This paper presents an improved genetic algorithm using novel crossover and mutation (IGA-NCM) to solve the combined heat and power economic dispatch (CHPED) problems. The basic genetic algorithm (GA) has been augmented in three aspects. First, the selection operation is excluded from GA in order to avoid excessive losses of population diversity. Second, two kinds of adaptive crossover operations are used to sufficiently excavate the information of parents and yield potential offsprings. Third, a novel mutation operation is used to replace a few genes of each crossed offspring by those of the other crossed offsprings' parents, which can further improve their quality. Furthermore, a new constraint handling method is proposed to repair the mutated offsprings and enable them to enter feasible regions easily. Experimental results show that our proposed IGA-NCM algorithm out-performs the other ones according to computation accuracy and runtime. Therefore, it is a potential alternative for the CHPED problems with or without prohibited operating zones.