how do dryer controls work?
 

I have a very old clothes dryer, a Kenmore that I'm pretty sure is
made by Whirlpool, that has never given me any trouble, and maybe it's
time to ask 2 questions about it.

1) The machine has a device to turn the dryer off when the clothes are
the desired dryness. You point the dryness knob to the chosen dryness
and turn on the dryer. But then the knob rotates and the pointer
moves. How does the dryer know where I set it? I can move it
clockwise and counter clockwise at any time. Sometimes I've moved it
CW to make it stop soon, but if that new position had been the
original position, it should have stopped already, and yet it
continues to run after I move the knob far clockwise. How does this
all work?

2) For the last 40 years, at the laundromat and with my own machine, I
always dry clothes on the lowest temperature that is warmer than fresh
air. I also usually take the clothes out when they aren't quite dry,
so they also aren't really hot yet.

But the air with this machine, even on gentle, must be a lot hotter
than gentle. Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. I'm
afraid to try the next temp up, because I think that hot air is bad
for everything but 100% cotton, and I always have elastic, polyester,
nylon, or other fabrics in the load. I don't think I'd be successful
trying to measure the air temp, but would you all describe the heat on
"gentle" as still pretty hot?

how do dryer controls work?
 

mm wrote:

1) The machine has a device to turn the dryer off when the clothes are
the desired dryness. You point the dryness knob to the chosen dryness
and turn on the dryer. But then the knob rotates and the pointer
moves. How does the dryer know where I set it?

With the "auto dry" feature, the timer advances in relation to the
demand for heat. The heater has two levels -- on and off. When the
dryer starts, the heater is on until the exhaust reaches a predetermined
temperature, then the heat stays off until the exhaust reaches a cool
point and the cycle repeats. The timer advances only when there's no
demand for heat. With a wet load, heat is lost in the moisture, so more
heat is necessary. As it drys, there is less opportunity for heat loss.

...But the air with this machine, even on gentle, must be a lot hotter
than gentle. Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. I'm
afraid to try the next temp up...

Is this different from what you experienced before? If the dryer has a
switch to select between two or more heat levels, is could be stuck at
the hot setting. In some dryers the low setting is determined with a
resistor near the thermostat that warms up to "fool" the thermostat into
opening (shutting off heat) at a lower temperature.

how do dryer controls work?
 

On Sun, 02 Mar 2008 06:36:24 GMT, Bob wrote:

mm wrote:

1) The machine has a device to turn the dryer off when the clothes are
the desired dryness. You point the dryness knob to the chosen dryness
and turn on the dryer. But then the knob rotates and the pointer
moves. How does the dryer know where I set it?

With the "auto dry" feature, the timer advances in relation to the
demand for heat. The heater has two levels -- on and off. When the
dryer starts, the heater is on until the exhaust reaches a predetermined
temperature, then the heat stays off until the exhaust reaches a cool
point and the cycle repeats. The timer advances only when there's no
demand for heat. With a wet load, heat is lost in the moisture, so more
heat is necessary. As it drys, there is less opportunity for heat loss.

I'll have to cogitate on this. :)

...But the air with this machine, even on gentle, must be a lot hotter
than gentle. Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. I'm
afraid to try the next temp up...

Is this different from what you experienced before? If the dryer has a

No. I should have said that explicitly. It's always been this hot,
and as long as I get there, or as long as the dryness setting makes it
stop, before it is totally dry, everything is fine. A couple times
that didnt' happen, and the clothes would be very hot, and the shirts
needed ironing etc. No clothese were ruined yet, but since I no
longer iron, I looked pretty wrinkled (until my body humidity and
warmth fixed the shirts while I was wearing them (except I don't think
I warm the collars.) So I've always thought something might be wrong.

switch to select between two or more heat levels, is could be stuck at
the hot setting.

Aha. (Slaps forehead)

In some dryers the low setting is determined with a
resistor near the thermostat that warms up to "fool" the thermostat into
opening (shutting off heat) at a lower temperature.

Uh-huh.

OK. Now it's on my list to take it apart and check for problems with
whatever of these this dryer uses.

how do dryer controls work?
 

On Sun, 02 Mar 2008 06:36:24 GMT, Bob wrote:

And thanks.

how do dryer controls work?
 

"mm" wrote in message
...
I have a very old clothes dryer, a Kenmore that I'm pretty sure is
made by Whirlpool, that has never given me any trouble, and maybe it's
time to ask 2 questions about it.
..................................................
But the air with this machine, even on gentle, must be a lot hotter
than gentle. Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. I'm
afraid to try the next temp up, because I think that hot air is bad
for everything but 100% cotton, and I always have elastic, polyester,
nylon, or other fabrics in the load. I don't think I'd be successful
trying to measure the air temp, but would you all describe the heat on
"gentle" as still pretty hot?

We have an old Kenmore elec. dryer (circa 1990), and several years ago when
troubleshooting and replacing one of the thermostats, I measured the
temperatures on the various temp. ranges running the dryer empty.
The low temp. had a cut-in temp. of 105° and a cut-out of 157°
The med. temp had a cut-in of 107° and a cut-out of 166°
And the high temp. had a cut-in of 116° and a cut-out of 169°
As you can see, there is hardly a difference.

how do dryer controls work?
 

On Sun, 2 Mar 2008 16:29:28 -0600, "SRN" wrote:


"mm" wrote in message
.. .
I have a very old clothes dryer, a Kenmore that I'm pretty sure is
made by Whirlpool, that has never given me any trouble, and maybe it's
time to ask 2 questions about it.
..................................................
But the air with this machine, even on gentle, must be a lot hotter
than gentle. Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. I'm
afraid to try the next temp up, because I think that hot air is bad
for everything but 100% cotton, and I always have elastic, polyester,
nylon, or other fabrics in the load. I don't think I'd be successful
trying to measure the air temp, but would you all describe the heat on
"gentle" as still pretty hot?

We have an old Kenmore elec. dryer (circa 1990), and several years ago when
troubleshooting and replacing one of the thermostats, I measured the
temperatures on the various temp. ranges running the dryer empty.
The low temp. had a cut-in temp. of 105° and a cut-out of 157°
The med. temp had a cut-in of 107° and a cut-out of 166°
And the high temp. had a cut-in of 116° and a cut-out of 169°
As you can see, there is hardly a difference.

You're right. And an incredibly wide range for each.

How did you do it? The exhaust air?

I've been measuring water temp lately with a meat thermometer with a
metal probe, but for some reason I didn't think it would work for air.

how do dryer controls work?
 

On Mar 1, 10:26*pm, mm wrote:
I have a very old clothes dryer, a Kenmore that I'm pretty sure is
made by Whirlpool, that has never given me any trouble, and maybe it's
time to ask 2 questions about it.

1) The machine has a device to turn the dryer off when the clothes are
the desired dryness. *You point the dryness knob to the chosen dryness
and turn on the dryer. *But then the knob rotates and the pointer
moves. *How does the dryer know where I set it? *I can move it
clockwise and counter clockwise at any time. *Sometimes I've moved it
CW to make it stop soon, but if that new position had been the
original position, it should have stopped already, and yet it
continues to run after I move the knob far clockwise. *How does this
all work?

2) For the last 40 years, at the laundromat and with my own machine, I
always dry clothes on the lowest temperature that is warmer than fresh
air. *I also usually take the clothes out when they aren't quite dry,
so they also aren't really hot yet.

But the air with this machine, even on gentle, must be *a lot hotter
than gentle. *Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. *I'm
afraid to try the next temp up, because I think that hot air is bad
for everything but 100% cotton, and I always have elastic, polyester,
nylon, or other fabrics in the load. *I don't think I'd be successful
trying to measure the air temp, but would you all describe the heat on
"gentle" as still pretty hot?


Could it be that the air is getting so hot because the exhaust vent is
blocked?
Not just the accordian hose behind the dryer, but the pipe in the
wall.
This blockage causes the unexpelled heat to build up.

Alisa LeSueur
Certified Dryer Exhaust Technincian
http://CleanYourOwnDryerVent.com

how do dryer controls work?
 

On Mar 3, 9:42*am, CDET 14 wrote:
On Mar 1, 10:26*pm, mm wrote:





I have a very old clothes dryer, a Kenmore that I'm pretty sure is
made by Whirlpool, that has never given me any trouble, and maybe it's
time to ask 2 questions about it.

1) The machine has a device to turn the dryer off when the clothes are
the desired dryness. *You point the dryness knob to the chosen dryness
and turn on the dryer. *But then the knob rotates and the pointer
moves. *How does the dryer know where I set it? *I can move it
clockwise and counter clockwise at any time. *Sometimes I've moved it
CW to make it stop soon, but if that new position had been the
original position, it should have stopped already, and yet it
continues to run after I move the knob far clockwise. *How does this
all work?

2) For the last 40 years, at the laundromat and with my own machine, I
always dry clothes on the lowest temperature that is warmer than fresh
air. *I also usually take the clothes out when they aren't quite dry,
so they also aren't really hot yet.

But the air with this machine, even on gentle, must be *a lot hotter
than gentle. *Even after I've opened the machine and taken out the
clothes for a few seconds, the clothes seem hotter than gentle. *I'm
afraid to try the next temp up, because I think that hot air is bad
for everything but 100% cotton, and I always have elastic, polyester,
nylon, or other fabrics in the load. *I don't think I'd be successful
trying to measure the air temp, but would you all describe the heat on
"gentle" as still pretty hot?

Could it be that the air is getting so hot because the exhaust vent is
blocked?
Not just the accordian hose behind the dryer, but the pipe in the
wall.
This blockage causes the unexpelled heat to build up.

Alisa LeSueur
Certified Dryer Exhaust Technincianhttp://CleanYourOwnDryerVent.com- Hide quoted text -

- Show quoted text -

Not just the accordian hose behind the dryer, but the pipe in the
wall.

Don't forget the ductwork internal to the dryer.

However, clogged ductwork typically prevents clothes from drying due
to the fact that the hot moist air has no place to go. That does not
appear to be the OP problem.

how do dryer controls work?
 

"mm" wrote in message
...
On Sun, 2 Mar 2008 16:29:28 -0600, "SRN" wrote:


"mm" wrote in message
. ..
I have a very old clothes dryer, a Kenmore that I'm pretty sure is

We have an old Kenmore elec. dryer (circa 1990), and several years ago
when
troubleshooting and replacing one of the thermostats, I measured the
temperatures on the various temp. ranges running the dryer empty.
The low temp. had a cut-in temp. of 105° and a cut-out of 157°
The med. temp had a cut-in of 107° and a cut-out of 166°
And the high temp. had a cut-in of 116° and a cut-out of 169°
As you can see, there is hardly a difference.

You're right. And an incredibly wide range for each.


Originally, I used a Fluke 52 digital thermometer with the thermocouple wire
stuck inside the dryer thru the door. But since you asked, I just went down
to the basement and drilled a tiny hole in the dryer duct and used my UEI
pocket digital thermometer to measure the temps. again. It's hard to get
consistency because the thermostat isn't very precise. On one cycle the
cut-in temp. might be 112° and the next time it might be 107°. But anyway
here is a summary

Hi cut-in 112° cut-out 163° (measured in dryer vent stack)
Med cut-in 110° cut-out 156°
Hi cut-in 91° cut-out 141°

When I used both methods to track temps. at the same time, this time I found
the dryer compartment temps peaking much higher than the exhaust vent temps.
I assume because the probe inside the dryer was receiving radiant heat
energy from the heat element. It peaked at 205° inside and corresponded to a
peak of 163° in the vent on high.


I've been measuring water temp lately with a meat thermometer with a
metal probe, but for some reason I didn't think it would work for air.

I would think that the meat thermometer would work ok. Drill a tiny hole in
the vent pipe and try it.