Misworking

[…] which apparatus is furnished with a whistle, which gives a continuous shrill call when the water is too low, or if there should be an over-pressure of steam by reason of any misworking of the safety-valve.

If you are disconcerted when faced with the workings – or misworkings! – of a machine or a computer and someone comes along and explains them simply and clearly in terms that can be understood, you become more confident.