LG Front-Load Slow Leak

[Apesbrain]

Our 2015 WM3370HWA front-load washer has developed a slow leak.  We first noticed it the day after doing laundry when my wife saw that some water had pooled in the cracks in the tile floor in front of the machine.  I cleaned it up and slowly over the next 15 minutes it reappeared.  Checked the rear of the washer and saw some water on the floor back there also, but not as much as front.  Checked all hoses/drain and no sign of leakage.  No water at all on rear panel of washer.  Cleaned up all water and ran a few empty load cycles.  Leak did not reappear and I hoped it was gone, but later that night it reappeared.

Turned off both water feeds overnight then opened the hot side for 24 hours with no issue.  Closed hot, and opened cold, and within 12 hours the water reappeared at the front of the washer.

I have a technician coming out next week, but I'm concerned about his ability to diagnose/solve the issue because the problem is intermittent and the leak very small.  If you've had any similar experience and can point us to the part(s) within the washer that might need repair/replacement, it would be appreciated.  Thanks.

[Whitegoodshelp (Andy)]

Hi. If you turned off the water taps and the leak stops it has to be leaking from one of the fill hoses where it connects to the wading machine or the tap. Try holding some kitchen roll or tissues i around there. If there is the slightest leak it’ll soak it up like a sponge. 

[Apesbrain]

Hi Andy, thanks for your reply.  I spent a fair amount of time today watching the rear of my washing machine with a flashlight/torch.  (Fun, huh?)  The leak is not coming from the hoses.  It appears as a slow drip at the bottom edge of the rear of the machine approximately in the center.  It stops after some time once the cold water tap is closed.  I am thinking that something in the electronic valve system interior to the washer and located at the top rear where the hoses attach is the source.  The cold water pressure in our building is very high (80 psi) and that may have contributed to the problem although it has worked well and without issue for five years.

[Whitegoodshelp (Andy)]

Hi. I’m struggling to work out how the leak can stop when the water supply is turned off. A drip from the bottom of the drum may well be running from higher up. Once you observe it dripping disconnected machine from mains and use a tissue to touch around the drum to see if water is running from higher up. 

[Apesbrain]

Just watched a good video on this:

https://www.youtube.com/watch?v=zPT1_ao0wkE

[Whitegoodshelp (Andy)]

That's the only other thing it could have been if turning the water valves off stops the leak. I didn't think of it though because it's exceptionally unusual. I can't remember the last time I had one do that. 

[Apesbrain]

Just wanted to close the loop on this: took me a while to get parts (LG 5220FR2075L & 5220FR2006H) and arrange for repair help, but replacing the two water inlet control valves above did solve the problem.  The leak was on the cold side, but it made sense once all the trouble had been gone through to unstack the dryer and open up the washer to replace both valves.  Thanks.

Edited January 11, 2021 by Apesbrain