A flow generator for a CPAP system configured to deliver a pressurized flow of respiratory gas to a patient's airways includes a housing and a motorized fan positioned within the housing. The motorized fan is configured to pressurize the flow of respiratory gas. In addition, an outlet port is provided in the housing. The outlet port is configured to connect to a humidifier or an air delivery tube and is in communication with an outlet of the motorized fan. The flow generator further includes a water collection receptacle in communication with the outlet port and the motorized fan outlet. The water collection receptacle is configured to collect water entering the flow generator through the outlet port before the water reaches the motorized fan outlet.