Lochinvar KNIGHT 399 - 800, Service Manual

Page: 18 / 44

18
Service Manual
1
Service
SH Differential
The SH differential sets how many degrees below the turn off
temperature the temperature has to go before the boiler will turn
on. This parameter can only be changed by the installer by
accessing parameter
B5 . The temperature range of this
parameter is 0°F (0°C) to 54°F (30°C). The default value is 20°F
(11°C).
C: Data logging
Hours running SH
The hours running SH parameter shows the total number of
hours the boiler has been in the SH firing position. This
parameter can be viewed by the user and the installer by
accessing parameter
C1 .
Hours running DHW
The hours running DHW parameter shows the total number of
hours the boiler has been in the DHW firing position. This
parameter can be viewed by the user and the installer by
accessing parameter
C2 .
Ignition attempts
The ignition attempts parameter shows the total number of
times the boiler has attempted to fire. This parameter can be
viewed by the user and the installer by accessing parameter
C3 .
Show last 10 errors
The control will log the 10 most current errors with the date and
time the error occurred. This parameter can be viewed by the
user and the installer by accessing parameter
C4 .
D: Functions
Reset last 10 errors
The reset last 10 errors parameter allows the error counter to be
reset to 0. This parameter can only be cleared by the installer by
accessing parameter
D1 . Once accessed, press the RESET key to
clear the counter.
Service mode delay
By pressing the pin button on the front of the display for five (5)
seconds, the control will be placed in Service Mode. This will
override all other heat demands. The Service Mode allows the
installer to set the unit to either maximum firing rate or
minimum firing rate for the purpose of combustion analysis.
The delay sets the length of time the boiler will stay in the
Service Mode if no keys have been pressed before going back to
its original state. This parameter can only be changed by the
installer by accessing parameter
D2 . The time range of this
parameter is 0 to 40 minutes. The default value is 20 minutes.
E: DHW settings
DHW boiler set point
When a DHW call for heat becomes active, the control will use
the DHW boiler set point to determine the firing rate of the
boiler based on the actual water temperature. This parameter
can be changed by the installer by accessing parameter
E1 . The
temperature range of this parameter is 50°F (10°C) to 190°F
(88°C). The default value is 180°F (82°C).
SH/DHW switching time
The SH/DHW switching time parameter sets the length of time
the control will stay in DHW Mode when a SH call has been
received. After this time period has expired the control will
revert to SH Mode. If a DHW call is still active the timer will
reset. After the time period has expired the control will revert
back to DHW Mode. This will continue until one of the
demands has been satisfied. This parameter can be changed by
the installer by accessing parameter
E2 . The time range of this
parameter is 10 minutes to 240 minutes. The default value is 30
minutes.
DHW tank set point
By installing a tank sensor, the SMART SYSTEM control can
perform the tank thermostat function. The SMART SYSTEM
control automatically detects the presence of this sensor, and
generates a DHW call for heat when the tank temperature drops
6°F (3.5°C) below the tank set point, and finishes the call for
heat when the tank temperature goes 4°F (2°C) above the tank
set point. This parameter can be changed by the installer by
accessing parameter
E3 . The temperature range of this
parameter is 32°F (0°C) to 212°F (100°C). The default value is
125°F (52°C).
F: Outdoor air reset
Outdoor air reset operation
If an outdoor air sensor is installed, the control will calculate the
water temperature set point based on the outdoor air
temperature. As the outdoor air temperature drops the water
temperature set point increases. This feature allows the boiler to
be more efficient in periods of mild weather, see FIG. 1-1 on
page 19.
Minimum air temperature
When the outdoor air temperature drops below this point, the
water temperature will be at its maximum setting (FIG. 1-1).
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 the installer by accessing parameter
F1 . The
temperature range of this parameter is -30°F (-34°C) to 90°F
(32°C). The default value is 25°F (-4°C).