Sub-Zero · Ice makers
Sub-Zero Ice Maker Repair
Sub-Zero makes ice two ways: a crescent-cube ice maker inside the freezer, and a separate undercounter ice machine that freezes clear cubes on its own refrigerated evaporator and needs a drain. Most failures on either come down to water, scale or one worn part, not the whole appliance.
$79 service call, applied to the repair. Monday to Saturday, 8 AM to 7 PM.
- $79service call, applied to the repair you approve
- In-housesealed-system work: compressors, evaporators, leaks
- Since 2022CA BHGS #50388, EPA-certified
- 90 daysno-fee return visit if the same fault comes back
In short: a freezer ice maker that stops is most often switched off, resting on its own timer, short of water or blocked by a frozen fill tube. An undercounter machine whose cubes come out thin, cloudy or fused together is usually scaled up, or has a drain or water valve fault. Owner checks are on Sub-Zero ice maker not working. We are an independent service, not affiliated with Sub-Zero Group; see Sub-Zero repair.
Which Sub-Zero ice maker you have
A bucket inside a freezer door or drawer means a freezer ice maker. A separate appliance with its own door and bin, usually under a bar counter, is an ice machine.
- Designer DEU1550I and DEU1550IP: the 15-inch ice machine of the newer Designer undercounter line; the IP model has a drain pump.
- UC-15I: the 15-inch ice machine of the UC line. Hard, clear cubes, 16 per cycle, about 50 pounds a day in a cool room. Pump and outdoor versions exist, and later production uses R290 refrigerant.
- 315 and 315I: the earlier clear-cube machine, indoor only, with a bin of about 26 pounds and a drain pump version.
- 235 and 235I: freezes a slab on a cold plate and drops it onto a heated wire grid that cuts it into cubes; its board has an ice-thickness setting and a clean cycle.
- 506, 506I and 506UI: the older slab-and-grid machine, bin up to about 35 pounds. Early units use R-12.
- Freezer ice makers: the crescent-cube module in Classic Series built-ins, the PRO 48, Integrated columns and drawers and the 600 and 700 series, plus small modular units in the UC-24CI and 200 series undercounters.
How each kind works
A freezer ice maker is a mold with eight crescent cavities. A valve fills it, freezer air freezes it, a thermostat on the mold calls for the harvest, a heater frees the cubes and the ejector blades push them out into the bucket. A wire arm resting on the ice stops production when the bucket is full.
An ice machine has its own compressor and condenser behind the kickplate. On the UC-15I and the 315 a pump sprays water into cube molds on the evaporator; on the 235 and 506 water runs over a flat freezing plate and forms a slab. Either way the purest water freezes first and most minerals leave with the drain water, so the ice comes out clear. Hot refrigerant gas releases the ice, and a bin thermostat (on the 235, a bin thermistor read by the board) stops the machine when the bin is full.
When a freezer ice maker is supposed to be idle
On Classic, PRO, Integrated, 600 and later 700 series units, several normal control states look like a failure.
- Switched off. Units ship with ice making off. No ice cube icon on the display, or no ICE on a 600 series, means it is off.
- Resting. The control pauses the ice maker for 45 minutes after each harvest, while the freezer door or drawer is open and, on Classic and Integrated units, for about three minutes after it closes.
- Sabbath mode. No ice while it is on.
- Bucket out of place. On several 600 series models the bucket presses a switch; not seated, no ice.
- Locked out after slow fills. Classic units time each fill. When fills keep running slow, the control turns the ice maker off and flashes the ice and service icons until the water problem is fixed and the fault cleared. See Sub-Zero service light.
MAX ICE on Classic units raises output by up to about 40 percent for 24 hours, then production returns to normal.
What fails on freezer ice makers
Water supply and filter
What it usually is: not enough water reaching the valve: a partly closed shutoff, a clogged saddle valve or an overdue filter. These ice makers need steady water pressure at the unit, and a slow trickle gives small or hollow cubes.
What you can check: the shutoff valve and the filter light. On Integrated columns water flows with the filter removed, so ice returning without it means the filter was the problem. More owner checks: ice maker not working.
What we do: measure flow at the unit, replace a clogged saddle valve with a proper shutoff, and replace the filter or line. See water dispenser not working.
Frozen fill tube or dripping valve
What it usually is: a burned-out fill tube heater, or a water valve that seeps after the fill. Ice then closes the tube and later fills never reach the mold. A seeping valve also welds the cubes in the bucket into one lump.
What you can check: a lump of ice in the bucket, or an icicle at the mouth of the fill tube. Leave it for us rather than chipping.
What we do: thaw the tube, then test the heater and valve and replace whichever failed. On Classic and Integrated units the control measures each fill, so a short fill means the supply or the valve.
Ice maker module or a warm freezer
What it usually is: the module itself (motor, mold thermostat or mold heater) or a bent shut-off arm. The mold must be well below freezing before it harvests, so a freezer running warm makes little ice before anything else shows. A unit out of level makes uneven cubes.
What you can check: the freezer temperature, that the shut-off arm is down, and that nothing blocks the air around the ice maker.
What we do: test the module through a cycle. On current Classic units it is replaced as a whole; its internal parts are not sold. If the freezer is warm, see freezer not freezing.
What fails on undercounter ice machines
Scale and overdue cleaning
What it usually is: Orange County water is hard, and rejected minerals build up as scale on the evaporator, the water distributor and the pump. Cubes turn thin or cloudy and output drops.
What you can check: clean the bin, replace the filter, and keep to the schedule in your owner's guide; the UC-15I calls for cleaning at least every six months.
What we do: descale and sanitize in place. The UC-15I also needs a yearly deep cleaning with its water system partly taken apart, so it should be installed where it can slide out.
Drain problems
What it usually is: these machines flush water every cycle. When a gravity drain clogs or its line sags, water backs into the bin and the ice melts into a block; on pump models a failed pump stops the machine or floods the bin.
What you can check: water sitting in the bottom of the bin, or a drain hose under the counter that dips before it reaches the standpipe.
What we do: open the drain path, replace a failed pump, and re-run a line that does not fall steadily. See Sub-Zero leaking water.
Harvest, water valve or bin thermostat
What it usually is: a hot gas valve that stays shut, so the ice never lets go of the evaporator; on the 235 and 506, a cutting grid that no longer heats and leaves the slab whole; an inlet valve with a clogged screen; or bin sensing (a thermostat on the UC-15I and 506, a thermistor read by the board on the 235) that stops the machine early or lets ice back up.
What you can check: an empty bin with ice still stuck to the evaporator or lying whole on the grid. Leave it in place.
What we do: test the valve, the grid and the bin control during a harvest, and replace the part that failed.
Heat, condenser and power
What it usually is: the condenser sits behind the kickplate and needs open air. Output also falls with heat: a UC-15I makes closer to 30 or 35 pounds a day in air well above 100°F.
What you can check: a clean grille, the breaker, and the GFCI on outdoor circuits. Turning the UC-15I off at its switch still leaves the board live, so switch the breaker off first.
What we do: clean the condenser and fan, then test the sealed system if output stays low. See outdoor kitchen refrigeration repair.
Repair or replace
- Freezer ice makers: usually worth repairing, even when the whole module is replaced.
- UC-15I: usually worth repairing. A sealed-system repair on an older machine is a call we make with you; R290 machines are repaired with LOKRING connectors, in-house.
- 315, 235 and 506: fewer parts are available. A failed compressor, especially on an early R-12 506, usually means replacement. The UC-15I needs a rough opening about 15 1/4 inches wide; we measure the old opening, drain and power before you order.
What ice maker repair costs
Either kind of visit is the same $79 service call, and it goes toward the repair once you approve the written price.
Built-in and undercounter ice maker repair
| Repair | Typical price, parts and labor |
|---|---|
| Descale and sanitize | $250 to $450 |
| Water valve | $350 to $600 |
| Water pump or drain pump | $400 to $700 |
| Bin thermostat or level sensor | $300 to $550 |
| Control board | $550 to $1,000 |
| Sealed-system repair | $1,200 to $2,500 |
Typical Orange County ranges for parts and labor. The $79 service call is applied to any of them. Parts that ship from the manufacturer and older or discontinued models can run higher. You get the exact written price after the diagnosis and before any work starts.
Freezer ice maker parts are priced under built-in refrigeration on our pricing page. Ice makers from other brands are on built-in ice maker repair; to book, tell us the model and serial.
Talk to the technician first
Monday to Saturday, 8 AM to 7 PM. The $79 service call is applied to the repair.
Sub-Zero ice makers: questions
Why does my Sub-Zero ice maker pause after every batch?
The control rests it for 45 minutes after each harvest so the next batch freezes solid, and it also stops while the freezer door is open. That is normal.
How often should a Sub-Zero UC-15I be cleaned?
At least every six months, more often with hard water, plus a yearly deep cleaning by a technician.
Does a Sub-Zero ice machine need a floor drain?
A gravity-drain machine needs an open drain below it; drain pump versions can send water up to a higher drain. Either way it needs a working drain, because it flushes water every cycle.
Can I use a water softener or reverse osmosis with a Sub-Zero ice machine?
Not on every model. On the 315, softened water can give soft cubes that clump in the bin, and a reverse osmosis system can leave a 235 short of water. A good filter usually does the job; we look at your water and your model first.
Why does my UC-15I make less ice in summer?
Output drops as the air at the grille gets hotter, by roughly a third in very hot air. A dirty condenser makes it worse.