A manifold for distributing a circulating fluid, such as water, to multiple zones of a hydronic system, such as a hot water heating system. The manifold is of unitary construction and includes a plurality of distribution branches and an air scoop extending from a common header conduit. The air scoop extracts air from the water being circulated through the manifold. The air scoop may be coupled to an air vent to purge air from the water. The manifold may also include an expansion tank coupling that is disposed on the header conduit to couple the tank to the header conduit. The air scoop may include a housing affixed to the header conduit and a baffle that protrudes into the header conduit to direct air into the housing so that it can be vented through the air vent. The baffle may be angled relative to the longitudinal axis of the header conduit.