I have an iPhone 6 purchased directly from Apple, so nearing the end of it's warranty, but has developed a little bit of Crescentgate.

I had already had the phone replaced because of the same issue, but the replacement has developed the same problem.

If I have this replaced now, what sort of warranty will be on the replacement. I am reluctant to have it swapped out for a refurbished unit to have the new one fail for some other reason a few days later (which has happened), to then find I am not covered because my original warranty term is up.

Does a repaired or replacement iPhone carry some sort of mandatory (say 3 month) warranty regardless of the original warranty period?