I asked for a recirculating system to ensure hot water to all taps in my new home. The plumber has installed a passive recirculating device on the COLD water side with an extra line extending from this device to the furthest Cold water tap. He maintains that this uses pressure from the cold water flow to passively circulate water BACK to the heater which will passively circulate the hot water side also. I think that he put it on the wrong side and won’t admit it! Anyone ever heard of this?? It doesn’t work anyway!