LG dryer problem

[DaveGan]

I have a LG gas dryer model DLG2524W and it stopped heating last night.  After searching this great site I found how to run the diagnostics and code 19:HO and U01 came up but I can't find what they mean.  Any help would be awesome!

[Washaman]

Is there a tech sheet inside the dryer?

[DaveGan]

I downloaded the service manual and have done some testing.  I think I have it narrowed down to the flame sensor.  I read 120V on both sides of it prior to the flame ignitor coming on.  Then both sides drop to about 1.5V when the ignitor comes on.  Once the flame starts, I read 120V again on both sides until the flame stops.  One side reads 120V and the other reads 40V.  What do you think?

[wildimaginations]

The flame sensor should be closed and reads 0 volts when initially starting up.  Once the flame comes on, the flame switch opens and should stay open for the duration till the control shuts it down.  It will read 120 volts when the flame comes on.  If the flame goes out and you're still reading 120 volts at the flame switch, the flame switch is not the problem.  Sounds more like the gas valve is failing.

[DaveGan]

Thanks for the info.  I've replaced the flame sensor, ignitor, and both thermostats just because they are easy to do and its not bad to have those around as replacement parts.  What I have noticed from further testing after putting those parts in is that whereas the burner previously would always at least fire, now it won't!!  I checked the voltages at the gas valve coils.  Sometimes I get the correct voltage, and sometimes I get nothing at all.  Also, one time I heard the valve open, gas coming out, and the ignitor wasn't on.  With the goofy voltages I'm getting and the sequence seeming a bit off, I'm leaning towards a new circuit board....Any thoughts on this?? 

[wildimaginations]

Pull the power cord on the dryer for a few minutes to reset the board.  Then try it again.  If it still is doing some goofy things, replace the board.