Sub-Zero Ice That Tastes Like Plastic: How to Clear It

Why ice picks up a plastic taste

Ice behaves like a sponge for smells. The cubes sit in an open bin inside a cold, closed compartment, and whatever odors are drifting around in there slowly work their way into them, which is why a bin that has gone untouched for a month rarely tastes like plain water. When people call the result plastic, the cause is usually one of a short list, and each one has its own fix. Before blaming the ice maker, pour a glass of water from the same supply and taste it side by side with a melted cube: a flavor already present in the water points upstream to the filter or the line, while a flavor that appears only in the ice points to the freezer or the machine.

• Stale ice: cubes left for weeks, especially in a home that uses little ice, absorb odors from food, wrappers and storage tubs.
• A spent or wrong filter: once the carbon inside is used up, it stops taking out the taste of the city's disinfectant, and many people read that chemical note as plastic.
• New parts: a fresh supply line, a new valve or a just-installed refrigerator can lend the first batches a resin flavor that fades with use.
• Buildup: scale and film inside the ice maker or along its water path hold on to tastes and hand them to every cube.

Clear out the bin before anything else

Start with the ice that is already made, because no other fix will show until the old cubes are gone. Switch the ice maker off at its control, lift the bin out and empty it into the sink, then wash it in warm water with a little mild dish soap, rinse it thoroughly and let it dry completely before it goes back in. Skip scented soaps and harsh cleaners; the bin's plastic will hold on to their smell, and you will have swapped one odd taste for another. While the bin is out, take a look around the freezer. An open package of fish, an uncovered container, or a new set of storage tubs with a strong smell can all flavor the ice. Wrap or seal what needs it and throw out what has been in there too long. Then turn the ice maker back on and throw away the first batch or two it produces.

• Seal or remove strong-smelling food and packaging in the freezer.
• In a household that uses little ice, empty the bin every couple of weeks instead of letting the cubes age.

Check the filter: its age, the right part and the first ice after a change

A filter at the end of its life is the most common reason the taste returns after a cleaning. Sub-Zero rates the water filter in its Classic CL and Designer DET and DEC refrigerators for up to 750 gallons (2,839 L) or twelve months, whichever comes first, and says to change it when the indicator shows, when water pressure drops, when cubes start coming out hollow, or every 12 months regardless. The data sheet for the Classic CL filter lists testing by NSF International against NSF/ANSI 42, the standard that covers taste and odor, and NSF/ANSI 53, so fitting the correct replacement is a real part of keeping flavor out of the ice. A wrong part, or a cheap lookalike that seats loosely, can let water slip past the carbon untreated. A new cartridge also needs flushing, since fine carbon dust and trapped air can give the first ice an off taste of their own. Sub-Zero says CL, DET and DEC models without a dispenser should throw out the first two full bins of ice after a change, dispenser models should run water for two minutes, and on a UC-15I the first batch goes in the sink.

• The twist-in filter 4204490, interchangeable with 9030868, fits the Classic BI and CL, Designer models including the DEC and DET, and the 648PRO, PRO3650 and PRO4850.
• Older Classic BI units with a two-prong push-in filter can no longer get the microbiological 7023811; its replacement, 7045454, is a color, taste and odor filter.
• The UC-15I uses filter 7042803, the part once numbered 7012333. Swap it every six months, or sooner if the unit has sat unused for a long stretch or the red REPLACE FILTER warning lights, which the machine triggers once it has run 8000 ice-making cycles; then keep a finger on CLEAN for 6 seconds so the warning clears.

A Sub-Zero with no filter inside

Plenty of owners go looking for a cartridge to change and find nothing, because a good number of Sub-Zero units are built without one. Sub-Zero's own list of filterless products covers the UC-24 and DEU undercounter refrigeration, the ID drawers and nearly all of its wine storage, the IW-30CI being the exception, plus several other series; the DEU1550I ice maker also leaves the box without one. On those units any filtering happens before the water reaches the appliance, usually in a cartridge under the sink or in the cabinet beside the refrigerator, put in by whoever ran the water line. That cartridge ages just like an internal one, but nothing on the control panel reminds anyone to replace it, so it is often years old by the time the ice starts to taste strange. The same goes for a Classic BI that was set up with the bypass plug 7011209 in place of a filter, because the plug filters nothing at all. When a BI has that plug fitted, or its twist-in cartridge has been pulled out, Sub-Zero's instruction is to tap the small white reset button on the left side of the filter five times inside a seven-second window, which switches off the filter-life monitor so it stops asking for a cartridge that is not there.

New lines, new appliances and a taste that fades

Fresh plastic tubing, a new inlet valve or a refrigerator that was installed last week can all give the first ice a faint resin flavor, and that kind of taste normally weakens a little with each batch as everyday use rinses the new materials. The practical approach is patience plus volume: keep making ice and discarding it for several days, and draw water through any dispenser so the line keeps turning over. A taste that is still strong after a couple of weeks suggests something other than break-in, such as tubing never meant for drinking water, a line coiled somewhere warm behind the cabinet, or a valve that is passing water poorly. Pressure deserves a look at the same time. The required supply pressure varies by model, with some needing 20-100 psi and others 35-120 psi, and since Sub-Zero supplies no gauge, ask a plumber to confirm the figure. Low pressure tends to show up as small or hollow cubes rather than a taste, but it often travels together with an aging filter or a partly closed shutoff valve.

Cleaning a dedicated Sub-Zero ice maker

An undercounter ice maker turns far more water into ice than the one inside a refrigerator, and on hard water it scales up steadily, so a full clean cycle is often what finally removes a stubborn taste. The UC-15I runs its own: Sub-Zero says to clean and sanitize it every six months by touching CLEAN, emptying the bin, pouring in 4 ounces (115 ml) of cleaner when the light flashes, and then repeating the process with 1 tablespoon (15 ml) of sanitizer. Allow roughly 30 minutes per cycle, and know that a cycle already under way cannot be canceled, so start it when the machine can be left alone to finish. The Designer Series undercounter ice maker should be cleaned when it is first started up and then every three to six months depending on water hardness; its reminder defaults to three months, and each clean uses 1/2 cup of descaler and 1/2 tablespoon of sanitizer. Given how hard San Diego's water runs, the shorter end of that range is a sensible place to begin in Hillcrest. Use the solutions meant for your model: the DEU1550I and UC-15I share theirs, but they cannot be swapped with 315I cleaners, and the product Sub-Zero used to sell as cleaner is now labeled descaler with nothing in the bottle changed.

• Empty and wash the bin before the cycle, and discard the first ice made afterward.
• On a UC-15I, the condenser behind the kickplate also wants cleaning every six months, so it makes sense to do both on the same day.

When the taste will not go away

If the bin is clean, the filter is new and flushed, the freezer smells of nothing and the ice still tastes of plastic, the cause probably lives in the water path itself: a valve, a fill tube or a length of tubing that needs replacing, or scale deep enough that a routine clean cannot reach it. That is the moment to book a visit. We handle ice maker and water supply repairs in Hillcrest, Uptown and University Heights, following the line from the shutoff valve to the ice mold and replacing only the part that is putting the taste in, and the same visit covers an ice maker that has stopped making ice or started leaking. If you would rather stay ahead of the problem, a maintenance visit can combine the filter change and a clean cycle with the rest of the unit's upkeep, and our guide to genuine Sub-Zero parts covers what to ask about a replacement filter or valve before it is installed. The booking button on this page is the quickest way to pick a time, or phone (858) 400-4615.