27 replies to this topic

[tking1375]

Timer mode works fine, but auto sense mode takes 3 cycles to dry. I have checked the vent, and it is totally clear. Does my dryer have an auto sensor that might be broken that I can replace? If not, what might be the problem?

[RegUS_PatOff]

... Timer mode works fine, but auto sense mode takes 3 cycles to dry.

doesn't make much sense ..
May need to post actual Vent temperatures in each mode.

[Samurai Appliance Repair Man]

A vent can be free of lint and still be bad. The name of the game is backpressure.

Try running it again with the vent disconnected from the back of the dryer and see how she does.

[tking1375]

OK, I checked the dryer with the vent in place (total length 4 ft) and it had strong pressure outside in both timed and auto dry modes.

I then tried running the dryer with the vent disconnected in both timed and auto dry modes. I tested each mode through 4 cycles and tried to be very consistent with the placement of my thermometer.

It seemed like there was a distinct difference between the two modes as far as how hot they got and when they cut off.

Timed dry was consistent through all 4 readings between 120 and 175 degrees. Auto dry was less consistent and ranged between 120 degrees and 142 degrees, but never went above 150 degrees and only got to 134 degrees during one reading before shutting off.

I can't find any kind of sensor in the parts list, does anybody know how the auto sense works on this dryer and
is the cycling thermostat involved?

[RegUS_PatOff]

... does anybody know how the auto sense works on this dryer and is the cycling thermostat involved?

Timed Dry and Auto Dry use the same Thermostats on that model ...
When Timed Dry is used, the Timer Motor runs continuously till the end.
When Auto Dry is used, the Timer only runs when the temperature reaches the operating temperature
(the clothes would then have no more moisture in them)
The temperatures tests should be done with an empty load.

[tking1375]

Yes, I did do the testing with an empty load, and thank you for the explanation, I think I understand a little better what's going on. What I still can not understand is why auto dry would cycle at lower temperatures than timed dry if that is the case?

[RegUS_PatOff]

... why auto dry would cycle at lower temperatures than timed dry if that is the case?

it shouldn't ..it uses the same thermostats
unless you're talking about any of the Low-Heat cycles

[john63]

<<<Timer mode works fine, but auto sense mode takes 3 cycles to dry.>>>

*********

This dryer has a *primitive* version of an AUTO DRY timer cycle.

When using AUTO DRY---is the timer dial set at MORE DRY?

If no---test a load of laundry in that setting.

Keep in mind that---the last 10 minutes (or so) of an AUTO DRY cycle on this Roper dryer---will be NO HEAT before the cycle ends.
This cools the laundry and reduces wrinkles.

If you have been setting the timer (in the AUTO DRY cycle) anywhere between LESS DRY and MORE DRY---the cycle may not be long enough to completely dry clothing.

[tking1375]

it shouldn't ..it uses the same thermostats
unless you're talking about any of the Low-Heat cycles

No, there are no heat settings to choose from. So...what on earth is it doing?

[RegUS_PatOff]

... No, there are no heat settings to choose from.
... So...what on earth is it doing?

1) sorry, I was looking at the "optional" parts on the wiring diagram
2) I don't know . . . both use the same Thermostat folr tghe temperature regulation
. . only difference is the Timer Motor "pauses" during in Auto-Dry
The Timer Motor only runs when the temperature reaches the Thermostat rating.
It's possible that the temperature never gets to that rating, (Gas Valve / Coil problem)
but then again it wouldn't get there in the Timed Dry Cycle, either.
Has this Dryer worked OK for you up till now at this location ?

[john63]

<<<So...what on earth is it doing?>>>

*************

Some lower-end Whirlpool built dryers (such as Roper/Estate/Capri) have super-short AUTO DRY duration/run time.

Having said that---the bigger question is...

Has the timer (in AUTO DRY cycle) been set to MORE DRY?

If yes and the laundry is still NOT drying---it may be that the AUTO DRY cycle on your particular model Roper dryer is---worthless for all but light fabrics (no towels/denims etc).

Edited by john63, 04 April 2012 - 06:18 PM.

[tking1375]

OK, thank you so much for your responses. I guess I just want a solution at this point. I know what the workaround is, which is to used TIMED DRY or MORE DRY instead of trying to fix the darn thing to work correctly. If it is just a lame piece of junk, OK, I'll accept that. Any final thoughts?

[Budget Appliance Repair]

You don't have any kind of option settings so all options/heat settings are dependent on what cycle the timer dial is set to.

The operating t-stat has an internal bias heater to make the t-stat cycle at a lower temp. From your temps that you have posted it appears that the auto-dry cycle is probably drying at a low/med heat setting and the timed dry is at normal high temp.

Look at all the wording around the timer dial and see if it says anything like "High Heat" around the timed section and "Low Heat" around the auto-dry cycle.

Without a wiring diagram I really can't say for sure that the above is what is happening, but it sure sounds like it is. I found the user manual and it doesn't show the timer dial settings, it's just a real basic/useless manual.

Do you only have one auto-dry cycle or two? I know for sure from what you have already said and from general knowledge about these low line units it most likely has an air dry cycle, timed cycle and at least one, (possibly two), auto-dry cycles.

[RegUS_PatOff]

... You don't have any kind of option settings
... The operating t-stat has an internal bias heater

NOTE: this model does not use the *optional* Temperature Selector circuitry (nor the bias heater circuit in the Thermostat )
Wiring Sheet - 8528187.pdf

It's possible that the temperature never gets to that rating, (Gas Valve / Coil problem)
but then again it wouldn't get there in the Timed Dry Cycle, either.

[tking1375]

Thanks for all of your help. Here is a Flickr link to photo of the dryer timer.

[tking1375]

Ok, that didn't work for some reason - here is the link: http://www.flickr.co.../in/photostream

[RegUS_PatOff]

yes, they're both High Heat cycles, uses the same Thermostat, same temperatures

[DADoESTX]

Notice that the AutoDry cycle has a much longer range beyond Very Dry. Assuming the cycle is functional the same there, you should be able to set it for a longer run than just the labeled Very Dry position.

As others have said, the AutoDry cycle does not utilize a direct moisture sensor. It measures moisture indirectly by way of the air temperature. The timer does not advance when the heating element (or gas burner) is active, and does advance when the target thermostat temp is reached and the heat cycles off. Moisture evaporating from the wet clothes at the beginning of running a load keeps the heat source on for a longer period of time to reach the target temp (probably 155°F), during which the timer does not run. After the target temp is reached, the heat source turns off (and the timer turns on) until the exhaust air temp drops 25°F or so below the target. The heat turns on again to reup the temp and the timer turns off. As the load dries, gives up moisture, the clothes retain heat longer, so the heat source runs less to maintain the target temp and the timer runs more .... until the selected "time" (moisture level) runs out to the Cool Down and then Off.

[jumptrout]

In my opinion Timed Dry is more efficient than Auto Dry.

[Budget Appliance Repair]

Well, I guess I was wrong about the t-stat having the internal bias heater. I didn't look at any pictures of the actual part, just looked at the parts list and it listed the operation t-stat as: "660039 Thermostat, Internal Bias", so I ASS U MEd that it had the bias heater.

That unit is for sure a low line unit, not even an air fluff setting, just have to set it at one of the cool down settings to get air only.

And only 30 minutes maximum time on the timed cycle, WoWWW!!!!