Elbow cross piece

[John Dodge]

Does the inside of the mixing elbow have any cross pieces inside or is that just a build up of gunk?

 

[robin]

on mine

there is a divider seperating top and bottom, on top is hot sea water, on bottom is hot air exhaust. Problems arise when top and bottom rust into one and water backs into air exhaust, into cylinders etc. If you cant tell that there is a difference, I would replace it and have peace of mind.