Lochinvar 2.5 Boiler User Manual


 
1 Service (continued)
Service Manual
19
HWG Minimum User Set Point
This setting controls the minimum user set point for the
tank temperature. The installer can adjust this by accessing
parameter B10.
HWG Maximum User Set Point
This setting controls the maximum user set point for the
tank temperature. The installer can adjust this by accessing
parameter B11.
HWG Boiler Set Point
When a HWG call for heat becomes active, the control will
use the HWG boiler set point to determine the firing rate of
the boiler based on the boiler outlet water temperature.
This parameter can be changed by the installer by accessing
parameter B12.
HWG Boiler Offset
This parameter reflects the degrees above HWG boiler set
point the outlet temperature can go before the boiler will
shut off. This parameter can be changed by the installer by
accessing parameter B13.
HWG Boiler Differential
This parameter reflects the degrees below HWG boiler offset
the outlet temperature has to go before the boiler turns on.
This parameter can be changed by the installer by accessing
parameter B14.
C: Outdoor Reset
SH Set Point at Low Outdoor Temperature
When the outdoor air temperature drops to or below the
Low Outdoor Temperature setting (parameter C3), the water
temperature will be at this setting (see FIG. 1-6). However, if
the user set point is set lower, the water temperature will be
limited by the user set point instead. This parameter can be
changed by accessing parameter C1.
SH Set Point at High Outdoor Temperature
When the outdoor air temperature rises to or above the
High Outdoor Temperature setting (parameter C4), the water
temperature will be at this setting (see FIG. 1-6). This
parameter can be changed by accessing parameter C2.
Low Outdoor Temperature
When the outdoor air temperature drops to its minimum
(C3), the water temperature will be at parameter C1 (FIG.
1-6). As the outdoor temperature continues to drop, the water
temperature set point will continue to rise. However, if the
user set point is set lower, the water temperature will be limited
by the user set point instead. This parameter can be changed by
accessing parameter C3.
High Outdoor Temperature
When the outdoor air temperature rises to or above this set
point, the water temperature will be at parameter C2 (FIG.
1-6). This parameter can be changed by the installer by
accessing parameter C4.
Outdoor Air Shutdown
When the outdoor temperature rises above this point, the
control will block all SH demands (HWG demands will still
be active). This parameter can be changed by the installer by
accessing parameter C5.
SET POINT AT
LOW OUTDOOR
TEMPERATURE
(SH)
SET POINT
SET POINT AT
HIGH OUTDOOR
TEMPERATURE
LOW OUTDOOR
TEMPERATURE
HIGH OUTDOOR
TEMPERATURE
Figure 1-6 Outdoor Air Reset Curve