Author Topic: LG Gas Dryer DLG2524W Error code 19:HO / U01: Unit spins, but no heat. Help?  (Read 2709 times)

Offline bagjr387

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  • Member Since: Apr 2014
  • Posts: 47
The flame sensor would prevent voltage from going to the coils if it was bad. If you read no voltage to the coils, you have to start running backwards...The flame sensor should have infinite ohms when its cold (if I'm not mistaken) The contacts inside(bi metal) should only touch once the ignitor/flame is there to heat it up. If the ignitor is coming on, The flame sensor is all thats left.

The flame sensor is in series with the burner coils...In case you were confused about it

Offline basnap

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  • Member Since: Apr 2014
  • Posts: 8
@bagjr387: I agree with you... partially...

The flame sensor could indeed be the issue here. I can see it throwing an 'exception'. Such that the control board never sends a voltage to the coils -> preventing the GAS VALVES to open -> no gas -> no heat.

Per the manual:

12. Flame Detect
Measure resistance of terminal to terminal:
Open at 370F ((Maximum)  Resistance value  ∞
Close at 320F                     Resistance value < 1Ω

Measuring the flame detect at room temp yielded a value of 0 (closed) Ohm... whether it would open (infinite Ohms) at 370F remains to be seen of course... never tested that.

BUT the 'open' condition would only occur if the whole thing was heating up which it wasn't. So with the flame detect in it's correct state it should tell the board to open the GAS VALVES by applying a voltage to the coils.

Some mitigating conditions:

A) It could be that the ignitor would heat the flame sensor up to the point where (>370F it would already be open (inifite Ohm) thus telling the control board to keep the valves shut?
B) It could be that the wiring back to the control board was bad and the CB never got the signal?

To your other point: I do not see how the 'coils are in series with the flame sensor', but it could be. In my mind's diagram the coils are independent and an 'end-point'. The thermistors-flame sensor-ignitor-thermostat complex decides if the conditions are right and via the control board a voltage is then applied to the coils opening so the gas can flow. That same thermistors-flame sensor-ignitor-thermostat complex then decides that there is enough heat (370F) and shuts the valves...

But all of this is mere speculation... see next post..

Offline basnap

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  • Member Since: Apr 2014
  • Posts: 8
Lost my post, will rewrite tomorrow.. Dryer works again..

Offline basnap

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  • Member Since: Apr 2014
  • Posts: 8
A promised here is my final update. Yesterday I closed out my browser without hitting Post.

The dryer works again! After I replaced the control board (CB) and reassembled it, it ran just fine.

I am still baffled by this as the CB does not have any moving parts to it. More over, the CB is never exposed to the heat/cold like the thermistors and thermostat are. Given that all pieces checked out ok and a replacement board solve the issue, I have to conclude that it was the CB which caused this the dryer to stop working

That said: When I perform the self checks it STILL cycles between the 19:H0 and UO1 error coders! That has not changed. Makes me wonder if it ever worked of whether I am performing the test incorrectly.

Some general recommendations based on my experience:

1) Find forums, read forums, post for help
2) Find the (system!) manual of your model but..
3) Don't get hung up on your specific model. A dryer is a dryer.. a gas dryer is a gas dryer
4) Do the basic checks (power plugged in, vent clear, lint filter clear?)
5) Perform the tests via the CB per the manual

6) When deciding to open the unit get your tools ready first, not special except volt/ohm meter
7) Where gloves! the inside pieces are sharp and heavy. I had to stop working at one point since I got a big gash
8) The unit can spin without the door frame being in place and just the harnass.
9) Do connect the door switch, without that connected nothing works
10) take pictures when undoing a complex part, saved me many times
11) Look up youtube video's for guidance
12) Look at the return policy of the components you buy. I had to return 2 of the ones and that went without an issue.


I made this thread super lengthy because we probably all want to save money in this economy so I tried to document my steps as careful as I could which I hope would be useful. If anyone comments on this post I will see it and will keep an eye on if anyone has a specific question I could help with.

Thank you all who contributed!

I have learned a great deal about dryers :) (I am a Linux engineer by trade)

Believe it or not, on the same day I put the CB in, our Badger 5 SINK ingenerator started leaking... NEXT project!



Offline john63

  • Technician
  • Member Since: Feb 2010
  • Posts: 508
<<<am still baffled by this as the CB does not have any moving parts to it. More over, the CB is never exposed to the heat/cold like the thermistors and thermostat are. Given that all pieces checked out ok and a replacement board solve the issue, I have to conclude that it was the CB which caused this the dryer to stop working>>>

**********

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