HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Blogs
Made by Monkeys

Dryer's Heater Element Ran Red Hot

View Comments: Threaded|Newest First|Oldest First
naperlou
User Rank
Blogger
Engineering needed
naperlou   5/30/2012 9:21:45 AM
NO RATINGS
In general the Kenmore appliances at very good.  We have a washer and dryer (gas) that have lasted a long time and work fine.  The issue that you ran into, and your suggestion, make sense.  You would think that a company that had been putting out these products for so long would have the engineering knowledge to avoid such problems.  This is especially true since it could have been a safety issue.

Rob Spiegel
User Rank
Blogger
Re: Engineering needed
Rob Spiegel   5/30/2012 1:29:31 PM
NO RATINGS
Good points, Naperlou. One of the questions would be -- how recent is this particular model? Time after time with the Made by Monkeys blog, the problems are with the newer models and their control panels.

Nancy Golden
User Rank
Platinum
Re: Engineering needed
Nancy Golden   5/30/2012 1:36:00 PM
Newer models and control panels...what does that say about this generation of engineering? You would think it would be rock solid and not subject to these issues because of the wealth of experience behind them. Control panels aren't rocket science - I find this A.puzzling and B.concerned about leaving the house if a household appliance is running...

Ann R. Thryft
User Rank
Blogger
Re: Engineering needed
Ann R. Thryft   5/30/2012 1:49:21 PM
NO RATINGS
I never leave the house when an electrical or gas appliance is running. The only exception is the wood stove, which is a lot more reliable, plus there's no off switch anyway (part of the design).

Nancy Golden
User Rank
Platinum
Re: Engineering needed
Nancy Golden   5/30/2012 2:07:53 PM
NO RATINGS
I see what you are saying Ann and it is no doubt excellent practice - but refrigerators run all of the time...and while I don't typically leave the house if appliances are running - I can't say that about the dishwasher which becomes invisible to me after the main wash cycle has completed...until a plastic spoon fell through the top basket and was lodged against the heating element when the heated dry cycle came on - between the burning smell and the smoke coming out of it - that could have ended quite badly. It really is hard to predict all of the scenarios that can happen in a household - especially with two teenagers! LOL I agree - only running appliances while you are home is safest...

Nancy Golden
User Rank
Platinum
Re: Engineering needed
Nancy Golden   5/30/2012 2:12:12 PM
And with all of the fancy electronic features that are being added all of the time, Rob - it will probably get worse. We just bought a washer a few months ago and we no longer set the water level - the washer senses it. I hate to think what will happen if the water level sensor circuitry goes out...

Ann R. Thryft
User Rank
Blogger
Re: Engineering needed
Ann R. Thryft   5/30/2012 2:51:00 PM
You're right Nancy, I should have included the fridge in my exception list. My main concern used to be the clothes dryer until I heard about all kinds of problems like the one you describe in your dishwasher. So I have a zero-tolerance policy with electric and gas appliances, with the exception of the fridge.

Rob Spiegel
User Rank
Blogger
Re: Engineering needed
Rob Spiegel   5/30/2012 2:03:20 PM
Good point, Nancy. In these Made by Monkey blogs, we regularly hear about how the families had washers and dryers for 20 or 30 years with no problem. Then they purchased a new one . . . Seems that the mechanical aspects of the appliances work just fine. But watch out for the electronics.

LloydP
User Rank
Gold
Re: Engineering needed
LloydP   5/31/2012 11:08:47 AM
I doubt that there is a "wealth of engineering knowledge" behind any of these products anymore. Most of those with that wealth of knowledge have been retired (if they are lucky), downsized, outsourced, or just plain let go. That's the way it is with the employer I retired from with 30+ years of design experience.

Both GM and Chrysler (disclaimer: I was an engineer at GM in the '80s and '90s) are now desperately trying to hire skilled engineers to repalce the ones they let go over the past 5 years. They can't find people with the skills they need, at the wages they are willing to pay.

Evan
User Rank
Iron
Re: Engineering needed
Evan   5/31/2012 12:04:14 PM
Actually, open nichrome heating elements, with their superior heat transfer characteristics,  have been used with very few problems since the electric dryer was first invented.  Before blaming the engineering (I have seen these machines in use for more than 50 years and still going strong), ask yourself about your maintenance habits.  Clothes dryers, both gas and electric, should be cleaned of lint at least once a year.  The residue of modern synthetic fabric materials that escapes around seals and clogged lint filters is much more flammable than that of cotton or wool. In reality, the cause of the problem that you describe is almost always indicative of a long-term clogged vent or lint filter.

econobiker
User Rank
Iron
Re: Engineering needed
econobiker   5/31/2012 1:37:01 PM
"In reality, the cause of the problem that you describe is almost always indicative of a long-term clogged vent or lint filter."

Very true. Don't forget to inspect the vent line for obstructions when you relocate to a new home/apartment.


Upon doing my first load of laundry in an apartment which I had just moved into, I had a brand new electric dryer run very hot (saw red coming from the coils underneath).

Upon inspection I found wadded up plastic groacery bags shoved down the vent tube to stop cold air entry during the winter.

Sad thing was that the apartment had been the complex's office until a new office/pool building was built.  That showed how much pre-inspection was NOT done by the "maintenance" person.  Had this been any other apartment with the same issue and a less than aware tenant, the issue probably would have caused a fire for the entire building.

Did the issue do damage to the dryer? I don't know.  Since the washer/dryer was provided by the management in the rent package, I did not really care. 

The dryer still worked 3 years later when I sold the units.(This was after the management removed the washer/dryer in rent provision package, I had moved to a different building and apartment unit [moving the washer and dryer under the old lease terms], and finally the complex was sold and changed management firing all the prior management maintenance/office personnel. At my final checkout inspection from the complex, the new manager said that if I didn't remove the units I would be charged a clean out fee.  Of course I said "Sorry, my friend was late to pick the washer/dryer up with his pickup." The units were removed post haste and I received my entire deposit back... )

Jon Titus
User Rank
Blogger
Check over-temp sensors, too.
Jon Titus   5/31/2012 1:43:34 PM
I have seen nichrome coils break in an electric-range oven and in a toaster. Failures happen.

I'd be surprised if the dryer didn't include thermal cut-off sensors. A company called Klixon makes a wide range of accurate thermal switches and I've seen them in dryers. When the temp gets above the switch's limit, power shuts off. The next time you open a dryer for repairs--usually a broken belt--look for temperature sensors on the exhaust tube and on the dryer compartment. They should be there.

See: http://home.howstuffworks.com/dryer6.htm

Rob Spiegel
User Rank
Blogger
Re: Engineering needed
Rob Spiegel   5/31/2012 2:43:41 PM

Good points, LloydP. In 2008, the automation industry was wringing its hands over the boomers retiring. Then the crash happened. 401s tanked and thousands of engineers put off retirement. But it has got to be a problem. I was talking to a vendor who noted that the last engineer who knew how to shut down a utility plant had retired. They had to hire the vendor to teach the control engineers how to shut down the plant.


GlennA
User Rank
Gold
Skills vs. Wages
GlennA   6/8/2012 2:30:03 PM
NO RATINGS
LloydP;  Yes.  I often hear news stories about the shortage of skilled workers.  There is no 'shortage' of skilled workers, just a shortage of skilled workers who are willing to work for the low wages offered.

Ann R. Thryft
User Rank
Blogger
Design-for-Failure?
Ann R. Thryft   5/30/2012 1:31:45 PM
NO RATINGS
Like naperlou, I've also had good experiences with Kenmore machines and I think their good reputation is well-deserved. Of course, I bought all of mine over 10 years ago, so I'm not sure how well that reputation has lasted. This Made by Monkeys makes me think that perhaps we need a new acronym: DFF (Design-For-Failure), along with all the other DFx designations. This heater layout obviously wasn't DFF-ed.

Charles Murray
User Rank
Blogger
Fire issues?
Charles Murray   5/30/2012 8:34:29 PM
NO RATINGS
I wonder if this design was notable for having any fire issues. Given the way it's described, it seems like that would be a possibility.  

TRCSr
User Rank
Silver
Clarification of original post
TRCSr   5/30/2012 11:05:32 PM
NO RATINGS
One thing that I must not have made adequately clear is that this occured over 20 years ago to a dryer that was at least 10 years old, as best I can recall at my advanced age. We have had many Kenmore appliances and for the most part they were very well built and reliable. This situation was an exception, but still an example of poor design.

Cadman-LT
User Rank
Platinum
Re: Clarification of original post
Cadman-LT   5/31/2012 9:33:32 AM
Good to hear that was an old model. I am about to purchase a new dryer. I actually hate buying new appliances all together. It seems every replacement lasts less and less than the one before it. Whether it be poor design or build quality, or that they just have more to go wrong with them.

OLD_CURMUDGEON
User Rank
Platinum
MORE comments about appliances.
OLD_CURMUDGEON   5/31/2012 10:26:22 AM
1)  The FIRST thing you must recognize is that KENMORE is a SEARS, ROEBUCK brand.  They do not manufacture appliances.  For the past 40 + (maybe 50+) years your good friends @ WHIRLPOOL have been the manufacturer of the KENMORE washers & dryers & other large appliances.  So, it is more fitting in light of the many negative posts here to blame the WHIRLPOOL CORP. for shoddy engineering / design.

2)  With the increased complexity and feature lists of modern appliances, it seems entirely reasonable that a particular model might have been designed w/ effective & high quality sensors to start, BUT when the "value engineering" group got together w/ the "bean counters", many of these sensors got "dumbed-down" in quality, ultimately leading to premature failures.  It would NOT have surprised me to be able to view the ORIGINAL design for the heating elements section and notice that there were several more ceramic standoffs in place, BUT ........

3)  We had a HAMILTON (natural) gas dryer along side a 1950s era LADY KENMORE washer, which served the needs of the family for several decades WITHOUT one hint of trouble.  The end came eventually for both but it was not after they racked up countless thousands of cycles.  The HAMILTON dryer failed for a part in the gas delivery system, but since HAMILTON had gone out of business, there were no replacement parts available.  The KENMORE washer had a totally fatigued transmission.  Although replacement parts were available, we splurged on an updated model.

ChasChas
User Rank
Platinum
not a common problem
ChasChas   5/31/2012 10:45:13 AM
NO RATINGS
 

Since this is not a common problem, I suspect an isolates assembly error or a one time faulty part. So we probably have just one Monday morning monkey.

notarboca
User Rank
Gold
Re: not a common problem
notarboca   6/6/2012 2:29:38 AM
B'gosh and B'golly I had the exact same experience with Whirlpool heating elements in the 80's.  Got sick of changing out the dryer element to the extent that I cobbled a new one out of the old ones so that it had a "proper" ceramic element distance involved. :-)

Battar
User Rank
Platinum
GFCI
Battar   5/31/2012 2:00:21 PM
Haven't you people heard of a ground fault circuit interrupter? If you had one in your main fuse box (mandatory in some enlightened countries) it would have cut the power as soon as the fault occured. (it trips when there is an imbalance in the phase and neutral currents, which would happen if current flows to ground).

Colorado Native
User Rank
Silver
Heating coils/elements
Colorado Native   5/31/2012 3:55:37 PM
I used to have a Speed Queen electric dryer, it was about 35 years old when it was pretty much just worn out after serving my parents family and then my family.  The heating coil failed three times during its lifespan, all three happened when the coil just broke and opened.  The length of each span was around 15 inches but each span was supported by two additional ceramic supports placed at the proper intervals, so it was virtually impossible for the broken wire to touch anything else.  An usupported span of 18 inches is wholly unacceptable and is asking for trouble.

The original heating element lasted nearly 25 years before breaking at a weak point in the wire.  The following two elements, same gauge and diameter coil, each lasted about 5 years because each one of them had a void in the wire which eventually failed from the thermal cycles.  A manufacturing defect.  In the larger gauge coils, such as dryer heating elements, a void in the alloy can manage to sneak through during the drawing process which is nearly impossible with finer gauge wire.

Generally, unless the wire breaks during drawing, it remains hidden, in rarer cases, the wire can also break during coil winding if the void is large enough, otherwise the coil makes its way into the finished product and there, waits to eventually fail.

William K.
User Rank
Platinum
dryer's heater element; ground fault detection.
William K.   5/31/2012 8:55:52 PM
The GFCI comment is abit off base, since in a dryer made to run on 140 volts there are several 120 volt items. Thus the GFCI would have had to monitor each side seperately, and would not have detected a draw to the neutral. Besides that, all of the large appliances usually also include a separate frame ground connection, and those that don't instead include a four conductor plug.

So don't go telling us that the only way to be safe is to mandate those GFCI devices in every breaker panel, OK? It is really offensive for municipalities to mandate all sorts of things under the premise that we are too stupid to be responsible for our own safety. 

Of course, inadequately supported heating elements is not something new to the Whirlpool company. There was a large dishwasher recall a year or so back because the heater element was not supported adequately in the plastic bottom of the dishwasher.

TRCSr
User Rank
Silver
Re: dryer's heater element; ground fault detection.
TRCSr   5/31/2012 10:34:21 PM
NO RATINGS
I would lke to reply to some of the comments made concerning my dryer overheating problem.

1. Old_Curmudgeon is correct; I should have mentioned that the monkeys that did this design were at Whirlpool, not Sears/Kenmore.

2. To Evan, and a few others that mentioned it. This was not a lint problem. The vent was always cleaned regularly and was a very short run to the outside. Also, when I took the back off of the heater compartment there was no sign of lint or dirt of any kind, other than what I would call a small amount of dust. We always cleaned the lint filter before running the dryer, and that was one of the first things I checked when the wife explained the problem to me.

3. To Jon Titus, as I said in my original post, all of the control switches, including the over-temperature sensor, were in only one side of the line. That is why half of the heater element was able to continue to be energized. The over-temperature element was actuated properly as was the control thermostat, but only on one side. The Monkey part was that the designers, or maybe the bean counters, decided that one was all that was needed. The only thing that controlled the voltage to both sides of the element was the main control switch, which was fortunate other wise the heater would have been half-on all the time.

 

 

Rob Spiegel
User Rank
Blogger
Re: dryer's heater element; ground fault detection.
Rob Spiegel   6/4/2012 3:13:14 PM
NO RATINGS
Thanks for weighing in on this, TRC Sr. It greatly enhances the value of these posts when the writer contributes comments to the discussion.

Battar
User Rank
Platinum
Re: dryer's heater element; ground fault detection.
Battar   6/6/2012 2:09:21 AM
William,

            It's not a question of being responsible for your own safety. The fault described here could have caused a fire, and a GFCI would have prevented it. A GFCI will also trip if a child sticks a wire in a mains socket and provides a path to ground for a lethal voltage. You only need one in  the main panel and they are not expensive. They are useful for protecting you from monkeys who can't design a heater element support.

William K.
User Rank
Platinum
dryer's heater element; ground fault detection.
William K.   6/6/2012 7:55:04 AM
NO RATINGS
Grounding an appliance is certainly about being responsible for your own safety, and in this area the GFCI circuit breakers are indeed relatively expensive. Those that install in an individual outlet box are less expensive, but you will not find one of them made for the 240 volt electric dryer outlets. In fact, you may not even be able to find a GFCI for 240 volt circuits. 

Besides that, in an electricly heated clothes dryer with the three wire plug, some of the components that only require 120 volts are connected between one side and the neutral, which would certainly provide a lot of unneeded tripping of a normal GFCI. A dryer with a 4 wire connection might not have that problem, but there is still the issue of finding a 240 volt, 30 or 50 amp GFCI device. 

So being responsible enough to provide an external ground connection to the dryer frame is still the way to provide adequate safety. You can not expect others to always watch out for your safety, sometimes you must do it for yourself. 

fire-iron.biz
User Rank
Gold
Roper too
fire-iron.biz   6/7/2012 1:46:55 AM
NO RATINGS
Not a long unsupported span but rather the element coils are not secured to the insulators.  Portion of the element came loose shorting to the housing, in time it overheated causing the high-limit to finally pop but it did not prevent operation of the drier.  When the motor was energized, the shorted portion of element was as well so there was no indication of failure until it caused the circuit breaker to open.  Checked the amperage finding it pulling 42a on one line and 5a on the other.  It's now repaired and modified with a different t-stat that allows for the "off" cycle to be disproportional to the "on" cycle, clothes dry in the same amount of time but the energy consumption is reduced by approximately 30%.

This unit "requires" a 3-pole/4-wire connection, however, it's a waste of time and money jumping through hoops to comply with the NEC and satisfy inspectors because the appliance mfg defeated the entire system by making an internal "common" to "equipment ground" connection.  Why are they allowed to get away with this nonsense?

Mark

bobjengr
User Rank
Platinum
DRYER
bobjengr   6/21/2012 5:43:49 PM

I retired from a major US appliance manufacturer and some of the design changes required, for the sake of the bottom line, had us all scratching our heads at times.  Even though all products in our country are approved by UL or ETL, there still exists "uncharted territory" in which design teams make the call.  More and more, the person or persons on the team have cost-cutting responsibilities and get the nod.  We engineers get the challenge.  There are two requirements I definitely applaud resulting from recent changes to applicable standards:  1.) Four-wire systems for 220 VAC inputs and 2.) Element fusing (or circuit breakers) for independent legs of 220 VAC system.     Unfortunately, these are fairly recent developments (within the last 10 years) some older appliances will not have these upgrades.

Partner Zone
More Blogs from Made by Monkeys
Made by Monkeys highlights products that somehow slipped by the QC cops.
Made by Monkeys highlights products that somehow slipped by the QC cops.
Made by Monkeys highlights products that somehow slipped by the QC cops.
Made by Monkeys highlights products that somehow slipped by the QC cops.
Made By Monkeys highlights products that somehow slipped by the QC cops.
Design News Webinar Series
12/11/2014 8:00 a.m. California / 11:00 a.m. New York
12/10/2014 8:00 a.m. California / 11:00 a.m. New York
11/19/2014 11:00 a.m. California / 2:00 p.m. New York
11/6/2014 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Jan 12 - 16, Programmable Logic - How do they do that?
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  67


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service