  We control the direction and magnitude of thermal radiation, between two
bodies at equal temperature (in thermal equilibrium), by invoking the concept
of adiabatic pumping. Specifically, within a resonant near-field
electromagnetic heat transfer framework, we utilize an {\it instantaneous}
scattering matrix approach to unveil the critical role of wave interference in
radiative heat transfer. We find that appropriately designed adiabatic pumping
cycling near diabolic singularities can dramatically enhance the efficiency of
the directional energy transfer. We confirm our results using a realistic
electronic circuit set-up.
