Service Manual
1Service
General Operation
How the boiler operates
The Knight wall mount boiler uses an advanced stainless steel heat exchanger and an electronic control module that allows fully condensing operation. The blower pulls in gas and air and pushes flue products out of the boiler through the heat exchanger and flue piping. The control module regulates blower speed to control boiler firing rate. The gas valve senses the amount of air flowing into the boiler and allows only the right amount of gas to flow.
How the control module operates
The Knight wall mount control module receives input from boiler sensors. The control module activates and controls the blower and gas valve to regulate heat input and switches boiler, DHW and system pumps on and off as needed. The user/installer programs the module to meet system needs by adjusting control parameters. These parameters set operating temperatures and boiler operating modes. Boiler operation can be based on boiler outlet water temperature, boiler return water temperature or system supply temperature, depending on the parameter setting.
Sequence of operation
Table 1 shows control module normal sequences of operation for space heating and DHW operation. The combined operation sequence is for a typical application, programmed to provide DHW priority.
Access modes
User
The user can adjust space heating set point using the UP and DOWN buttons at any time during normal operation. By entering the USER code (0704), the user can also change temperature units, time and date, and night setback settings. In user mode, the following parameters can be viewed but not changed: Boiler outlet water temperature in DHW mode; boiler model number; software version; total operating hours, and total cycles.
Installer
Most parameters are available only to the installer, accessible only by entering the installer access code (5309).
Saving parameters
To save parameters:
Press the ENTER/RESET button.
To keep parameter settings only for a current operating cycle:
Press the MENU/EXIT button 1 time to return to the parameter listings; press again to return to the menu listings.
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