My lg dryer DLEX5170W does not heat and check filter flashes (no obstruction in filter or filter sleeve)

SOURCE: Dryer won't work, Check Filter light is on

I had exactly the same problem with my newish LG dryer. I deduced that the dryer's computer essentially needed to be rebooted. I pulled the plug for a minute or so, then plugged it back in. It works perfectly now.

SOURCE: My LG dryer will not power up

You may have a broken door switch.  That would be the most likely source of your problem since the machine will not work if the computer senses that the door isn't closed.

SOURCE: 2008 LG Dryer will not heat.

i am sending you all the possibilities for your problem, check either of these causes ----and than let me know if it is solved----

Power from the house
Check to see whether there's power getting to the dryer. Is it plugged in? Check for blown fuses or tripped circuit breakers--your dryer uses two fuses or circuit breakers. The dryer could tumble but not heat if only one of the two fuses is blown. If you have circuit breakers, one of the two circuit breakers can trip, even if the two for the dryer are connected.


Heating element
Often a dryer heating element burns out, but doesn't trip the circuit breaker or blow a fuse. The heating element is simply a long coil of special wire. You can check it for continuity with an ohm meter. No continuity means the element is bad and you need to replace it--electric heating elements aren't repairable.


Thermal fuse
On many dryers, there's a thermal fuse mounted to the exhaust duct inside the back cover panel. The fuse--which is about an inch long--is usually embedded in black resin and mounted in a white plastic housing. If the fuse has blown, you need to replace it. (You can't re-set it.)


Wiring
A common problem is for the main wiring connection from the house, at the dryer, to burn and break its connection. Because the dryer can still tumble with partial power, the connection may be only partially defective. You may need to replace both the power cord to the dryer and the terminal block inside the dryer that the wire is attached to.

SOURCE: LG DRYER DLE2532W DISASSEMBLY INSTRUCTIONS

This gives you what you need.

http://136.166.4.200/contents/Laundry/DLE2532/DLE2532_Service_Manual.pdf

SOURCE: check filter light wont shut off and setting.lg tromm dryer

You might need to check the exhaust on the rear of the Dryer, or the blower motor iether one has lint inside, restricting the air flow