A huge part of your problem is also that you are healing these dungeons well over geared for the job.

Consider that you are likely i230-240 in a dungeon that has a minimal ilevel of 170-180.

No consider that if they made content that was particularly heal heavy at i230, it would be nearly impossible to complete at i180, since healing throughput, hp levels and defensive abilities won't cover that large of a gap.

You're basically complaining that your job isn't to spam heal a tank. Welcome to something that isn't totally boring.