We study the electron thermal transport in granular metals at large tunnel conductance between the grains, $g_T gg 1$ and not too low a temperature $T > g_Tdelta$, where $delta$ is the mean energy level spacing for a single grain. Taking into account the electron-electron interaction effects we calculate the thermal conductivity and show that the Wiedemann-Franz law is violated for granular metals. We find that interaction effects suppress the thermal conductivity less than the electrical conductivity.
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