How to clean and descale an ice maker

These machines fail in two ways, and cleaning addresses only one of them. Descaling keeps a machine making ice at the rate it was sold as making it. Sanitising keeps the ice tasting like nothing. They are different jobs, they use different products, and doing one does not do the other.

Descaling: the performance job

Every litre of water that passes through the machine leaves behind a little of the calcium and magnesium it was carrying. That deposit builds on the coldest surfaces, which are the exact surfaces that need to transfer heat, so a scaled machine runs longer cycles, makes less ice per day and draws the same power doing it. In hard water areas the effect is noticeable within a couple of months.

1. Unplug the machine and empty the reservoir and the ice basket completely.
2. Mix a descaling solution: one part white vinegar to ten parts water is the common manufacturer instruction, or a citric acid solution at the strength the manual states. Check the manual first, because a few machines specify a proprietary solution and using vinegar in them voids the warranty.
3. Fill to the marked line and run two or three complete ice cycles, discarding all the ice. Running the cycle is the point: it circulates the solution over the freezing surfaces, which wiping cannot reach.
4. Drain fully using the drain plug underneath, not by tipping it over the sink.
5. Refill with clean water and run at least two more full cycles, discarding the ice, until there is no trace of vinegar smell. Under-rinsing is the most common complaint after a descale and the fix is simply another cycle.

Sanitising: the taste job

Biofilm grows wherever water sits still and warm, which describes the reservoir of a machine that is switched off between uses. It is what causes the musty smell people usually blame on the ice. Descaling with an acid does not remove it reliably.

• Wipe the reservoir, the lid, the basket and the scoop with warm soapy water, then rinse.
• Pay attention to the seams and the underside of the lid. Those stay damp permanently and are where the smell actually lives.
• Do not put any part in a dishwasher unless the manual says it is dishwasher safe. Most baskets and lids are not, and the heat warps them.
• Leave the lid open and let the inside dry completely before closing it up. A closed damp machine is the ideal environment for the thing you just removed.

Storage, which is where most of them die

Demand for these machines in Australia is sharply seasonal, and so is the damage. A machine used hard from November to February and then shoved in a cupboard with a centimetre of water in the base comes out in spring smelling of a pond, and sometimes with a seized pump.

1. Descale and sanitise before storing, not after. Scale left in place over months sets hard.
2. Pull the drain plug and leave it out. The residual water that a tipped machine does not release is exactly the water that causes the problem.
3. Leave the lid open for a day or two until it is completely dry inside.
4. Store it upright. Some compressor machines need to stand upright for a period before being run again after being laid on their side, and the manual will say how long.

When cleaning is not the problem

Two symptoms get blamed on cleanliness and are usually something else. Ice that comes out small or hollow is generally the mechanism working as designed rather than a fault, which is covered in what each machine actually makes. Cloudy white ice is trapped air from fast freezing, not dirt, and filtering the water changes it only slightly.

If a full descale does not restore output, the next thing worth checking is the water itself and any filter in the path, covered in water and plumbing requirements. After that it is a warranty question, and who honours a warranty in Australia varies a great deal by brand.

Common questions

How often should I clean a countertop ice maker?

Rinse the reservoir and wipe the basket weekly while it is in regular use, and run a full descale roughly monthly, sooner in a hard water area. The interval that matters more than either is the one before storage: a machine put away with water in it over winter is the single most common way these machines are ruined.

Can I use bleach in an ice maker?

Only if the manufacturer explicitly says so, and never together with vinegar or any other acid. Mixing bleach with an acid releases chlorine gas, which is genuinely dangerous in a kitchen. Most manufacturers specify a dilute white vinegar or citric acid solution instead, and bleach can attack the metal evaporator prongs in machines that use them.

Why does my ice smell or taste odd?

Usually biofilm in the reservoir or the water line rather than anything in the ice itself. It builds up in the parts that stay permanently damp, which are also the parts most people never wipe. Plastic that has absorbed odour will keep releasing it, so if a full descale and sanitise does not fix it, the reservoir itself may be the problem.

Is white residue in the water tank dangerous?

It is limescale, which is dissolved calcium and magnesium left behind as water freezes and evaporates. It is not harmful to drink, but it insulates the freezing surfaces, so a scaled machine takes longer per cycle and makes less ice for the same power. That is why descaling is a performance job and not just a cosmetic one.