DLE5955 Tromm Dryer. We have had this dryer for 3 months. The cooling light has started to come on during the entire cycle and stays lit. Clothes are not drying as quickly as before. They are damp at the end of the cycle. Lint filter and dryer vents checked and okay.

I would check your vent. It may be clogged somewhere. Cool light is normal.

did u do a hard reseet>?

Try a timed dry cycle instead of an automatic cycle. If that works, then you will need to clean off the moisture detection bars inside the dryer to get the auto cycle to work again. Look for two curved metal bars, about 3/16 inch wide and 4 inches long, about an inch apart, located just inside the front of the dryer, near the right side of the lint filter. (you'll have to stick your head in the dryer drum to see them) Often times, use of dryer sheets will result in a waxy coating forming on these bars, preventing the dryer from detecting the moisture in the clothes. The dryer sees no moisture, it goes into the cool down mode and then stops. Clean the bars off, and you should be back in the laundry business.

It sounds like your solenoid coil(s) might be no good. Easy fix and not very expensive.

Hi,
I am using LG Tromm DLE2514 washer dryer. It 's running but didn't dried the clothes. I clean it's lint but still it's not working. The one thing i notice now is it's drying light is blinking and cooling light is turn on all the time during the cycle. So what's the problem with my dryer?

The cooling light stays on so that is not the issue. Check to make sure you have power in both hot legs of your 220v power outlet.

the flame sencer window my need cleaning

check the vent or condensor depending on what type of dryer.

check and make sure it has a clear clean vent.no kinks in vent hose.if yours vents thru roof then you may want a chimney sweep to come and sweep your vent out.if it goes thru a wall check and make sure know blockage.

The vent is clogged.  To make sure, disconnect the vent from the dryer and run the dryer normally.  If your clothes dry normally, then have a professional vent cleaning company take care of the vent.  
The cooling light will always stay on during the run.  When it is blinking, the heat has stopped and is in the cooling process.
If there is no heating, you have a problem with the high limit switch or something else electrical and needs to be addressed by a qualified LG technician.