A flow generator for delivering breathable gas to a patient includes a processor coupled with operation sensors and a user interface. The processor is programmed to generate at least one of time-based or event-based messages relating to at least one of flow generator operation, flow generator service, flow generator use, patient health, peripheral devices and services, patient treatment, and reminders. Time-based messages are generated at predetermined time intervals based on either time of use or elapsed time. The event-based messages are generated based on signals from the operation sensors. The user interface is configured to deliver the messages to at least one of a display, a flow generator service provider, the patient and a physician. By this system, operation of the flow generator is facilitated and enhanced.