--- title: "Cleaning and Sanitizing an Ice Machine: Descaler First, Sanitizer Second, Never Together" description: "The two chemicals and their separate jobs, the six-month and three-month schedules the makers set, how the clean cycle runs on cube, nugget and clear ice units…" url: "https://icemachinerepair.center/guides/cleaning-and-sanitizing-an-ice-machine/" date_modified: "2026-09-26" --- Maintenance and prevention # Cleaning and Sanitizing an Ice Machine: Descaler First, Sanitizer Second, Never Together Cleaning and sanitizing an ice machine are two separate steps: an acid cleaner or descaler removes mineral scale, then a sanitizer kills slime and mold. Manitowoc and Scotsman ask for both at least every six months, U-Line every three months on its clear ice units, using the maker's own products at the stated amounts and never mixing the two. By [IceMachineRepair.center technical team](https://icemachinerepair.center/authors/technical-team/) Published September 26, 2026 ## At a glance. Ice is food, and the machine that makes it is wet, dark and cold on the inside, which is exactly where slime and scale settle in. Two chemicals keep it safe and working, one after the other, each from the maker's own list and never poured together. Read the whole guide ### Two jobs Descale with cleaner, then disinfect with sanitizer Manitowoc says the two perform separate functions. ### How often Every six months at least on commercial machines More often near yeast, flour or heavy dust. ### With what The products your maker names, at its amounts Manitowoc approves only its own descaler and sanitizer. ### Never Mix cleaner and sanitizer Manitowoc's caution; the others run them one after the other. In this guide 1. Cleaner and sanitizer are two different jobs 2. How often the makers and the Food Code ask for it 3. How the cleaning cycle runs on different ice machines 4. The ice bin, the scoop and the outside of the cabinet 5. Step by step 6. Questions ## Cleaner and sanitizer are two different jobs The makers use the words carefully. Cleaner, also called descaler or scale remover, is an acid; Manitowoc describes its own as citric and phosphoric acid that dissolves lime scale so water can flush it away. Sanitizer is a disinfectant that kills algae, slime and the organisms behind them. One does nothing for the other's job, so a machine that is only descaled can still grow slime, and one that is only sanitized keeps its scale. They are never combined. Manitowoc's manual puts it as a caution, do not mix descaler and sanitizer solutions, and reminds owners that federal law requires these chemicals to be used exactly as labeled. Every procedure below runs the cleaner first, flushes it out and only then brings in the sanitizer. - Wear rubber gloves and eye protection; Manitowoc and U-Line both ask for them when handling the solutions. - Measure the amounts the manual gives for your model; more is not better with an acid. - Keep each solution in its own clean container, labeled, and rinse the container between uses. - Throw away every cube made while either solution was in the machine. Source: [Manitowoc — Parts & Service Communicator MII-106, Ice Machine Cleaner and Sanitizer Usage](https://www.manitowocice.com/asset/?id=ojrcs) — Cleaner (citric and phosphoric acid) removes scale, sanitizer removes algae and slime; do not mix; sanitize at least every six months and more often near airborne yeast such as bakeries; cleaner not weekly or monthly, not more often than every two months, only when scale is visible; [Manitowoc — Indigo NXT Ice Machines Installation, Operation and Maintenance Manual](https://www.manitowocice.com/asset/?id=bepmjn) — Do not mix descaler and sanitizer, federal labeling law; gloves and goggles; descale and sanitize every six months; only Manitowoc products approved; clean cycle up to 35 minutes, stops if the curtain is open; discard all ice made during the procedure; no chlorinated, citrus-based or abrasive cleaners on exterior panels; [U-Line — User Guide and Service Manual, Clear Ice Machine U-CLR1215B](https://www.u-line.com/userguide/pdf/index/sku/U-CLR1215B-00B/) — Clean when alerted or every three months; only U-Line Clear Ice Machine Cleaner; cycle about 45 minutes; wipe storage area with diluted bleach and rinse; gloves and goggles; discard first harvest ## How often the makers and the Food Code ask for it Federal food rules defer to the maker here. Section 4-602.11 of the FDA Food Code puts ice bins and the closed-in parts of ice-making equipment on the maker's own cleaning interval, and only when a maker gives none does it fall back on a plain test: clean before soil or mold can gather. Health departments write the code into local rules and check machines against it. ### What the manuals set as a minimum Manitowoc asks for descaling and sanitizing every six months on its Indigo NXT machines. Scotsman sets a minimum of twice a year for its cube machines and says the bin should be sanitized as often as local health codes require and every time the machine is cleaned. U-Line's clear ice machine shows a cleaning alert and, without one, should be cleaned every three months. ### When a machine needs it sooner Airborne yeast is the usual reason. Manitowoc names bakeries as a place where sanitizing has to come more often, and Scotsman warns that a machine near a yeast source will need more frequent sanitation. Hard water brings the descale forward instead. Visible slime, a smell or ice that tastes off means the machine is due now, whatever the calendar says. ### Why more descaling is not better Manitowoc's service note on its chemicals says cleaner should not be used weekly or monthly, that intervals shorter than two months must be avoided because the acid is corrosive, and that cleaner is needed only when scale is visible. Sanitizing, by contrast, may be repeated between descales whenever the machine needs it. Source: [FDA — Food Code 2022, 4-602.11(E)(4)](https://www.fda.gov/media/164194/download) — Ice bins and enclosed components of ice makers are cleaned at the manufacturer's frequency or, absent one, often enough to preclude soil or mold Close on the removed water distribution tube of an ice machine in a tray of cleaner. ## How the cleaning cycle runs on different ice machines Most current machines have a clean mode that runs the solution through the water system on its own once it is started. On Scotsman's cube machines, the owner presses Clean, waits for the display prompt, pours the stated amount of scale remover into the reservoir and lets a 35-minute cycle circulate and flush it. Parts such as the curtain, distributor and sensors are then washed by hand before the same cycle runs again with sanitizer. Manitowoc's touchscreen warns that its clean cycle can last up to 35 minutes and stops if the water curtain is left open. Nugget and flake machines work differently. Scotsman's manual for them has the owner shut the water supply, drain the reservoir, pour in a warm scale remover solution and run the machine making ice until the solution is used up; the ice made during the process is melted or thrown away. The sanitizer follows at 200 parts per million, as the manual specifies. U-Line's clear ice units run a 45-minute cycle with the maker's cleaner in the trough, and the storage area is wiped separately with a diluted bleach solution the manual gives and then rinsed. Source: [Manitowoc — Indigo NXT Ice Machines Installation, Operation and Maintenance Manual](https://www.manitowocice.com/asset/?id=bepmjn) — Do not mix descaler and sanitizer, federal labeling law; gloves and goggles; descale and sanitize every six months; only Manitowoc products approved; clean cycle up to 35 minutes, stops if the curtain is open; discard all ice made during the procedure; no chlorinated, citrus-based or abrasive cleaners on exterior panels; [Scotsman — Installation and User's Manual, Modular Cuber Prodigy Plus E Series](https://www.scotsman-ice.com/service/User%20Manuals/17359901.pdf) — Clean and sanitize at least twice a year; sanitize the bin as local health codes require and at every cleaning; yeast raises sanitation needs; 35-minute cycle with scale remover, then sanitizer; rinse chlorine residue from panels; [Scotsman — Installation and User's Manual, Modular Flake and Nugget Ice Machines, Prodigy Plus A Series](https://www.scotsman-ice.com/service/User%20Manuals/17370601.pdf) — Drain, add warm scale remover solution, run while making ice until used up, discard that ice; sanitizer at 200 ppm; [U-Line — User Guide and Service Manual, Clear Ice Machine U-CLR1215B](https://www.u-line.com/userguide/pdf/index/sku/U-CLR1215B-00B/) — Clean when alerted or every three months; only U-Line Clear Ice Machine Cleaner; cycle about 45 minutes; wipe storage area with diluted bleach and rinse; gloves and goggles; discard first harvest ## The ice bin, the scoop and the outside of the cabinet The bin holds the finished ice, so it needs the same attention as the water system. Empty it completely, wash every inside surface with the solution the manual lists, then sanitize, and pour what is left into the bin drain rather than onto the floor. The scoop and its holder are cleaned at the same time, and the scoop goes back in its holder rather than being left buried in the ice. Outside panels have their own rules. Manitowoc says never to use chlorinated, citrus-based or abrasive cleaners on its exterior panels and plastic trim, and Scotsman asks for chlorine residue to be rinsed off stainless panels with clean water. - Pouring cleaner and sanitizer into the machine back to back without the flush between them. - Using a stronger mix than the manual gives, in the hope of a faster result. - Serving ice made while a solution was still in the water system. - Leaving the curtain open or the front panel off while the cycle runs. - Cleaning the machine but not the bin, the scoop or the dispenser chute. Source: [Manitowoc — Indigo NXT Ice Machines Installation, Operation and Maintenance Manual](https://www.manitowocice.com/asset/?id=bepmjn) — Do not mix descaler and sanitizer, federal labeling law; gloves and goggles; descale and sanitize every six months; only Manitowoc products approved; clean cycle up to 35 minutes, stops if the curtain is open; discard all ice made during the procedure; no chlorinated, citrus-based or abrasive cleaners on exterior panels; [Scotsman — Installation and User's Manual, Modular Cuber Prodigy Plus E Series](https://www.scotsman-ice.com/service/User%20Manuals/17359901.pdf) — Clean and sanitize at least twice a year; sanitize the bin as local health codes require and at every cleaning; yeast raises sanitation needs; 35-minute cycle with scale remover, then sanitizer; rinse chlorine residue from panels ## Where to stop Stop at the parts the manual shows an owner removing. Do not take off panels that cover wiring or the compressor, and switch power off at the service switch before reaching into the evaporator area. If a solution splashes in the eyes, follow the first aid on its label. If slime returns within weeks, the machine will not finish its clean cycle or water pools under it, book a visit. Written by [IceMachineRepair.center technical team](https://icemachinerepair.center/authors/technical-team/). Our ice machine technicians write these guides from their own service calls and each maker's published manuals. Sources: [Manitowoc — Parts & Service Communicator MII-106, Ice Machine Cleaner and Sanitizer Usage](https://www.manitowocice.com/asset/?id=ojrcs) · [Manitowoc — Indigo NXT Ice Machines Installation, Operation and Maintenance Manual](https://www.manitowocice.com/asset/?id=bepmjn) · [Scotsman — Installation and User's Manual, Modular Cuber Prodigy Plus E Series](https://www.scotsman-ice.com/service/User%20Manuals/17359901.pdf) · [Scotsman — Installation and User's Manual, Modular Flake and Nugget Ice Machines, Prodigy Plus A Series](https://www.scotsman-ice.com/service/User%20Manuals/17370601.pdf) · [U-Line — User Guide and Service Manual, Clear Ice Machine U-CLR1215B](https://www.u-line.com/userguide/pdf/index/sku/U-CLR1215B-00B/) · [FDA — Food Code 2022, 4-602.11(E)(4)](https://www.fda.gov/media/164194/download) ## Step by step. Five steps, in the order worth doing them. 01 ### Read your model's procedure Open the cleaning pages of your own manual or the label inside the front panel, and set out the maker's cleaner, sanitizer, gloves and goggles. 02 ### Empty the bin Stop the machine at the end of a harvest as the manual directs, then remove and discard all the ice in the bin or dispenser. 03 ### Run the cleaner cycle Start clean mode, add the measured cleaner when the display or manual says, and let the cycle finish and flush without interrupting it. 04 ### Run the sanitizer separately With the cleaner fully flushed, run the sanitizer through the same way and wipe the parts and bin the manual lists. 05 ### Restart and discard the first ice Return panels and covers, restart ice making and throw away all ice made during the procedure. For the heart of your home. ## Questions owners ask. ### Can I use vinegar or bleach to clean an ice machine? Only where your manual names them. Manitowoc approves only its own descaler and sanitizer and warns that other products may cause harm or damage; U-Line uses a diluted bleach wipe for the bin but its own cleaner in the machine. ### What happens if I skip cleaning and sanitizing an ice machine? Scale builds on the plate and probes, cutting ice output and slowing harvest, and slime can grow in the water system and bin. Both show up as off-tasting ice and repair calls. ### Do I have to throw away the ice after cleaning? Yes. Manitowoc says all ice made during descaling and sanitizing must be discarded, and U-Line asks for the first harvest after cleaning to be thrown away. ### How long does an ice machine cleaning cycle take? Roughly half an hour to three quarters of an hour of machine time in the manuals we cite, plus the time to empty the bin, wash parts and restart. ## The problems behind it. Each has a page of its own: what it usually means and the causes in the order worth checking. [All 17 problems](https://icemachinerepair.center/problems/) Problem ### Slime or Mold Growing in the Ice Machine Bin 6 causes, cheapest first Problem ### Ice From the Ice Machine Tastes Stale, Chemical or Musty 6 causes, cheapest first Problem ### Cloudy, Soft or Wet Ice From an Ice Machine 6 causes, cheapest first Problem ### Ice Machine Not Harvesting: Ice Stays Stuck on the Plate 6 causes, cheapest first ## When it needs a technician. The repairs on the right are where this guide ends when the checks do not settle it. ### Ice machine cleaning and sanitizing Scale off the evaporator and distribution tube, slime out of the bin, curtain and drain, with the maker's cleaner and sanitizer on its schedule. ### Ice machine harvest repair The hot gas valve, harvest assist, curtain switch and thickness probe that decide when a sheet of cubes is done and make it drop. ### Ice machine diagnostic visit A visit that watches a freeze and a harvest, checks water, drain and condenser, reads stored codes, and names the part holding the ice back. ## More in maintenance and prevention. The routines that keep an ice machine off our schedule, from cleaning and sanitizing on the maker's schedule and changing the water filter to washing the air filter and keeping the condenser clear. [The whole section](https://icemachinerepair.center/guides/maintenance-and-prevention/) Habits that keep the bin full for years ### Scale and the Ice Machine Water Filter: Purge, Polyphosphate and a Six-Month Cartridge Where minerals settle as water freezes, what a cartridge can and cannot stop, the chlorine trade-off, reverse osmosis limits and the signs a filter is overdue. Habits that keep the bin full for years ### Keeping the Condenser Clean: The Monthly Filter, the Six-Month Coil and the Air Around It What grease, flour and lint do to ice output, washing the air filter, checking the coil with a flashlight, the tools each maker allows, and the room the machine needs. Guides ### All 18 guides Six sections, by what you are trying to find out. --- **[Read on the site: Cleaning and Sanitizing an Ice Machine: Descaler First, Sanitizer Second, Never Together](https://icemachinerepair.center/guides/cleaning-and-sanitizing-an-ice-machine/)** **[Book a visit with IceMachineRepair.center](https://icemachinerepair.center/schedule/)**