Kenmore dryer thermal cut-off popped again

This is the third thermal cut-off that's gone out in the past few months. We're about ready to toss the dryer and buy a new one (and stay as far away from Kenmore as possible). Here's our Kenmore saga:
Almost two years ago the heating element in our first Kenmore dryer went out (it was 6 years old). The unit would spin, just no heat. The element was replaced. About a month later the dryer wouldn't even start spinning. We bought a new Kenmore dryer shortly thereafter thinking the first was a lemon.
Fast forward one year to Oct2005. At 16 months old, the new dryer stopped heating. It would spin but there was no heat. I tested the various heating canister parts and discovered that the hi-temp cutoff device was open-circuited (everything else was fine). Here's a thread on that incident:
http://groups.google.com/group/alt.home.repair/browse_thread/thread/3f718ba2ba9f3b87
Everything seemed to be fine until Jan2006 when the exact same thing happened: http://groups.google.com/group/alt.home.repair/browse_thread/thread/307a3c26a98d1c69
So I replaced the cutoff switch again and cleaned out the dryer vent with a "toilet snake" device. There was quite a bit of lint build-up but nothing extreme. I figured that this would solve the problem once and for all. Yeah, right.
A few days ago, the dryer wouldn't heat again. Yep, same part went out. The guys at the appliance parts store told me repeatedly that the vent is blocked and causing the overheating. They said to run a leaf blower in it to clear out any blockage. Well, I just did that and there was no big chunk of lint that came out. I simply don't think lint build-up is the problem.
How do these damn dryers work? For example:
1) There are various temperature settings on the unit (Cotton-high heat, etc.). Does the dryer controller use the main thermostat to sense the temperature and turn on the coil when it needs more heat? What happens if this main thermostat underestimates the temperature, will it overheat the unit and blow the cutoff switch?
2) Could the heating element stay on too long after the dryer shuts off? I could see this blowing the cutoff switch due to lack of circulation.
3) Regardless of the exact cause, why isn't the resettable temperature cutoff triggering **first** and preventing the non-resettable one from blowing. Makes no sense to me. I believe the guys at the parts store said there's a 100deg temperature difference between their triggers.
4) Could the heating element be too close to the cutout switch?
For reference, there are three devices attached to the heating element can: the main thermostat, the resettable cutoff switch, and the nonresettable cutoff switch. They're aligned from front to back in that order.
Any help would be appreciated. Mike
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Mike, I had the same problem with my Kenmore dryer shortly after I bought it (about 3-4 years ago), they keep telling me the vent was plugged, I cleaned it as you have done. Problem reoccurred. Same technician said the vent was still plugged. I called the service center back, and told them to send out another technician that knew what he was doing. Next tech, came out and tested the controller board. It was defective, replace it and have had no problem since. Good Luck.

away
out
incident:
http://groups.google.com/group/alt.home.repair/browse_thread/thread/3f718ba2ba9f3b87
http://groups.google.com/group/alt.home.repair/browse_thread/thread/307a3c26a98d1c69
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Yeah,
The
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can:
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mikegi wrote:

http://groups.google.com/group/alt.home.repair/browse_thread/thread/3f718ba2ba9f3b87
http://groups.google.com/group/alt.home.repair/browse_thread/thread/307a3c26a98d1c69
Non-resettable? Are you talking about a thermal fuse? If so, then yes, look at the temperature sensor, or the heating element. More likely the sensor.
--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
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I don't know the exact terminology. The thing I've been installing is a two part kit ( #279769 ):
http://shop.store.yahoo.com/buyitnow64/wh27hitethki.html
I replace both parts even though the fuse part is the one that open-circuits.
The guys at the appliance parts store said that the thermostat part is supposed to keep the element from overheating (ie. the fuse is basically a last ditch safety device).
Rick Bryson's post makes sense to me. The dryer controller is screwed up and not handling the temperature sensors properly (not all the time, just occasionally). This lets the element overheat and pop the cutoff fuse.
I'm not willing to put another dime into this Kenmore crap. I'll throw in the new cutoff kit today and start looking for another brand of dryer. When this Kenmore crap dies again, I'll toss it and get a different brand. I have better things to do with my life than babysit the sh*t Kenmore sells...
Thanks, Mike
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Hi,
Is the element grounded or grounding to the frame and possibly staying on? A bad operating thermostat ( or coated with junk ) can cause too high of temps and allow the thermal cut off to open up. A vent may be clean but could also be too long or have too many elbows and cause problems.
jeff. Appliance Repair Aid http://www.applianceaid.com /
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