A system and method for retrofitting appliances for use with an appliance automation system and for augmenting and expanding the function of an existing appliance automation system. A universal transmitter is provided which can receive instructions from a central audio/visual controller or from any instruction issuing appliance automation controller. The universal transmitter is configured for use with a single appliance and can be used with any appliance having an infrared receiver to which it transmits infrared signals. Control signals, issued by a hand-held infrared transmitter or any appliance automation controller which is connected to the signal-carrying bus, direct the universal transmitter to transmit infrared signals to the appliance being controlled. The present invention also senses whether the appliance is in an on or off state and operates to prevent a power on command from being issued if the appliance is already on. A plurality of receivers placed in different rooms in a building or structure are all connected to the signal-carrying bus (preferably the AC wiring bus) and thus convey instructions which they receive to the transmitter(s) and their associated appliance(s).