  We investigate thermoelectric transport through Andreev interferometers. We
show that the ratio of the thermal and the charge conductance exhibits large
oscillations with the phase difference $\phi$ between the two superconducting
contacts, and that the Wiedemann-Franz law holds only when $\phi=\pi$. A large
average thermopower furthermore emerges whenever there is an asymmetry in the
dwell times to reach the superconducting contacts. When this is the case, the
thermopower is odd in $\phi$. In contrast, when the average times to reach
either superconducting contact are the same, the average thermopower is zero,
however mesoscopic effects (analogous to universal conductance fluctuations)
lead to a sample-dependent thermopower which is systematically even in $\phi$.
