better handled by a technician.
Is it safe to use my refrigerator while the F516 code is active?
The F516 code specifically affects the hot water dispensing system. The refrigeration and freezing functions are on separate systems and should continue to operate normally. However, it is best to avoid relying on the hot water dispenser until the fault is diagnosed and repaired, as the control board cannot confirm accurate water temperature during this fault condition.
How much does it cost to repair a GE refrigerator F516 error?
Repair costs depend on the root cause. If the issue is a loose or corroded connector, the cost may be minimal, covering only a service call fee in the range of $75 to $150. Replacing a thermistor typically costs between $20 and $60 for the part, plus labor if a technician performs the work. A control board replacement, if needed, is the most expensive scenario, with parts and labor potentially ranging from $200 to $500 or more depending on the model.
Will resetting my GE refrigerator clear the F516 error code?
A reset may temporarily clear the F516 code, but it will return if the underlying fault is still present. Because the error triggers after 60 seconds of heating when the thermistor differential exceeds 10°F, the control board will detect the problem again the next time the hot water system operates. A proper repair of the faulty thermistor or wiring is necessary to permanently resolve the code.

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