Have a Kenmore 796.8031 electric clothes dryer. I want to vent the dryer by running an 8 ft. vertical smooth rigid metal duct up through the ceiling into the attic to a 90 degree elbow and continue with another 10 ft. horizontal straight run of duct to and through the side of the house. Is this ok to do? Also, should I insulate the duct and should the duct be secured to prevent movement?

The CHECK VENT duct blockage sensing system detects and alerts you to blockages in the duct work that reduce exhaust flow from the dryer. This light does not indicate any problems with your dryer. If this light blinks, it indicates that your home's exhaust system/duct work has a serious restriction

Every time the dryer is turned on, the CHECK FILTER LIGHT WILL BLINK, as a reminder to make sure the filter is clean. Always make sure the lint filter is clean before starting a new load; a clogged lint filter will increase drying times.

The Kenmore Elite dryer has a sensor that detects poor exhaust venting, and when it does, a light flashes on the control panel. This warning light does not include a mechanism to stop gas flow, but if it is allowed to flash for an extended period, poor venting may cause the dryer to overheat. As a result, a fuse might blow and disable the gas valve or ignitor. You can prevent this by diagnosing the reason for the flashing indicator light as soon as possible.

In many cases, LINT has built up somewhere in the exhaust pipes.

Check under the lint filter. Pull it out,look inside the slot it fits in, and clear all lint from this area.

Is it possible you have used the WRONG VENT MATERIAL?
Check your vent to make sure it is 4 inch rigid or semi-rigid metal ducting. If your venting is plastic or flexible foil, replace it before using the dryer.

Check your vent hood outside. You may have a restricted or damaged vent hood. It must be clean and free of lint buildup. Check the damper and make sure it opens fully and easily and is free of lint.

I know you said you have no elbows, but I have posted the pipe run lengths with and without elbows. Keep in mind this is with 4 inch rigid or semi rigid metal ducting.

Measure the length of your exhaust system and count the elbows. Use the chart below to see if your duct is too long. If it is too long, have the duct routed to another location that is within the venting guidelines.

0~90 degree elbows=65 ft of 4 inch rigid metal duct.
1~90 degree elbow=55 ft of 4 inch rigid metal duct.
2~90 degree elbows=47 ft """"""""
3~90 degree elbows=36 ft """"""""
4~90 degree elbows=28 ft """"""""

You should always use duct tape or metal tape on all joints, NEVER USE SCREWS, as screws capture lint inside the pipe.

One more note. Lots of people overlook the fact that fabric softeners can build up on the lint filter over time. This buildup can restrict the airflow through the filter reducing dryer efficiency and lengthening drying times. After removing lint, if the filter looks dark or dirty when held up to the light, follow these steps to clean:

Use hot soapy water and a stiff brush to clean
the filter.
Make sure the filter is completely dry before
reinstalling it and using the dryer.
NEVER operate the dryer with a wet lint filter.

Good Afternoon Famties4,

I understand that the dryer portion of your laundry center, model#FEX831FS2, takes too long to dry, even after making sure the vents are clear. First, I suggest checking the exhaust duct, making sure it is at least 4 inches in diameter and made of rigid or flexible metal. Secondly, make sure the duct has no more than two 90 degree bends and must not exceed length listed in the INSTALLATION INSTRUCTIONS. Lastly, make sure your dryer is connected to a 240 volt circuit. Drying time will be 20% longer than drying on a 240 volt circuit. I ask that you please follow up with a comment on the post, at your convenience, to advise if further troubleshooting is needed or if your dryer status has changed successfully.

-Best Regards-
WP

The vent pipe codes are based on the fact that the blower in a typical gas dryer can only 'push' a certain volume of air through a certain sized duct for a certain number of feet. Reduced volume of airflow means higher temperatures thus higher risk of fire.
First option ... is your dryer anywhere near a side wall, which would allow you to shorten the total length of duct required to reach the outside to something less than the 14 ft code limit ?
Second option ... upsize the standard 4" dryer exhaust duct to 6" to compensate for the 30ft length
Either way, in the absence of an external forced draft booster fan ( a.k.a. 'power vent' fan ) you should be using metal exhaust duct not plastic.

Get a portable vent system from home depot or lowes. It will save you money

This may seem too simple of an answer based on your extensive troubleshooting thus far, but the most common reason for cold air running of any electric dryer is a broken heater coil. This is simply a coil of wire that is heated to warm the air in the fan duct. These often overheat and break if the vent duct is blocked, too long, or has odd bends that can restrict flow. Recommend replacing heater coil and use smooth wall vent pipe. Avoid coil type flexible duct.

the problem is most likely an airflow problem. if you have a flexible duct connected to the back of the machine then replace it with a smooth rigid (not pvc) metal duct. clean inside the wall or wherever the air goes to get outside (must be smooth metal at least 4" in diameter) in the wall, without too many bends. the electrical arc you spoke of would not have an effect on the heating element unless the machine is not heating at all.

DISCONNECT THE EXHAUST FROM THE BACK OF THE DRYER. RUN ONE LOAD OF LAUNDRY. IF THE LOAD DRIES O.K., THE EXHAUST DUCT IS RESTRICTED. CLEAN OUT THE DUCT WORK. IF IT IS FLEXIBLE MATERIAL, REPLACE WITH RIGID METAL DUCT WORK.

This complaint is most often caused by the dryer's vent being blocked with lint. Dryers need to be properly vented, otherwise the moisture in the air can't be properly carried away. Vents that go out the roof are particularly problematic-- the dryer may take far too long to dry clothes and the vent pipe may even drip water that can't be exhausted. Minimum size for a dryer's roof vent is 4 inches. If your dryer has chronically poor drying, if possible, have the vent moved to where it exits a house wall near the dryer. The vent should be made of 4-inch aluminum rigid duct and elbows or, where absolutely necessary, flexible metal (but not flexible thin foil). Do not use flexible plastic duct-- it restricts air flow and is combustible. The dryer should vent outside--never into a crawl space, wall, ceiling chimney, or other type of flue. The bottom of the exhaust hood should be located at least 12 inches above the ground. Here is what to do: 1) Check the lint trap and clean it. 2) Be sure the dryer isn't pushed so close to the wall that it pinches off the airflow through the vent's air duct hose. 3) Check the point where the air duct vents away from the house. Be sure plants, birds, or anything else hasn't blocked it. If the duct vents out the roof, it could easily be blocked with lint. 4) Disconnect the air duct hose from the back of the gas dryer and clean out built-up lint. Note: For safety, first turn off the gas to the dryer, then unplug the dryer; this means you will have to re-light the pilot light later if the dryer has one (read your owner?s manual for proper re-lighting techniques). 5) If necessary, clean out the ductwork from the dryer to the exterior wall where it vents; this may involve disconnecting sections. One trick that sometimes makes this job easier (but only if the dryer duct is fastened firmly at all connection points) is to blow lint and debris through the duct and out the exterior wall vent, using an electric leaf blower.