Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Limescale builds up inside any machine that heats water, and in a coffee machine it shows up as slower brewing, a cooler drink, a noisier pump and eventually a machine that stops. Descaling is the routine that dissolves it out again. The cycle itself is mostly waiting, takes about fifty minutes including the rinses, and needs no tools at all.
The one decision that matters is which descaling agent to put in, and this is where the manufacturers genuinely contradict each other rather than merely differing in wording. Hamilton Beach tells you to pour plain white vinegar into the reservoir of its coffee makers. De'Longhi says vinegar and the other kitchen-cupboard acids can corrode the machine and leave a taste behind, and tells you to use its own descaler. Breville says to use a shop-bought solution, then gives a vinegar ratio anyway, and finishes by telling you to consult your own manual. This page does not average those three into a house recommendation, because there is no such thing: what one maker publishes as routine maintenance, another publishes as a cause of corrosion. It tells you where to look, and what each maker actually said.
| Item | Note |
|---|---|
| Large container | The container must hold the full quantity of the water tank. |
| Damp cloth | For the outside surfaces of the machine. |
| Measuring jug optional | The documentation gives the quantity in a unit that a jug shows. |
| Descaling agent material | Use only the agent that the documentation for your machine names. |
| Clean water material | Soft water or filtered water decreases the rate of limescale. |
Estimated 7 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
READ THE DOCUMENTATION BEFORE YOU SELECT A DESCALING AGENT.
An incorrect agent can cause corrosion in the machine.
Estimated 4 min
Estimated 20 min to 34 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
KEEP THE DESCALING AGENT AWAY FROM CHILDREN AND ANIMALS.
The agent is an acid and can cause an injury.
DO NOT PUT COFFEE IN THE MACHINE FOR THE DESCALE CYCLE.
The descaling agent makes the coffee unfit to drink.
DO NOT TOUCH THE LIQUID FROM THE MACHINE DURING THE CYCLE.
The liquid is hot and can burn your skin.
KEEP YOUR HAND AWAY FROM THE STEAM PIPE.
Steam and hot liquid can burn your skin.
Estimated 12 min to 16 min
RINSE THE MACHINE AFTER THE DESCALE CYCLE.
Some descaling agent stays in the machine. This agent gives the first drinks a bad taste.
Estimated 6 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
Do not use a descaling agent that the documentation for your machine does not name. De'Longhi says that vinegar and the other home acids can cause corrosion.
Stop if the machine shows the descale message again after two full procedures. A blockage that stays is not part of this procedure. Speak to the manufacturer.
Stop if liquid flows from the body of the machine. Disconnect the machine from the power supply. Speak to the manufacturer.
Do not open the body of the machine. Only a qualified technician must do work inside a coffee machine.
It depends entirely on who made it, and this is the one question on the topic where the manufacturers flatly contradict each other. Hamilton Beach tells you to pour plain white vinegar into the reservoir of its coffee makers and gives quantities for it. De'Longhi says the opposite: that DIY methods such as lemon juice, baking powder or vinegar can incur corrosion and leave behind a lingering aftertaste and residue of their own, and points you at its own descaler instead. Breville sits in between, saying you should always use a store-bought espresso cleaning solution but giving a vinegar ratio anyway. We are not going to pick a winner, because the answer is a property of your machine and not of the question. Read what your maker says and do that.
Hamilton Beach gives a calendar: monthly for a machine used every day, and as often as weekly in a hard water area for one of its models. De'Longhi gives no calendar at all and instead tells you to test your water hardness, set the machine to the right level and let the machine tell you. Both are reasonable, and the reason they differ is that the real variable is your water rather than your machine. If your water leaves white marks in the kettle, descale more often than any schedule says.
Whatever your own documentation says, and this page deliberately prints no general figure. Hamilton Beach alone gives three different answers for three of its own machines: one pint of undiluted white vinegar for a drip maker, 14 ounces of undiluted vinegar for one single-serve model, and half a cup of vinegar with half a cup of water for another. Breville gives one part water to one part vinegar. Those are different concentrations for different machines, so there is no number here that would be safe to copy across.
De'Longhi is the manufacturer that states the case most directly: its concern with the kitchen-cupboard acids is corrosion inside the machine, plus an aftertaste and a residue that stay behind afterwards. That is the claim this page can stand behind, because it is what De'Longhi actually publishes. What we will not tell you is how your own warranty treats it, because that is a question for your warranty document and your maker, not for us. If the machine is still under warranty, the named product is the safe choice for that reason alone.
Limescale is the usual reason on any machine more than a year or two old, especially in a hard water area. The deposit narrows the water path and coats the heating element, so the machine takes longer, delivers less, and runs cooler. Machines with a descale warning light will usually have been asking for a while by the time you notice the symptom.
Less often, but not never. Filtering reduces the minerals that form scale rather than eliminating them, which is why De'Longhi recommends its own water filter specifically as a way to lengthen the gap between descales rather than to remove the need. Keep to whatever interval your documentation gives and treat filtered water as a bonus.
Smell and taste. Hamilton Beach's own guidance for its machines is two to three full cycles of cold tap water after the vinegar, and that is a reasonable floor for any machine. Keep going until there is no smell of the descaling agent in the water, then make one drink and throw it away. If that drink still tastes wrong, rinse again.
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
Current version 1 · updated 2026-07-29 · next review due 2027-07-29
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