My sister has a 2016 303RLS 5th wheel and from day one had an issue with the furnace. When new the it would not work and the dealer replaced the circuit board saying they had got it wet while washing the unit. On the next trip out furnace again failed to operate and after much discussion the dealer again replaced circuit board again saying they got it wet. Again furnace did not work and she has had no success getting any further assistance from dealer or Grand Design. On a trip we met a couple with same unit who stated they had the same issue and their dealer had relocated the circuit board however we cannot locate anyone with info on the issue and after 3 years of ownership the furnace does not function. She has ignored the issue as here in Florida we seldom need the furnace however on an October trip to Virginia it was needed. I have a 2017 337RLS and have had no problems with furnace. Any help or advice would be appreciated. Steve Cook