FreeMDU: Open-source Miele appliance diagnostic tools | Hacker News Reader

FreeMDU: Open-source Miele appliance diagnostic tools

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334 pointsMedusalix90 comments

This is a great project. The blog post explaining how they reverse engineered everything is a good read, too:

https://medusalix.github.io/posts/miele-interface/

Great reverse engineering documentation, with colors and nice diagrams !

A really great read. Although, I now feel like I 'need' a logic analyzer, looks fun! And I'm looking forward to the firmware analysis mentioned at the end.

The good and bad news is that a USB logic analyzer is very cheap. ;)

this is the sort of thing that makes me want to buy Miele. and I'm just starting to think about buying a dishwahser as well.

Sweet mother of god. The sheer number of different skills marshalled to reverse engineer that little board is inhuman. Huge respect to the guy for all that work and the patience he had to constantly push through every failure.

This reminds me of my own troubles with my AEG washing machine.

Probably, the most important lesson (for someone who wants to fix their washing machine ASAP) that I learned from that was that there are non-userserviceable error codes and you need to perform an undocumented procedure on your machine to get those codes. I wrote about it in more detail here: https://andri.yngvason.is/repairing-the-washing-machine.html

I would have loved to have an open source diagnostics dongle for my AEG. Maybe next time I'll try and make one. :)

After having used their repair service for over 10 times for my dishwasher during its warranty period and having broken off its front handle (well, the entire front panel really) after 2 more years, I'm never buying an AEG device ever again. I opened it up and fixed it myself, and oh my god, the whole thing just screamed cost cutting. They literally used the power button of a different model or machine, and then just mounted a different power button on top that presses the underlying one. And of course the load bearing thing that holds the front panel and display onto the door frame is a just two tiny bolts in the corners. Great idea to have the entire thing flex constantly in one place. Absolute junk.

Or as my mom used to say: AEG auspacken, einschalten, geht nicht.

Which translates to: unpack, switch on, doesnt work.

She owned a couple of AEG devices and all broke immediately except the oven. AEG ovens and stove tops seem to be mostly OK for whatever reason.

It's crazy how long those reputation can last. AEG made good product 30-40 years ago, like everyone else as is was standard to build quality gear.

AEG was sold to Electrolux which produces rather mid tier equipment. They are not a part of the old German trifecta (BSH, AEG and Miele).

This is the downward spiral for a lot of brands. They sell out to an investor, who uses their brand reputation inertia, reduces cost and quality, etc. There's barely any brands left. IIRC Miele is still one of the few good brands for home appliances, but they're also significantly more expensive. At least for the initial purchase, I'm sure it evens out long term.

How new is your washing machine? Mine (US market, Electrolux branded) displays fault codes through the main 8 segment LCD and makes component tests available from that same diagnostic menu. Service literature was available directly from Electrolux — from a paid service with a free trial, although there are plenty of youtube videos covering the same information.

It's either the current or previous generation.

The blog post that I linked to answers your question.

I was able to get at the diagnostics menu (also explained in the blog), but I had to interrogate a service tech in order to learn how to trigger it (also mentioned in the blog).

The manual did not contain this information and I could not find it via Google.

Where did you sign up for the "paid service with a free trial"?

I hate that.

I had an old suv that would throw errors about the suspension.

Turns out there are lots of systems on a car that you can't diagnose with standard OBD2 readers. Same with transmission, etc.

As a matter of fact, don't know why all of this isn't easily available to the owner, not just a code, but a full message.

Ah, Miele.

When after some time the water pump on my 2014 Miele dishwasher gave up the ghost, I had a look at their parts catalogue. I had mixed feelings.

On one hand, they still produce parts for things they sold in 2008, maybe even earlier, I was looking for a pump. Very repair-friendly, very anti-ewaste. Kudos.

On the other hand, for the price they have of that pump and labor, I could buy a perfectly serviceable new midrange Bosch thing. Which I, after a short inner struggle, did. After all, the pump may have been the tip of an iceberg of more costly repairs. It's a real Apple or Porsche of home appliances — it costs a lot when you buy it, and then it keeps costing you later.

But maybe this knowledge is going to be handy with the Miele fridge I still have...

Some people love the fact that they have old appliances still running fine. I have my grandma Siemens fridge, 30 years old, still running fine. On one hand, a more efficient fridge would cost less money on the long run, but on the other hand i'm afraid to buy a lemon. So I'm patiently waiting for my Siemens to die

This is the thing, the day they stop working you wonder if you should repair them for X money or byy a new one for X / 1.5 money. Guess which wins in both time and money.

> repair them for X money

Plus (X / 1.5) * (1 - S), where S is probability of successful repair.

Plus the repair cost of the next thing to go if many parts are reaching the end of the design life (= warranty * 1.1)

Plus the cost of your time either repairing it yourself or finding someone to repair it.

> On one hand, a more efficient fridge would cost less money on the long run, but on the other hand i'm afraid to buy a lemon. So I'm patiently waiting for my Siemens to die

There's a piece of wisdom about cars and appliances that unless there's some egregious defect that turns it into infinite money sink, the least costly (and in fact the most environmentally friendly) option is to run the one you currently have until it disintegrates. Because the price of a new one is usually like your electrical bill for the current one over multiple years, adjusted for inflation and price hikes.

There are of course exceptions, but rules of thumb are never 100%.

I have a 30-year-old Frigidaire upright freezer in my basement. I'd been assuming for a while that it's wasting power due to leaked refrigerant or some such, but I borrowed a power logger from work, and whadda ya know: it's actually reasonably efficient.

The thermostat is dying, so I picked up one of those thermostat plugs with a probe on a wire. Gonna keep it as long as I can. (Plus it's the perfect size for its space, and they don't make that size any more.)

Keep the door gasket in good sealing shape (replacements are definitely available) and they will be very efficient.

(Owner of a ~90-year-old Frigidaire here.)

Could you actually buy those parts? Miele started locking down their parts to just registered Miele repair centres a few years ago, making a mockery of the right-to-repair movement (and slipping a big middle finger to business which repair a variety of brands, not exclusively Miele).

I had to call a repair guy, but first I needed to check with Miele's call center if a part was available. Replacement of the refrigerator door gaskets cost me roughly an equivalent of $400.

All Miele refrigerators (at least currently) are made by Liebherr.

what we miss is a universal control computer to control those washing machines. It is very often that part that breaks and that is "so expensive that you'd better replace the whole machine".

ah... https://www.aliexpress.com/w/wholesale-universal-washing-mac...

I’ve been having good luck buying pieces of part-outs on eBay for old appliances.

Someone will take a machine apart and list all of the pieces individually. It’s a fraction of the price of a new one. It’s a used part so it’s a gamble, but they can be so cheap I just buy two and have a spare.

If you live in a reasonably large metro area (at least in the US), there is an ecosystem of used appliance places that will often sell you parts from parted out machines. I've saved silly amounts of money this way. Dunno is that's 'better' than eBay, but you can at least inspect the part for obvious defect.

I fixed a malfunctioning refrigerator by replacing the control board, which happened to be a PIC16-based device used by many brands. This design is as close to "universal" as you can get, and this generic board was around 20% the price of the official replacement part.

https://www.ebay.com/itm/152763501102

That's because many different brands are actually made by Whirlpool. They're like the GM of the appliance industry.

It is still worthwhile to try to troubleshoot something like a washing machine these days before calling someone to service it, or buying new.

We just had a ~8 year old washer start dying with an error code, with digging it turned out it was the hall effect sensor on the drum motor that needed replacing. Cost $12 and change and was over nighted from Amazon.

What would have been nice if we got a detailed diagnostic code and not just "FE" on the front panel.

Yeah, and for service manuals to not have this "DO NOT LEAVE WITH OWNER" notes.

I replaced the heating element - twice - and the control board for the motor on my washing machine.

Never needed to touch the controller board, so my experience is different.

With a little work, it's sometimes surprising how easy things are to repair. My TV died a few years ago and just refused to power on. I don't really know much about electronics, but I assumed since there were no lights of any kind that it was probably a bad power supply. I opened it up and it turns out the power supply is a separate board with an easily detachable cable. I ordered a new one for less than $40 on eBay by looking at the part number and it only took a few minutes to replace and saved me several hundred dollars.

I'd imagine someone more familiar with electronics possibly could have figured out what specific component was wrong and replaced only that for an even smaller fraction of the cost.

Power supplies may fail in a cascading manner. Unless it's something like a fuse that was blown due to a known external event, one broken component can take out a couple of friends with it.

If you can get a new board for 40$, that's probably the best course of action.

As long as the small PCB is $40 it's fine. I had a central vacuum fail like that a couple of years ago, and the small PCB would have cost $350.

The PCB had already been replaced twice during the warranty period. Googled the major components and they were $3 - $5 a piece, just a couple of half bridge rectifiers, resistors and diodes.

Didn't want to risk a fire from a DIY job, which would have definitely voided my insurance, so I spent $400 on a new central vacuum unit (from a different brand).

Not a lawyer but I don't think home repairs void most home insurances in common law countries unless you are working with parts that are particularly dangerous, part of a safety system to protect others, and/or absolutely require a skilled professional.

I'm pretty sure that if a fire starts in my central vacuum unit, and my insurance company does an investigation that finds a DIY swap of power electronics components in that unit, I would at the very least be in a lengthy legal battle to get any money back.

That’s not true in the US, which is what the post above yours was trying to explain.

This would be a $1000 custom part in a Miele appliance though.

This. My miele door closed detector sensor broke. The part was 700 euros

I'd imagine someone more familiar with electronics possibly could have figured out what specific component was wrong and replaced only that for an even smaller fraction of the cost.

Probably electrolytic capacitors (usually in the tens of cents each, or less.) They are the #1 suspect in any electronics as they have the most well-known and finite lifespan of all parts. They became particularly infamous for failing when this happened: https://en.wikipedia.org/wiki/Capacitor_plague

The term has even created a noun in other languages: https://sv.wikipedia.org/wiki/Kondensatorpest

This was my assumption that it's a good chance that there was a failed capacitor. But at the time I didn't have a capacitance meter and I still don't have the confidence in soldering to be able to fix if that was the case.

Just replaced a £500 IKEA combi microwave because the main circuit board is just behind the grating at the top of the door which had gotten dirty and had been slightly more enthusiastically cleaned by my partner than it was designed for.

It would have been a 10 minute job to change the circuit board but I only ever found an old advent on a Polish website. Apparently it's discontinued.

I refuse to believe every model needs a completely custom main board but there you have it.

Sometimes yes, but I've also got a fair number of appliances with a cooked main CPU which I can replace, but have no hope of ever being able to get the firmware for.

I'd rather have the machine use compute running open source firmware from my tower in the next room

Ive seen these universal boards for sale on AliExpress. Always wondered how they perform.

I need a new dishwasher. I am considering a German-made Miele.

I’ve read so many horror stories. I don’t think I could consider any other brand.

Miele, Bosch, and Speed Queen do the old-school engineering based on failure analysis and have basically the same reliability as the super-simple machines from the 70s and 80s, so 20 years is a common lifespan with outliers in the 30- and 40-year range. If you adjust for inflation, you find that the super-simple machines from the 70s and 80s cost basically the same as machines from these more expensive brands, so if you care about filling landfills with broken appliances, you should probably consider purchasing them and supporting the business model.

No one would make cost-engineered stuff that fails just outside the warranty if people didn't buy it.

Speed Queen is the ONLY washer dryer brand I would consider. I currently have a Kenmore set from 2001. Works great.

Alliance Laundry which makes Speed Queen recently IPOed:

https://ir.alliancelaundry.com/news-events/press-releases/de...

Once a company goes public they tend to focus more on earnings per quarter, causing decision making to be more short-term.

Not great when, as a consumer, you hope to get a product that will last 20+ years.

Oh no... better buy one now if you have the chance.

Pass. I replaced an early 00s Whirlpool/Maytag/Kenmore top loader a few years ago and had SQ front loaders at a previous place. The top loader needed a tub that was difficult to find and expensive ($400+).

The SQs were very noisy, not super reliable, and didn't seem to clean that well. The SQs that built their reputation were the old top loaders with minimal electronics. Plenty of really obnoxious problems with the current TR series, dunno if the current TCs are as good as the old ones… and I still couldn't imagine living with one of those in my home.

The Electrolux front loader that I've got now has all the benefits of a front loader and does a good job cleaning. If I hadn't been burned by LG I'd probably consider one of their front loaders that everyone seems to fawn over.

Bosch has been making washing machines where replacing the drum bearings is not supported (the bearings are sealed in a plastic housing) for a while now, not sure if this is the case in all of the models or the cheaper ones only.

We had a Samsung dishwasher. Took exactly 5 years for it to spill water to the floor.

Now we have a Miele, as we do have their laundry machine and fridge already. The laundry machine is soon 20 years old, been doing laundry around 5-6 times every week and works still like new. The fridge is supposedly built by Liebherr. It feels really high quality: the door handle feels nice and locks the door properly. There are multiple different temperature areas that hold the temperature quite steady.

The dishwashers have certain tiers. I don't know if it makes sense to pay for the TwinDos detergent system: you can wash dishes without filling detergent. The detergent is proprietary and quite expensive. Sadly if you want to connect the dishwasher to your home assistant, that feature is only in the most expensive models. The door that opens automatically when the program is done is great though. You can do the eco program which is quite slow, but it spends the last hours just the door open, and in the morning you have clean and dry dishes with minimal water and energy use.

You can refill detergent cartridge if you want. There are sds datasheets so it's possible to select something similar

Samsung is bottom tier across the board for white goods. If it uses fire, electricity, and/or water you're best looking elsewhere. There's plenty of room to buy something decent without having to pay the full price of Miele. I do love my "old" Miele stick vac tho.

It's not that much more expensive though. And the quality just feels better. If you love to spend time in kitchen, these small details make you appreciate the time even more.

Yeah premium stuff feels nice, as it should given the price. In this case "not that much more" is somewhere north of a 50% premium over mid-range models from the leading brands. If you're cross shopping Samsung then the premium is much larger since they're constantly on deep discount due to their well earned reputation.

I paid $1,100 for my Bosch 500 series dishwasher a couple years ago. The current generation looks like it's on sale for as low as $800. Yale Appliance shows Miele dishwashers currently starting at $1,400. With that kind of premium it should feel better. And, yes, the Bosch feels super cheap.

Miele washing machines start at $1,600 about twice what an entry level LG would cost. While I would never buy an LG, they are generally well regarded in terms of actual washing performance.

We paid 1000€ for a Miele dishwasher, the cheapest model is 800€. You can get a Bosch for 500€ right now, but these are black Friday deals (the site says the original price is over 1300€, but I doubt they never sell them that expensive). Although they seem to be on sale quite often.

The Miele laundry machine was 700€ back in the days and the fridge 1400€.

So, it is not that much more expensive here in Germany.

List prices are not real when it comes to the kitchen. They exist to be „limited time“-offered.

My fridge (AEG/Frigidaire) cost about $600. I miss a couple things about my older fridge, but the current one is significantly more efficient and still maintains (durable, easily repairable) mechanical controls. There's a zero percent chance I'd find $1,000 of value in a luxury refrigerator. And a nearly 100% chance that any out of warranty repairs will be more expensive with the Miele.

Sure, for a few thousand dollars more I could get a dual compressor Bosch. Or I could spend the money on pretty much anything else. Miele is sold as a luxury brand out here and while luxury white goods are nice they command a hefty premium.

I like my Miele old school stick vac, but it was made in China just like everything else these days… and I wince every time I have to buy bags and filters for it.

bought a few years pretty much top of the line miele. works great. ability to insert cartridge and just to forget about having to add detergent for a few weeks is amazing

We’ve had our Miele dishwasher for 5 years. Running on average 1.5 times a day. It’s flawless.

Here in the UK the customer service has been amazing. The company we bought from (AO.com) installed it incorrectly (the water pipe plug wasn’t removed) they told us to get stuffed. We called Miele. They sent someone to us the next day and fixed it free of charge

>free of charge

I think you mean "included in price", and for double the price they can sure afford it.

Cautionary tale from here in UK. We had a Neff (same company as Bosch and Siemens) dishwasher which we used heavily for 10 yrs then it started to leak because they'd used plastic in the base which got warped with heat. So, ditched a perfectly running machine due to a design flaw. Replaced it with a Miele in the hope that'd be better. So got a nice-and-simple base model, about £750 I think (as opposed to £400ish you can pay for another Neff). Turns out its made in Czech, not Germany. Although apparently Germans are cynical about their own factories these days, and it may be same quality. So far, it has a design fault that the drain detector is over sensitive. If bits of food fall on the base it interpets that as its still got water in and perpetually keeps trying to drain unless you pour a jug of water in to disperse food bits. Also depending how you close the door sometimes it seems to not engage, have to open and re-shut to make it work. One of the solenoids somewhere sounds a little rattly / not totally healthy, but that may be nothing. Quality of cleaning, and ease of stacking, appears less good than the Neff was. Suffice to say, I reserve judgement on whether paying extra for a Miele is worth it. They claim they're good for 20 yrs but if you read the small print that's at only 5 runs a week or something , not every day. So it may not actually be much better than the Neff in the end. But the Neffs now look cheaper and tackier than the ones from 10 yrs ago. Not an easy decision. Our best appliance purchase ever was a "Tesco value" microwave, which is Chinese cr*p that's still running fine almost 20 yrs later. ;) Good luck with your purchase ;)

Related (but no comments yet):

Reverse Engineering the Miele Diagnostic Interface - https://news.ycombinator.com/item?id=45953572

Also:

Reverse Engineering the Miele Diagnostic Interface - https://news.ycombinator.com/item?id=44593975 - July 2025 (4 comments)

Wait, so with a strong enough IR led, someone could disrupt washing machines in their entire neighborhood?

If everyone had a Miele washing machine and put it on their front porch facing the street, maybe.

Did you know that with a strong enough LED pointed through a window into the living room they could also disrupt TVs by changing the channel or even turning them off remotely!

TV-B-Gone

https://www.tvbgone.com/

Yes but I suppose it is more fun to shrink someone's socks than to turn off their TV.

With a strong enough LED pointed through a window, you could also disrupt TVs by melting them.

No, obviously not.

Fun fact: Speed Queen also uses IrDA as a communications method on many commercial washing machines for programming and diagnostics.

They used to use a PalmPilot (and a WinMo) app. Nowadays it can be done with a PC with a weird NFC-based interface they’ve built with a wand you hold in front of the control panel in a specific location.

https://www.youtube.com/watch?v=thnxm821yco

Time for some overclocking... 10k RPM.

Stellar Work!

Tune the washing machine chip for aggressive popcorn effect on deceleration, vroooom!

Ehh, you were going to knock out those terrible worktops anyway. It's really saved you a lot of labour.

https://www.youtube.com/watch?v=vROdVsU_K80

I guessed rightly what that would be before clicking on it.

I'm both pleased and disappointed.

I love reverse engineering efforts, and like to partake myself from time to time, so I'm very happy to see this; but, for a fraction of an infra-red-wave period I thought Miele had decided to be cool and open source some diagnostic tools for everyone to benefit.

If I'm not mistaken, they were the first (and only?) to open source 3d models for vacuum cleaner accessories.

I know HN loves Miele, but they are very Apple like when it comes to repair — they don’t make their parts available to the public and since a few years neither to independent repair shops.

In contrast I had a great experience repairing a Smeg stove and buying all the necessary parts directly from them, so it’s not like it’s impossible.

> they are very Apple like when it comes to repair — they don’t make their parts available to the public

False on both counts.

Both Apple and Miele offer Self Service Repair.

Specifically in the case of Miele (since its the subject of this thread), you can buy spares directly from Miele. They openly show exploded parts diagrams on their website, and if you can't find it, you can call their parts sales number.

Yeah but also for an upright vacuum I bought they stopped selling parts less than one year after I bought it. They couldn’t even tell me the basic dimensions of the vacuum belt I needed. For a vacuum that was less than a year old.

The instant they stop selling a model, all the documentation is thoroughly whisked away and inaccessible to customers or anyone a customer can reach.

And they never gave me that kind of documentation so it’s not even something I “should have” saved myself.

> Specifically in the case of Miele (since its the subject of this thread), you can buy spares directly from Miele.

With the caveat that the prices are ridiculously high to encourage you to just buy a new one. My brand new Miele C3 vacuum cost 300 EUR and I just checked the official spare parts store you mentioned. Replacement handle is 90 EUR (not including the telescopic pipe, that's another 80 EUR, or hose, that's another 40 EUR), cable reel is 100 EUR, new motor is also 100 EUR, top plastic cover (which can't cost more than 5 EUR manufactured and delivered) costs 50 EUR, and so on.

My bad, a few years ago this was reported in the press (in the Netherlands). Maybe the regulatory framework caught up with them in the mean time.

Apple's self service repair is an absolute joke and its only purpose is to exist on paper while deterring everybody away. They will ship a pelican case of factory level equipment to your house, which you need to rent ($49/week) and pay a massive deposit for ($1200). Companies that actually want users to be able to repair their stuff will write at-home repair guides and sell minimal kits similar to what's on iFixit (e.g. tell the user to heat adhesive with their hair dryer rather than a $500 piece of commercial repair equipment)

Miele... Expensive, works great (when it does), but absolute shit customer service in the US.

One of my largest local retailers cut back on Miele in general, they had a high return rate. Miele makes a number of great products, but their customer service is so so so so so bad. Stuff like this is great to see.

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