“I installed this at the junction point of the feed manifold from my boiler to all the zones in my house, a direct replacement of a failed automatic bleed valve. This Taco 400-4 works like a charm. Upon refilling of the system, it immediately started hissing, which is good. Overall it took about 20 minutes to purge all the air out of the system. Very impressed. The material, construction and heft of this Taco 400-4 is quite good.”