[Robert Kulagowski]

LG DLG0452W dryer isn't drying.

Tech has already come out and replaced the control board. Still not working. Or at least not working consistently. I might get two or three "on" cycles when the dryer first starts; we can hear the whoosh of the gas burner, it'll run for 2 minutes during the "on" cycle, but then after a few "off" cycles, it doesn't come back on and just spins, essentially air drying the clothes.

Output duct is clean and only about 5 feet long; direct vent through the wall. There is sufficient blower pressure to open the flaps on the vent cover outside.

The igniter ignites, but no flame. Tech states that there are two parts to the gas valve; an upper and lower. The upper has voltage when it's supposed to, but the bottom never gets "90 volts", so it doesn't open the gas flow.

He said that he's seeing the same thing at the control board; no voltage when the bottom valve should open, (but there is voltage on the top) so he thinks it's not the wiring harness.

He says that the various flame sensors and limit sensors are wired in series, and they're normally closed. If any of the sensors were defective and open then the igniter would never come on but the igniter does glow for about 15 seconds.

At this point he's going to put the old control board back in and return the new one, so I'll get credit for it. But I don't want to "buy" a new dryer through replacement of everything on the old one, and I don't want $400 in labor costs for the tech to basically rebuild a dryer in my laundry room.

Any ideas? I'm reasonably handy, and now that I've seen him take it apart I think I can do it on my own if there are parts or tests I can run, but if it's time to get a new dryer then it's time to get a new dryer.

[logangm]

I would replace the thermistor. They often go out on these newer LG and are a pretty cheap part. Under 30 dollars

[Robert Kulagowski]

Originally Posted by logangm

I would replace the thermistor. They often go out on these newer LG and are a pretty cheap part. Under 30 dollars

OK, assuming I'm competent, what's the flowchart of checking things? (Is there one online somewhere to help isolate the failing part)

As in:

Check thermisistor: it should be normally closed.
Check High limit switch: normally closed.
Check "top" solenoid on gas valve: should read "x"
Check "bottom" solenoid on gas valve: should read "y".

(etc).

That will help me narrow down what might be broken.

[Robert Kulagowski]

OK, I purchased one of each part to do a "pluck and chuck" Still nothing.

I have replaced the gas valve assembly, igniter, flame sensor and thermostat. I forgot to order a high-limit thermostat, but if it's normally closed at room temperature, I can jumper the sensor wires and force it closed. Somehow, with the dryer pulled apart, I can't see the high-limit tripping since it's basically an open box right now.

I think that everything that has to do with the actual flame part of the dryer has now been replaced.

What do the thermostat and thermisistor on the blower duct
(Parts AP4441539 and AP4440976) normally do?

Should the dryer actually operate if it's taken apart, or have I actually fixed a broken part and just not know it yet because I haven't put the dryer together, and somehow it being "open" is causing some sensor to not read correctly because the heat is escaping or whatever?

(I've already jumpered the door sensor switch harness, and I pull up on the tension pulley so that the blower motor starts I still get one 15 second initial flame, then it cycles off, then about 2 minutes later I get 2-3 seconds, then the flame goes out. The clothes will never dry at that rate.