By West Appliance Service ·
Confirm the ice maker is on and not just full
Start with the easy things. Many Sub-Zero models let you turn the ice maker on and off from the control panel, and it is easy to switch it off by accident while cleaning or to forget it was turned off before a trip. Check the controls and your owner's manual for how your model shows ice maker status. Next, look at the bin. Ice makers stop when they sense the bin is full, either with a wire arm or a sensor. If the arm is stuck in the up position or ice is piled against the sensor, production stops. Clumped ice can also jam the bin or the ejector. Empty the bin, break up frozen clumps by hand rather than with a knife or ice pick, and make sure the bin is seated fully. After restarting, be patient; a fresh batch of ice often takes several hours to appear.
Check the freezer temperature
An ice maker needs a cold freezer to work. If the freezer is running warm, the ice maker may not cycle, or it may produce small, soft or hollow cubes. Freezers are commonly set around 0°F. Check the display, then place an appliance thermometer between frozen items for a second opinion. If the freezer is warm, look for causes you can fix: a door left ajar, a gasket that is torn or not sealing, or a freezer packed so tightly that air cannot circulate. On many built-in models the condenser sits behind the top grille, and dust and lint there make the system work harder. You can gently vacuum it with a brush attachment, but shut off power at the breaker first and avoid bending the fins. If the freezer stays warm after these steps, the ice maker is a symptom rather than the problem, and the refrigeration system needs a technician.
Look at the water supply and filter
No water, no ice. If your refrigerator has a water dispenser, test it; weak or no flow points to a supply problem rather than the ice maker itself. Make sure the shutoff valve feeding the refrigerator is fully open, especially after plumbing work or a remodel. A clogged water filter is a common cause of slow or stopped ice production. If the filter is past its replacement date, install the correct filter for your model and flush the line as your manual describes. Low household water pressure can also be a factor, and older saddle-type valves on copper lines can clog over time. Check any visible section of the supply line for kinks. Be cautious about pulling the unit out to inspect the line: built-in Sub-Zero refrigerators are heavy, are usually secured to the cabinetry, and can damage flooring or the water line if moved incorrectly.
Check for a frozen fill tube
If the freezer is cold and water is reaching the refrigerator but the ice maker still sits empty, the small tube that delivers water into the ice mold may be frozen. You can sometimes spot ice blocking the tube opening at the back of the ice maker. To thaw it, turn the ice maker off, then warm the area with a cloth soaked in warm water or a hair dryer on a low setting held at a safe distance. Keep the dryer and its cord away from any dripping water, and never use a heat gun, open flame or sharp tool, which can crack plastic parts or damage wiring. Let melted water drain or wipe it up before turning the ice maker back on. If the tube freezes again within days, something is causing it, often low water pressure, a valve that drips between cycles, or a door seal letting warm, humid air in.
When it is time to call a technician
If you have checked the switch, bin, temperature, water supply and fill tube and there is still no ice, a component has likely failed. Common culprits include the water inlet valve, the ice maker assembly, a temperature sensor or the control board. Clues that point to a part failure include a humming or clicking sound with no water entering the mold, an ice maker that overflows or leaks, or cubes that never eject. These repairs involve line-voltage wiring and pressurized water connections behind panels, so unplugging or shutting off the breaker is essential, and the work is best left to a trained technician. If you see water pooling under the unit, shut off the water supply valve right away. Problems involving the sealed refrigeration system require a technician certified to handle refrigerant; never puncture or cut refrigerant lines or attempt to recharge the system yourself.
Common questions
How long does it take a Sub-Zero ice maker to start making ice?
After the ice maker is turned on or reset, the first cubes often take several hours, and filling the bin can take a day or more. Timing depends on freezer temperature and water flow. If the freezer is cold, water is flowing and you still have no ice after about 24 hours, work through the other checks or call a technician.
Can a clogged water filter stop my ice maker?
Yes. A clogged or overdue filter restricts water flow, which can lead to small cubes, slow production or no ice at all. If your dispenser also runs slowly, the filter is a likely suspect. Replace it with the correct filter for your model, flush the line according to your manual, and give the ice maker several hours to recover.
Why is my Sub-Zero making small or hollow ice cubes?
Small or hollow cubes usually mean the mold is not getting enough water or the freezer is not cold enough. Common causes include a clogged filter, low household water pressure, a partly frozen fill tube or a failing inlet valve. Check the freezer temperature and filter first. If those are fine, the valve or water supply may need professional attention.
Most Sub-Zero ice maker problems come down to a switch, a jammed bin, a warm freezer, restricted water or a frozen fill tube, and many of those are safe to check yourself. If you have worked through these steps and the ice maker still is not producing, call West Appliance Service at (877) 775-4968. We are open 24/7, and the $95 service call and diagnosis is credited toward the repair.