Review on Grundfos 595926 Replacement Comfort Circulator by Mike Sutton

The original one I bought as a replacement had a Watts hot water circulation system that consisted of a pump and this valve exists.The pump will be installed at the outlet of the water heater and the valve will be installed under the farthest faucet.Our water heater is in the basement in the middle of our house and we have bathrooms at both ends so we have a valve in both bathrooms installed under the sinks. The pump is a small fraction HP (1/20) which creates a slight positive pressure. on the hot water line from the water heater. The valves are temperature sensitive and likely use a bimetallic sensing element set at 95 degrees Fahrenheit, I think.When the temperature of the water in the valve is below 35 degrees Celsius, it opens and since the pressure on the hot side is slightly higher, water flows through the valve. into the cold water line until it reaches 95F, at which point the valve should close. This will instantly supply hot water to the faucet so you don't have to leave the water running to heat it up. The system works well as long as the valve works properly. The downside is that if you want cold water in the faucet, it will be warm for a while when you open a cold faucet because the valve releases warm water into the cold line to warm up. Tap water. The valve appears to be made by Grundfos (as is the pump) and sold to Watts for private label, and is a cheap design that doesn't last long. We have highly filtered Lake Michigan municipal water and a newer water softener that works well and both valves have failed after only a few (2-3) years. Honestly, $50 for it is a bargain, but it is what it is and there are no easy alternatives.