Saturation of electron plasma waves excited by a spatially localized driver and the electron acceleration in these plasma waves are studied by means of numerical simulations. The model consists of the set of Zakharov equations for the electron plasma and ion acoustic waves coupled to the quasi-linear equation for the electron distribution function. The saturation levels of both electron plasma and ion acoustic waves and the number and energy of hot electrons are studied in function of the driver wave number and amplitude and the size of the excitation region. A correlation between the onset of the strong Langmuir turbulence and the efficient electron heating is discussed.