  We study the low temperature properties of the differential response of the
current to a temperature gradient at finite voltage in a single level quantum
dot including electron-electron interaction, non-symmetric couplings to the
leads and non-linear effects. The calculated response is significantly enhanced
in setups with large asymmetries between the tunnel couplings. In the
investigated range of voltages and temperatures with corresponding energies up
to several times the Kondo energy scale, the maximum response is enhanced
nearly an order of magnitude with respect to symmetric coupling to the leads.
