A sulfur hexafluoride (SF6) insulated circuit breaker system having a controller coupled to at least two different sensor devices and operative to control a heat output of an SF6 heater based on signals from the sensor devices. An SF6 insulated circuit breaker system includes a controller coupled to a circuit breaker position indicator and operative to control an SF6 heater based on a signal from the contact position indicator sensor. An SF6 insulated circuit breaker system has a controller coupled to an SF6 density monitor and operative to control an SF6 heater based on a signal from the SF6 density monitor.