Ice cubes that come out of the ice maker noticeably smaller than they used to be, or that have developed a hollow, incomplete quality rather than freezing into a genuinely solid cube throughout — as distinct from the ice maker failing to produce any ice at all, which represents an entirely different and more complete failure — usually points toward a reduction in water flow reaching the ice maker mechanism, rather than indicating an actual mechanical failure of the ice maker unit itself as the primary underlying issue.
If yours has stopped producing anything at all, that is a different article: why a Sub-Zero ice maker stops working.
Thirty seconds, and it halves the problem. Both the dispenser and the ice maker draw through the same filter and supply line, so how the dispenser behaves tells you where the restriction sits:
Our post on a dispenser that has slowed to a trickle covers the shared causes in more detail.
A partially restricted water line represents one common cause behind this specific pattern, and it's genuinely worth understanding why this particular type of restriction produces smaller or hollow cubes specifically, rather than simply stopping ice production altogether the way a completely blocked line would. A partial restriction still allows some water through, just at a reduced rate compared to full, normal flow, meaning the ice maker's mold doesn't fill completely with water during each individual freezing cycle before that cycle begins, resulting in cubes that form smaller than intended, or that develop a hollow center since there wasn't sufficient water volume present to fill and freeze the entire mold cavity solidly all the way through.
A specific version worth knowing about: the fill tube that delivers water into the mould can itself partially ice up. It produces exactly this symptom, and unlike a filter it tends to come and go — better after the appliance has been left alone, worse with heavy use.
An aging water filter that's still technically letting some water through, but not the full volume it should be allowing at this point in its service life, produces this exact same kind of partial restriction pattern. This is genuinely worth distinguishing from a filter that's become completely clogged, which would more likely stop ice production entirely rather than simply producing smaller, incomplete cubes — a filter somewhere in between fully functional and completely clogged, still passing some water through but at meaningfully reduced volume, is precisely the scenario that tends to produce this specific small-or-hollow-cube symptom pattern.
If you have just changed the filter and the cubes got worse rather than better, that is expected for a short while. Changing a filter admits air, and the system needs purging before flow settles — run several quarts through the dispenser and discard them before judging the result.
Water pressure at the source feeding your home more broadly matters here as well, and it's worth considering even factors that might seem entirely unrelated to your refrigerator specifically. If household water pressure has genuinely dropped for any reason at all — including something as seemingly unrelated as separate plumbing work being performed elsewhere in your home around the same time, or changes to municipal water supply pressure in your area — the ice maker may simply not be able to fill its mold completely during each cycle due to this broader pressure reduction, even in situations where the refrigerator's own filter and internal water line are both functioning perfectly normally and aren't independently causing any restriction on their own.
Check the shut-off valve behind the unit while you are considering this. One left partly closed after any work in the kitchen produces reduced flow that no filter change will address.
If you've already replaced the filter with a fresh one and separately confirmed that normal water pressure is present throughout the rest of your home's plumbing system, but small or hollow cubes continue being produced despite these two potential causes being ruled out, the ice maker's fill valve itself may not be opening for a sufficiently long duration during each individual freezing cycle, or it may not be opening fully and completely each time it does activate. This represents a genuine component-level issue with the fill valve itself, rather than reflecting any water supply problem originating outside the appliance, and this specific type of issue typically requires a technician's hands-on diagnostic assessment to accurately confirm and properly address, since it involves testing the valve's actual functional performance directly rather than simply ruling out external water supply factors through the kind of checks a homeowner can reasonably perform on their own.
Yes — it is a quality problem rather than a hygiene one. What they do tell you is that something has changed in the water path, and that is worth following up before it becomes no ice at all.
Not necessarily. Cloudiness is mostly dissolved air and minerals, and it is normal in home ice makers. Judge by size and solidity rather than clarity.
That points at the filter more strongly than anything else, since a filter past its rated volume stops treating the water before it starts restricting it. Taste and reduced flow arriving together is a filter due for changing.
Give it a day and a few full harvest cycles. Purge the air first, then discard the first batch of ice — cubes made while the system was still clearing are not a fair test.
It can, but it is the last suspect rather than the first here. A mechanism that is producing ice on schedule is largely working; what has changed is how much water it is getting.
Dispenser strong but cubes still small? Then water reaches the appliance fine and the fill side is the problem. We repair Sub-Zero refrigerators, freezers and wine storage throughout Arlington, Alexandria and the surrounding Northern Virginia communities, plus Washington, DC and Potomac, Maryland — book a diagnostic visit.
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