My Whirlpool front loader would not drain. It was the water pump.
My installation just had a pan with no drain hose to outside. Hopefully this got fixed with your 7 year newer Newmar.
Pump was easy to replace once the washer was out of the cabinet. Was fairly difficult to get back in. Washer was heavy with the built-in concrete weights in it. Mass dampens out vibrations.
Good Luck and let us know what you find.