When a shower or other faucet is located some distance from a tankless heater it may take a bit longer for the water to reach the desired temperature. In order to save this water, a re-circulating pump can be installed under a nearby sink. Such a system diverts the cold water back into the supply system until the hot water reaches the pump and then shuts itself off. A manual or programed switch is used to activate the pump. The best systems employ a local and/or remote switch for activation. _{See the Taco D'Mand Systems carried by our sponsor Pex Supply}