Lochinvar CREST 3 - Manual (Page 10)

1
Service
10
Service Manual
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. 1-5).
- From the Home Screen (FIG. 1-1), press MAIN
MENU, then press SETUP on the Main Menu
Screen (FIG. 1-2).
- Press ENTER on the Password Screen (FIG. 1-3)
(do not enter any values) and then press INITIAL
SETUP on the Setup Screen (FIG. 1-4).
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).
Figure 1-1 Home Screen
Figure 1-2 Main Menu Screen
Figure 1-3 Password Screen