Viking Ice Maker Error Code 4 blinks

The 4-blink code means the control board has detected that both the bin thermistor and the evaporator thermistor are either open-circuited or short-circuited. Both sensors are outside the acceptable resistance range for the current temperature conditions. The ice maker shuts down because it cannot safely manage the freeze or harvest cycles without reliable temperature data from both sensors.

A power cycle or reset may temporarily clear the error display, but the code will return as soon as the control board re-checks the thermistor circuits and finds them out of specification. The underlying fault in one or both sensors, or in the wiring connecting them, must be repaired before the error will stay cleared and the unit will resume normal operation.

Repair costs vary depending on the root cause. Replacing one or both thermistors typically ranges from around $50 to $150 in parts, plus labor if a technician is involved. If the wiring harness needs repair or replacement the cost can increase to the $150 to $350 range. A control board replacement, if that is the confirmed cause, is the most expensive outcome and can range from $300 to $600 or more including labor.

A knowledgeable DIYer with a multimeter can perform the core diagnostic step, which involves disconnecting each thermistor and testing its resistance, then comparing the reading to the resistance versus temperature chart. If a thermistor is confirmed faulty, replacing it is straightforward. However, if the wiring harness or control board is involved, the repair becomes more complex and may be better handled by a certified technician.

The ice maker will not produce ice while this fault is active because the control board halts operation when both temperature sensors are unreadable. There is no immediate safety hazard from the error itself, but you should not attempt to bypass the fault or force the unit to run without functional sensors, as the machine relies on those readings to prevent damage to the evaporator and compressor components.