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Kenmore 90 electric. STILL no heat

Urbansherpa

Premium Member
Joined
Nov 1, 2012
Messages
11
Location
Canada
Model Number
110.62922100
Brand
Sears Kenmore
Age
6-10 years
Kenmore Series 90. Model. 110 C62922100

A month ago wife complained no heat. I took it apart, did basic continuity test and thought the problem was the thermal cut-off. (the thermostat thing toward the back of the heating element). I replaced it, and also the hi-limit thermostat (came as a set of two pcs, $57.). I totally vacuumed the exhaust vent and every speck of lint anywhere.

It worked for a month and yesterday stopped heating again. I took it all apart and checked the thermal cut-off (TCO) for continuity. It read '1' on the ohm meter.

I read on this forum that I can bypass the TCO by simply connecting the wires.
i started the dryer, with the drum out (and belt tensioner pulled up) the heating element comes on VERY hot, glowing orange, as it should. I had previously checked the element and it's intact/perfect.

So, it worked fine when I bypassed the TCO, but when I refitted the wires the element wouldn't come on at all. I guessed the Thermal Cut-Off is blown/faulty.

i took the parts back to the shop claiming it was a faulty TCO and the owner replaced the part for me free.

Went home and replaced the good parts and dryer worked over night. Today no heat! TCO blown again.

Any ideas??? Element seems to be getting full current, i have good airflow, I'm stumped.
i can't afford to replace the $57. parts over and over.

Your help is very much appreciated

Karl
 

rickgburton

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The machine must be completely assembled for it to work correctly. If it is, then you have an air flow issue. TCO= Thermal Cut Off. There's not enough air flowing past the TCO and the heat is piling up on it and blowing it. Remove the vent hose and take it outside and give it a good cleaning. Clean out the vent outside. I've seen birds nests and critter nests that can block it. Make sure when you reinstall the vent hose that it doesn't collapse or "Kink" on you. The shorter the better. Cut off any excess.
 

Urbansherpa

Premium Member
Joined
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Messages
11
Location
Canada
The machine must be completely assembled for it to work correctly. If it is, then you have an air flow issue. TCO= Thermal Cut Off. There's not enough air flowing past the TCO and the heat is piling up on it and blowing it. Remove the vent hose and take it outside and give it a good cleaning. Clean out the vent outside. I've seen birds nests and critter nests that can block it. Make sure when you reinstall the vent hose that it doesn't collapse or "Kink" on you. The shorter the better. Cut off any excess.
I am so bloody frustrated now. Been working on this all evening and STILL NO HEAT. I pulled the whole dryer apart and vacuumed EVERYTHING....and I mean EVERYTHING inside the dryer. I pulled out all the parts and physically made sure there was NO problem with airflow. I ripped out the old ducting (it is 7' long plus an elbow top and bottom) and replaced it with the solid duct pipe (not corrugated). I took out the lint trap, and washed it with soap and brush. I replaced ANOTHER thermal cut-off, reassembled and ran the dryer. Got heat immediately, went outside to check air flow, and it was blowing a gale thru the flapper VERY STRONG AIR FLOW.
it heated for a few minutes and then NO HEAT. This is the third TCO I've blown and they're charging me $57. for the kit. (x3) Laundry is piling up and wife is screaming for a new dryer. The broken one still looks brand new. I'm sure it's a ten cent problem, but WTF?

I will entertain ANY solution as I am at my wits end. Thanks for your help.
 

rickgburton

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I will send you one. What setting were you on? When you were replacing the TCO's did you have the element housing out? Do you have a meter that can read temperatures or a meat thermometer will work. Where are you getting the TCO at? The high limit thermostat should open before the thermal cut off blows but before that the cycling thermostat should open. This is how we're going to check it; First, remove the lower front panel and use your ohmmeter to check the element terminals to ground (Element housing). Temporarily bypass the TCO by shorting the two wires together. Tape them so they don't touch anything. Take the vent hose off the dryer vent. If you have a meter that can read temperatures, clip the thermocouple to the dryer vent. If you use a meat thermometer, place it just inside the dryer vent. Dryer empty, timer on timed dry around 50 minutes (anywhere over 30 minutes is OK), high heat. Start the dryer and watch the temperatures. If it climbs over 200*F, stop the dryer and unplug it. Pull one of the wires off the cycling thermostat and check it for continuity. I have a feeling this is where the problem is going to be. Most thermostats like the thermal cut off fail to the open position. Occasionally, they stick closed and won't open. Send me an email where to send you a TCO.
 

Urbansherpa

Premium Member
Joined
Nov 1, 2012
Messages
11
Location
Canada
I will send you one. What setting were you on? When you were replacing the TCO's did you have the element housing out? Do you have a meter that can read temperatures or a meat thermometer will work. Where are you getting the TCO at? The high limit thermostat should open before the thermal cut off blows but before that the cycling thermostat should open. This is how we're going to check it; First, remove the lower front panel and use your ohmmeter to check the element terminals to ground (Element housing). Temporarily bypass the TCO by shorting the two wires together. Tape them so they don't touch anything. Take the vent hose off the dryer vent. If you have a meter that can read temperatures, clip the thermocouple to the dryer vent. If you use a meat thermometer, place it just inside the dryer vent. Dryer empty, timer on timed dry around 50 minutes (anywhere over 30 minutes is OK), high heat. Start the dryer and watch the temperatures. If it climbs over 200*F, stop the dryer and unplug it. Pull one of the wires off the cycling thermostat and check it for continuity. I have a feeling this is where the problem is going to be. Most thermostats like the thermal cut off fail to the open position. Occasionally, they stick closed and won't open. Send me an email where to send you a TCO.
Thanks for the offer of a free TCO, but I'm in Canada, so you may not wish to do the customs declaration.
the dryer is on the hottest temp setting. Although I took the element out several times, it was in when I installed the TCO. I replaced the hi-limit once on Nov2, and again 29 days later (it came as a kit with the TCO). I think wife has a meat thermometer, but I'll get one if she doesn't. The first two TCOs I purchased were at a store near home, and the third one was purchased at a different store. They are all labelled similarly. I will try the thermometer and see what the temp is. Also, I can test the cycling thermostat for continuity. Is this the same thing as an 'operating thermomostat'?

So, if I understand, the cycling thermostat is supposed to open and close, based on the temp inside the exhaust vent pipe. It opens when the temp reaches 'too hot'......but perhaps has failed, and stuck closed causing the heat to build up and not shut off......thus, tripping the TCO? (I'm trying to visualize this)
Therefore, if the cycling thermostat is faulty (stuck closed) I should get continuity? ....... or would it normally be in a closed position when tested outside of the dryer? Would a brand new one show continuity, ie 'closed position?

Thanks again for the offer to send me a free one, but I'm afraid it wouldn't get here for a week, and I need to get this done ASAP! Very kind of you, though.

Karl
 

rickgburton

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Yes, the cycling thermostat is the same as the operating thermostat. It's normally closed. You'll notice that it has two wires on the top of it. They're actually connected to an internal heater for low heat settings. The thermostat opens at 155*F. So on high heat the temperature will climb to around 170*F to 180*F (give or take 15*F). The only way you'll be able to tell if it's stuck closed is if the vent exhaust temperature exceeds 200*F and it shows continuity. Now, I'm sure you're a smart guy but I'm going to say it anyways. If you're tempted to leave that TCO bypassed to get some laundry done, you'll risk burning your house down. Here's the thermostat:

Cycling Thermostat 3387134 Order now for same day shipping. 365 day return policy. RepairClinic.com
Cycling-Thermostat-3387134-00693204.jpg

[video=youtube;5AVVv7nN5do]http://www.youtube.com/watch?feature=player_embedded&v=5AVVv7nN5do[/video]
 

Urbansherpa

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Joined
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Messages
11
Location
Canada
Yes, the cycling thermostat is the same as the operating thermostat. It's normally closed. You'll notice that it has two wires on the top of it. They're actually connected to an internal heater for low heat settings. The thermostat opens at 155*F. So on high heat the temperature will climb to around 170*F to 180*F (give or take 15*F). The only way you'll be able to tell if it's stuck closed is if the vent exhaust temperature exceeds 200*F and it shows continuity. Now, I'm sure you're a smart guy but I'm going to say it anyways. If you're tempted to leave that TCO bypassed to get some laundry done, you'll risk burning your house down. Here's the thermostat:

Cycling Thermostat 3387134 Order now for same day shipping. 365 day return policy. RepairClinic.com
View attachment 7741

[video=youtube;5AVVv7nN5do]http://www.youtube.com/watch?feature=player_embedded&v=5AVVv7nN5do[/video]

Thanks Rick, I am a smart guy. (your quote above). Also, I've been a full-time firefighter in a LARGE, industrial Canadian city for 23 years......so I know what you mean about bypassing safety controls and burning the house down!!!
i could tell you stories of stupidity that would have you rolling on the floor!

I will do the temp test and see what we get. I sent wife out to buy a new cycling thermostat, so I'll replace it anyway.
(store closes in two hours and is closed tomorrow, so if I need one I'd be SOL till Monday)

Thanks again for the very quick replies. I am truly grateful (and desperate) for the help!
 

rickgburton

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OK my friend, are you going to be able to check the element connections with an Ohmmeter? Otherwise you're just throwing parts at it and hope one fixes it.
 

Urbansherpa

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Messages
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I hear ya, Rick. I am now doing a temp test on the exhaust duct. I will check the element for continuity, too (after I pull the element out I just put the meter leads on the plug ends, right? BTW, the parts guy told me that when the element gets hot it can sag and touch the frame.... Could that contribute to this, too? ....I'll visually check that.

I just figured I'd buy the cycling thermostat this morning because if I don't then I won't be able to get one for a few days.
If the package is sealed he will take it back.

Ill let you know how the temp test goes.
 

rickgburton

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remove the lower front panel and use your ohmmeter to check the element terminals to ground (Element housing).
You don't need to remove anything, leave the element installed and connected. Check from each terminal end on the element to the element housing. You should read 1 or infinite resistance. Any other reading would indicate a short.
 

Urbansherpa

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Ok, here's what I got! I put the digital ohmmeter leads on BOTH element terminals (while the wires were hooked up to it) and it read '0.01'. I put one lead on a terminal and other lead on the housing and got '1 .' Same reading on the other terminal. I had previously inspected the element and there are NO breaks in the wire. Also, it isn't sagging and touching the housing.
I also did the temp test with meat thermometer for about 30 minutes. (drilled a small hole and slid probe inside).
Dryer cycled between 148-172*F. I watched and it was pretty consistent fot the 30 minutes. I could hear he thermostat clicking inside and could see the element cycling on/off. (laundry room lights off and I could see the glow/reflection from inside the case). Element comes on for about 1 minute, off for 1m 15s consistently.

I was hoping the temp would go over 200*F, I'd change the cycling therm and be done..... but now I'm more confused.
 

Urbansherpa

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FYI, I tried a different thermometer and the range is btween 126-165*F. Not sure hitch one is more accurate.
Should have mentioned before that element was replaced about two years ago.
 

rickgburton

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OK, that sounds right. And since that is turning the element off at the correct temperature, the TCO's you got must be from a bad batch. That does happen sometimes and is more common than you think. See if you can return them for a replacement.
 

Urbansherpa

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OK, that sounds right. And since that is turning the element off at the correct temperature, the TCO's you got must be from a bad batch. That does happen sometimes and is more common than you think. See if you can return them for a replacement.
Huh? I hear what your saying but I bought the TCOs from two different stores. I had replaced the first one a month ago (with the hi-limit), and then I went back to complain of getting a faulty one after it blew the other day (29 days later). The store guy replaced it.....it blew. Yesterday I went to a different store and bought two more. (due to the distance of store #2) The third one blew again. Thats three in a month!
i have a fourth one, but......

Unfortunately, nobody else close to me has them in stock. All I need is ONE that works!
 

rickgburton

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It must be a coincidence or maybe something wasn't right but you can clearly see the element is turning off at the right temperature and no where near the 300*F it takes to blow the thermal. The safety didn't turn off and that's 290*F so the last TCO had to be bad.
 

Urbansherpa

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Oh, OK. I wasnt sure what temp the TCO would trip at. 300* is certainly much higher than the correct operating range.
it is quite a coincidence. I guess I'll have to go for a drive Monday and see if I can track down yet ANOTHER part, from a different manufacturer.
BTW, despite two different stores the parts were all FSP brand (says regtrademark of Whirlpool!)...... So maybe they ARE from the same batch.

Anyway, thanks again for the time and effort you have given me, Rick. I appreciate all the advise I can get.
 

rickgburton

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The only other thing it could possibly be, the back end of the element housing isn't properly positioned in the hole. Make sure the screw is in the L bracket and mounted to the back wall. And the element is far enough back in the housing.
 

Urbansherpa

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I had it out last night to clean it all out and check it. I'm sure I seated it properly, but I will check again as I'm out of ideas. If, by L bracket you mean the 2-screw mount at the front of the housing then yes, it is in properly.

Thanks.
 

Urbansherpa

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Still at it! As I had already paid for the TCO and cycling thermostat i figured I'd install them. I then turned on the empty dryer with my thermometer still in the exhaust vent. Well, the thermometer got up to a high of 98*F and that was it. After running a total of about two minutes it quit heating. The temp then went down to ambient temps around 80.
I guess I've blown another TCO. (that's four now).

I then took out the TCO, bypassed it by connecting the wires and turned it on again (empty). Thermostat shows it cycling between 125-165, give or take. Also, I can hear it clicking off and on.

Would this confirm that the TCOs are ALL faulty? Kinda coincidental that I got four bad ones from two different stores.
 

rickgburton

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It doesn't seem likely that another TCO would be bad. You may need to have a tech look at it.
 
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