A process for the solution polymerization of olefins with improved on-stream time is provided. The solution polymerization process of the current invention comprises a method for the on-line removal of foulant material from one or more heat exchangers downstream of a polymerization reactor. Removal of foulant material is accomplished by deliberately applying a positive pressure differential across a heat exchanger. In the process of the current invention, reactor shut down is not required for the purpose of cleaning foulant material from a heat exchanger.