If the unit is powering the hot water inlet solinoid at the same time as the drain pump then I would say you have a definate controller problem. Something in the control circuitry has shorted acrost and is engageing both at the same time.
Obviously this is not desirable.
If you feel like tracing down circuits you might try back tracking the hot water solinoid to its relay source and see if you might find the bad componant that way. Personally I would not waste my time unless I was feeling lucky that day. And yes I have been lucky more than once but the end results were still the same.
Install a new controll board and you should be fine.
Before you spend the money for the board. Put in a call to LG and see what they have to say about the problem. They have a good reputation for helping their customers solve problems like yours. They may have a better fix than replacement.
If this answer satisfies your question please click the accept button. I will not be paid if you dont.
You can always ask follow up questions after you accept. I will be here to answer them.
If for some reason you are not happy. Please tell me what I can do to put a smile on your face.
Thank you for using Just Answer. Please tell someone about us.
Best regards; The Home Smithy
After you have accepted it is important that you leave positive feedback.