The Toilet That Flooded My Apartment – MY QUESTIONS CLARIFIED

: I posted a message a few days ago regarding the toilet in my new apartment. I dont : think my questions were clear – as you were kind enough to respond and gave me some : important information, but didnt quite answer the questions I hoped to have answered.: To recap, my son used the toilet in our new apartment for the first time (he urinated : only), and we immediately left to finish moving out of our old apartment. When we came : back a few hours later, there was water coming out our front door. Inside, there was at : least 3 inches of water in almost every room! Upon investigation, we found that the : water was coming from the toilet. We turned off the water and called the manager. He : came and plunged the toilet. Immediately, the water level in the toilet bowl (which had : been overflowing) dropped. The manager said that the toilet was clogged, and that is : why our apartment flooded. I say that a clogged toilet doesnt usually overflow enough : water to flood an entire apartment – unless something else is wrong with the toilet. When : we looked in the tank, we noticed that the flapper wasnt closing, because the flapper : line/lift chain (or rubber line attached to the lever and the flapper) was folding up and : catching onto itself, preventing the flapper from closing onto the valve in the bottom of : the tank. We think that this is why the flooding occurred – the toilet was clogged and : because the flapper did not seal onto the valve, the water continued to run into the bowl : for three to four hours. For weeks after this incident , that same flapper/lift chain : mechanism continued to catch and fold onto itself, preventing the flapper from dropping : down to seal the valve. It got so bad that we ended up leaving the tank lid off and : manually replacing the flapper onto the valve after each flush. My questions: How could : the toilet be clogged when we had only used it once and then only to urinate? : Why would a clogged toilet flood a large apartment? Ie, would an otherwise : functioning but clogged toilet cause such a flood – or would there have to be : something else wrong with the toilet to make it release so much water?You are quite correct, your descripition of the flapper hanging up most likely caused the mess. Often when a flapper hangs the water level in tank is so low that the incomming water from ballcock sprays up and onto lid which then leaks out onto floor. Although a stopped up toilet will overflow, it usually a couple of gal. at most. if this is a 1.5 toilet then it would take repeated flushs to overflow. on rare occasions I have seen the incomming water pressure keep the flapper from seating and causing a overflow if toilet is plugged.