| 摘要 |
An integrated diagnostic module is connected as an integrated part of a hot water heating unit. The module has a circuit board with an electrically isolated power supply and sensing leads connected to sensors in the operating system and coupled to components of the hot water heating unit. The diagnostic module has a visual display and descriptive panel 37 secured to the circuit board as a part of one wall of the housing. The display panel has a vertical row of LEDs 78-87 in a operating display section 42 and a vertical row of LEDs 90-95 in a malfunction display section 43 to the opposite sides of a heater illustration 77. The panel carries indicia to form a descriptive display of the operational status and of the state of the components. Each system state and component is provided with a suitable sensor having a switch connected in the circuit, and connecting the LED of an opto-isolator which includes a transistor turned on by the LED. Each transistor is connected with one of the LEDs units, and selected transistors are connected in an interrelated logic whereby two different conditions control one of more LEDs. The operating section includes a "standby" LED 80 and a "heat" LED 81. A pump display includes a "pump-on" LED 82 and a "cool-down" LED 83. An ignitor LED 84 and a series of three or more burner LEDs 85-87 provide information as to the state of the burner. The malfunction section includes a water flow LED 92, a temperature LED 93, a low gas pressure LED 94 and a restricted gas flow LED 95. Flue LEDs 90, 91 can be provided to monitor a blocked flue or excessive CO in the flue gases. <IMAGE> |
