Why are the cubes hollow when the freezer is clearly cold enough?

Because the machine times its stages rather than sensing them. It meters a shot of water, waits a fixed freeze, and harvests whatever is in the mould. When the fill runs short, the water freezes from the outside inward and what comes out is a shell. That is a water fault wearing a temperature fault's clothes.

Why does ice production fall away every summer?

The freezer has less margin to spare in July. Warmer room air across the condenser, more door openings and a longer recovery between harvests all eat into the freeze time the mould gets. A machine that was borderline in February starts missing harvests in August without anything new having broken.

Is a mould that fills but never releases worth repairing?

Usually, yes. A harvest that never completes is generally the heater, the motor or the module driving the cycle rather than the cabinet itself, and the table above is where that lands. Living with a tray you fill by hand is a fair choice too, and it costs nothing at all.

Sub-Zero repair in Mandarin

Sub-Zero ice maker repair in Mandarin

Thin cubes, hollow cubes, a mould that fills but never harvests, and production that falls away through the summer.

Two stainless freezer drawers pulled fully open on their runners, the interiors lit blue and holding clear plastic bins, with the open refrigerator compartment above them. — A full fill, freeze and harvest, timed

An ice maker is a water system that lives in a freezer

It meters a measured shot of water into a mould, freezes it on a schedule, warms the mould just enough to break the bond, and sweeps the cubes out. Every stage of that is timed rather than sensed, which is the key to understanding almost every ice complaint: the machine does not check whether the mould filled properly. It assumes the valve delivered what it was asked for, waits its allotted freeze time, and harvests whatever is in there.

That is why nearly everything that goes wrong with an ice maker goes wrong at the water end rather than the cold end.

Where a short fill comes from

Every fill leaves a trace of dissolved mineral behind on the seat the water passes through. Nothing happens for the first few years. Then the passage narrows by a fraction, the metered shot falls short by a fraction, and the mould stops filling completely. The freezer is doing its job perfectly; the water is simply arriving in the wrong quantity. The cube freezes from the outside in, as it always does, and the middle has nothing left in it to freeze. You get a shell.

JEA publishes tap-water hardness ZIP by ZIP, and Mandarin’s 32223 is listed at 254 parts per million. That is enough dissolved mineral to narrow a valve seat measurably over a decade of fills, which is why a gradual decline in cube weight points upstream of the freezer rather than at it.

The supply line does the same thing from the other end, and in most Mandarin kitchens the line is older than the appliance it feeds. A quarter-inch run put in at the last remodel, never inspected since, possibly kinked the last time the unit was pushed back into place, delivers less than it did when it was new. We measure what is actually arriving at the appliance before condemning a valve, because a new valve fed by a restricted line is a repair that lasts about eighteen months and then books itself another visit.

A homeowner can usually date the fault by how it arrived. Gradual thinning over a season or two points at deposit, in the valve or the line. A sudden change points at the valve itself, at the supply line, or at something that happened to the plumbing in the house.

The mould that fills but never harvests

This is a different failure and it needs different parts on the van, which is why it is worth saying which one you are seeing when you call. Harvest depends on warming the mould slightly so the bond releases, then a mechanical sweep clearing the cubes into the bin. If the warming stage fails, the cubes stay locked in place and the machine sits there full. If the sweep fails, you may find cubes half-ejected and jammed. If the bin’s level control is confused, the machine may believe the bin is full and simply stop.

Listen before you call, if you can bear to. A machine that is cycling and failing sounds different from one that has stopped cycling at all.

Production that falls away in summer

Ice production is heat rejection, and heat rejection depends on the condenser. On a built-in, that condenser sits at the top of the cabinet behind the upper grille. Mandarin’s shaded lots put a lot of pollen and fine litter into the household air, and that is exactly what the grille draws through. A unit that made plenty of ice in February and struggles in August, with everything else in the cabinet behaving, is usually short of airflow rather than short of refrigerant.

There is also a genuine demand effect and it is worth naming honestly: a house uses more ice in a Florida August than it does in February. Before we call anything a fault, we establish what the machine is actually producing over a measured period rather than what the bin looks like at 6pm.

Ice that tastes wrong

Ice absorbs odour readily because it is stored open, in a cold dry place, next to whatever else is in the freezer. If the taste arrived suddenly, look at what else went into the freezer that week. If it has crept up over months, look at the water filter and the supply line. Old ice that has been sitting in the bin since a holiday will taste of the freezer no matter how healthy the machine is.

What a visit involves

We check the fill volume, the valve, the supply line pressure, the harvest cycle and the condenser, in that order. The diagnostic is a flat $80, credited toward the repair, with a written estimate before any part is ordered. Parts are genuine OEM, covered for 365 days, with 90 days on the labour.

We service Sub-Zero refrigeration only. No other brand.

What it costs

What does Sub-Zero ice maker repair cost in Mandarin?

Narrowed to the bands that fit this fault rather than the whole book, because quoting you the sealed-system ceiling for an ice maker would be no use to anybody.

Parts and labour for the repairs this page is about, plus the diagnostic that comes first.
What is being put right	Parts and labour
Diagnostic visit	$80 flat, credited toward the repair
Ice maker, water valve or supply line	$250–$650 parts and labour, after the diagnostic
Electronic control board	$440–$820 parts and labour, after the diagnostic

Every line above is a range because the firm figure is written down after the diagnosis and not before it. The $80 covers coming out, testing the system and telling you what is wrong, and it comes off the repair the moment you say go ahead. The whole table, and what happens when a repair is not worth doing, is on the what it costs page.

Why Ice Cubes Come Out Hollow A hollow cube is a water problem wearing a temperature problem's clothes. Here is how to tell the two apart before you call anyone.
The Condenser Is Above the Doors, Not Below The one piece of maintenance that reliably extends the life of a compressor, and the first thing we check on any cabinet that never stops running.

Sub-Zero built-in refrigerator repair A cabinet running warm on one side, frost creeping across the freezer wall, or a unit that runs and runs without ever settling down.
Sub-Zero integrated column repair Panel-ready refrigerator and freezer columns that sit flush with the cabinetry until something moves, ices up or stops responding.
Sub-Zero undercounter and refrigerator drawer repair The small units in islands, bars and outdoor kitchens, where heat, tight clearance and a long run from the main cabinet make life hard.

$80 flat diagnostic, credited toward the repair. You get a written estimate before any part is ordered or any labour begins.

Questions we are asked

What owners ask about this repair

Why are the cubes hollow when the freezer is clearly cold enough?: Because the machine times its stages rather than sensing them. It meters a shot of water, waits a fixed freeze, and harvests whatever is in the mould. When the fill runs short, the water freezes from the outside inward and what comes out is a shell. That is a water fault wearing a temperature fault's clothes.
Why does ice production fall away every summer?: The freezer has less margin to spare in July. Warmer room air across the condenser, more door openings and a longer recovery between harvests all eat into the freeze time the mould gets. A machine that was borderline in February starts missing harvests in August without anything new having broken.
Is a mould that fills but never releases worth repairing?: Usually, yes. A harvest that never completes is generally the heater, the motor or the module driving the cycle rather than the cabinet itself, and the table above is where that lands. Living with a tray you fill by hand is a fair choice too, and it costs nothing at all.

Customer reviews

Owners who called about this

Chosen for this page because they describe the same fault, and printed in full.

4.64.6 out of 5 across all 64 reviews published on this site

5 out of 5
The cubes had gone small and light over about two years. He measured what was arriving at the valve before touching anything and found the supply restricted rather than the machine itself at fault.
Odalys N.July 2026
5 out of 5
Production fell away every July and we assumed the freezer was losing its grip. He explained the timed freeze and why summer eats into it, cleared the condenser, and output climbed back.
Augustin D.June 2026
4 out of 5
The mould filled and then simply sat there. He showed me the harvest cycle failing, ordered the part against the plate rather than from a photograph, and came back when he said he would.
Clementine H.July 2026

A wider selection, three-star entries first, is on the reviews page. All 64 are published across this site, beside the repair or the street each one came from.