Unvented Undersink Water Heaters. For D.I.Yers.

OlympusMons: 
 

I have never found one that correctly installed has leaked. They are a fit and forget fitting. …

Z.

depends on the composition of the brass and its age. Dezincification can occur which leaches out the zinc leaving just copper. I have stripped out old copper pipes and the brass fittings are the first things to snap on bending. You often see it on the brass waste outlets in basins which turn to cheese, or perhaps that has more to do with unblocking chemicals used. Also, they do tend to weep slightly over time and need nipping up occasionally.

Perhaps the limescale on the insides of the pipework and joint will seal any minor imperfections, and/or protect the brass from corrosion.

Z.

OlympusMons: 
 

I have never found one that correctly installed has leaked. They are a fit and forget fitting. …

Z.

depends on the composition of the brass and its age. Dezincification can occur which leaches out the zinc leaving just copper. I have stripped out old copper pipes and the brass fittings are the first things to snap on bending. You often see it on the brass waste outlets in basins which turn to cheese, or perhaps that has more to do with unblocking chemicals used. Also, they do tend to weep slightly over time and need nipping up occasionally.

Perhaps the limescale on the insides of the pipework and joint will seal any minor imperfections, and/or protect the brass from corrosion.

Z.