The unit on the bottom left (inside the flap) is a heat exchanger. It tends to get wet around this area when the pump isn't clearing the water up into the tank properly. You can check this by removing the heat exchanger, and lifting the flap located approx 18" into the opening, underneath should be relatively dry - if not the pump isn't working. The pump and associated float valve cut-out is located to the left of the flap you should have just lifted.
An owner..., January 2012
