The plumbing is all copper, but the nipples on the water heaters are steel. I seem to be getting a lot of corrosion (green copper) near the water heaters. I thought to just put a CPVC female/male coupling between the nipples and the copper. Could the green just be an excess of flux?
The green is either flux or a corrosion from a small leak. Just use teflon paste or tape and torque new copper threaded fittings onto the steel threaded fittings coming out of the water heater. The more fittings and different types of materials you use, the more opportunity there is for problems down the road. Never had an issue in four decades doing as described.
