NB: this post is a departure from my usual focus on
technology as I delve into DIY appliance repair. If
you're looking for just the How To Fix Your LG Washer Dryer without
the background, see below.
In April 2007 we purchased an LG Washer - Dryer combo appliance
(WM3431HW) after looking for a solution to our
laundry space constraints. The year before we had moved into
a downsized home and were looking to downsize our appliances as
well. From the very beginning we were thrilled - as much as
you can be when it comes to laundry at least. It was
short-lived.
Even before the one-year warranty had expired the unit stopped
drying clothes properly and a few days later the auto-dry setting
stopped working altogether. We called LG and they referred us
to a local appliance repair service. A few days later the
service technician arrived (his appearance didn't inspire a great
deal of confidence) and proceeded to give me a lecture on how to
clean the lint from the unit - something we'd been doing all
along. After cleaning the lint he could, he declared it fixed
and left. It wasn't fixed.
After several more visits from the same service technician (at
least he stuck with it) and replacing a pump, a sensor, and the
main control board (twice) the unit began working as expected
again. This took a full-month and four visits and resulted in
numerous scratches to the unit and to the (new) laundry room floor;
not to mention a month without a functioning dryer. We live
in Bellingham, Washington where hanging clothes out to dry in May
is not a viable option due to the rain.
In November of 2008, scarcely 6-months after the prior repairs
had been completed, the unit began exhibiting the same behavior as
before with the auto-dry setting not working. This time I
immediately called LG where they informed me that they would be
unable to fix the unit as the warranty had expired. They had
a record of the prior issue and resolution but refused to
acknowledge that this was the very same issue and the unit had not
been repaired properly. They were very kind and apologetic
but utterly useless. As we had purchased an extended warranty
when we purchased the unit I called the extended warranty provider
and left a message as requested (thrice), I have not yet heard back
from this provider - four-weeks and counting.
After four-weeks of damp clothing I became frustrated enough to
try and determine the cause myself - along with some strong
encouragement from my wife. I had seen the service technician
access the inside of the unit and knew that it was quite simple to
open the unit.
The short-version is that the design of the unit is such that
lint build-up inside an internal component obstructs the dryer's
airflow to the extent that the drying function is reduced and the
unit's logic board incorrectly reports the clothes as being dry,
even when they are not.
How to Fix Your LG Washer - Dryer Combo When The Dry
Function is Not Working
I am not an appliance service technician, referenced no official
guides, and used no special tools to accomplish this repair.
That said, you are on your own here if something goes wrong - good
luck!
- Turn off the water and unplug the unit
- Remove the top cover - 2 screws at rear
- Remove the interior cover - screws around perimeter
- You should see this:

- Locate the air return/lint drain
- Vertically oriented plastic component below the blower
housing
- Unclamp the water supply hose - see below
- Remove the heat sensor from air return - see below
- Unscrew the blower unit
- You may want to clean the blower fan of lint while you're at it
- it's under the white cover
- The seal between the blower unit and the washer drum had
disintegrated on my unit, I ordered a replacement from here.

- Lift off the blower unit and carefully set aside
- From the rear of the unit unscrew the air return
- There is one screw which is accessed from the shipping lock
hole - it is awkward but keep at it and you'll get it
- Clean and/or rinse the air return to remove any lint - I found
about a softball sized clump
- Re-assemble in the reverse order, plug it in, turn on the
water
- Wash and DRY your clothes again
Let me know if this worked or didn't work for you and let LG
know too!
-Paul