Knight WH 399, Service Manual

Page: 20 / 48

1
Service
20
Service Manual
SH1 - SH3 Offset Set Point
The SH Offset sets how many degrees above set point the
temperature has to go before the boiler will shut off. This
parameter can only be changed by the installer by accessing
SH1, 2 and 3 Offset Set Point parameters. The temperature
range of these parameters is 0°F to 20°F. The default value
is 10°F.
SH1 - SH3 Differential Set Point
The SH Differential sets how many degrees below the offset
the temperature has to drop before the boiler turns back
on. This parameter can only be changed by the installer by
accessing the
SH1, 2 and 3 Differential Set Point parameters.
The range is 0°F to 60°F. The default is 20°F.
3-Way Valve Time
The optional Lochinvar Multi-Temperature Loop Control
Board (MTLCB) can be used to control the supply temperature
up to three (3) sub-loops, corresponding to each of the three
(3) SH set points, through the use of 3-way mixing valves. To
ensure the MTLCB will control these temperature properly,
it is necessary to let the control know how much time these
mixing valves require to fully open and close. Program
this time into the
3-Way Valve Time parameter. Since this
parameter applies to all of the mixing valves used, the actual
open/close time must be approximately the same for each
one. The minimum setting is 1 second, and the maximum
setting is 255 seconds. The default setting is 20 seconds.
Data Logging
Reset log errors
The reset log errors function clears the last 10 errors log.
Functions
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 any 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
the
Service Mode Delay parameter. The time range of this
parameter is 1 to 10 minutes. The default value is 10 minutes.
Freeze Protection Pump On
The SMART SYSTEM control will turn on the boiler and
system pump outputs whenever the inlet temperature drops
below this setting. This is done to prevent the water in the
heat exchanger from freezing. Certain low-temperature
applications (such as snow melt) can operate at temperatures
around freezing, so this setting needs to be lowered in these
cases. The installer can adjust the temperature at which the
pump outputs are turned on by accessing
Freeze Protection
Pump On parameter. The minimum setting is -3°F (-19°C),
and the maximum setting is 45°F (7.2°C). The default setting
is 45°F (7.2°C).
To save any changes and return to the Home Screen, press
the RIGHT SELECT [HOME] key. To return to the Status
Screen without saving the changes, press the LEFT SELECT
[EXIT] key.
Display Timeout
This is the time in which the display remains illuminated.
The range is 10 seconds to 10 minutes. The default is 3
minutes.
Temperature Settings
Space heating (SH) set point parameters limit boiler operating
set point. When the outdoor air sensor is connected, the
boiler operating set point is calculated using the outdoor
reset curve. Residential boilers with inputs less than 300,000
Btu/hr require the use of a control that automatically adjusts
water temperature in relation to heat demand. Outdoor reset
is a feature that increases the temperature setting of the boiler
as outdoor temperatures rise. The outdoor reset parameters
can be accessed through the
Outdoor Reset menu.
Space Heating (SH1, SH2, SH3) Set Point
There are three (3) individual space heating set points for
better zone control. These are listed as
SH1 Set Point through
SH3 Set Point . When outdoor reset is used, these set points
provide an upper limit to the reset curve for each zone. If
multiple space heating set points are calling for heat, the
highest set point has priority. If the outdoor sensor is not
connected the boiler will operate at
SH Set Point . For models
requiring outdoor air reset (WH 55 - 285), the display screen
will indicate “Outdoor Sensor Fault” until the sensor is
reconnected. The range of this parameter is
SH Minimum Set
Point to SH Maximum Set Point . The default is 125°F (52°C).
Space Heating (SH) Minimum Set Point
The SH Minimum Set Point sets the minimum water
temperature set point allowed for SH Set Point (1 - 3)
adjustment. The user or installer will not be able to program
the control with a lower SH set point. This parameter can
only be changed by the installer by accessing the
Minimum
SH Set Point parameter. The temperature range is 32°F (0°C)
to the space heating maximum set point. The default value
is 32°F.
Space Heating (SH) Maximum Set Point
The SH Maximum Set Point sets the maximum water
temperature set point that can be used for space heating.
The user or installer will not be able to program the control
with a higher SH set point. This parameter can only be
changed by the installer by accessing the
Maximum SH Set
Point parameter. The temperature range of this parameter is
the space heating minimum set point to 180°F (82°C). The
default value is 180°F.
CAUTION
Mixing valves are required for the
protection of any low temperature loops.
NOTICE
Never put the Freeze Protection Pump
on a setting lower than the Freeze
Protection Burner On setting.