RECIRCULATION PUMPS
Are you waiting at your sink or shower for the water to get hot? In a standard home, when a hot water valve is opened, the water in the hot water pipe has usually been sitting in the pipe for a while and is no longer hot. Anyone needing hot water turns the faucet on and waits until hot water from the water heater tank reaches the fixture. In large homes, especially at the plumbing fixtures farthest from the water heater, this can take a while and the water running in the meantime is wasted.
Hot water recirculation systems circulate water in the hot water pipes, so that hot water will always be available and less water is wasted. This causes the water heater to run more, but how much more depends on the type of system. If the home uses a solar water heating system, this is less of a concern, since heating water is inexpensive or free.
WHAT IS A HOT WATER RECIRCULATION UNDERSINK SYSTEM?
This systems is typically used on retrofits but may also be installed in new construction. A pump is installed under the bathroom sink farthest from the water heater. The pump contains a sensor which switches the pump on when water temperature drops below 85รยฐF and switches it off when water temperature reaches 95 รยฐF. Newer pumps are adjustable from 77รยฐ to 104รยฐ.
In this system hot water is re-circulated intermittently. Hot water is returned to the water heater via the cold water pipes. This raises the temperature of the cold water slightly, but it returns to the usual cold temperature in a short time.
HOT WATER RECIRCULATION SYSTEM INSTALLED AT THE WATER HEATER

TANKLESS WATER HEATERS GAINING IN POPULARITY
Tankless water heaters have been in use in Europe and Asia for over 20 years.ย They are just starting to gain wider acceptance and use in the United States. Tankless water heaters are more energy efficient than traditional tanks because they heat water as it is used, rather than heating and re-heating water in a storage tank.ย They are also common in Europe and Japan in large part because they take significantly less physical space.
RECIRCULATION PUMPS