  Unlike charge, heat flows are difficult to control. We show that, in
mesoscopic conductors, electronic thermal currents can be manipulated with a
magnetic field by using the Aharonov-Bohm effect: the magnetic control of the
interference pattern enhances the thermoelectric effect, while heat transport
can be totally suppressed. In a three-terminal configuration, the flux-induced
broken reciprocity generates a non-local thermoelectric response and translates
to the circulation of heat. This way, efficient thermoelectric generators,
thermal switches and thermal circulators, as well as energy harvesters can be
defined for minimally disturbing thermal management at the nanoscale.
