Hot water circulating systems are hot water systems that circulate hot water through the hot water piping so that obtaining hot water is nearly instantaneous. They are often referred to as re-circ, re-circ or re-circulating pumps.
Hot water recirculation systems deliver hot water to fixtures quickly without waiting for the water to get hot. Rather than relying on low water pressure common in most water lines, re-circulating systems use a pump to rapidly move water from a water heater to the fixtures. Hot water recirculation systems can be activated by the push of a button, or by a thermostat, timer or motion sensor. Systems that use a thermostat or timer automatically turn on the pump whenever water temperature drops below a set-point, or when the timer reaches a setting. These systems ensure that hot water is always available at the faucet without any waiting. Systems that use a thermostat or timer may use more energy than on/off button or switch operated systems,