Sub-Zero Ice Maker Repair

Ice makers take the worst of Arizona water. At 16 to 28 grains (very hard water), scale builds up in the fill tube and the water valve, and you get small, hollow or cloudy cubes long before it quits altogether. If a unit's never had a softener on it, we look for scale first.

Sub-Zero ice makers come in two setups, and they break in different ways. The ice maker built into a refrigerator column uses that compartment's cooling. So when it stops making ice, the real problem is often the refrigeration, not the ice maker, and replacing the ice maker module first usually wastes money. The standalone under-counter machines have their own sealed refrigerant system, their own condenser, and a drain that matters a lot. A clear-ice machine flushes water nonstop to keep the cubes clear, so a clogged drain or a failing drain pump stops ice production completely while everything else seems to work fine. Here in Arizona, scale (mineral buildup) is the big issue on both types. On the under-counter machines, hard water leaves deposits on the evaporator plate, the cold plate the ice forms on, and those deposits insulate it from the water running over it. Cubes come out small, hollow or cloudy well before the machine quits, and descaling on a regular schedule decides whether it lasts or ends up needing a new plate. The ice maker inside the freezer works differently: it fills a cube tray with water, freezes it, then twists the cubes out. There, scale shows up first in the water filter and the fill valve, so the tray doesn't fill all the way and the cubes come out small.