The Rotor-Rooter guy just left and my water heater is no longer dumping water directly into the drain. All it was was a bad o-ring. The o-ring belonged to some kind of trap that the repair guy said didn't even need to be there since I had a relief valve in place. He thought that someone was trying to make a little extra money by installing it.
I'm glad that I don't have to pay for water, because I'm sure a few gallons were being dumped each hour. I'm just glad that it is repaired. I felt bad about wasting water, but I did let the management company know what was happening.