These systems are designed to move hot water from your water heater to your most remote fixture within seconds. At the push of a button the cool water you normally let run down the drain is circulated back to the water heater through the cold water line so it isn’t wasted. Systems can easily be installed under the sink farthest from your water heater.
Learn more about these systems here.
Systems can be activated by an on/off button, motion sensor, thermostat or timer. Thermostats or timers automatically turn on the pump whenever water temperature drops below a set-point, or when the timer reaches a setting. Although these systems ensure that hot water is always available at the faucet without any waiting, they may use more energy than an on/off button due to more frequent recirculation cycles.
While limiting wait time these may or may not help with water conservation. These can be installed with gas/propane or electrical connections. They do not require a tank for storing and maintaining hot water. Water is heated instantly and on demand only, eliminating the need to store and constantly heat water. Tankless water heaters can provide an endless supply of hot water which means the capacity of your water tank does not limit the use of hot water.
For more information, see Energy Star Tankless Water Heaters.
The City as well as many other water providers and state agencies have looked into the effectiveness of these systems over the years and have not seen significant water savings data to justify a rebate program. The City’s rebate programs are based on a cost-effective threshold for the avoided cost of water that is saved. Water savings varies widely per household and is generally quite minimal, i.e less than 5 gallons a day. (For more info you can click here). The City certainly encourages all customers to evaluate the benefits of installing these systems, but does not offer rebates on them at this time.