Dryness sensors

[akronman]

I have an electric 1975 Maytag, DE606, and a 1990 Hotpoint gas dryer, DLL2650BHL, and a 1992 Kenmore gas model, #110.97273100. In the last week or so, I have done minor repairs, also complete lint cleaning/lube/oil, had all the machines partially apart.
The Hotpoint says "Automatic Dry Control" and "Automatic Sensi-Dry," but the schematics only show temp sensors, high and lo and overlimit, nothing at all to do with moisture content. Schematic is very difficult to copy and post, sorry.

Kenmore does not say it's automatic sensing, true, but 2 of the cycles say "more dry, less dry" as opposed to timed. Again, going through the schematics, there's a fusible link and 2 temp sensors, nothing about moisture/humidity sensing at all.

The 1975 Maytag, on the other hand, has so much humidity and sensor bars in the drum, etc, it's more than my weak electrical engineering mind can fathom, but it most assuredly does excellent dryness sensing, perfectly.

Am I not understanding something in the later models, the Hotpoint and Kenmore? Is it just a marketing ploy, all cycles are actually timed only, but they re-paint the dial to make me think it's deluxe?

 

[akronman]

more

H0tpoint pic, 1990

 

[akronman]

Kenmore pic

Kenmore does not say it's AUTOMATIC SENSING anywhere, but has these "More-Less" cycles which made me believe it was moisture sensing.

 

[akronman]

Kenmore/WP dryer

Also, while we are on the dryer subject----KM/WP has run well for 2 months since I bought it($20), but I like to tune-up and de-lint all dryers, so it's apart right now. Solidly built. I think all I need to do is clean up the motor, I'm good at that,. and then just light oil on the 2 spindles for the wheels? I don't think that the drum front and back, where it rides on nylon circles( the rear bulkhead and the entire front circular assembly), need any lubing of any type. True? Any other pointers before I put it back together?

 

[appliguy]

If I am not mistaken.....

Your Kenmore and Hotpoint dryers use a thermostat in the exhaust system to monitor the temp of the air leaving the dryer in the Auto Dry and Sensi Temp cycles. How it works is when the exhaust air reaches a certain temprature in these cycles the thermostat cuts off the heat and turns on the timer. When the air cools below the trip setting of the thermostat the thermostat turns on the heat and turns off the timer. This keeps happening until the timer hits the cool down portion of the cycle at which time the timer runs another 5 to 10 minutes with the heat off to make the clothes easier to handle. That is also why you have a range between More Dry and Less Dry....so you can dial the degree of dryness you want. The closer to More Dry you set the dial the longer the dryer  will take the to reach the cool down portion of the cycle If I am mistaken guys please let me know....PAT COFFEY

 

 

[akronman]

Thanks Appliguy

News to me, and a good explanation, thanks. I can see how, at the exact same spot on the dial, a full load of thick towels would take longer than a small load of 6 boxers. Also, why I should choose MORE for those towels. Both of those dryers work perfectly well, but it surprised me to find no moisture sensing devices whatsoever when I got inside. I also have an 07 Kenmore 800 TOL dryer, it specifically says "Automatic Moisture Minder Plus", so I am betting it really does have humidity sensing. But I de-linted it a few months ago and paid no attention, so I'm not about to open her up soon to see. Still, the 1975 DE606 is the only one of all 4 where I can be assured, on "Heavy," that everything will be totally bone dry.

Thanks again for your input, it helps me know how to get best and most efficient results--
Mark

 

[DADoES]

 
Thermostatic auto-dry came into use some years before moisture-sensing systems were developed.  Evaporating moisture in the exhaust holds the air temp down, so a wet load runs more heat and less timer at the start, then segues toward less heat (although the target temp remains the same) and more timer as the items dry.  External factors, such as running the dryer in a very cold or very hot room, can have an effect on performance accuracy and consistency ... which factors have less effect on the moisture-sensing method.

 

[appliguy]

I also have an 07 Kenmore 800 TOL dryer, it specifically say

If this dryer has the lint screen on back right corner of the top of cabinet the moisture sensor would be at the 4 o clock position on the bulk head at the rear of the dryer drum. If it has the lint screen inside the door the sensor is right below the grate that covers the lint screen (if you stick your head in the dryer drum you can see it)......PAT COFFEY

 

[kenmore71]

In case you are wondering how the Maytag Halo-of-Heat dyrness sensing system works in a very "technical" way, I did a pretty thorough explanation of it a few weeks ago in this thread:

Maytag DG606 Capacitor

Hi, My vintage Maytag DG606 does not shut off after it's activated. The heat cycles correctly so I'm certain that the thermostats are working correctly. The dryer has an electronic controller in it that has a large capacitor on the outside. I was able to test the components inside the...

www.automaticwasher.org

 

[macboy91si]

Hotpoint Dryer

I have this very same dryer in electric and it has sensors in the front of the drum (2). Mark, feel around on the other side of the lint filter for 2 nubs. I always thought these were electronic? I don't recall mine having anything in the exhaust stream. Just the sensors in the drum.

-Tim

 

[akronman]

Thank you

Kenmoreguy--- I read your entire post when it was new, and reread it now. Electronically over my head, but helpful in knowing what to expect from my DE606, and it keeps me praying I don't have trouble there, thanks.

Appliguy----stuck my head in, yes the moisture sensor is at the right-side base of the front lint screen grille. I'm glad for ALL responses, lets me know best about each different system's operation.

So the 75 Maytag and 07 Kenmore are genuine moisture sensing, the 90 Hoptoint and 92 Kenmore are thermostatically controlled timer designs.

Also---I have a 1960 Whirlpool Washer, 29" wide, and this 1992 Kenmore/Whirlpool dryer, 32 years later, is still a 29" wide machine! In some small way, a matched set, and thank god for big old ugly basements with tons of space.

 

[akronman]

Hey Macboi

Tim----Yes, the Hotpoint has 2 thermostats right as the filter comes out of its slot. One is High temp cycling, the other is lo-temp, nothing to do with humidity/moisture. Also, another high-limit cut-off thermostat just beyond the burner. So plenty of temp sensing, hi- and low and over-limit, but nothing at all for moisture humidity. KM/WP of mine is the same, thermostats and a over-limit fusible link, no moisture sensors.

I really like the inside of the Whirlpools, looks like they are built to last and no trouble to align and reseat the drum and great quiet turning. The Hotpoint, with new glides/guides, proper lube per service manual, etc, still seems to need fine-tuning and alignment of the front assembly to get it sort-of quiet again, keeps wanting to do a slight scrape on the left side of the inner opening. I have to have it running, top open, and carefully tighten the upper left side tinnerman bolt while pressing all my weight against the left side of the cabinet to keep it quiet, more an art than an engineered science. It runs and it dries, I just can't imagine it's as trouble-free or long lasting a design as the Whirlpool/KM. Oh well, it was $20 and needed only $30 total in parts, igniter and glides

 

[DADoES]

 
<blockquote>... feel around on the other side of the lint filter for 2 nubs.</blockquote>Per a parts diagram on model DLL2650BHL, the high- and low-temp thermostats are mounted in the filter duct.
#272 (142°F)
#273 (135°F)