With our current system our DHW is heated by our OWB as a sub-zone off a plate hx that then runs into a hot water heater that has a copper coil hx inside it. Our new system configuration will involve removing the plate hx and have the water from our storage tank run directly into the house as well as the hx inside the hot water heater. We were contemplating running new lines to the storage tank (involving much trenching and tunneling under a concrete pad ~ 4') so a hx could be installed in the storage tank as opposed to the hot water heater. Is there any advantage to this? Or would it be better (and much less work) to keep the hx in the hot water tank as is? Many thanks!