My low point drains will not drain the tank itself either.. Because the low points are not connected to the system in a way that makes it possible.
The only hose from the tank to the system is routed to the pump. The pump draws the water from the tank and thru the system. Simply opening the low points will not pull the water from the tank...
You should have a separate drain plug for the tank itself.
You should be able to drain the hot water tank thru the low points however.. But you will probably have to open the pressure relief valve to do it..
Good luck!
Mitch
