Since you are getting the E13 but get no leaks, I recommend that you check the faucets for the fill hoses to make sure that they are fully open. Shut these faucets and pull the water hoses off of the back of the washer. Place the ends of the hoses in a bucket and briefly turn on the faucets to check the water pressure and flow from the hoses. If the water supply going to the washer is inadequate, it could cause this problem. Check the inlet screens for the water valves on the back of the washer to make sure that they are not clogged with debris or deposits. If you find no problems with the water supply, check the installation of the drain hose system. An improperly installed drain hose could cause the fill water to siphon out of the washer as noted above. If you find no problems with the drain hose installation then I recommend that you unplug the washer and check the air pressure hose on the water level pressure switch. I provided an image and information on that switch below.