Model: WF338AAW/XAA
Serial: W03F54AQ800196T 2008.08
I have a Samsung Front Loader that intermittently won’t drain. 1 of 4 loads will either finish soaking wet or throw a “nd” code. I’m an Electrical Engineer by day, a pretty handy DIY-er and I have had the machine apart 4-5 times now and I am totally stumped on this one.

Before we get into it, I have replaced:
DC96-01700A Pump Assembly with cleanout assembly and Inlet hose assembly
DC92-00154A PCB Main (Control Relays and Power Supply)
DC97-03716C Water Level Sensor (pressure sensor)
Per the troubleshooting manual pamphlet on the washer:
* Check for kinks on drain hose – Done
* Check for restrictions in the drain hose – Done
* Close the door and press the pause/start button – Done but this doesn’t help solve anything..
* When it is freezing.. – It wasn’t freezing
* Check if water level signal is correct – Replaced the sensor, and it was fine before.
* Do Drain pump test – Done, but pump spins every time, may or may not actually drain..
* Check for hose twist – Done, nope.
* Check if pump reads 120V AC – Done, 120v..
* Read winding resistance of pump motor 14.2 ohms+-7% – Done. Both pumps old and new were fine.
* Check pump at CN3 pin 3 on PCB.. – Same as the last 120V check but still not a problem.

I’ve checked the cleanout many times (and I replaced the whole assembly).
I have blown out all the hoses at least twice (inlet hose, outlet hose).
I have leveled the machine, and tipped it forward, and backwards.
I’m now only testing with just water in the tub, so no new clogs showing up.
The biggest thing that seems to be a clue is that when the pump starts laboring for a really long time, I’ll go over and lift the drain hose down and put it into a bucket, and that will start the chain reaction and then a ton of water comes out fast.. It couldn’t get over the hump (32” up into the drain on the wall) on its own. I even hooked it up in the garage and it only had to go up 22”, but that didn’t solve it. Still throws the code the same way.. This is the theme time and time again. Sometimes if I let it sit after it throws the code, it will then drain. Really seems like this is a design flaw, but it use to work.
Anybody got any ideas here?

Did you ever figure out the issue? I am going through exactly the same issue now. Thanks