Reply To: Copper/Cast Iron Union Corrosion

Steel boilers have been plumbed with copper tubing for half a century without worry about corrosion. As long as the system is sealed without leaks, so no fresh oxygen comes into the system regularly through makeup water, there will not be the problem. There is more of a problem that can occur from improper reaming and acidic water; both of which can be avoided. Teflon tape at the threads of such bi-matal connections can add extra precaution.