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Error code reference

Frigidaire Refrigerator Error Code Water Tank-Heater Error

Water Tank Heater Open detected

Frigidaire codesFrigidaire refrigerator codes

Water Tank Heater Open detected: separation of housing part, bad contact, wire disconnection.

First step from the service manual

After separating MAIN PCB CN79 from PCB, check resistance between Pink <-> White wire: shall be 72 ohm +/- 7%. 0 Ohm = heater short, infinite Ohm = wire/bimetal open.

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

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What Water Tank-Heater Error means on a Frigidaire refrigerator

The Water Tank-Heater Error on a Frigidaire refrigerator indicates that the control system has detected an open circuit condition in the water tank heater circuit. This heater is responsible for preventing the water supply tank from freezing, and the error is triggered when the main PCB loses proper electrical continuity through that heater circuit. The fault can originate from a physical separation of the heater housing, a poor or corroded electrical contact, or a disconnected wire within the circuit.

Diagnosing this error begins at the main PCB connector CN79. After disconnecting CN79 from the PCB, a resistance measurement should be taken between the Pink and White wires in that connector. The correct resistance for a properly functioning water tank heater is 72 ohms, plus or minus 7 percent (approximately 67 to 77 ohms). A reading of 0 ohms indicates a short circuit within the heater element itself. An infinite resistance reading (open line) points to a broken wire, a failed bimetal thermal cutout, or a complete separation of the heater assembly.

The bimetal component referenced in the diagnostic is a thermal protection device integrated into the heater circuit. If this bimetal cutout has tripped or failed permanently due to an overheat condition or age, it will break the circuit and produce an infinite resistance reading. Wiring integrity along the full path from CN79 to the heater assembly should also be inspected for breaks, loose terminals, or corrosion before condemning the heater unit itself.

Source: manufacturer service documentation.

Common causes of Water Tank-Heater Error

  1. 01

    Disconnected or broken wiring

    Wiring / connection

    A wire in the circuit between connector CN79 and the water tank heater has become disconnected or has broken internally. This produces an infinite resistance reading when measured between the Pink and White wires at CN79.

  2. 02

    Failed bimetal thermal cutout

    Part replacement

    The bimetal thermal protection device in the heater circuit has tripped permanently or failed open due to age or a prior overtemperature event. This also results in an infinite resistance reading and requires replacement of the heater assembly or the cutout itself.

  3. 03

    Poor or corroded electrical contact

    Wiring / connection

    Corrosion or loose terminal connections at connector CN79 or along the heater wiring harness can cause intermittent or total loss of continuity. Inspect terminals for oxidation, bent pins, or debris preventing solid contact.

  4. 04

    Separation of heater housing

    Part replacement

    The physical housing of the water tank heater assembly can separate due to vibration or age, pulling internal connections apart. Visually inspect the heater unit for any cracking, separation, or displacement from its mounted position.

  5. 05

    Shorted heater element

    Part replacement

    A resistance reading of 0 ohms between the Pink and White wires at CN79 indicates an internal short in the heater element itself. A shorted heater requires full replacement of the heater component.

See the test procedure for each cause

Frequently asked questions about Water Tank-Heater Error

What does Water Tank-Heater Error mean on a Frigidaire refrigerator?
This error means the refrigerator's control board has detected an open or faulted circuit in the water tank heater, which is the component that prevents the internal water supply tank from freezing. The fault can be caused by a disconnected wire, a failed bimetal thermal cutout, a bad electrical contact, or physical separation of the heater housing. The control board monitors heater continuity and triggers this alert when the circuit falls outside normal parameters.
How do I fix the Water Tank-Heater Error on my Frigidaire refrigerator?
Start by disconnecting connector CN79 from the main PCB and measuring resistance between the Pink and White wires. A correct reading is 72 ohms plus or minus 7 percent. If you read 0 ohms, the heater is shorted and needs replacement. If you read infinite resistance, trace the wiring for breaks or disconnections, inspect the bimetal cutout, and check for housing separation before replacing any parts.
Is the Water Tank-Heater Error on a Frigidaire refrigerator a safety concern?
The error itself is not an immediate safety hazard in the way a gas appliance fault would be. However, if the water tank heater has failed, the water supply tank may freeze in certain operating conditions, which can damage internal components and stop the water and ice dispenser from functioning. Addressing the fault promptly prevents further damage to the water system.
How much does it cost to repair the Water Tank-Heater Error on a Frigidaire refrigerator?
If the fix is simply reseating a loose connector or repairing a broken wire, costs are minimal, generally in the range of a service call fee. If the water tank heater assembly or bimetal cutout requires replacement, parts and labor combined typically range from around $100 to $300 depending on the specific model and your location. Getting a diagnosis first helps determine whether a simple wiring fix or a part replacement is needed.
Will resetting my Frigidaire refrigerator clear the Water Tank-Heater Error?
A power reset may temporarily clear the error code from the display, but if the underlying fault in the heater circuit still exists, the error will return once the control board runs its diagnostic cycle again. A permanent resolution requires identifying and correcting the root cause, whether that is a wiring issue, a failed bimetal cutout, or a defective heater element.

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