in this paper we present a spatially homogeneous locally rotationally symmetric (lrs) bianchi type -v perfect fluid model with heat conduction in scalar tensor theory proposed by saez and ballester. the field equations are solved with and without heat conduction by using a law of variation for the mean hubble parameter, which is related to the average scale factor of metric and yields a constant value for the deceleration parameter. the law of variation for the mean hubble parameter generates two types of cosmologies one is of power -law form and second the exponential form. using these two forms singular and non -singular solutions are obtained with and without heat conduction. we observe that a constant value of the deceleration parameter is reasonable a description of the different phases of the universe. we arrive to the conclusion that the universe decelerates for positive value of deceleration parameter where as it accelerates for negative one. the physical constraints on the solutions of the field equations, and, in particular, the thermodynamical laws and energy conditions that govern such solutions are discussed in some detail.the behavior of the observationally important parameters like expansion scalar, anisotropy parameter and shear scalar is considered in detail.