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A client sent this to me. We are going to be installing a new high efficiency boiler later this year. His current system is hot water w/ fintube baseboard, 80% cast iron boiler with a vent damper. City water. Does this look like electrolysis? Any ideas on what to do about it? I'm thinking we need to replace it all. This pipe was located in an attic run - under 12" of insulation.