What action is suggested if the whistle is confirmed to be non-operational?

Inspecting the whistle isolating cock is a crucial initial step when addressing a non-operational whistle. The isolating cock is a valve that controls the flow of air to the whistle. If the cock is closed or there is a blockage, it can prevent the whistle from operating properly. By inspecting this component first, you can determine whether the issue lies with the supply of air rather than with the whistle unit itself. This targeted approach helps to efficiently diagnose the problem, ensuring that time and resources are not wasted on unnecessary replacements or further checks. It is important to start with the simplest potential causes before moving on to more complex solutions.