Abstract: A control system for well stimulation equipment including a source of electrical power, a source of injection fluid, a fluid injection system, and a downhole electrical heater, electrically connected to the source of electrical power includes one or more of temperature and pressure sensors both above and below grade for the purpose of monitoring process conditions. The sensor output is gathered in a computational unit and then manipulated for process control. The control system includes a response time which is defined as the time between a no flow condition at the heater and a shutting off of power, which response time is used to establish a temperature set point for the well stimulation equipment. A method of stimulating hydrocarbon recovery is also disclosed.