Re: Tankless Water Heater, CNG?
I've got an old Wolter. The installation venting issue was that you needed at least a foot of flue pipe before the mushroom vent. The vent needed a foot of clearance from other stuff like dorade vents hatches etc. that could cause a downdraft. This ensures that the flow goes out the pipe and not back into the boat. For the unit itself you needed about four inches of clearance on the side and eight above. There needed to be an air supply about 20 sq inches. While tankless units are lots better now the same principles probably apply