Bean-to-Cup Machine Problems: Finding and Fixing Causes

The short answer: Each brand assigns its own causes to a symptom, so the fault table for your model comes before any general rule. A foreign object in the grinder is a case for the hotline and customer service with Melitta and Jura. Whether a repair is worthwhile depends on age, according to Stiftung Warentest (2018): in the first four years of use it may cost half the purchase price at most.

This guide collects faults in the machine technology itself: grinder, brew unit, milk system, water path and messages. How you set grind size, ground coffee amount and temperature for taste is covered in the guide Bean-to-cup machine settings. All details below come from the instructions for the De’Longhi Magnifica Plus (ECAM32X.6Y to 32X.7Y), the Siemens EQ600 and EQ6 plus, the Philips 4300 and 5400 series (EP5447), the Jura E6 (2026) and the Melitta CI Touch, plus authorities, studies and Stiftung Warentest. The order of causes in the tables is the order in the instructions, not a ranking by frequency.

Which cause the instructions give for which symptom

Each brand assigns different causes to a symptom. The table reproduces what the fault table of the named model says, and applies only to that model.

Start with what changes nothing on the machine, that is the spout, ground coffee chute, tank, drip tray and brew unit. Settings take effect with a delay on bean-to-cup machines (more on this shortly), so every attempt to troubleshoot via the grind size costs several cups.

Coffee drips or does not flow at all

The remedies for Siemens: if the grind is too fine, you set it coarser. With heavy scaling, you descale. You get air out of the water filter by holding the filter in the water with the opening upwards until no more bubbles rise. With a dirty machine, you clean the brew unit and descale and clean the machine. Melitta separates out two cases in which no coffee runs through at all: water tank not filled or not inserted correctly, brew unit blocked.

With the Magnifica Plus, De’Longhi has the machine itself tell you. If the grind is too fine, the display shows a message asking you to raise it by 1, and the table explains that the coffee then flows out too slowly or not at all. The same table also has the messages “Reduce the intensity” and “Reduce the amount of ground coffee”.

Anyone turning the grind setting needs to know two things. First, Philips, Siemens and De’Longhi require you to adjust the dial only while the grinder is running, as do the Nivona NICR 790 and the 2018 generation of the Jura E8 according to our evaluation for the settings guide. In the instructions for the Jura E6 (2026), the Jura E8 (2025) and the Melitta CI Touch the rule does not appear. Siemens warns of damage to the grinder, and Philips wants to prevent damage to the grinder this way. Second, a change takes time to show. Philips advises brewing 2 to 3 drinks before you taste the difference, and adjusting only one position at a time. With De’Longhi the effect shows after at least 2 coffees on the Magnifica S and Dinamica Plus, after at least 3 on the Magnifica Plus and Rivelia, and with Siemens after the second cup. The table with all machines is in the guide Bean-to-cup machine settings.

For limescale, the mechanism is documented. When heated, the hydrogen carbonates of calcium and magnesium decompose, and sparingly soluble carbonates are deposited as scale (Spektrum Lexikon der Chemie, entry on hardness). The Umweltbundesamt (German Environment Agency, as of 09.04.2024) writes for coffee machines and kettles: if the heating elements are increasingly scaled, this impedes the transfer of heat to the water, or the appliance even breaks.

Grinder loud, blocked or without ground coffee

The manufacturers describe little here. For a loud grinder, the table above gives only the foreign object, with a referral to the hotline or customer service. The Melitta instructions do not describe self-help with tweezers or a vacuum cleaner, and for De’Longhi, Siemens, Philips and Jura no procedure for clearing a blocked grinder is given. Siemens in any case allows repairs only by trained specialist staff. A sequence of steps with a vacuum cleaner, tweezers and opened covers is therefore not backed by any manufacturer, and we do not pass one on.

What is described is the area around the grinder. De’Longhi wants the ground coffee chute cleaned with a brush about once a month and the interior with a crumb vacuum, with the machine switched off and unplugged. According to the instructions, foreign objects in the chute can cause damage to the machine. With De’Longhi you always empty the coffee grounds container whenever you take out the drip tray, otherwise it fills too much and the bean-to-cup machine clogs.

If no ground coffee follows, oily beans are a documented reason. Siemens (EQ6 plus and EQ600) and Melitta list that beans that are too oily do not fall into the grinder. Remedy according to Siemens: tap the bean container lightly, change the variety, do not use oily beans, and clean the empty container with a damp cloth. Siemens also writes that unsuitable beans could block the grinder, and permits only pure, roasted espresso or bean-to-cup blends, no glazed, caramelised beans or beans treated with sugary additives. Jura names additives such as sugar, as well as ground and freeze-dried coffee, as a danger for the grinder.

The widespread advice to use medium roasts for bean-to-cup machines does not appear in any of these instructions. Siemens even recommends a darker roast if the coffee is too sour. If a machine gives trouble with a particular bean, change the variety, as Siemens and Melitta write, before you have anything changed on the machine.

Brew unit cannot be removed or inserted

Philips describes the position precisely. When inserting, the arrow on the yellow cylinder must line up with the black arrow and the N, otherwise you press the levers until the underside touches. Then you slide the unit in along the guide rails until it locks in with a click; the PUSH button stays untouched. If it cannot be removed or inserted at all, Philips attributes this to a wrong position and requires: close the service door, insert the water tank, switch the machine off and on again and wait until the drink symbols light up. To insert it, you pull the mains plug, wait 30 seconds and switch on again.

Melitta names three reasons: brew unit blocked, not locked correctly (the handle is to be checked), or drive not in the right position. For the last one, a key combination helps, after which the machine carries out an initialisation. Siemens reports “Please insert brew unit” when the brewing chamber door is inserted wrongly; you check that the brew unit is correctly inserted and firmly locked, slide the red lever at the top to the left and insert it again.

De’Longhi forbids removing the unit while the machine is switched on. It cannot be removed if switching off was not carried out properly. If it sits tightly, you bring it to the right size before inserting by pressing the two levers. It is cleaned with water only: soak for about five minutes, then rinse under the tap, and remove coffee residue at the seat with a brush. According to De’Longhi, cleaning agents could cause damage. Siemens prohibits washing-up liquid and vinegar-based or acidic cleaning agents, because improper cleaning can damage the brew unit. Philips lets the unit air-dry and not with a cloth, because of lint.

The brew unit is permanently installed in the Jura E6 and the Jura E8. There the question does not arise, and what remains is the cleaning programme; its rhythm is shown in the next section.

How often the brands require brew unit and cleaning programme

There is no uniform rhythm. Stiftung Warentest (27.07.2026) writes that many providers recommend rinsing the brew unit under running water about once a week; with a permanently installed unit, a cleaning programme takes over. The instructions and our reviews show how far apart the brands are.

Greasing is therefore not a general obligation. Philips and Saeco provide for it, the Magnifica Plus does not, and in the sources for Siemens and Jura it does not appear. Anyone who greases uses only the manufacturer’s grease; Philips also permits only its own degreasing tablets.

Our assessment: if you no longer have the instructions, weekly rinsing with water is the most cautious start for a removable unit, because Philips, and according to Stiftung Warentest many providers, do it this way, and De’Longhi gives monthly as the lower limit. The instructions for your model take priority.

Milk system: foam, temperature and hygiene

Stiftung Warentest (27.07.2026) names as daily care: empty the grounds container and drip tray, change the water in the tank and rinse the milk system, after every cappuccino or latte macchiato. Many machines have automatic milk programmes, but according to the instructions for use, individual parts should be cleaned by hand, otherwise germs can quickly build up.

A series of measurements on milk drinks from vending machines comes from the Kantonales Labor Zürich (cantonal laboratory of Zurich, notice of 07.07.2025). Of 15 samples from 2024, in 4 the number of Enterobacteriaceae was above the guideline value; the businesses concerned wanted to improve the type and frequency of cleaning. These were commercial machines in catering, at petrol stations and in institutions, and the figures cannot be transferred to household appliances. As a consequence, the laboratory names regular, thorough cleaning of the machines and good cooling of the milk.

How the brands have you clean is in their instructions and reviews:

• Siemens EQ6 plus: Despite steam rinsing (autoMilk Clean), the instructions require cleaning the milk system after every use and taking it apart by hand regularly. Hot water is only available with the milk hose removed, and milk residue can come out. The review of the EQ6 plus records this; the EQ600 cleans the system with steam after every drink.
• Jura E8: The rinse starts by itself 15 minutes after the milk drink, you take the fine-foam nozzle apart once a week according to Jura, and the milk hose and milk outlet count as wear parts that are replaced about every three months.
• Philips LatteGo 5500: no automatic milk cleaning; remove LatteGo after every milk drink, quick clean with Quick Milk Clean, then rinse or put in the dishwasher.
• Melitta CI Touch: After every milk drink the machine asks for Easy Cleaning, and once a week the milk system is cleaned.

When foam fails to appear, the tables mostly point to fit, dirt and milk. With Philips it is a wrongly assembled LatteGo; when assembled correctly, a click sounds. Jura attributes missing foam and splashing milk to a dirty fine-foam nozzle; a connector blocked by milk residue or limescale flakes you unscrew, clean and screw back on firmly by hand. De’Longhi requires milk at fridge temperature, about 5 degrees, and names water in the channel under the milk froth regulator as the reason for large bubbles.

Which milk froths is disputed. For the EQ6 plus, when there is no foam, Siemens gives as remedy cold milk with at least 1.5 per cent fat, not boiled, and does not explain why. Philips names cow’s milk (semi-skimmed or full-fat) and lactose-free milk as frothing well. In the laboratory it looks different: Ho and colleagues (2024, Food and Bioprocess Technology) refer in the introduction to earlier work according to which fat has a negative effect on foamability and foam stability. They measured themselves: at 0.5 per cent protein, skimmed milk powder dispersions foamed 16 times higher than whole milk powder and whole milk dispersions. That was a laboratory study with powders and a supermarket whole milk, not a household appliance. It does not support the reasoning behind the Siemens statement, but it cannot be transferred to the machine. You go by the type of milk your manufacturer names. Why temperature and protein determine foam formation is explained in the guide How to froth milk.

On temperature, the figures differ. Barista Eric Wolf gives 65 to 70 degrees in test 2/2018, otherwise the foam becomes coarse-bubbled. Sage recommends 60 to 65 degrees for its espresso machines, and De’Longhi gives 60 degrees as the ideal value for the Dedica (also an espresso machine). Ho and colleagues (2024, International Journal of Dairy Technology) write that with steam frothing the milk is heated to 65 to 70 degrees; their highest frothing temperature studied was 65 degrees. According to Kamath (2007), whey proteins only denature when milk is heated for one minute at 75 to 85 degrees. In 2016 the IARC classified drinks above 65 degrees as probably carcinogenic for the oesophagus, but that concerns drinking temperature and not the foam. With 60 to 70 degrees as the range, you are within what the study and the barista name.

Water under the machine, tank message and descaling

If there is water on the work surface, De’Longhi names for the Magnifica Plus first the grid of the drip tray, which was not put back after cleaning. The drip tray has a red float; you empty it before it protrudes from the cup grid, otherwise water can overflow and damage the machine or the surface. After filling the water circuit, water in the drip tray is normal; if the problem remains, you press the tank firmly down when inserting it.

Philips points to a case that many take for a defect: the machine rinses the internal circuit and the brew unit with water that flows directly into the drip tray. This is normal; if you place a cup under the hot water spout, you catch it. Real causes according to Philips are a full drip tray (empty it daily, at the latest when the indicator is red), a water tank not fully inserted, a dirty brew unit and a machine on uneven ground.

For the “Fill water tank” message despite a full tank, Siemens names seven causes for the EQ600: the tank is seated wrongly, there is carbonated water in the tank, the float in the tank is stuck, a new water filter was not rinsed according to the instructions, the filter contains air, it is old, or limescale deposits block the system. There is no mention of a sensor that becomes scaled; it is a float. With Philips, the machine does not detect an inserted filter by itself; every new AquaClean filter must be activated in the cleaning menu. After 95 litres it no longer works, and it is replaced at least every 3 months; an older filter can clog, and the coffee then runs slowly or not at all. With De’Longhi, after inserting a new filter you look in the instructions, otherwise you remove it.

When to descale is decided by the machine. De’Longhi: descale when the message appears on the start screen. Siemens reports when a service programme is due. Stiftung Warentest confirms that the machines themselves show when they should be descaled. None of these sources gives an interval in weeks; the only figure in weeks we found comes from WMF for a filter machine, not for a bean-to-cup machine. For the message to match reality, you need the correct water hardness in the menu. Siemens writes that the correct setting is important so that the machine signals in good time; you determine the hardness with the strip supplied or from your water supplier.

The supplier is obliged to tell you anyway. Under the Wasch- und Reinigungsmittelgesetz (German Detergents and Cleaning Agents Act, § 9), it must communicate the hardness range at least once a year. The law knows three ranges: soft below 1.5, medium 1.5 to 2.5 and hard above 2.5 millimoles of calcium carbonate per litre. With 1 mmol/l equal to 5.608 degrees of German hardness, that is below 8.4, 8.4 to 14 and above 14 °dH (German degrees of hardness; our own calculation). The menus divide more finely or differently: Siemens has four levels (1 to 7, 8 to 14, 15 to 21 and 22 to 30 °dH), Philips five. More in the guide Water hardness and coffee.

What descales is disputed. The Verbraucherzentrale (as of 28.04.2025) writes that kettles and coffee machines can be descaled without problems using diluted citric acid. For the EQ600, Siemens prohibits pure citric acid, vinegar-based agents and phosphoric acid, and permits only specially developed descaling tablets. Philips prohibits descalers based on sulphuric, hydrochloric or acetic acid under all circumstances, and De’Longhi permits only its own. The Umweltbundesamt warns against vinegar essence, saying it is corrosive and can damage fittings and chrome-plated parts. Here you follow the instructions for your machine, because De’Longhi expressly writes that unsuitable descalers and descaling not carried out regularly could cause defects that the manufacturer’s guarantee does not cover.

Two descalers from our reviews show the difference in chemistry. The De’Longhi EcoDecalk is a lactic acid descaler; the 500 ml is enough for five descaling runs of 100 ml each, and De’Longhi recommends it for its own coffee machines. The Durgol Swiss Espresso contains amidosulfonic acid (10 to 15 per cent according to the safety data sheet, pH below 1) and according to the manufacturer is intended for bean-to-cup machines, without a soaking time. As rinse water, the review names 1 to 2 tank fillings. Stiftung Warentest advises rinsing the machine thoroughly several times after descaling, and points out that sulfamic acid is hard to degrade and sewage treatment plants do not remove it. Amidosulfonic acid is the chemical name of the same substance. How to fit care and descaling together is described in the guide Descaling and cleaning.

Coffee is not hot enough

De’Longhi separates four reasons. The internal circuits have cooled down because two to three minutes have passed since the last preparation; a rinse then runs before the drink. The coffee temperature is set too low. The cups are not preheated. Or the machine needs descaling. Philips names a temperature that is too low (select the highest level) and a cold cup (preheat), and points out that milk always lowers the temperature. The highest level is documented as the adjustment to make.

Repair: rule of thumb, workshop and legal position

In 2018 Stiftung Warentest evaluated surveys of readers and workshops, a network of independent workshops and its own life cycle assessments. According to this, bean-to-cup machines break down after about five years on average. Their rule of thumb: in the first four years of use a repair is worthwhile up to half the purchase price at most, from the seventh year of use up to 20 per cent at most. For the fifth and sixth year there is no limit. The foundation’s worked example: with a purchase price of €810 and three repairs of around €118 each (the first after five years), the costs over ten years come out lower than without repair, with around two machines in ten years (new purchase after five years).

A lot depends on the workshop. For test 3/2021 (24.02.2021), Stiftung Warentest prepared the same faults at nine repair services for bean-to-cup machines, six manufacturer customer services and three independent workshops: a dripping water tank seal, a blocked milk frother and a cracked power cable. Only three of the nine repaired well. The seal was partly ignored, the blocked nozzle partly went unnoticed, and the power cable was very often overlooked by the services. The detailed results are behind the paywall.

What you may do yourself is governed by the manufacturers. In the EQ600 instructions, Siemens writes that repairs may only be carried out by trained specialist staff, with original spare parts. For the Grundig KVA 6230, according to the review the instructions name only an authorised specialist or customer service, and you do not open the housing yourself (electric shock). For the Saeco Xelsis, the review lists repairs by the Philips contract customer service, and for the Nivona NICR 790 flat rates of €99, €179 or €239 for the 5’ to 10’ series.

For the right to repair (Directive (EU) 2024/1799) we claim no consequence for bean-to-cup machines. The IHK Frankfurt (chamber of industry and commerce) names for Germany from 31.07.2026 a one-off extension of the limitation period by twelve months if the consumer chooses repair, and a right to repair against the manufacturer for listed product groups. Coffee machines are not on its list. How long the statutory warranty and the guarantee last is in the FAQ below.

What the sources do not provide

The gaps are collected here. We found no statistic on which fault occurs most often. For the rule of adjusting the grind setting only while the grinder is running, no instructions describe a mechanism. The instructions we read give no degree figures for the temperature levels of the bean-to-cup machines, and no source has confirmed to us that milk foam collapses above 65 degrees. We have repair prices only from 2018. Whether brew units, seals or grinders on mid-range machines can be replaced without a workshop, we found not documented; all that is documented is that the brew unit of the Xelsis (CP0683/01) is in the Philips catalogue. Whether the right to repair already applies in Germany, the IHK page does not say.

Which machine for which care effort

According to the reviews, the machines can be sorted by three ways of working. Anyone who does not want a brew unit in their hands takes a Jura with a permanently installed unit and lives with the cleaning programme. Anyone who rinses it themselves gets a removable one with Philips, Saeco, De’Longhi, Siemens, Melitta and Nivona, with the rhythms given above. For milk, the field divides on how much the machine takes over: the Siemens EQ600 cleans with steam after every drink, the Melitta CI Touch requires Easy Cleaning, the De’Longhi Dinamica Plus 380.95 requires the CLEAN cleaning on the rotary knob after every milk drink, and the Philips LatteGo 5500 has no automatic cleaning.

The De’Longhi Magnifica Plus has a LatteCrema jug that may go into the fridge with milk residue after Clean, and the Dinamica Plus 370.70 is taken apart every two days according to the review. The Rivelia reports the grounds container after 72 hours even if it is not full, and provides no cleaning tablets. The Magnifica S froths milk only by hand via the steam wand, so there is no milk system there to clog.

Anyone who can do without a milk system saves this source of faults; the Melitta Solo has none, and its fault table names dripping with a grind that is too fine. For anyone who leaves repairs to the workshop anyway, as Siemens, Grundig and the Philips contract service for the Xelsis provide, the care routine is the better criterion, because only that part lies with the user.