Miele TwinDos detergent sensor - how it works

This video describes how a Miele washer determines if it is able to pump detergent as part of its TwinDos system.

[@btimur1]

Upvoted. How much did the technician charge you for the part and labor? Official Miele technician?

[@paulspieker7008]

This was a very interesting insight (I think TwinDos comes "dose", but I don't know). Do you by any chance know, if it's possible to get the information of whether there is still liquid in the tubes from the API of the Miele cloud?

[@nickydoes]

I looked at the API a while back. I only remember it is not too granular. It sends back the calculated % remaining for the wash reagents, from recollection.

[@rayeverett8501]

Just had to have the Platinum Sensor replace due to the error message. Total cost £252 including the 30 minutes Labour to change this plug and play part. Total and utter rip off, and I called Miele Customer Service to say exactly that. The machine still works perfectly fine with the error, but it annoyingly pops up constantly. We use powder straight into the drum before the clothes go in, and Twindos once per month. We use white vinegar instead of softener, which is far better for fabrics. Conditioner we only use on items that need waterproofing. If the sensor breaks again I am going to ignore the error messages.

[@Ivanovitchkalach]

if you have a faulty sensor, and don't want to pay for the replacement + don't care about empty tank detection, you can solder in a 120 ohm 1% resistor. That's what the stock sensor measures at room temp.

[@nickydoes]

That's doubtful to work. The sensor measures the cooling time after heating. A current is passed through the resistorm the temperature is measured. After a time, the temp is measured again. The drop in temp tells if the tube is filled with liquid or if it is empty.

[@Ivanovitchkalach]

I would think they don't actually measure the cooling time, but just have a temp threshold above which they deem it's empty, with some counting/deglitching for good measure. So my reasoning with the R120 trick is that, a "normal" (ie, low temp coefficient) resistor value won't change with the applied power (or to non-discernable ammount by the crappy adc of the 8-bit twindos mcu). Which is, even with a Pt100 probe, probably what actually happens when there is liquid in the tube. As It would probably not be very reliable to measure (and actually expect / enforce) in the code logic the slight temp elevation when the sensor is actively cooled by the detergent (plus, given the very thin leads, power must be very low and cannot really heat the detergent under resonable time) I'd expect the code logic to be something like: apply power, cut power, wait x seconds (for heat propagation through the metal tube), measure adc, adc_val > empty_threshold ? empty_cnt ++; redo that whole cycle a few time, if empty > confirmed threshold count --> actually_empty = true + warn user. Anyways, the only way to actually know if miele code is more clever than that (i'd expect not, it's an 8-bitter afterall) would be to test it :p ! And, in any case, the R120 trick might be worth the few cents it costs (vs $100+ for the original Pt100 assembly) if it works :D !

[@btimur1]

I got the dreaded F214 error which indicated issue with TwinDos 2 compartment. I replaced with brand new sensor, went smoothly. Same error. Any other ideas?

[@evermeu388]

Very interesting. I have an issue with this sensor. I think it has to do with the fact that the machine is placed on top of a dryer in a closet. I think that the cool down curve is such that the software states that it is faulty. F0 211. Could this be true?

[@nickydoes]

The common way to run these sensors is to measure the resistance, apply energy to heat, then measure the resistance again. I'm not certain how Miele implemented this sensor exactly.

[@moeity]

I'm curious... do you think the machine uses this as just a true/false kind of flow sensor, or is it able to measure flow rate as well with these?

[@nickydoes]

This is a liquid presence sensor, not a flow sensor. I presume it reports presence of air or liquid only, and does not give more information about the liquid. It is definitely not a flow rate sensor.

[@moeity]

@@nickydoes Good to know -- my unit has been overdosing detergent, and Miele recommended to the tech that they replace the platinum sensor. After watching your video, it seems like that may not be the issue if this sensor doesn't providing any flow info...

[@NicholasDeMarcoDoes]

$500, authorized tech, extended warranty is a must on Miele.

[@ozzy1337]

is there any chance to repair this part alone if it was diagnosed as faulty by miele technician?

[@UkSkin]

Also interested to know if it's repairable, It's a very expensive part to replace!

[@evermeu388]

Can it be cleaned?

[@philips170t]

This sensor erode easily by the detergent. I left the faulty sensor connected to the silicone hose and plug a new sensor to the pcb. I hope this hack will save the new sensor from contacting the detergent thus increase its longevity.

[@PaniczAdam]

I own Miele W1 since 2019 and bum - error F0212. My parents own Samsung washing machine and it works perfectly for over 10 years now. Never again Miele...

[@panino.c]

Recurrent revenue isn't strictly fair. You can use the provided refillable containers to add your own detergent.

[@nickydoes]

It's fair in the US. The UK/EU refillable containers can't fit in the US machines, and the software omits the option to select other agents. www.reddit.com/r/Miele/comments/y857p4/do_the_european_twindos_refillable_containers_fit/

[@panino.c]

@@nickydoes I stand corrected. Does beg the question as to why?! No logical sense.

[@nickydoes]

EU/GB is less tolerant of anti-competitive tie-ins? If so, it makes fiscal sense. If you find out, please share.

[@panino.c]

@@nickydoes Do you know what the difference is between US and EU/GB cartridges? I find the refillable containers are slightly different anyway and don't always register well with my machine. Also, in my opinion, I think it is probably closer linked to issues with liability in the US. If they can't regulate what people are putting in and will be held liable for damage, makes sense to restrict it.

[@bucks_in_6]

@@panino.c Im close to buying the set of Miele washer and dryers with TwinDos, and thought about the refillable cartridges. First reason was my wife really likes Tide, second reason was cost long term. If we cant get the refillable options i have seen some "hacks" where people are refilling the TwinDos cartridges with their own detergent. All of this said, i am very curious about how efficient these units are with the Miele detergent via TwinDos vs using 3rd party detergent. If its more expensive for the Twindos detergent but its more efficient in its usage, i will be fine with that. Has anyone really analyzed this from a cost perspective?