The Grundfos Comfort System is a hot water pump and valve combination that delivers you hot water in an instant to any faucet or bath in your home. The Comfort System uses a water pump at your water heater along with the patented under sink valve beneath the sink furthest away from the pump. This patented hot water recirculation combination creates a pressure differential that allows the cold and cool water in the hot water supply line to “by-pass” (at low volume) into the cold supply line through a thermostatically controlled valve that is mounted under the sink furthest from the water heater.
This water recirculating combination works together to keep the water in your hot water line at temperature to provide “no-wait” hot water throughout your home. The timer on the hot water recalculating pump makes it more efficient during downtime, like nights or mid-day. It’s quiet, maintenance-free, and keeps
Comfort System Hot Water Recirculation Installation and Operating Instructions