Bosch WTA3200 not drying on auto cycle

[Valvo]

Our 6 year old overworked dryer has stopped drying on the auto sensing cycles but works(heats) OK when set to 30 minutes manual cycle.
Wife tells me it seems to go into its cool down mode after about 10 minutes then soon stops….I’m thinking worn brushes to the sensor slip rings. Any other suggestions before I pull it apart??
Cheers ….Valvo

[Martin]

Re: Bosch WTA3200 not drying on auto cycle

I think you’re on the right track there Valvo, worth a closer look :tup:

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Hi Martin,
Sadly it doesn’t appear to be an easy quick-fix, the sensor brushes have plenty of life left in them and are nicely bearing down on the drum.
When it is set to position 3 (cupboard dry plus) it blows warm air for about 10 seconds then reverses and then blows cold, the indicator lights on the front cycle through in about 10 minutes. I notice there are relays on the controller board….are these a replacment part? Are there any other areas I can check before calling in the local Bosch boffins? (ps: I’m a telecoms tech so I can read cicuitry & have a multimeter)

regards….Valvo

[Martin]

Re: Bosch WTA3200 not drying on auto cycle

Most likely the Control Board is the fault and sadly the components on it are not individually replaceable. At least as far as Bosch and the like are concerned. If you can effect a DIY repair on that board, then that will be a bonus as replacement boards aren’t cheap 🙁

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Thanks Martin….any way of proving it’s the controller board?(other than changing with a new one) I doubt if there is anyone in Oz repairing these boards, is there a repairer in the UK?

Are these generally a reliable machine and do they have any common problems?…..We’ve certainly found it has performed well for 6 years except I suspect it overcooks when mostly polyester fabrics are being dried. What is the life expectancy for these driers?

Interestingly I notice that it seems to heat only when tumbling in a clockwise direction when set to 30 mins manual position but wifey says it is drying a load of towels in 1 hour OK on this setting.

regards…Valvo 🙁

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Martin,
Before I order a new board I figure I should check all the inputs from any other sensors besides the drum “paddles” and slip rings. I can see a probe (thermostat?) in the duct at the bottom of the door…..are there any other sensors?…..a circuit would be nice 😉

Cheers from sunny Sth Australia…..Valvo

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Time to resurrect this thread from 10 yrs ago.
The machine has worked fairly well up until now, SWHMBO used it on the timer for 6 years and then it mysteriously fixed it’s auto cycle problem.
But now it only blows hot on the clockwise cycle(very short cycle) only with the timer.
The element and 2 rear thermostats check OK so I will remove PCB and check for dry joints etc and maybe change the capacitor.
How do I test the probe mounted in the front panel airway?
Is it an NTC device?
There are a couple of brown wires from the PCB that appear to go down to this probe and it tested open cct.

cheers…Valvo
(Oh, also the fault co-incided with Aust losing the Ashes) 👿

[Martin]

Re: Bosch WTA3200 not drying on auto cycle

Its an NTC that it’s readings are in Kohms. Heat in one direction is normal.

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Thanks Martin, I’ll check the reading again and hit it with a heat gun and see if it varies.
I’m wondering if this model is a rebadged Bosch from another manufacturer(Crosley?) as it was also sold in Oz as a Kleenmaid.
From memory it heats for 2-3 mins in anti-clockwise direction, then reverses for about 20 secs….I only feel heat for the 20sec clockwise direction.

cheers….Valvo

[Martin]

Bosch WTA3200 not drying on auto cycle

A heat gun?

It is 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} Bosch made by the way. Not Crossley.

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

http://www.bosch-do-it.com.au/au/en/diy … 0-dce.html

don’t worry will set it to 75degC

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

OK I tried again and got a reading of 17k at 11degC and it dropped down to about 3k after a bit of heat.
Do those readings appear within spec?
Won’t get a chance to remove PCB until the weekend as it’s cold and dark outside by the time I arrive home at night.

cheers….Valvo

[Martin]

Re: Bosch WTA3200 not drying on auto cycle

Valvo wrote:Do those readings appear within spec?

Dunno about within spec but clearly the NTC resistance varies as the temp varies. As a new one is relatively inexpensive I would advise replacing it anyway.

[qas]

Re: Bosch WTA3200 not drying on auto cycle

Those NTC readings look about right, there is another NTC on the heater as well which should be about twice the resistance at equal temperatures as the front one.

[Valvo]

Re: Bosch WTA3200 not drying on auto cycle

Thanks qas…I’ll check it out on the weekend, I remember checking the element and cut-out thermostat were OK but not the other one.
No urgency anymore, after 30 years of Bosch in the laundry I have reluctantly joined the Miele ecosystem with basic TDA150C & WTA110 delivered.
Main complaint with Bosch/Siemens is the sealed drum and difficult (expensive in OZ) shock absorber replacement.
cheers…Valvo

[Author]

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