I have an LG dryer Model # ddle7177rm/dlg7188rm.when we start the dryer it starts to heat then stops and it blows cool air. the ducts are all clean.

That is more indicative of a fan failure. The element is supposed to get hot, but the fan blows the heat through the clothes and cools the element at the same time.

did you clean the vent line?THAT COULD MAKE IT RUN HOT THE AIR CAN'T BLOW OUTSIDE,BUT WITH THE DRYER HAVING HEAT WHEN IT STARTS AND THEN AFTER LIKE 10 MINUTES NO HEAT IT SOUNDS LIKE YOU HAVE BAD GAS COILS,WHEN THE COILS ARE STARTING TO FAIL THEY WILL WORK FOR LIKE THE FIRST 10 TO 20 MINUTES AND WHEN THEY HEAT UP NO GAS,WHEN THE COOL THEY WILL WORK AGAIN,I WOULD CHANGE THE COILS AND CLEAN OUT THE DRYER AND VENT LINE,THIS SHOULD BE DONE ONCE A YEAR SO YOU DON'T HAVE A FIRE AND YOUR CLOTHES WILL DRY ON TIME,EVERYONE THINKS SOMETHING IS WRONG WITH THE DRYER AND ALL THAT HAPPENS IS THE VENT LINE AND THE DUCT WHERE THE LINT FILTER SLIDES INTO FILLS WITH LINT AND THE AIR CAN'T BLOW AROUND GOOD ANYMORE,ALSO WITH A SHOP VAC VAC UP THE LINT WHERE THE BURNER AND MOTOR IS AND THEN SET THE VAC UP TO BLOW AND BLOW THE MOTOR AND GAS BURNER OUT,DO THIS AND YOU'LL HARDLY HAVE ANY PROBLEMS WITH THE DRYER

Take off your LINT Ducting and clean out completely, all the way to the outside hole in your house.


There is a heat limiting switch that turns off the unit if the heat gets to a temperature in the Lint Duct that is too high and is very dangerous.


If the air flow is limited too much, then the free flow of air can not be carrying out the heat generated by the machine to dry the clothers. You could have, and probably do have a nasty clog in your ducting, so hence, the air is not getting out successfully and it is staying all in the dryer unit. When the temperature reaches the LIMIT ALLOWED, then it shuts it off to prevent a instant FIRE.


The good news is your sensor is working, and the bad news is you gotta take the ducting apart and clean it good.


HINT: Make sure you DO NOT have any loops or low spots or lengths of hose that make the dryer have to blow the lint UP HILL. That is a common mistake because damp lint is heavy and it will build up anywhere there is a place that the air flow will not carry the weight of the damp lint, hence it drops it right there and starts a build up until it is blocked and then the sensor feels the temperature reach the Upper Limit and shuts off your machine. You may have to reroute your dryer ducting in a manner that the air flow is always level or even better, slopping down a little.


Good luck, and be sure to unplug the dryer before you start digging around the back and/or inside your machine.


kindly,


Jim

if the flame is liting most likely problem is bad air movement.go outside with thedryer running and check the hood to see how strong the air is blowing out,if there's a cage or anything blocking the hood remove it,if the vent line is a long run remove the vent line from the back of the dryer,stick a leaf blower into it and blow out the lint to the outside.also with the dryer unplugged,remove the bottom panel,remove the lint filter and metal duct the filter slides into,clean that out and blow out the blower wheel with a shop vac,you can blow out the gas tube where the flame ignites to make sure it's clean blow off the motor and the cabinet and vac up all lint that blows forwards.you can try running the dryer with the vent line removed to see if it runs any better.when the dryer first heats up the flame will come on until the temp. is reached and it will shut down,one more thing to check,when gas coils start to fail you'll have heat for like the first 15 to 30 minutes,then when the coils heat up the ignitor will glow but no flame,after the coils cool down they will work again.how are you running it on timed dry or more or less dry,if you run it on auto or more or less dry there's a sensor inside where the lint filter is,try cleaning it up or try running it on timed dry to see if it runs any different,when on auto the heat comes on,when it reaches temp. the heat stops and the timer will advance,when it calls for heat the timer stops and the heat comes back on,it will do this until the clothes are dry.your model has an even heat board in it that can also cause problems but if the flame is liting it sounds like you have a block somewhere.go here this will tell you a little more about your model dryer.
http://fixitnow.com/wp/2009/03/17/easy-fixes-for-two-common-problems-with-the-whirlpool-even-heat-dryers/

you have a bad motor,most likely you don't clean out the dryer,this is the number 1 killer of dryers.the vent line,the duct that the lint filter slides into and the cabinet where the motor is needs to be cleaned out if it's gas once a year,electric once every two years.all a dryer does is move air,when lint starts to build up the dryer starts to run hotter then normal from the lint build up and the dryer can't move the air as easy as when everything is cleaned out and then parts start to brake like the thermal fuse will pop from running to hot or the motor starts to over heat like yours and shuts down.when the motor gets hot the oil that's inside it leaks out,you'll see it stuck to the side wall and on the rear end of the drum with lint stuck to it.there's an overload in the motor that pops when the motor gets hot and after a while when it cools down the overload resets,that's why you can start it again after a while so basicly you have to replace the motor and clean out the dryer,if the vent line is a long run,remove it from the back of the dryer and with a leaf blower blow it out,you'll see all kinds of stuff blow out through the outside duct and clean out the duct that the lint filter goes into and the cabinet where the motor is or replace the dryer.

if it's a gas dryer and you have heat for the first 15 to 30 minutes and then no heat you have bad gas coils.when the coils are starting to fail they will work until they heat up and then stop working,when they cool you'll have heat again.very simple to fix,unplug the dryer,remove bottom panel or front panel to get at the gas valve.on top of the valve are the gas coils,remove two phillips screws,you might need a 1/4 inch socket with a phillips bit to take out the screws depending on your model and next time send model number so i can help you better,then remove cover,change one coil at a time.there is a little plastic ball on the top of the coils that line up with the cover and a metal spacer on the large coil that slides onto the post,if you don't see the spacer on the post poke it out of the old coil and slide it onto the post and then install the new coil.it's very simple.also if your clothes take a long time to dry you might have to clean out the dryer,all a dryer does is move air,if the lint blocks the vent line or the duct that the lint filter slides into you're gonna have problems.with a gas dryer you have an open flame inside and lint catches fire,you should clean the dryer every year and you'll have mostly no problems with it.if the vent line is long blow it out with a leaf blower,you'll see all the lint blow outside,then remove the duct that the lint filter slides into and clean that,next with a shop vac vac out the cabinet where the motor is and then put the vac on blow and blow the motor off and all your gas parts.if you need any more help let me know and send model number next time

Most of the time this problem is attributed to a blocked or more precisely, a partially blocked dryer vent system. When a dryer vent is blocked it stops the air flow and the heat backs up into the dryer turning the heat sensors on and off prematurely taking longer for the clothes to dry. Over time this may cause the heat overload fuse to blow and you will have no heat at all.
First take a look at the dryers ducting between the dryer and the wall to make sure the vent duct (normally a flexible style) has not been crushed or kinked.
If the dryer duct to the wall is in good shape then in most cases there is a blockage some where between the wall where the ducting connects to the vent and where it exhausts outside.
The major cause of a blocked dryer duct occurs when the water in the clothes is heated to a high temperature and turned into steam, which is then exhausted out the back of the dryer to outside. As the steam cools on its journey and gets closer to the outside of the house, it tends to get cooler and turns back into water droplets. This is going to be the point where the dried lint, as it escapes past the lint filter, sticks to the newly formed water drops and starts a gradual chocking down of the 4" diameter vent to 3",2",1" and finally stops all flow of air.
Remember, the dryer is designed to exhaust so many cfm's and the more choked the vent the more heat is backed up into the dryer.
If you cannot access the dryer ducting, because it is in the wall or ceiling, to look for the obstruction, then look in the yellow pages or contact the local appliance repair service company and get the name for a good duct cleaning company.

Check to make sure that the thermal fuse is not blown. Small plastic piece with 2 wires coming off of it. Typically this is problem.

Sounds like you need an ignitor part number 5318EL3001A but you will need a gas technician to work on this legally. Best off to call a reliable service company such as Sears.

Does the dryer heat up or is it just cool air drying the clothes ? If it does actually dry the clothes eventually then it sounds like it is heating up. First thing to check would be exhaust hose. Is warm air blowing out of it ? If warm you got heat. If cool then your heating element isn't working. It should be fairly strong current of very warm air. If weak but warm, then somewhere between lint filter and end of hose you have a blockage caused by lint buildup or hose is bent and blocking air flow. Check hose first. You can disassemble lint trap and go beyond the lint screen into metal duct within dryer and clean with a long brush and vacuum. You can also disconnect exhaust duct flexible hose at back of dryer and work through metal duct from that end too. If you notice increased air flow then it should solve problem,