This depends on which flavour you have initially used. For example, if you were to refill your vape with an Original Menthol Ice Cool flavour where before you have been using Original Menthol, there wouldn’t be any issues as the menthols would combine and ultimately your new flavour would not be affected. However, if you were using an Original Cherry Bomb here you previously had Original Ice Blast, then it might be advisable to change the coil before you do so, as the incompatibility of the flavours would affect the flavour of the Cherry which will be overtaken by the Ice Blast.
Try to use similar flavours if you don’t want to replace your coil yet, and be sure to clean your vape tanks when changing flavour profiles. If you were a previous Cirro e-liquid user, you shouldn’t have any need to change your coil as our liquid is the same recipe as the old Cirro e-liquids.