: I have a newly constructed home with Gerber gravity toilets (28-972). On several occasions the toilets have backed up and the water continues to flow. If we do not recognize the problem right away then the water would flow forever!

: I understand why low-flow toiletss will back up easier and that "double flushing" can help but I do not understand why the water would keep running. This just happened with our neighbor as well in their upstairs bathroom and caused thousands of dollars in damage.

: Please explain and make recommendations to improve our situation.

Scott,
The toilet backing up and water continuing to run, are two different problems, which can occur at the same time. I would check the flapper to see if anything is "hanging" it up. With some toilets, the ball can be set too close to the flapper, causing the flapper to not seal. There have been cases of water spraying up from the fill valve and hitting the tank lid, dripping down onto the floor.