Abstract: The improved assembly of the invention includes a novel valve which comprises a housing having a first channel, specifically a single fluid-receiving channel, extending therethrough and a second channel, specifically a valve body-receiving channel, intersecting the first channel to obstruct it or not, depending on the position of a floating, specially contoured valve body in the second channel. The valve body is automatically variably positioned in the second channel in response to relative pressures exerted on its opposite ends. One of its ends is exposed to fluid pressure, such as from a cold water line connected to the first channel, such pressure being passed to such end from the first channel via a small side passageway. The opposite end of the valve body is exposed to fluid pressure passed to it from a remote source, such as a hot water line, as by a pressure conduit. The hot water line does not directly connect with nor cause hot water to pass near or through the housing.