Posted by Chris Shaw (76.190.201.74) on April 26, 2008 at 19:46:13:
I had a new Rheem hot water heater installed in Mar-08. Each time hot water is pulled for an appliance, and the tank refills, about 1/2 cup of water is expelled from the relief valve. We are currently catching this in a pail. I realize from the Rheem literature that this copper relief pipe is sometimes connected to a drain in the basement. However, my question is: why have none of the previous 3 hot water heaters I have purchased over a 30-year lifetime of homeownership, ever had to express water due to expansion? I thought that's what hot water heaters did - they heat water, which expands (and stays in the tank!). I have called Rheem, but a representative simply reads me his script about expansion of hot water, which I already understand. Does anyone have an explanation?