I have an LG washer that displays the "NOT DRAINING. CHECK THE DRAIN HOSE & FILTER" error. I've replaced the drain pump, blown out the drain hose (it's clear), completely removed the tub to drain hose (it's clean) and cleaned filter housing, but still get error. When the error occurs, I open the drain hose and get no more than a quarter cup of water coming out so I know the system is draining. Also tried Tub Clean and got the error. Any suggestions as to what is wrong? Thank you.