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Field pattern: Sub-Zero ice maker stopped (frozen fill tube, dripping valve or low pressure before a new ice maker)

The usual root cause is upstream of the ice maker: a water valve that does not shut off fully and drips into the fill tube until it freezes, low or restricted water pressure, or a freezer that is not cold enough. Replacing the ice maker without fixing the supply brings the same freeze-up back.

Cross-checked ~60 min moderateBrands: Sub-Zero

Before you start

Turn the unit off or unplug it before thawing near electrical parts
Keep the hair dryer on low and away from plastic parts; never use a heat gun or sharp tools on ice in the mold or fill tube
Shut off the water supply before opening water connections

Diagnostic steps

Unlock all 7 steps with expected values

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Water freezes in the tube that feeds the ice maker. Thaw it with warm air, then find the cause or it will come back. The usual causes are a valve that seeps between fills, low pressure (slow fills freeze), a freezer set too cold, or cold air blowing on the tube. Replacing the valve is the most common lasting fix.

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