Miele WT2670 , WT2780 , WT2796 Dryer sensor problem.

[patchitos]

I am currently having a problem with the drying on a WT2780. (The other models seem to use the same system)
On timed dying everything is fine.
On sensor drying there are problems….the clothes come out hot but soaking wet….the machine behaves strangely , eg , going into a fast spin during drying program and letting in far too much water at times during drying!!
Changing the whole door has solved this in the past.
My questions.
How does the sensor drying system work?
What happens when it is faulty?
Can it be fixed or is changing the door glass the only option?.
i
It seems like a simple set up with a wire going from the metal plate at the back of the door glass to the door catch – How does this work?
Any suggestions would be much appreciated….Thank you….John.

[patchitos]

I found this.
The dampness of the laundry is sensed by electricity flowing from a carbon brush at the rear, through the drum with laundry touching the metal plate on the door. The signal passes through the door latch..
Does anone know if the carbon brush at the rear is likely to wear out or is the solution likely elsewhere?
Thanks

[electrofix]

yours is a washer dryer so things are different

its not unusual to go into spin on dry as its a energy saving feature to get as much water out by spinning

dont know hyow the door glass controls the system but if there is a sensor on the glass it must have a wire which may break by opening and closing the door

Dave

[patchitos]

Thanks Dave.
Not quite sure what you mean by “yours is a washer dryer so things are different”.

The dampness of the laundry is sensed by electricity flowing from a carbon brush at the rear, through the drum with laundry touching the metal plate on the door. The signal passes through the door latch.. – this statement is exactly specific to my machine..

I’m afraid the wire is contained within the door so cannot break by opening and closing the door.
It runs from the metal plate on the back of the door glass to the door latch (hidden by plastic) – the door interlock picks up a reading (I’ve tried changing this)

[patchitos]

Update.
I’ve got into the Service menu:). …residual moisture sensor (B3–1).
When tested.
B3-1 High resistance…..reads most of the time fault – occasionally ok.:confused:
B3-1 Low resistance….reads always fault.:(..
I’ve tried changing the small carbon brush at the rear -no difference…
I’m stuck now on how to proceed – please help.

[electrofix]

in dryers only they split the drum electrically and detect dryness. they cant do that with washer dryer as far as i know so the carbon brush may only be for static

there should be a couple of sensors one as the air enters the tub the other as it exits. they use these to detect moisure content

I am guessing a bit because Miele wont share tech info

Dave

[patchitos]

Thanks Dave.
The carbon brush runs off the drum spider spindle..

Seems like the dryness is detected electrically on these machines.!
The dampness of the laundry is sensed by electricity flowing from a carbon brush at the rear, through the drum with laundry touching the metal plate on the door. The signal passes through the door latch.

I now have the B3-1 High resistance test reading ok by tightening the nut that holds the wire to the metal plate at the back of the door glass.
The
B3-1 Low resistance test still reads fault..
I think I need the help of a Miele expert who knows these machines intimately……Please anyone?

[electrofix]

miele are pigs
they hold on to tech info like gold

which means I dont know anyone with miele info. cant even find decent pics of the door sensor to get an idea what you mean

Dave

[patchitos]

Yes – Irritating.
I’ve attaced some photos.
Excuse the first 2,…They’re from an old door I butchered.:confused:./
Now I have the B3-1 High resistance test reading ok….The machine seems to be functioning correctly. – Testing right now.
The B3-1 Low resistance test still reads fault.!!.
Hmm…..still trying to send photos.

[patchitos]

I give up.:(.

[electrofix]

got them

see what you mean now

when you say
“The B3-1 Low resistance test still reads fault.!!.”

is this in the test programme

if yes maybe you have to short out the sensor to the drum to check its being detected. get the same thin in a Beko test prog where you have to touch the sensor to prove its working

Dave

[electrofix]

well its telling you to link the contacts or remove the link to do the test

so on the low test is telling you to link out the contact to earth to check wire continuity

Dave

[patchitos]

Thank you Dave – You’re a genius..:rolleyes:
I was being dim.- not understanding what it was telling me.
I was just pressing ok in both cases..
I’ve just wired the drum to the plate on the rear of the door glass!
Hey Presto…..The low resistance test comes back …ok.
I would never have sussed it without your help.
Thank you very much.
I’m coming to know these machines quite well.:D

[electrofix]

patchitos wrote:
I’m coming to know these machines quite well.:D

you teaching me as well, not seen one yet

Dave

[electrofix]

patchitos wrote:Update.
I’ve got into the Service menu

can you post how you got into this menu as Miele will never tell anybody and its good info to have

Dave

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