Method of detecting errors in the connections in a humidification system

Various control methods can indirectly determine incorrect connections between components in a respiratory therapy system. For example, errors in the connections can occur between a patient interface, a humidifier and/or a gases source. The methods can indirectly detect if a reverse flow condition exists or other error conditions. A reverse flow condition can occur when gases flows in a direction different from an intended direction of flow. The detection of the reverse flow condition can be indicative of likely errors in connections between the humidifier, patient interface and/or gases source.