Lochinvar Sync Condensing Boiler 1.3 - Manual (Page 9)

General Operation
How the boiler operates
The SYNC uses two (2) advanced stainless steel heat
exchangers and two (2) electronic control modules that allow
fully condensing operation. The blowers pull in gas and air
and push flue products out of the boiler through the heat
exchangers and flue piping. The control modules regulate
blower speeds to control total 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 module operates
The SYNC control modules receive input from boiler sensors.
The control modules activate and control the blower and
gas valves to regulate heat input and switches boiler, Hot
Water Generation (HW) and system pumps on and off as
needed. The user/installer 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 shows control module normal sequences of
operation for space heating and HW operation for each
individual control module. Additionally, the control
modules are programmed to synchronize their combined
modulation rates in order to maximize total boiler efficiency.
The combined operation sequence is for a typical application,
programmed to provide HW priority.
Access modes
User
The user can view all of the settings on the LCD screen. By
entering the user password (0704), the user can adjust the
User Set Point, Outdoor Shutdown, Night Setback, Boost,
HW Boiler Output Set Point, Backlight Time, and Backlight
Brightness settings.
Installer
Most parameters are available only to the installer, accessible
only by entering the installer access code (5309).
1
Service
(continued)
9
Service Manual