We have a tank less water heater, it works well, saves gas, but there is a lot of water waste while we wait for hot water at the far end of the house. We are in California, have a major drought going in need to do something about the water going down the drain. When we had a regular 40 gallon water heater we had a recirculating pump and it worked fine. We were told that we couldn't use the pump on the tank less heater. Does anybody know of a device or method that can do the job for the tank less heater?