1 Service
General Operation
How the boiler operates
The Crest uses an advanced stainless steel heat exchanger and electronic control module that allows fully condensing operation. The blowers pull in air and push flue products out of the boiler through the heat exchanger and flue piping. The control module regulates blower speeds to control the boiler firing rate. The gas valves sense the amount of air flowing into the boiler and allow only the right amount of gas to flow.
How the control modules operate
The Crest boiler is equipped with a SMART TOUCH control module. The SMART TOUCH control module receives inputs from boiler sensors and external devices. The control module activates and controls the blowers and gas valves to regulate heat input and switches the boiler, Hot Water Generator (HWG), and system pumps on and off as needed. The user programs the control module to meet system needs by adjusting control parameters. These parameters set operating temperatures and boiler operating modes.
Sequence of operation
Table 1A (page 12) shows control module normal sequences of operation for space heating and HWG operation. The combined operation sequence is for a typical application, programmed to provide HWG priority.
Access modes
User
The USER can adjust various space heating and HWG operating variables:
- Navigate to the Initial Setup Screen (FIG.
-From the Home Screen (FIG.
-Press ENTER on the Password Screen (FIG.
The USER can set the date and time and adjust temperature set points, and outdoor reset points.
Under the ADVANCED SETUP menu, the USER can change the TEMPERATURE UNITS and the LCD BACKLIGHT TIMER.
Installer
Most parameters are available only to the INSTALLER, accessible only by entering the installer password (5309) in the Password Screen (see the User Section).
Service Manual
Figure 1-1 Home Screen
Figure 
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