Hello, hope you are all well despite the times we are in. Was not here for a while - busy with work and getting repairs done to the house eaves, not to mention installing a flue liner for my oil boiler and putting on 14 gallons of paint to a rough cast rendered wall - thank god its all over and looking forward to the autumn and the hiking. Interesting one on our 13 year old Miele W-1513 washer. Last 2 washes I noticed the detergent tablets in the normal (no prewash) drawer were not being dissolved into the drum, the soggy tablets still sitting in the drawer at the end of the cycle. The washer spent its first 7 years in our last house which had very hard water, then was idle for 6 months while renovating our present house (we were in a rented house with its own washer) - this idle period probably did not help as things would have dried out. Ruled out the water supply and the two filters and took the top off to investigate further (to remove top, the little caps on the front edges of the top cover are pried off carefully, the screys slackened 3 turns then pressure applied to the screws to disengage the internal clamps while lifting up the front edge and pushing backwards. Was surprised to see only one water solenoid, till I realized on further disassembly that the (over-engineered, in my opinion) method used here was a motor driven diverter. This was jammed and the discharge nozzles for the #2 drawer badly clogged with scale as well. The diverter consists of a synchronous motor (like an old timer motor) which operates the diverter valve via reduction gearing, the second-last gear incorporating contacts like a park switch on a car wiper motor which form a rudimentary encoder when in contact with the PCB in the upper cover. There are 4 positions, numbered as follows: 1:fill direct to drum via door rim 2:fill via prewash dispenser 3:fill via mainwash dispenser 4:fill via fabric conditioner dispenser. The selected number is embossed on the red gear and visible through a round opening in the diverter valve assy cover. The water from the fill solenoid enters the centre of the hollow paddle and is switched to the selected port. The paddle rotates one way only, but a synchronous motor can start in either direction, so the one-way detent/ratchet assy forces the synchronous motor to always start in the correct direction - red gear runs clockwise when viewed from top. A good descaling with a powerful toilet descaler and thorough cleaning and lubrication of the valve paddle and gear train got everything working again. Not overly impressed with the amount of plasticky over-engineeering here, it certainly does no justice to the very well built stainless steel tub/drum assembly with cast counterweights. Surely an array of separate fill solenoids would be a simpler and more reliable solution. Hope this helps someone in a similar situation. Main things to watch out for are the fragile gear train and encoder contacts and do not forget to reconnect the drum fill outlet pipe - easy to overlook.
I agree with you, it is over-engineered and overly complex for the function it is supposed to achieve... an awful lot of moving parts involved. Simple solenoid valves would be easier to implement.
Those 'feathery' contacts on the cogged wheel in photo #12... they remind me of something I've seen on here in the past... and then I realised... Didn't the original Hoover Keymatic timers have such an arrangement?
Post# 1085474 , Reply# 2 8/18/2020 at 04:26 (1,346 days old) by Rolls_rapide(.)
Forgot to add, but the interesting thing I found is that the centre row of jets on the main wash detergent dispense is not used at all on this machine. They are fed from the unused hose stub, visible on pictures #7 and #9. Looks like it was intended to use a separate water solenoid at some time, or else this dispenser was used on other models of Miele machines. In fairness to Miele, the inside of my machine looks immaculate after 13 years and the main drum assy looks to be very well built, the drum carrier bearings look as substantial as the ones on a small FWD car! Still sounds like a very smooth jet engine when the spin spools up to its max 1300 RPM. The last pic also shows the washer beside its 20 year old stablemate, a T490 vented dryer, a lovely machine that I bought second-hand in 2001, and has been flawless since. Unfortunately, it has been doing more than its usual quota of work lately due to the miserable Irish July and August 'summer' weather. As per the previous post, those fragile contacts on the gear wheel driving the diverter remind me of the 'wafer' switches used on vintage radio and TV tuners. Going by the companion PCB, they seem to give no indication of the position selected, only that they have reached that position - there are just 2 signal wires back to the Novotronic controller PCB from that encoder. Looks like it just checks how many on/off pulses it reads back as it energizes the synchronous motor to move the diverter paddle.
Comes to the Rescue!
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