Moisture in dryer

Hello. To test properly, the dryer must be put in diag mode--a key dance of pressing "more dry, less dry--more dry, less dry" within 5 seconds with the door closed and dryer off. All lights will be illuminated and "88" will be in the display. If you open the door and a tone is heard, along with seeing a software revision number in the display, this means that the moisture circuit is shorted. *If this does not happen*, then open the door and, using a wet cloth or finger, bridge the moisture sensor bars located on the filter holder(metal strips approx 1/2 apart and several inches long). If you do this and a tone is heard and the software revision number is seen, THE SENSOR PASSES THE TEST. If it doesn't, you're going to have to troubleshoot further with a voltage/ohm VOM meter, or better, call for service because, unless you've done this before and know what to expect, you are gonna be INVOLVED in disconnecting sensor wires and checking electrical resistances and so on. You'll have to remove the toe panel(bottom panel on front of unit) to access the sensor wires. To exit diag mode, simply unplug the dryer for about 30 seconds. One thing though, if there is a lot of lint build-up, the sensor bars could be shorted by a bunch of lint crammed between the contacts--have seen that one on occasion.

You might want to take a flashlight and check the vent and duct from the outside in. Lint will build up in the duct and vent over time. When you turn on the dryer with wet clothes in it, the lint will get damp quickly and it will dry out quickly too which make the dryer cycle shorter but not long enough to dry the clothes. Clean the vent and duct regularly and that should take care of your problem. You can buy brushes for doing this and they are not costly.

A dryer moisture sensor can stop working without notice, until you notice your clothes being over dried or still wet at the end of the cycle. It is a good practice to test the dryer moisture sensor periodically. There are two types of moisture-detecting sensors for dryers. Once you understand how they work you will see how to test each one.
1. Sensor BarThese sensors contain digits that protrude outwardly. They work on an electrical current and the moisture from the clothing.
The first step to test is to place completely dry clothes in the dryer and turn on the dryer; it should run for a few moments and then shut down right away.
Secondly, place damp clothes into the dryer, turn on the dryer and watch the timer. As the clothes begin to dry the timer will move and shut off.
2. ThermostatThe timer is regulated by the thermostat. The thermostat rests in a closed position. To test this type of moisture sensor, place damp clothes in the dryer. Watch the timer; as the clothes begin to dry, the thermostat should open and the timer will move forward ,eventually shutting off.

Hi Alicia Rosa - Typically it indicates a faulty issue with the timeout program. Contact a professional to move forward accurately. Technician will check for anything that would cause extend dry times such as: no heat, restricted vent, blower fan blade broken or loose, dryer installed in closet with solid door, bad connection in moisture sensor bar circuit or dirty bars. If dryer operates normally after it has be diagnose and code returns, the main control will possibly need replacing.

Clogged Vent
If your dryer seems to run forever, it could be because of a clogged vent or internal ductwork. Your dryer may have an automatic cycle that turns off the dryer when the clothes are dry. It does this with a special thermostat or moisture-sensing system.
Normally, this is what happens during an automatic cycle:
The thermostat tells the dryer to heat until the interior of the dryer reaches a pre-set temperature--say 135 degrees.
When the dryer reaches the pre-set temperature, the thermostat tells the timer to begin advancing. (If there's a moisture sensor, the timer advances only if the moisture content of the clothing is low enough.)
The timer advances until the interior cools, then the thermostat tells the timer to stop advancing, and tells the dryer to start heating again.
This cycle continues until the clothes are dry. But...if the vent is clogged, the dryer may never reach the proper operating temperature, so it doesn't send the signal to the timer and the dryer continues to run indefinitely, even if the clothes are completely dry. To fix the problem, clean the vent and/or internal ductwork.
Heating Element
Your dryer's heating element may be partially burned out. If it is, your dryer still heats, but at such a low temperature that it takes three or four times as long to dry the clothes. If the element is partially burned out, replace the heating element. You can check for an ohm reading but will need to refer to the service manual for proper reading. This sometimes on the tech sheet located somewhere on the dryer. Usually between 9-13 ohms.
Cycling thermostat
Although this isn't a common problem, one of the thermostats that controls the temperature in your dryer may break and cause the dryer to heat poorly. If so, you need to replace it. The thermostat is usually a small, round, black device mounted to an oblong steel plate. The plate is mounted to the internal ductwork . This thermostat usually has four wires going to it. Check the 2 terminals that are opposite each other and are the closer together of the 2. These 2 terminals should have continuity. If not replace the thermostat.
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Check for a restriction in your exhaust vent. not just behind the machine but all the way to the outside vent,should have good warm airflow at outside vent. With no good air flow you have no way to get rid of the moisture. and all you will end up with is warm moist clothes. this can happen slowley happen over time and next thing you know it takes several cycles to dry the clothes .it cost a lot to dry them this way

Depending on how damp they are, it could be normal or you could have a plugged dryer vent. I say that because on these dryers, the software in the control is programed to leave cloths a little damp in the sensor dry. This is for energy efficiency and less shrinking on clothing. If they are coming out to damp and you need to run them through two cycles to dry them, then the vent is plugged, either in the dryer or the house, and needs cleaned out. When the vent is plugged, the moisture isn't getting out, and the cloths will not dry.

The identification label from a Frigidaire Gallery Commercial Heavy Duty Moisture Sensor drier has come off. I need to download operating/user manual. How can I get the serial no. or model no. The drier is 4 years old.

mamch,
You said,We have a Frigidaire Gallery dryer with a moisture sensor. I've had this model in the past with no concerns, but our current model doesn't seem to work as well. When set to an "automatic" cycle (where the moisture sensor is used) the clothes don't always come out dry and it has to be turned on again. Would there be any reason for this?

What's the model # and the age?
There are two types of moisture sensors.
One has to strips of metal on a black disk looking thing on the dryer rear wall and the other works on steam rather than contact!
Could be you had the better on before that was the contact one rather than the steamm sensor!
How long to dry a load of clothes ?