Many Valley neighborhoods went up within a few years of each other, so toilets on the same street are often about the same age. A tank that refills when nobody has flushed usually has a flapper letting water through, and hard water can be tough on soft parts like flappers. A toilet that keeps running often has a fill valve wearing out. If the toilet rocks at the base, the mounting has usually gone loose and the wax seal may fail next, and in a second floor bathroom a failed seal can leak into the room below.
Repair usually has the advantage. The parts inside can be replaced one at a time, and parts suited to hard water are worth asking about. Replacement makes sense when the porcelain is cracked, when repairs keep stacking up on a spent fixture, or as an upgrade, since modern units use far less water and a bidet can be added to any replacement.
One thing that saves time is knowing that a toilet that backs up again and again usually points to a drain line problem, which has its own service and page. Everything on the toilet itself, whether it runs, rocks, leaks, needs a new seal, needs replacing or needs an upgrade, is performed by or under a licensed contractor, set and sealed properly, explained in plain English, and decided by you at your pace.
