LG washer erratic draining problem and resolution

[wildimaginations]

I had a customer with an erratic draining problem on her LG washer.  Most of the time, everything would work fine but about every 4th to 8th wash load, the OE error code would come up and would not drain.  I've come to her aid every time for the last 3 months trying to figure this thing out and every time I was there, it would work fine.  Today, I was able to get it to not drain and found the problem.  The drain pump was working fine but when it wouldn't drain, I could hear the drain pump cavitating like there was air inside the pump.  It would take about a minute of pumping till all of a sudden you could hear the water slowly get sucked into the drain pump and start draining out of the washer. 


In the picture below, I pulled the drain line siphon hose and found that it was clogged up.  I used some compressed air to blow it out and now the washer is draining perfectly.  What's happening is the siphon hose was plugged up and not allowing an air break at the drain line U turn when the pump stops causing the drain water to pull water out of the tub to the point of pulling air into the drain pump and trapping it inside the pump.  When the next time it tries to pump water out, the air is stuck inside the drain pump cavitating until some water from the tub gets into the pump area.  By clearing out the siphon break hose, the air break causes the water to go back down towards the drain pump and removes the trapped air inside the pump.  Now the pump is fully primed and ready to pump water out when it's called for.







Just thought I'd share this with everyone what I learned today.

[AJ]

Interesting, thanks for sharing.

[john63]

<<<I had a customer with an erratic draining problem on her LG washer.  Most of the time, everything would work fine but about every 4th to 8th wash load, the OE error code would come up and would not drain.>>>

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In 9 out of 10 cases---this is due to a weak/failing (intermittently slow) DRAIN MOTOR.

Since the MODEL & SERIAL number are not provided---it's hard to know for sure. Most often this occurs in LG washers at or about 5 years old and used often (a family of 4 for example).


The function of the black anti-siphon hose (pictured) is to prevent *continuous draining* of water---especially right after a drain cycle has completed---and rinse-water begins entering the tub.

Particularly in circumstances---where an installer has jammed the drain hose far into a drain standpipe (into the "trap") or secured the hose to a utilitub---with the outlet at the bottom of the utilitub.

Early LG washers were prone to complaints of : "Fills & Tumbles/Loses Water--- Fills Again & Tumbles/Loses Water---repeatedly.

The black anti-siphon hose was added to remedy this symptom.

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<<<What's happening is the siphon hose was plugged up and not allowing an air break at the drain line U turn when the pump stops causing the drain water to pull water out of the tub to the point of pulling air into the drain pump and trapping it inside the pump.  When the next time it tries to pump water out, the air is stuck inside the drain pump cavitating until some water from the tub gets into the pump area.  By clearing out the siphon break hose, the air break causes the water to go back down towards the drain pump and removes the trapped air inside the pump.  Now the pump is fully primed and ready to pump water out when it's called for.>>>

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Correction---the Pump Housing is *always* "primed" whenever water is in the tub.
At the end of a drain/spin cycle---at least 2 to 4 cups of water will remain in the Pump Housing.

[wildimaginations]

<<<

Correction---the Pump Housing is *always* "primed" whenever water is in the tub.
At the end of a drain/spin cycle---at least 2 to 4 cups of water will remain in the Pump Housing.

The model number is WM3677HW.  Serial #508KWBY00165.




I always thought that way too but this job proved me wrong.  There was air trapped inside the drain pump and there was no way to get it out with the siphon hose plugged up.  The next time you come across an LG washer with the siphon hose, pull it out and plug the line and see what happens.  It's really interesting.

[tgoods]

I believe a pump can cavitate with a tub full of water.  I've seen it a lot with dishwashers, especially Frigidaires.  Thanks for the heads up. You may have saved me from some frustrating callbacks in the future.

[john63]

<<<There was air trapped inside the drain pump and there was no way to get it out with the siphon hose plugged up.>>>

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Anecdotal observation.

And incorrect.

The *original* LG washers did NOT have an anti-siphon tube at all and draining wash water was never an issue.

Improperly installed drain hoses---*was* a concern---hence the black tube/anti-siphon.

This washer was manufactured August 2005---more than 6 years old.

The DRAIN MOTOR is the likely culprit

Not trying to convince *you* to believe otherwise---however---others reading this thread should be informed.

[wildimaginations]

The drain pump was replaced 3 weeks earlier.  Drain pump was not the problem. Customer still called me back with the same issues.

[john63]

<<<The drain pump was replaced 3 weeks earlier>>>

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What other critical details have you left out or forgotten ?

Was the drain hose attached to a standpipe---and wrapped with tape to prevent water from gushing out?

A partially-restricted drain can give the symptoms you've described initially.

The main point here is that---we don't want other servicers and DIYers---to say:

"Hey my LG washer drains erratic too---let's check that little black hose-thingy at the top of tub."

The function of the anti-drainback hose is to prevent siphoning of water during wash---if the drain hose has been improperly installed (not inhibit draining---even if it becomes plugged).

I have never encountered a problem with a blocked anti-siphon tube *preventing drain*.

The original LG washers (which did not have a siphon tube) drained just as fast and reliably.

In 14 LG training seminars---not once has this been discussed as a possible "Slow or No Drain" issue.

An incorrectly installed drain hose---is a possibility to consider when servicing an LG washer with the complaint that you've described.

[john63]

Alrighty---I have just completed two loads of wash in my LG washer (both were Speed Wash cycles).

For this "laboratory test" (in our laundry room)---the "offending" black hose was disconnected from the nipple fitting at the top of the tub---and plugged/blocked.

The findings were stunning---the wash water drained precisely the same as it had when the little black anti-siphon tube was still attached to the tub. Confounding.

During my test procedure---it dawned on me that---perhaps when "Wild" had used compressed air to blast the little black hose *clear*---he had dislodged a partial drain restriction in the section of DRAIN HOSE that "runs" from the Pump Housing-to-the-plastic-gooseneck.

And then---incorrectly concluded that indeed---a blockage at the black anti-siphon tube was the source of the *erratic drain* complaint.

These findings can also be performed by anyone & everyone with an LG washer---for verification/confirmation.

[tgoods]

I don't know why you're going to all this trouble to discredit Wild.  He has been the LG expert on this site and I appreciate his informative posts.  Since the drain problem is so intermittent, two wash cycles may not re-create the problem.  Try leaving vent hose plugged for a few weeks and see what happens.  As for me, if I find an intermittent draining LG washer, I will check for all possible causes including a plugged vent hose.

[john63]

<<<I don't know why you're going to all this trouble to discredit Wild.>>>

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So---if someone posted that a Whirlpool washer is not agitating or spinning but *does* fill and drain the water...

And has found that the DRIVE MOTOR is the cause...

To you---that is not only "accurate or possible" but also inappropriate to challenge?


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<<<Try leaving vent hose plugged for a few weeks and see what happens.>>>

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A moot exercise---if you've read any of the above posts carefully---you'll notice that the *original* LG washers did NOT have an anti-siphon tube.

There are still LG washers being used in this configuration---without issue.

[wildimaginations]

John63... try leaving the anti siphon hose plugged for 6 months.  That's when the customer starting noticing the problem but let it go for 3 months before it got to me and I was on it for 3 months as well.  Also, this was an erratic problem so it didn't happen all the time. She says it happens about every 8th to 10th wash load.  This customer uses this washer 7 days a week, 2 times a day.  You only did it 2 times, but I kept testing this machine till it gave me an OE error code.  Fill and drain, fill and drain, fill and drain. 

Yes I did use compressed air to blow out the anti siphon hose, but before I did, the drain line would clear out properly whenever it was working.  After blowing the line clear, there was no difference in the flow of water drained out and there was no debris.  I checked by putting the end of drain hose into a 5 gallon bucket to see if any debris came out.  Little pieces of lint debris came out but that's it.

Another thing I forgot to mention is that this is a washer / dryer combo.  So the lint buildup problem may have something to do with it.  Don't know though.

[ApplianceGuru]

I could see a siphoning drain hose siphoning all the water out of a drain pump, and leaving an air pocket inside the drain pump. 

You would think the drain hose would allow air to be pushed out of the pump when the tub filled with water again.

I will definitely keep this tip in mind if I run into intermittent drain problems on an LG combo.

[john63]

If the DRAIN HOSE is installed correctly...

Not installed completely into a standpipe---down to the drain trap...

No tape has been installed on the drain hose at the top of the drain standpipe...

Not installed in a utilitub near the bottom ---slow draining of the *utilitub* will cause siphoning of water from the washer---if the LG washer is an older model without the anti-siphon hose OR in a newer model with a plugged siphon tube...

There will be no issues or complaints with "slow" or no drain".

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 <<<As for me, if I find an intermittent draining LG washer, I will check for all possible causes including a plugged vent hose.>>>

<<< I will definitely keep this tip in mind if I run into intermittent drain problems on an LG combo.>>>

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That's perfectly fine.

Others would be wise to avoid wasting their diagnostics effort/time trying to identify slow/no drain complaints---by incorrectly assuming that the small/black anti-siphon hose at the top of the tub assy---is the culprit.