Abstract: A diagnostic tool for an energy conversion appliance, which may be a heating, ventilating or air conditioning appliance, comprises a sound receiving transducer (1) coupled to output means (5) to identify, discriminate and log the acoustic signatures of a sequence of events within an operating sequence of an appliance. Individual event occurrences are identified by comparison of a received acoustic signature with stored data to determine whether an event occurrence has occurred in a proper manner and at a correct position in the sequence of a plurality of event occurrences.

Abstract: A diagnostic tool for an energy conversion appliance, which may be a heating, ventilating or air conditioning appliance, includes a sound receiving transducer (1) coupled to output elements (5) to identify, discriminate and log the acoustic signatures of a sequence of events within an operating sequence of an appliance. Individual event occurrences are identified by comparison of a received acoustic signature with stored data to determine whether an event occurrence has occurred in a proper manner and at a correct position in the sequence of a plurality of event occurrences.

Abstract: An information display module comprises a liquid display module sandwiched between a back lens module and a transparent front window module, said front window module comprising a main body part and at least one light guide for conducting light from an LED, said light guide and main body part of the front window module being formed integrally with one another and interconnected by a connecting section which defines a tortuous light transmission path whereby a transmission of light from the LED light guide to the main body part of the window module is suppressed.