Thermal conductivity κ(T ) and thermoelectric power S(T ) studies on (Y,Gd)Ba2(Cu1−xMnx)3O7−δ (x 0.02) superconductors are presented here. Thermal conductivity for all the samples exhibits a hump below the superconducting transition temperature Tc. The peak height of the hump decreases with the Mn content in both the Yand Gd-based systems, barring GdBa2(Cu0.99Mn0.01)3O7−δ. The peak height reduc...