water heater drain mod

coolmom42 wrote:


I've been told that the water heater will not drain through the low point drains. Apparently there is a check valve on the incoming cold line. There must be some reason it won't drain through the low point drain on the hot water line, although that doesn't make a lot of sense to me.

It won't drain through the hot line because the intake for the hot line is set high up in the tank. (Hot water rises.) As soon as the tank water level falls below that, it quits siphoning. Draining through the cold line is better, but you don't know just how low the water inlet is inside the tank. Once the water level falls below that intake, it quits siphoning. Another thing is you have to open the pop-off valve to vent the tank so it can drain. That is probably the reason you were told it can't be drained through the low point drains. It is not good for the pop-off valve to be opened like that on a regular basis. It is not an on/off valve. It can lead to premature failure of the pop-off valve.