I am planning to install a recirc unit to save water. I am leaning toward the Watts 500800 mostly because it is outside in the garage and I won' have to listen to the pump motor. Are there better units ? What is the downside of this unit? I have read that the hot side dumps into the cold side and heats the cold water. Is that True? Is that bad? What other questions should I ask? Also, Isee the units on Amazon For bargain prices. Any Comments?
I am looked at the watts system and the grundfos comfort system. They are the same with the only difference is the color of the pump. They both use the thermostatic crossover valve which gets installed at the farthest faucet on the hot water line. Those crossover valves close once 95 degree water contacts the valve to prevent hot water from entering in to your cold water line. This being true, it also means that anytime less than 95 degree water "is not" contacting the valve, then the valve is "OPEN". Connecting your hot and cold water lines with a normally open valve has it's problems. If the valve is open and you use cold water, water siphons out of the hot water line into the cold water line until the valve closes. This happens because of pressure differences between the hot and cold lines during cold water use. Flushing your toilet, with this valve installed can now fire up your water heater due to siphoning through the open valve. One site explains it more clearly than I ever could. Check out http://www.redytemp.com/hot-water-circulators.htm.