Attempting to remove copper pipe from water lines which are plastic. The problem is I cannot separate them. The copper pipe will turn freely but will not come apart from plastic fitting.
Normally a water heater has 24" of metal piping before you convert over to PEX or CPVC.
Being that is the case, we use 24" flex connectors, either copper or stainless steel. Not the braided supplies, but the corrugated supplies.