FreeMDU: Open-source Miele appliance diagnostic tools
github.com149 points by Medusalix 5 hours ago
149 points by Medusalix 5 hours ago
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.
This is a great project. The blog post explaining how they reverse engineered everything is a good read, too:
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)
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".
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.
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.
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.
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.
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.
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!
Yes but I suppose it is more fun to shrink someone's socks than to turn off their TV.
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.
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
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.
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.
> 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.
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.