Caleffi 5213 series mixing valves..

Jean-David Beyer

I looked up their mixing valves and this series has anti-scald mechanism. Sounds dandy to put between my domestic hot water heater that I might wish to run at 140F and my shower. Now many of the Caleffi mixing valves come with a thermometer on the output, and they supply one optionally for the others.

However they say they are not to be used with the valves with anti-scald feature.
Any idea why not?

I have a fancy mixing valve from Lawler for my darkroom. It comes with check valves, a pressure balancing mechanism, and a temperature control mechanism with an anti-scald feature. It comes with a well with a big thermometer in it. Since Lawler supply a thermometer with their valve, I wonder why Caleffi advise against it.