12 replies to this topic

[WTA3510US]

bosch axxis series, dryer model wta3510us (type WTA3500UC)

I am not sure what part may be failing. Hopefully someone can help me troubleshoot this. Thanks.

It seems to take a long time to dry a load and it doesn't seem to be getting very hot inside (warm is probably a better description)
If i reach into the dryer after opening the door mid-cycle and touch the back vent, which the heating element sits behind, it is warm, but not hot.

I've thoroughly cleaned inside the lint trap area as well as the underneath air flow duct. Also, the airflow at the outside exhaust vent seems decent (but again the air is only warm at the exhaust, not hot).

Also, I've removed the heat element and both vacuumed it out and used compressed air to get any lint out from it.

I've cleaned the damper sensors with white vinegar per the user manual. It seems to have this problem of only getting warm regardless of whether I try a timed heat cycle or a cycle which senses the dampness/dryness.

Also, it seems to intermittently stop tumbling mid-cycle and pause momentarily and then restart. This pause can happen after 5-10 seconds, or 30 seconds, or longer. It just seems to randomly happen and happens often. in other words, it doesn't turn on constantly tumble to completion. Even if I do only a 10 minute timed heated dry cycle there will be plenty of pauses along the way.

Some google searching seems to suggest this model has an issue with the hi-limit thermostat. could that be what's going out with mine? Is it limiting the temperature too severely? Is that why the pauses happen (even though they are very brief) to allow some cooling?

Is the thermostat what I should test? I believe it's the piece with the red button in the middle

Is it also called a temperature - limiter? I was trying to find the part on repairclinic.com and couldn't find hi-limit thermostat, but did find Item # 423792 called a "limiter-temperature" but there wasn't a photo.

also, here is a link to the back assembly diagram:
http://ww2.justanswe...22457_image.gif


Are there instructions for testing it? Or should I just replace it and see? Or should I be looking elsewhere as to the source of the problem? if it was the heating element going out, would it not warm up at all? I visually inspected the heating element when I cleaned it and the coils inside looked fine to me.

I am pretty sure it's not the vent, as the airflow seems good and I tested it without the duct in place.

Or is there a temperature sensor which may be faulty? and if so, how do I test it? should the temperature sensor also be cleaned with white vinegar?


THANKS

[kdog]

Start by verifying proper voltage to outlet (120/240)

[WTA3510US]

Start by verifying proper voltage to outlet (120/240)

Thanks for the reply. It's a 4 wire receptacle on the back wall. The condo was built in 2004.
I used a small digital multimeter and at the 300 AC voltage setting, I got a steady reading of 213 volts between the 2 hot outside vertical slots, although the probe tips were a bit short so I had trouble getting a good contact, but once I had contact it would usually stay at 213 but might have fluctuated from 209 to 214.

Then I rotated the meter dial to 200 volts and between the hot and L-shaped neutral, one side read 119 and the other 120, which is what I was seeing on other outlets in the condo as well.

The fuse box on the back of the dryer says use receptacle only for 208-240 VAC washer. That is a 3 wire receptacle that the stackable washer plugs into and I checked it too and got 120 from both sides, and a 212 reading between the 2 hot slots. I also examined the 15a fuses in the fuse box and they appeared ok.

What should I check next? What other potential culprits are there?

THANKS

[WTA3510US]

I found the attached diagram and measured E2 (reading of 73) and E3 (reading of 29) so the hi-limit overheat thermostat looks to be ok.

However for the NTC R2, I couldn't get a reading between points 1 & 2. Does that mean it is defective? It appears it is supposed to be 21 ohms at room temperature.

Should I order this from repairclinic.com:

Fuse, thermal fuse or breaker Item #940343 (OEM Part) $41.40 Limiter-temperature Manufacturer Number 163297

Does that correspond to NTC R2 from the attached diagram?

How do I know it's not working properly?
Or is that supposed to be an open circuit, i.e. I wouldn't have gotten a reading.

Not sure whether to order this part or keep looking and checking other parts.

Any guidance is appreciated. Thanks.

Attached Files

•  schematic3.png   177.62K   16 downloads

[WTA3510US]

It seems to take a long time to dry a load and it doesn't seem to be getting very hot inside (warm is probably a better description)
If i reach into the dryer after opening the door mid-cycle and touch the back vent, which the heating element sits behind, it is warm, but not hot.

Also, it seems to intermittently stop tumbling mid-cycle and pause momentarily and then restart. This pause can happen after 5-10 seconds, or 30 seconds, or longer. It just seems to randomly happen and happens often. in other words, it doesn't turn on constantly tumble to completion. Even if I do only a 10 minute timed heated dry cycle there will be plenty of pauses along the way.

Wanted to add additional information to the description of what's happening. I've run some more loads recently and tried various settings and the dryer still stops briefly even if I run the "air fluff" cycle which I believe doesn't involve any heat, so this has me puzzled as to whether it's temperature / thermostat related or something else. Also, when turning on the delicates button, which I believe limits the heat, the dryer still does the frequent brief pauses. However it does stop and restart most frequently when I run the regular dry cycle where it senses the dampness. If I runned the timed cycle it stops and restarts less frequently.

[RegUS_PatOff]

Drum Motor over-heating ?

[WTA3510US]

Drum Motor over-heating ?

Thanks - perhaps I have more than 1 part failing?
The pauses are very brief - perhaps 1-2 seconds and it immediately goes back to normal tumbling speed.
And it still takes way too long to dry a load despite the brief pauses.
And when I reach inside after popping the door open mid-cycle it's just lukewarm instead of hot inside and I've tried every setting.
I could live with the brief pauses for now if it would only heat up and not take forever to complete a cycle.
It's not normal for the tumbling to pause is it? Perhaps that is something unique to Bosch and they are supposed to do that??
would posting video on youtube help?

[Joshua Scholar]

Tomorrow I'm going to see a customer who is reporting the same problem.

 

Did you get any resolution on what caused the pausing and long dry times?

[jb8103]

Motor cut out switch cuts out heater if motor shuts down

[Comstock_Services]

Are you in the US? if so that voltage seems awful low to me

[jb8103]

This is an old thread, from August 2011. We didn't help the OP much, I guess.

 

My first thought was, aside from low voltage, there's a short somewhere, because the drum motor is on the 120 VAC side and the heating element is on the 220 side.

 

My second thought was, man these Euro-schematics are a bitch to read.

[RegUS_PatOff]

... My second thought was, man these Euro-schematics are a bitch to read.

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[certified tech group 51]

Gotta recheck the model on the unit I repaired...............I just replaced both the thermostats, one is the cycling thermostat and the other is the high-limit............The dryer would test o.k., ( heat wise) for a while then the  heat would  not get hot , Kinda like clothes warmer............Reversing tumble, never timed it for cycles.........P/N's   429523 and 429522..........Verify for your model.....