Installing a Caleffi 521 mixer

We got a sweat model. Adapter ends are to be taken off to solder so as not to melt the o-ring that joins body to adapters. Why not sweat directly w/o adapters ? There are plastic check valves that go in the hot and cold inlets, so those would melt.

So far so good. Fit it, solder the ends , then when I went to install it one check valve wouldnt push in very far. Manual said it might take a small amount of force to get it to click in. Okay.. push… 'ping' off it goes inside the pipe to a tee and down.

Long story ensues involving vac/blow in different ports, wife getting a face full of water and possibly flux, and discovering the check will only exit in one orientation.

We had soldered the outlet adapter to the cold pipe. The check will move past that adapter if you convince it to.

The mixer body is clearly labelled H C Out. I didnt notice any markings on the adapters, but I'll admit I didnt inspect closely. We're just not going to use the cold inlet check. I dont think it's a big deal in our setup. Cant swap them as they're slightly different lengths and I'd be into a bunch of re-do.

I think Caleffi should make these 3 port adapters identical.

Adding, we did get the check out of the pipe in the end.