Re: Tankless Water Heater, CNG?
Since hot rises on its own ,I'd bet it wouldn't breath well out the transom. CO could be an issue. Any way the pressure inside has to be greater than outside or it inhales to your peril.One way to a bi annual shower is a black solar water bag with a small connection thru deck head into washing area. control valve inside. Unless you run some pipe either shower at the galley sink or pile the dishes in the head.