The ATLAS experiment, located at the LHC at CERN, requires a flexible and comprehensive Level-1 Trigger configuration to meet its diverse scientific goals. A robust framework, presented in this contribution, validates such a configuration throughout every year of data-taking. The Level-1 Central Trigger system is built with software-programmable custom hardware and issues the trigger decision depending on this configuration. Testing involves simulation and a hardware replica of the system itself. With the advanced monitoring capabilities of the system, we check that any input signal in the CTP will produce the expected trigger items in the expected time frame, and with the expected trigger information (in both hardware and simulation). This presentation covers testing methods and challenges due to the ATLAS detector's complexity and introduces a new user interface for the testing framework.