How to Clean a Sub-Zero Ice Maker, Model by Model

Cleaning a Sub-Zero ice maker comes down to two jobs: dissolving mineral scale from the parts that carry water, and sanitizing the surfaces that touch ice. On an undercounter UC-15I you do both with the built-in CLEAN cycle: touch CLEAN, empty the bin, pour in 4 ounces (115 ml) of cleaner when the light flashes, then repeat the cycle with 1 tablespoon (15 ml) of sanitizer, with each pass running about 30 minutes. An ice maker inside the freezer of a full-size refrigerator is simpler still: switch it off, empty and wash the bin, and keep the water filter on schedule. Which steps apply to you, and how often, depends on the model in your kitchen and on how much mineral your tap water carries.

Work out which ice maker you are cleaning

Sub-Zero makes ice in two quite different ways. The undercounter machines, the UC-15I and the Designer Series undercounter unit (DEU1550I), are dedicated ice makers with their own water path, their own condenser and a clean cycle built into the control. The other kind is the automatic ice maker tucked into the freezer section of a full-size Classic (CL) or Designer (DET, DEC) refrigerator, which offers the owner no descaling cycle at all.

That split decides your routine. A dedicated machine handles water all day long, which is why Sub-Zero gives it a scheduled descale and sanitize. A freezer ice maker mostly needs a clean bin, a fresh filter and a condenser that can breathe.

Running the clean cycle on a UC-15I

Sub-Zero asks for a UC-15I clean and sanitize every six months. Plan on about an hour, because the job is two cycles back to back.

1. Buy the right bottles. The UC-15I uses the same cleaner and sanitizer as the DEU1550I, but neither is interchangeable with the products sold for the older 315I. Newer labels call the cleaner a descaler; only the name changed.
2. Touch CLEAN and empty the bin. Every cube goes in the sink. Ice left in the bin through a cleaning pass picks up the solution.
3. Add the cleaner at the flash. When the light flashes, pour in 4 ounces (115 ml) as the use and care guide directs, then let the pass run for roughly 30 minutes.
4. Repeat with sanitizer. Start the second pass and add 1 tablespoon (15 ml) of sanitizer when the light flashes again.
5. Let it finish. A UC-15I clean cycle cannot be canceled once it starts, so pick a quiet afternoon rather than the hour before a dinner party.

Wash the scoop by hand in warm, soapy water while the machine works, then rinse it well. While you are kneeling there, pull the kickplate: the UC-15I condenser sits behind it and also wants cleaning every six months.

The filter runs on the same calendar. The UC-15I uses part 7042803, which replaced the earlier 7012333. Swap it every six months, after the unit has been shut down for a long stretch, or whenever the red REPLACE FILTER light appears, which happens after 8000 ice-making cycles. Then touch and hold CLEAN for 6 seconds to clear the light, and throw away the first batch of ice. If the house sat closed while you travelled, our notes on shutting a unit down for weeks cover the restart.

The Designer Series undercounter model and its reminder

The Designer Series undercounter ice maker wants its first clean at startup, then another every three to six months depending on water hardness. Its reminder ships set to three months. The measures here are 1/2 cup of descaler per clean, followed by 1/2 tablespoon of sanitizer, which differs from the UC-15I, so check the amounts against the model you actually own instead of repeating last season’s habit.

The DEU1550I does not come with a water filter, so whatever minerals arrive from the tap go straight into the machine. Denver Water and the other Front Range utilities publish an annual water quality report that gives a hardness figure. If yours reads low, the six-month end may suit you. If cubes come out cloudy, or a chalky film shows on the bin or around the water area, stay at three months.

Ice makers inside a full-size refrigerator or freezer

The ice maker in a Classic or Designer freezer has no cycle for you to run, so cleaning it means the bin, the surrounding surfaces and the filter.

• Switch the ice maker off at the control so it does not drop a harvest on your hands.
• Lift out the bin, dump the ice, and wash the bin in warm water with a little mild dish soap. Rinse it, then dry it completely, since water left in the corners freezes the next cubes into a clump.
• Wipe the shelf area under the ice maker with a soft cloth. Leave the ice maker mechanism itself alone.
• Keep the filter current. Sub-Zero gives the CL, DET and DEC cartridge a life of twelve months or 750 gallons (2,839 L), whichever arrives first; replace it sooner if the indicator comes on, the water flow weakens, or cubes start coming out hollow. The touch control shows Snooze/Refresh when one is due, and pressing Snooze holds the reminder off for 24 hours.
• After fitting a new filter, discard the first two full bins of ice on a non-dispenser model. On a dispenser model, run water for two minutes before drinking it.

A maintenance calendar you can actually keep

Task	Which units	How often
Clean and sanitize cycle	UC-15I	Every six months
Descale and sanitize	Designer Series undercounter	At startup, then every three to six months
Water filter 7042803	UC-15I	Every six months, after a long shutdown, or at the REPLACE FILTER light
Water filter	CL, DET, DEC	Up to 750 gallons or twelve months
Condenser behind the kickplate	UC-15I	Every six months
Condenser	Full-size refrigerators	Every six to twelve months, sooner with pets
Bin and scoop wash	Every model	Whenever ice smells or tastes stale

Denver’s semi-arid climate means fine dust drifts into everything, and a floor-level grille collects its share. Brush or vacuum the condenser gently and keep the brush moving with the aluminum fins rather than across them, because bent fins block airflow. Sub-Zero says chemical condenser sprays are unnecessary and not recommended. A dog or cat in the house moves that job toward the six-month end.

Leaks, odd noises and no ice

A clean bin will not stop a leak. Water in front of an undercounter ice maker usually means the drain is not keeping pace or a supply connection is seeping; on a full-size unit, check whether the drip lines up with the water line at the back. Close the shutoff valve and get it looked at before the floor or the cabinetry soaks it up.

Some noise is part of the job: water filling, cubes landing in the bin, the steady hum of the cooling system. A harsh buzz during each fill, or a rattle that never settles, deserves attention. Weak water pressure can make a fill valve chatter, and the Classic filter data sheet lists a working supply pressure of 35-120 psi.

When the ice stops altogether, run through the easy checks first: the ice maker switched on, the filter not overdue, the supply valve fully open and the freezer holding its normal temperature. A filter well past its date can starve the ice maker of water before anything has actually broken.

What a professional tune-up adds

You can handle the cycles, the bin and the filter yourself. A technician adds the work behind the panels: cleaning the condenser without damaging the fins, inspecting the fill valve and supply line for slow seeps, checking water pressure at the valve, confirming the drain runs clear on an undercounter machine, and reading the freezer temperature so a sluggish ice maker is not blamed for a cabinet that is running warm.

If a part has failed, ice maker, water valve and supply line repairs usually run $280–$800, and you get the firm price once the diagnosis is done. Getting someone to your door costs a flat $89 for a proper look at the unit, and that $89 drops off the invoice if you approve the repair. The wider picture is on our repair cost page, and the ice maker repair service page explains what that visit covers. Homeowners in Park Hill, Cheesman Park, Platt Park and University Hills can call (720) 790-9436 or use the booking button on this page.