I have a brass male inlet boiler drains that I use to put water in my hot tub and it leaks when I turned it on. Since it was against the wall inside of this white case, how do I replace it? Do I just turned counter clock-wise until it loosen? Do I have to worry about anything breaks? It's a really tight space to turn this thing. I don't know anything plumbing work but it looks like the white plastic thing case is sandwich between the inlet boiler drain and water pipe. I can't really tell from this angle. If can I loosen this current boiler drain, I can replace with a new one easily. I'm just worry I might damage the water pipe.

 

Where did the water leak from? If it leaked around the stem for the knob your packing nut may need tightening a bit. If it leaked where the hose attaches your hose may need a new gasket.

 

Pilot Dane, thank you so much. You just saved me from paying a bunch of money for service calls. And yes, all I did was tighten the nut around the knob.