How to Clean an Ice Maker (Descaling and Sanitizing Are Two Different Jobs)

Written & researched by Derek Holt Home & Appliances Editor

Updated August 2026

Cleaning an ice maker is two separate jobs, and most people only do one of them. Descaling uses an acid — white vinegar at one part to three parts water, or citric acid at about a tablespoon per quart — to dissolve the mineral scale that builds on freezing surfaces and inside the pump. Sanitizing uses a dilute bleach solution, one tablespoon per gallon of water, to kill the biofilm that lives under and around that scale. Descaling fixes slow, small or misshapen ice. Sanitizing fixes ice that tastes or smells wrong. You need both, and you must never mix the solutions.

Why Two Passes, Not One

Ice makers fail for two unrelated reasons, and each has its own cure.

Scale is mineral deposit — mostly calcium and magnesium carbonate — left behind when water freezes and evaporates. It coats the metal freezing fingers or the evaporator cylinder, insulating them, so cycles get longer and cubes get smaller and hollower. It also builds inside the water pump, which is why pump failure is the most common death of a countertop ice maker. Scale is dissolved by acid, and only by acid.

How fast it builds depends entirely on your water. The U.S. Geological Survey's water hardness classification puts water above 121 mg/L as calcium carbonate in the "hard" band and above 180 mg/L in "very hard" — and much of the country sits in one of those two. On very hard water an ice maker needs descaling monthly. On filtered or softened water, every couple of months is fine.

Biofilm is different: a slimy layer of bacteria and the matrix they secrete, clinging to plastic surfaces and the inside of tubing. It grows anywhere water sits warm and still, which describes an ice maker reservoir perfectly. Biofilm is what makes ice smell musty or taste stale even when the water going in is fine. Acid does not reliably kill it. A sanitizer does.

Worth remembering why any of this matters: ice is food. The FDA Food Code, the model regulation most state and local retail food rules are built on, treats ice as a food and requires it to be made from drinking water and handled accordingly. Commercial kitchens clean ice machines on a documented schedule for exactly this reason. Home machines get the same biofilm and much less attention.

What You Need

• White vinegar or food-grade citric acid for descaling
• Unscented household bleach for sanitizing — plain sodium hypochlorite, nothing with added fragrance or detergent
• A soft cloth and a small soft brush (an old toothbrush is right for the corners)
• A measuring spoon and a gallon jug
• Your manual, if you still have it, because some manufacturers specify a cleaner and void warranty claims for others

Cleaning a Countertop or Portable Ice Maker

Allow about 90 minutes, most of it waiting. Your actual attention is needed for maybe fifteen of them.

1. Unplug it and empty everything. Take out the basket and the scoop, tip out any ice, and drain the reservoir through the plug on the underside. Discard the ice — you are about to run vinegar through the machine, and the ice in there is the reason you are doing this.
2. Wash the removable parts. Basket, scoop and lid in warm soapy water. Rinse well and set aside to dry.
3. Mix the descaler. One part white vinegar to three parts water, enough to fill the reservoir to its normal line — usually 1.5 to 3 quarts depending on the machine. Or citric acid at roughly one tablespoon per quart of water, which some manufacturers prefer because it is gentler on gaskets.
4. Circulate it. Fill the reservoir, plug the machine in and start a normal ice cycle. It will begin pumping the solution over the freezing surfaces, which is exactly what you want. Let it run 15 to 30 minutes. Some machines have a dedicated clean or self-clean button — use it; it does the same thing with the freezing disabled.
5. Discard any ice it makes. It will be vinegar ice. Throw it out.
6. Drain and flush. Unplug, drain completely, then refill with plain water and run a full cycle. Drain again. Repeat this twice more. Three plain-water flushes is not excessive — residual vinegar tastes obvious in ice for days, and any bleach that meets leftover acid is a chemistry problem.
7. Sanitize. Mix one tablespoon of unscented bleach per gallon of water. Fill the reservoir, run the machine for two or three minutes to draw the solution through the pump and lines, then switch it off and let it stand for 10 minutes.
8. Flush again, thoroughly. Drain, then two or three more full reservoirs of plain water, running the pump each time, until there is no chlorine smell at all.
9. Wipe and dry. Clean the interior walls, the underside of the lid and around the water level sensor with a damp cloth. Leave the lid open and let the machine dry completely — several hours — before you use it or store it. A sealed damp reservoir is where biofilm restarts.
10. Discard the first full batch of ice after cleaning, on principle.

Cleaning a Nugget Ice Maker

Same chemistry, more urgency, and one extra place to look. A nugget machine has an enclosed auger housing and a compression head — a warm, wet, dark space with mechanical clearances in it, which is close to ideal for biofilm and also the place where scale does the most damage. Scale on the evaporator cylinder means the auger scrapes a thinner layer of ice, output drops, and eventually the machine stops producing altogether.

Practical differences:

• Use the built-in clean cycle, and use it more often. Every nugget machine has one because the manufacturers know the mechanism needs it. Every three to four weeks on hard water.
• Descale before it slows down, not after. On a nugget machine the first symptom of scale is wetter, slushier pellets, followed by reduced output. If you have noticed either, descale now.
• Listen for the warning. A grinding or clicking sound before the ice stops usually means the auger is struggling. Running a descaling cycle at that point is the cheapest repair available; ignoring it is how the drive gear strips.
• Clean the basket and chute separately. Pellets sit in their own meltwater, and the chute is a place people never wipe.

If a nugget machine has already stopped producing, work through why is my ice maker not making ice before assuming it is dead — scale accounts for a large share of those cases and a cleaning cycle fixes them outright.

Cleaning a Refrigerator Ice Maker

You cannot circulate a solution through a plumbed refrigerator ice maker, so the maintenance is different in kind.

Wash the bin in warm soapy water, rinse, and dry it fully before it goes back — a wet bin freezes into a solid block with the next batch. For the filter, our walkthrough on replacing a refrigerator water filter covers the models that need the supply shut off first.

Cleaning an Undercounter or Built-In Machine

Plumbed machines run continuously on whatever your water supply delivers, so they scale faster than a countertop unit that gets used in bursts. Nearly all of them have a cleaning cycle and a specified cleaner — use both. The bin also needs attention: it is refrigerated but not sterile, and a bin that is never emptied accumulates a layer of old ice and slime at the bottom.

Two things owners commonly miss. The condenser or air filter at the front needs vacuuming, because a blocked condenser makes the machine run hot and produce less ice, which people misdiagnose as a refrigeration fault. And the drain line needs flushing, because a partially blocked drain leaves standing water in the bin.

A Realistic Schedule

The single best predictor of how long a countertop ice maker lasts is whether it gets descaled. Two to four years is the realistic range for these machines, and the difference between the bottom and top of that range is mostly this maintenance — see how long do ice makers last.

Mistakes That Cause Most of the Problems

Descaling but never sanitizing. The commonest error. Vinegar makes the machine work better and does nothing about the smell.

Under-flushing. One rinse is not enough. Vinegar taste lingers in ice for days, and bleach residue is worse. Three flushes each time, minimum.

Mixing chemicals. Bleach plus vinegar produces chlorine gas. Do them as separate passes with a full flush between, every time.

Scented bleach or dish soap in the reservoir. Fragrance and surfactants stay in the plastic and end up in the ice. Unscented bleach only, and soap only on removable parts you can rinse properly.

Sealing it up wet. Storing a machine with water in the reservoir and the lid shut is the fastest way to grow a smell. Drain, dry with the lid open, then store — and store it somewhere that does not freeze, because water left in a pump can crack it.

Ignoring longer cycles. A machine that used to make ice in six minutes and now takes nine is telling you it is scaled. That is the moment to clean it, not three months later when the pump has given up.

If the Ice Still Tastes Wrong

If ice comes out cloudy after a proper clean, that is normal and it is the water rather than the machine — fast freezing traps dissolved minerals and air, and no countertop machine makes clear ice. If it tastes or smells wrong after cleaning, the cause is usually a place the cleaning missed: the underside of the lid, the drain plug seat, or the freezer itself if you are bagging ice into it. Our page on why ice tastes bad works through each source in order.

And if a machine is scaled beyond recovery — pump failed, output halved and unresponsive to descaling — the honest answer is often replacement, because pumps are rarely worth the labor on a $130 appliance. Our countertop ice maker picks and the wider ice maker roundup cover the current field, and how we rank explains how we assess it.

More from this hub: small kitchen appliances · best nugget ice maker · why is my ice maker not making ice · how to descale a coffee maker.