Caleffi521519AC Mixing Cal 3-Way Thermo Mixing Valve with checks, Low-Lead Brass with Adaptor

I have solar hot water and my water tank temperature varies from 125 to about 170 degrees. I have the valve adjusted to maintain a steady temperature of 125 degrees. I'm not sure of the exact temperature range, but I think this valve ranges from just below 120 degrees to just above 130 degrees. Other valves limit the maximum temperature to somewhere just below 125 degrees, which could be a little unacceptable in some circumstances. You'll want to confirm the operating temperature range if you're still shopping around. The competing valves often run a few degrees below their stated maximum so make sure the valve is advertised to go above your target temperature by a few degrees. By measuring the temperature of this valve I have determined that the output water temperature remains steady although the pressure and tank temperature varies quite a bit. I'm very satisfied with the installation and the temperature consistency. The product quality is high and It comes with check valves plus a temperature guage to help you keep an eye on the output temperature.

Heavy duty, solid design, very well machined (fit and finish). Controls temperature within 7 deg or so with varying water usage including startup (from zero water draw to demand), within a degree or so with constant water draw. This unit might be a bit oversized for my house, hence the initial variation at startup (a couple smaller point of use devices wouldlikely work better for me) - but thats not a fault with the product. Will buy caleffi ptoducts again.

Installed in a system with a boiler serving both an air handler and indirect hot water tank. In my system, this valve serves two benefits: 1. I can raise the storage temperature high enough to kill legionella bacteria; 2. effectively, it takes much longer to empty the hot water tank--so the boiler does not shift priority from heating the home to heating hot water as often. That's particularly useful on cold winter days.The valve itself is made in Italy and seems to be very accurate and responsive to small changes to the dial. This is a get-what-you-pay-for product. Highly recommended.

This is a VERY high quality water mixing valve. I installed it as a whole house scald preventer at the oil fired hot water tank. It works perfectly and let's me set the house water temp at any level including over 120 degrees (if I choose).

This valve allows me to use a smaller tank and keep water in tank at 140 degrees to protect against bacteria growth.Nice quality from Caleffi. Make sure you chose the one with the integral check valves.