I'm trying to repair my in-law's LG gas dryer. The dryer will not generate any heat while running. I've researched this extensively, downloaded the service manual for this specific model. From everything I read, it seemed it would be a simple switch out of one the 3 thermostats, whichever had no continuity. I took the unit apart and tested the thermostats, all of which have under 1 ohm of continuity, as specified in the one of the service manual's tests. The sensor and igniter also have continuity, as well as the thermistor. I checked the igniter coil for any cracks and it looked clean. I put everything together, except for the front cabinet cover, so that I can run the dryer while still having visibility to the igniter to see if it starts up, glows red and the burner fires off. It did just this, but only for a few seconds, then shuts down and obviously no hot air. I've done the same thing with the vent duct detached, in case of any lack of air flow, and the same thing happens. I've also checked continuity at each of the 2 valve terminals on the gas valve assembly, and that is as specified in the service manual. I'm stumped with this one, and wondering if any of the thermostats, or the sensor could still be bad even though there is continuity in them. Possibly the hi limit thermostat, or the sensor which I'm told serves as a thermo coupler? Any input would be greatly appreciated!!

the gas valve number is 5221el2002a

I was having similar symptoms and have finally solved my issue.

We noticed that clothes weren't drying as well as they use to...when using sensor dry they would come out slightly damp (just barely). Intermittently we would smell natural gas in the laundry room. After reading numerous forum posts, I decided to swap out the main control board because many people said changing the ignitor and gas valve didn't fix the problem. I thought that I had fixed the problem as we didn't smell gas for a few weeks.

Well, the problem did come back a few weeks later. Eventually the dryer stopped heating as the gas wouldn't ignite. I ordered a gas valve thinking that was the most likely culprit. The swap out that part I had to remove the drum which exposed everything in the dryer nicely. It turns out the exhaust tube had dislodged internally and a decent amount of lint was being blown inside the machine. Lint was everywhere.

The lint had built up inside the gas tube and must have caused turbulence in the gas flow which prevented it from lighting properly. I cleaned everything up, reconnected the exhaust tubing and taped it securely before putting everything back together. I didn't replace the gas valve as the original one ohmed out properly. The dryer has been working like new for several weeks now.

I hope this helps other with similar problems.

Other issues that may prevent your dryer from heating apart from the heating element include: a tripped circuit breaker, the dryer vent, lint trap, and/or lint screen is suffocating the heating element. Other issues could be a faulty thermal fuse a broken thermostat or a defective timer motor. If you checked all of these and still can't figure it out I am sure a local dryer repair service can help.