A heat exchanger assembly includes a first and second manifold. Each of the manifolds includes a tubular wall and a pair of manifold ends spaced from each other defining a flow path. A plurality of flow tubes extend between the manifolds and are in fluid communication with the flow paths. An insert is slidably disposed in the flow path of the first manifold. The insert divides the flow path into a plurality of chambers. The chambers and the flow tubes cooperate to establish a plurality of flow passes. The flow passes are for directing a heat exchange fluid through the heat exchanger assembly. The chambers are useful for orienting and connecting plumbing connections at various locations along the manifolds.