The housing is made of matt Cromargan Edelstahl Rostfrei (stainless steel), as WMF writes on the product page, and the manufacturer cites this metal as the reason for the machine’s sturdiness. Underneath is a filter machine with 1,000 watts, a glass carafe and exactly one button. Silver is the only colour the Amazon catalogue lists for this model.
In our price box on Amazon.de it stands at approx. €47. Every product statement in this text comes from the WMF page for the glass carafe variant (CMMF 3200000037), from the instruction manual linked there (Model 04 1215 0011), from the WMF warranty statement or from the Amazon catalogue entry for ASIN B00JJAU9FI. In four places these sources contradict each other. Where they do, the contradiction is stated here instead of us picking one of the figures. Nobody on our team has had the machine in their hands, and our rating is an editorial assessment.
Cromargan outside, a single button
The instructions list seven parts: filter lid, filter, water tank lid, water tank, water level indicator, start/stop button with indicator light and the Aroma glass carafe. That is all there is to this machine.
Tank and filter do not sit beside the carafe but above it in an upright body, and the carafe slides in from the front onto the heating plate below. In the product photo the water level indicator runs as a narrow vertical strip down the middle of the front of the housing; WMF lists it in the data sheet as a viewing window and the Amazon text as external. That is the practical difference from machines with a scale inside the tank: you see the fill level without opening the lid.
The filter insert can be removed but not swivelled. The water tank stays fixed in the machine and is filled there. The start/stop button is illuminated and, according to the instructions, glows blue as soon as preparation begins. Five further lines in the data sheet say No, and they describe the machine more precisely than any list of what it has: no 1 to 4 cup function, no swivelling filter holder, no water filter system, no adjustable warming temperature, no adjustable warming time.
The instructions and the product page give CMMF 3200000037 and Model 04 1215 0011 for this variant, plus the EAN 4211129109116. The article number 0412150011 appears in the Amazon bullet point, and the catalogue field of the same listing additionally shows the model 6130241110 and the part number 0412150011 again. That ties the listing clearly to the same article. The manufacturer is WMF Business Unit Consumer GmbH, WMF Platz 1, 73312 Geislingen an der Steige. WMF gives the item weight as 2.045 kilograms, 2.881 kilograms packed, and the package measures 33.5 by 38 by 39 centimetres. In the same field Amazon lists 4.23 pounds, by our conversion roughly 1.92 kilograms and so a good six per cent lighter. That puts the weight on the list of places where the two sources disagree, and it is the most harmless of them.
One figure on the manufacturer’s page should be read with caution: there the machine stands at 3.2 out of 5 stars from 14 reviews, and WMF notes beside it that it does not verify reviews. Fourteen voices are a thin basis for a buying decision.
How many cups really fit in the carafe?
Ten, if you take the manufacturer’s cup size, which is 125 millilitres. In litres it gets confusing. The WMF page lists an Aroma glass carafe of 0.65 litres in the scope of delivery, while the Amazon text gives 1.25 litres for ten cups for the same carafe.
Arithmetically, ten cups of 125 millilitres fit the 1.25 litres and not the 0.65 litres. We still do not fix a litre figure of our own, because the 0.65 litres come from the WMF page, the 1.25 litres from the Amazon text, and we found no third source to settle the dispute. In the product photo the carafe carries a scale with the marks 4, 6, 8 and 10, and the lid is described as a flow-through lid.
One passage in the instructions says more about volume than any data sheet. For the rinse cycle before first use and after descaling, WMF prescribes filling the tank only up to the 8-cup mark, explicitly for the glass carafe variant, otherwise the carafe could overflow. We read that this way: when brewing normally, part of the water stays behind in the coffee grounds and the paper, whereas without coffee it all arrives at the bottom. So the carafe evidently no longer holds ten cups of plain water.
For everyday use, the cup size is the more important figure anyway. 125 millilitres is a classic coffee cup and not a mug. If you drink from 200-millilitre mugs, a full carafe gives you a good six fills instead of ten.
In detail: 1,000 watts, drip stop and the 40 minutes afterwards
The product page and the instructions agree on 1,000 watts, plus 220 to 240 volts at 50 to 60 hertz and protection class I. According to the instructions the machine complies with Directives 2014/35/EU, 2014/30/EU and 2009/125/EU.
What happens after brewing is more interesting. The warming function activates automatically as soon as preparation has finished. The warming time is 40 minutes, after which the machine switches off and the start/stop button goes out. You can switch it off earlier at any time with the same button. In the data sheet the same figure appears as switching to standby mode after 40 minutes.
This is exactly where the second contradiction in the WMF data lies. The product description advertises that the warming plate keeps the coffee warm all morning long. Further down, in the technical table on the same page, Keep warm says No. We go with the figure from the instructions, because the Amazon text confirms it word for word and because a figure in minutes is more concrete than a morning.
What happens to the coffee during this time is not a quirk of this model. Finished coffee is a solution of acids, oils and roast products, and heat speeds up what continues to happen in it. That is chemistry and applies to every carafe on every plate. WMF itself describes the purpose of the function soberly: it keeps the finished coffee at serving temperature. Our recommendation follows directly: if the carafe is to stand for longer, pour the coffee into another container instead of leaving it on the plate.
One detail on the switch-off that gets lost in the Amazon title: the Automatic switch-off section in the instructions applies explicitly only to the variant with the thermal carafe. With the glass variant, switching off hangs on the end of the warming period. What the catalogue text lists as automatic switch-off is the energy-saving automatic switch-off of the warming plate, so the same thing under a different name.
You may pull out the carafe in the middle of the cycle. WMF writes that you can pour the first cup while brewing is still under way, thanks to an automatic drip stop and an overflow protection. After the carafe is removed, a drip stop valve prevents coffee from dripping on, according to the instructions. Two counter-warnings stand in the same document: during the cycle you must never swivel out the filter or open the lid, as there is a risk of scalding from escaping steam. The first part of that is standard text for the product line, since the filter holder of this model cannot be swivelled according to the data sheet at all. Preparation can be cancelled at any time with the start/stop button, and at the end you wait a few more minutes until the coffee has run completely into the carafe.
What else comes into question?
| Model | The difference | Price | Our rating | Choose this one if |
|---|---|---|---|---|
| WMF Stelio Aroma (this one) | Cromargan housing, a single button, warming ends after 40 minutes | approx. €47 | 8.5 | you want a metal housing and drink the carafe within 40 minutes |
| Russell Hobbs Textures+ (our review) | Digital timer with programmable start time, in addition to the button for start and stop | approx. €39.99 | 8.1 | you want to set a time the evening before and the Cromargan housing is not important to you |
| Braun PurShine KF 1500 (our review) | Also ten cups of about 125 ml according to Braun, material given by Braun as metal and plastic | approx. €29 | 7.9 | you want to save around €18 |
| Moccamaster KBG Select (our review) | 92 to 96 degrees brewing temperature as a manufacturer figure, copper heating element with 1,450 W | approx. €259 | 9.5 | a documented brewing temperature is worth more to you than the purchase price |
The prices are the guide values from the data sheets of our own reviews, as of September 2026, and they change daily. The rating column shows how we judge the data and equipment; nobody on our team has measured anything on these four machines.
When this machine suits and when another one does
First measure where it is going. And expect to find two sets of figures: WMF gives 30 by 34 by 15.2 centimetres (width by height by length), the Amazon bullet point 25 by 17 by 34.1 centimetres. Both agree on a height of around 34 centimetres, and there must still be room above it for the water tank lid to open. Add a rule from the instructions that scuppers many kitchen plans: the coffee machine must not be inside a cupboard during operation. A closed niche or a pull-out is therefore ruled out, even if the dimensions fit.
The second question is your morning routine. Ten cups is a lot for one household, and you cannot choose a small quantity, because this machine has no function for one to four cups. If you need a single cup in the morning, you heat the whole machine every time. Conversely, if you spread a carafe over the morning, you need an insulated flask to pour it into, or the thermal variant straight away, because the plate switches off before then.
Third question: how much do you want to adjust? The answer here is short, because apart from the one button there is nothing to operate. That is a disadvantage for anyone who likes to tweak parameters, and an advantage for anyone looking for a machine with no menu, where nothing can go wrong. Which equipment features make a difference on filter machines at all is sorted out by our guide to the drip coffee maker buying guide, and how much coffee and water you need for a given number of cups is worked out by the brew calculator.
Filter papers, coffee quantity and what running it costs
Paper filters of size 1x4, as the instructions and the Amazon text say. You fold over the sealed edge beforehand, and the filter must not protrude beyond the rim of the filter insert, so you press it down lightly by hand.
Per cup WMF calculates, depending on taste, approx. 5 to 7 grams of medium-ground coffee. It must not be ground too fine, otherwise the filter can overflow according to the instructions. Medium is therefore the only grind specification WMF gives for this machine.
The running costs can be estimated from that. A full carafe of ten cups needs 50 to 70 grams of grounds. If you brew it every day, that comes to around 18 to 25.5 kilograms of coffee a year and 365 filter papers. That is our calculation from the values in the instructions; WMF never makes it itself. According to the manufacturer the box holds three things: the filter coffee machine, the Aroma glass carafe and the water tank. A permanent filter, a measuring spoon or a trial pack of filter papers are not included.
Descaling by water hardness, and what happens if you skip it
The instructions give a table with four hardness levels, and the intervals between them are larger than most people expect: for soft water of 0 to 7 °dH (German degrees of hardness) every six months, for medium water above 7 to 14 °dH every three months, for hard water above 14 to 21 °dH every six weeks and for very hard water above 21 °dH monthly. These are guide values for daily household use. One German degree of hardness corresponds to approx. 0.18 millimoles per litre of calcium and magnesium ions. Where to get your value and what else it influences is covered in the guide to water hardness and coffee.
What WMF describes as the consequence of limescale goes beyond a slower machine: longer brewing time, lower coffee quality, energy losses and a reduced service life of the machine. If the scale layer gets too thick, the machine switches off prematurely, and then it is very hard to remove. According to the instructions, you must descale at the latest when the brewing time is considerably longer or there is more noise.
On the descaler, the manufacturer is explicit. WMF literally requires a high-quality commercially available descaler suited to the purpose, and gives the reason: suitable products contain inhibitors that protect seals and surfaces. Substances based purely on vinegar or citric acid are ruled out. There is no warranty claim for damage caused by an unsuitable product or by failing to follow the descaling instructions. The Amazon text names Cromargol as a recommended product. The procedure itself is short: insert a paper filter and place the carafe so that larger pieces of scale collect in the paper, then empty the carafe, switch the machine off and let it cool for five minutes, then run fresh tap water through to rinse. If the scaling is heavy, you repeat the process. Keep children away from descalers, and do not breathe in the vapours that arise.
How a descaling run works in general is covered in the guide to descaling and cleaning; for this machine the rest of the care is added. According to the instructions you clean the filter and glass carafe under running water. The housing itself must never go into water; it is only wiped on the outside with a damp cloth to which a little washing-up liquid is added. Harsh or abrasive cleaners are ruled out.
Spare parts, service and what WMF leaves open
Two sentences in the manual decide who stands behind a fault. The first is short: no warranty is given for glass breakage. The second draws the line wider: in cases of misuse, incorrect operation, failure to follow the descaling instructions or improper repair, WMF accepts no liability for damage, and warranty services are likewise excluded. Our assessment of this: it makes the descaling table from the previous section not a recommendation but a condition, and the glass carafe is the part for which a household is most likely to answer itself.
If something does break, the route is via an authorised WMF service point. There you hand the machine in personally or send it well packed, as the warranty statement describes. According to the instructions, a damaged power cord may in any case only be replaced by the manufacturer’s central customer service or a similarly qualified person, because improper repairs bring considerable dangers for the user. The same instructions require that you do not switch the machine on at all, or pull the mains plug immediately, if the machine or mains cable is damaged or if a defect is suspected after a fall. Customer service in Germany can be reached on +49 (0)7331 256 256.
WMF sells accessories, consumables and spare parts that the end user can replace via wmf.com. The spare parts page lists selected spare parts for coffee and tea products and advises checking the product description, series and compatibility notes before buying. We searched there for a replacement glass carafe for the Stelio series on 8 September 2026 without success. When the machine reaches the end of its life, according to the instructions it does not belong in household waste but in the collection and return systems. WMF gives the WEEE registration number DE 80399995 for this.
And here is the list of what is missing from the WMF sources we checked, gathered in one place: a brewing temperature in degrees, a brewing time for the full or half carafe, the temperature of the warming plate, the heat-up time, the noise level in decibels, the volume of the water tank in litres, the material of the lid, filter insert, water tank and controls, the cable length, the country of manufacture, the energy consumption per brewing cycle, the design of the brewing outlets, a dishwasher approval, prices for spare parts and the number of years WMF keeps spare parts available for this model. If one of these figures is at the top of your list, you are deciding on this machine without it.
Who the Stelio Aroma is built for
For households that brew a carafe of pre-ground coffee in the morning and prefer a metal housing to a plastic one, without moving up to the premium class. In our filter coffee and pour-over category that is the niche it occupies: lots of material, little electronics. That includes what the instructions tie to the power connection and what appears in no catalogue text: a correctly installed earthed socket, a dry cable and plug, an extension lead only in perfect condition, and the cable neither pulled over sharp edges nor trapped nor hanging down.
It is the wrong purchase for anyone who wants to leave a machine working unattended. The instructions prescribe operating the machine only under supervision, and they bar two popular places to put it: hot surfaces such as hobs and the vicinity of open gas flames, because the housing could melt, and water-sensitive surfaces that splashes would damage. If you put the machine in a home office and let it run in the next room, you are working against this requirement.
How the other filter machines in our catalogue stand side by side is shown by the best filter coffee makers list. And if you want to know before buying what the machine demands in operation: the instructions for use and the warranty statement are available as downloads on the WMF product page, the instructions under document number NC00905338/02.
