KBXII-SER Rev F
Service Manual
Models: 400 - 801
This manual must only be used
ƽ WARNING
by a qualified heating installer /
service technician. Read all
instructions, including this manual
and the Knight XL Installation and
OperationManual, beforeinstalling.
Perform steps in the order given.
Failure to comply could result in
severe personal injury, death, or
substantial property damage.
Save this manual for future reference.
Service Manual
Please read before proceeding
Installer
–
Read all instructions,
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
ƽ WARNING
NOTICE
including this manual and the Knight
XL Installation and Operation Manual,
before installing. Perform steps in the
order given.
Consider piping and installation when
determining boiler location (see the Knight
XL Installation and Operation Manual).
User – This manual is for use only by
a
qualified heating installer/service
Any claims for damage or shortage
in shipment must be filed immediately
against the transportation company by the
consignee.
technician. Refer to the Knight XL User’s
Information Manual for your reference.
Have this boiler serviced/inspected by
a qualified service technician at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
Handling ceramic fiber materials
REMOVAL OF COMBUSTION CHAMBER LINING
The combustion chamber insulation in this appliance contains ceramic fiber material. Ceramic fibers
can be converted to cristobalite in very high temperature applications. The International Agency for
Research on Cancer (IARC) has concluded, “Crystalline silica inhaled in the form of quartz or cristobalite
from occupational sources is carcinogenic to humans (Group 1).” Normal operating temperatures in this
appliance are below the level to convert ceramic fibers to cristobalite. Abnormal operating conditions
would have to be created to convert the ceramic fibers in this appliance to cristobalite.
ƽ WARNING
The ceramic fiber material used in this appliance is an irritant; when handling or replacing the ceramic
materials it is advisable that the installer follow these safety guidelines.
Avoid breathing dust and contact with skin and eyes.
• Use NIOSH certified dust respirator (N95). This type of respirator is based on the OSHA
requirements for cristobalite at the time this document was written. Other types of respirators may
be needed depending on the job site conditions. Current NIOSH recommendations can be found on
manufacturers, and phone numbers are also listed on this website.
• Wear long-sleeved, loose fitting clothing, gloves, and eye protection.
Apply enough water to the combustion chamber lining to prevent airborne dust.
Remove the combustion chamber lining from the appliance and place it in a plastic bag for disposal.
Wash potentially contaminated clothes separately from other clothing. Rinse clothes washer thoroughly.
NIOSH stated First Aid.
Eye: Irrigate immediately.
Breathing: Fresh air.
3
Service Manual
Please read before proceeding
When servicing boiler –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
Boiler water –
• Thoroughly flush the system (without boiler
connected) to remove sediment. The high-efficiency
heat exchanger can be damaged by build-up or
corrosion due to sediment.
• Do not use petroleum-based cleaning or sealing
compounds in the boiler system. Gaskets and seals in
the system may be damaged. This can result in
substantial property damage.
• Do not use “homemade cures” or “boiler patent
medicines”. Serious damage to the boiler, personnel,
and/or property may result.
• Continual fresh make-up water will reduce boiler life.
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger, and
causes failure. Addition of oxygen carried in by makeup
water can cause internal corrosion. Leaks in boiler
piping must be repaired at once to prevent the
introduction of makeup water.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited
propylene glycol solutions which are specifically
formulated for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used in hydronic
systems.
4
Service Manual
What is in this manual?
Service
Maintenance
• Service and maintenance schedules
• Address reported problems
• Inspect boiler area and boiler interior
• Clean condensate trap
• Check all piping for leaks
• Check air openings
Near boiler piping
• Typical system components
The Knight XL display
• Display panel readout, buttons and their functions
• Flue vent system and air piping
• Check water system
• Check expansion tank
Control module inputs
• Control module inputs and options
• Check boiler relief valve
• Inspect ignition electrode
• Check ignition ground wiring
• Check all boiler wiring
• Check control settings
• Perform start-up and checks
• Check burner flame
• Check flame signal
• Check flue gas temperature
• General maintenance
Control module outputs
• Control module outputs and options
General
• How the boiler operates
• How the control module operates
• Access modes -- user and installer
• Sequence of operation -- Domestic Hot Water
(DHW)/space heating
• Review with owner
Control panel menu access
• Cleaning boiler heat exchanger
• Oiled bearing circulators
• Accessing programming mode and locating menus
(See separate guide covering the interface.)
Troubleshooting
Control panel parameter access
• Accessing and changing parameters from the display panel
• Troubleshooting table - No display
• Checking temperature sensors
• Sensor tables
• Troubleshooting table - Fault messages displayed on
boiler interface
Quick start information -- parameter
table
• An index of available adjustments and readouts, where to
access them and where to find detailed information.
• Combustion analysis procedure
• Gas valve adjustment procedure
Knight XL operation
• A: General
• B: Temperature Setting
• C: Data Logging
• D: Functions
• E: DHW Settings
• F: Outdoor Reset
• G: Anti-cycling
• H: Control Modes
• I: Circulation Pumps
• J: Building Management System (BMS)
• K: Service Notification
5
Service Manual
1 Service
Near boiler piping
This piping reference is included to specify the Near Boiler Piping specific to the Knight XL. This piping scheme is important
for proper operation of the SMART SYSTEM control. See the Knight XL Installation and Operation Manual for more detailed
piping diagrams.
DOMESTIC HOT
WATER PUMP
DIRT SEPARATOR
INDIRECT
SYSTEM SENSOR
DOMESTIC
HOT WATER
TANK
SYSTEM PUMP
Y-STRAINER
(RECOMMENDED)
BOILER PUMP
TO FLOOR
DRAIN
6
Service Manual
1 Service
(continued)
The Knight XL display
NAVIGATION DIAL
The information on the bottom of the display shows the functions of the two SELECT keys (on either corner), and the
NAVIGATION dial (in the center):
MENU = Left SELECT Key
SETPOINTS = NAVIGATION Dial - Pressing Down
SHDN = Right SELECT Key
7
Service Manual
1 Service
Control inputs
SYSTEM PUMP SPEED CONTROL
GAS PRESSURE SWITCH
DHW THERMOSTAT
ROOM THERMOSTAT /
ZONE CONTROL
LOW VOLTAGE
CONNECTION
BOARD
FLOW SWITCH
SYSTEM SENSOR
OUTDOOR SENSOR
SEQUENCER / BUILDING
MANAGMENT SYSTEM
LOW WATER CUTOFF
O-TEMP
HEAT EXCHANGER SWITCH
INLET TEMPERATURE
SENSOR
OUTLET TEMPERATURE /
HI-LIMIT SENSOR
FLUE GAS SENSOR
AIR PRESSURE SWITCH
LOUVER PROVING SWITCH
FLAME SENSOR
BLOCKED DRAIN SWITCH
SMART CONTROL
MODULE
DISPLAY PANEL
PC INTERFACE
IMG00006
8
Service Manual
1 Service
(continued)
Control outputs
ALARM BELL
LOW VOLTAGE
CONNECTION
BOARD
LOUVER RELAY
RUN TIME CONTACTS
BUILDING MANAGEMENT
SYSTEM
BOILER PUMP
SYSTEM PUMP
DHW PUMP
IGNITOR
BLOWER
SMART CONTROL
MODULE
GAS VALVE
DISPLAY PANEL
PC INTERFACE
9
Service Manual
1 Service
Access modes
General Operation
How the boiler operates
User
The user can adjust space heating and tank target temperatures
by pressing the NAVIGATION dial when “SETPOINTS” is
flashing at the bottom of the display. The date and time, and
the temperature units can also be changed.
The Knight XL uses an advanced stainless steel heat
exchanger and an electronic control module that allows
fully condensing operation. The blower pulls in gas and air
and pushes flue products out of the boiler through the heat
exchanger and flue piping. The control module regulates
blower speed to control boiler firing rate. The gas valve
senses the amount of air flowing into the boiler and allows
only the right amount of gas to flow.
Installer
Most parameters are available only to the installer, accessible
by entering the installer password (5309).
How the control module operates
Saving parameters (reference the Parameter Table -
Table 1-4 on pages 15 - 18 of this manual)
The Knight XL control module receives input from boiler
sensors. The control module activates and controls the
blower and gas valve to regulate heat input and switches
boiler, DHW and system pumps on and off as needed.
The user/installer programs the module to meet system
needs by adjusting control parameters. These parameters
set operating temperatures and boiler operating modes.
Boiler operation can be based on boiler outlet water
temperature, boiler return water temperature or system
supply temperature, depending on the parameter setting.
Please note that the brackets ([]) denote
screen status.
NOTICE
To save parameters and exit programming:
Press the RIGHT SELECT [SAVE] key and then press the
RIGHT SELECT [HOME] key.
To enter a parameter and continue programming:
Press the RIGHT SELECT [SAVE] key 1 time to return to the
parameter listings; press again to return to the menu listings.
Remember to press the RIGHT SELECT [HOME] key when
finished programming in order to save the changes made.
Sequence of operation
Table 1-1 shows control module normal sequences of
operation for space heating and DHW operation. The
combined operation sequence is for a typical application,
programmed to provide DHW priority.
10
Service Manual
1 Service
(continued)
Table 1-1 Sequence of Operation
OPERATION
DISPLAY
1. Upon a call for heat, the gas pressure switch(es) must be closed.
2. Once the gas pressure switch(es) are closed, the control turns
on the appropriate pumps (system and boiler pumps for space
heating, DHW pump for DHW). The flow switch and/or LWCO
must close.
3. The control turns on power to the louver relay. The louver
proving switch, air pressure switch, and blocked drain switch
must close.
4. The control starts a prepurge cycle by initiating the blower.
5. The control starts a trial for ignition by firing the spark
electrode and opening the gas valve.
6. If flame is not detected after the sparking ends, the control will
perform a postpurge, then start another prepurge cycle and try
to light the burner again. On the 501 and larger models, the control
will lock out if this second attempt also fails. On the 400 model,
the control will perform a total of 4 attempts before locking out.
7. If flame is detected, it holds the firing rate steady for a few
seconds to let the flame stabilize, then it begins to modulate the
firing rate based on a set point or some other command (such
as a 0-10V BMS signal).
a
11
Service Manual
1 Service
Table 1-1 (continued from previous page) Sequence of Operation
OPERATION
DISPLAY
8. If the space heating call for heat is active, and the tank thermostat
or sensor starts a DHW call for heat, the boiler will switch to the
DHW mode. If programmed for normal DHW operation (not as
a zone), the DHW pump will turn on first, then the boiler pump
will turn off (boiler and DHW pump operation briefly overlap to
ensure flow is maintained through the unit). This will divert the
boiler’s outlet water from the heating system and send it to the
tank coil instead. The control will then modulate to maintain the
outlet temperature to the DHW boiler set point.
9. If the boiler is not part of a Cascade, and both the space heating
and DHW calls for heat remain active long enough, the boiler will
switch back and forth between the two heating modes until one
of them is satisfied.
10. Once both calls for heat are satisfied, the control will turn off
the burner. The blower will continue to run during the postpurge
period.
11. Any pumps that are running will continue to run for their
respective pump delay times before turning off, unless
programmed to remain on continuously. A 60 second anti-cycle
period will start, which will delay any new call for heat until it
times out.
12. In Standby, ready to start a new cycle.
12
Service Manual
1 Service
(continued)
Display panel menu access
Table 1-2 Use this procedure to access menus from the display panel
SCREEN
STATUS
BUTTON
OPERATION
DISPLAY
[SHDN]
Press the RIGHT SELECT soft key [SHDN].
[YES]
Press the LEFT SELECT soft key [YES].
Press and hold the LEFT SELECT soft key [MENU]
for five (5) seconds.
[MENU]
Rotate the NAVIGATION dial clockwise until 5 is
displayed (first digit on the left).
Press the NAVIGATION dial to select the next digit.
Rotate the NAVIGATION dial clockwise until 3 is
shown in the display.
Press the NAVIGATION dial 2 times to move to the last
digit. Rotate the NAVIGATION dial counterclockwise
until 9 is displayed.
[SAVE]
Press the RIGHT SELECT soft key [SAVE].
Rotate the NAVIGATION dial counterclockwise to
select a category.
13
Service Manual
1 Service
Display panel parameter access
Table 1-3 This is a typical example of accessing a parameter, shown for parameter Temperature Settings, MIN
SH Setpt
SCREEN
STATUS
BUTTON
OPERATION
DISPLAY
This example shows how to access parameter Temperature Settings. The first display shown is at the beginning
of the menu listings, after entering the installer access code.
Rotate the NAVIGATION dial counterclockwise until
the arrow (>) is next to TEMPERATURE SETTINGS.
Press the NAVIGATION dial one time.
Rotate the NAVIGATION dial counterclockwise until
the arrow (>) is next to MIN SETPT.
Press the NAVIGATION dial one time.
Rotate the NAVIGATION dial to the desired
temperature.
[SAVE]
[EXIT]
Press the RIGHT SELECT soft key [SAVE] one time.
Press the LEFT SELECT soft key [EXIT] if all desired
changes have been made.
[HOME]
Press the LEFT SELECT soft key [HOME].
14
Service Manual
1 Service
(continued)
Parameter table
Table 1-4 This table lists SMART SYSTEM control module parameters and where to access them
User Access
Installer Access
See
Menu
Description
Page
Display Modify Display Modify
Time and Date
18
18
18
18
18
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Software Version (read only)
Temperature Units (ºC/ºF)
SH Night Setback Offset
SH Night Setback On Times
Yes
No
Yes
No
Yes
Yes
Yes
No
No
SH Night Setback Off Times
DHW Night Setback Offset
DHW Night Setback On Times
DHW Night Setback Off Times
Display Timeout
18
18
18
18
19
19
19
19
No
No
No
No
No
Yes
No
No
No
No
No
No
No
Yes
No
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
SH1 Set Point
Minimum SH Set Point
Maximum SH Set Point
Yes
Yes
Yes
Yes
SH1 Offset
19
19
19
19
19
No
No
No
No
Yes
Yes
No
Yes
Yes
No
SH1 Differential
SH2 Set Point
SH2 Offset
Yes
No
Yes
No
Yes
Yes
Yes
Yes
SH2 Differential
No
No
SH3 Set Point
SH3 Offset
19
19
19
19
Yes
No
No
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
SH3 Differential
3-Way Valve Time
Reset Log Errors
19
No
No
Yes
Yes
Service Mode Delay
19
19
19
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Freeze Protection Pump On
Freeze Protection Burner On
Freeze Protection Burner Differential
20
No
No
Yes
Yes
DHW Boiler Set Point
Tank Set Point
20
20
20
20
No
Yes
No
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Tank Set Point Differential
DHW Boiler Offset
No
No
DHW Boiler Differential
SH/DHW Switching Time
DHW/SH Switching Time
Tank Minimum Set Point
Tank Maximum Set Point
DHW Type
20
20
20
20
20
20
20
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Fan Speed Limiting for DHW
15
Service Manual
1 Service
Parameter table
Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where
to access them
User Access
Installer Access
See
Page
Menu
Description
Display Modify Display Modify
Outdoor 1 Low
Outdoor 1 High
21
21
21
21
21
22
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Set Point 1 at Low Outdoor Temp 1
Set Point 1 at High Outdoor Temp 1
Outdoor Air Shutdown SH1
Outdoor Air Shutdown Differential SH1
Shift Reset Curve SH1
Outdoor 2 Low
22
21
21
21
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Outdoor 2 High
Set Point 2 at Low Outdoor Temp 2
Set Point 2 at High Outdoor Temp 2
Outdoor Air Shutdown SH2
Outdoor Air Shutdown Differential SH2
Shift Reset Curve SH2
21
21
22
22
21
21
21
21
21
22
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Outdoor 3 Low
Outdoor 3 High
Set Point 3 at Low Outdoor Temp 3
Set Point 3 at High Outdoor Temp 3
Outdoor Air Shutdown SH3
Outdoor Air Shutdown Differential SH3
Shift Reset Curve SH3
Boost Temperature
Boost Time
22
22
22
22
22
22
23
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Anti-Cycling Time
Anti-Cycling Override Differential
Ramp Delay
Ramp Settings
16
Service Manual
1 Service
(continued)
Parameter table
Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where
to access them
User Access
Installer Access
See
Page
Menu
Description
Display Modify Display Modify
Controlling Sensor
BMS Tstat Input
BMS
23
23
23
23
23
23
23
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
ModBus
ModBus T/O
Cascade Address
Cascade Type
Max Cascade Set Point
Cascade Offset
24
24
24
24
24
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Cascade Differential
Min On/Off Time
Min Next On Time
Boiler Size
24
24
25
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
System Pump Delay
Boiler Pump Delay
DHW Pump Delay
25
25
25
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Boiler Pump Anti-Seize Delay
Boiler Pump Min Voltage
System Pump Type
DHW Pump Anti-Seize Delay
DHW Blocks Sys Pump
DHW Forces Sys Pump
System Pump Anti-Seize Delay
BMS Type
25
25
25
25
25
25
25
25
25
25
26
26
26
26
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Volts at Min
Volts at Max
Rate at Min Volts
Rate at Max Volts
Set Point at Min Volts
Set Point at Max Volts
On Volts
Off Differential Volts
Service Notification Months
26
No
No
Yes
Yes
Service Notification Running Time
Service Notification Cycles
26
26
26
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Reset Maintenance Reminder
Service Name and Phone Number
26
No
No
Yes
Yes
17
Service Manual
1 Service
Viewable and changeable control parameters
Space Heating (SH) and Domestic Hot Water (DHW)
Night Setback On Times
Before changing parameters, note the
settings so that the unit can be returned to
its original operating parameters.
CAUTION
This is the time in which the SH Night Setback Offset becomes
active. There are 7 start times and 7 stop times each for the
space heating and DHW night setback features. Both may be
set to any time within a 7-day week. These settings are referred
to as triggers. Multiple start or stop triggers may be set within a
single day, if desired. When a start trigger and a stop trigger are
set to the same time, the stop trigger has priority. The installer
may adjust the space heating night setback start triggers by
accessing the SH Night Setback On Times parameter. The DHW
start triggers in the DHW Night Setback On Times parameter.
This screen shows the start trigger number, the day of the week,
and the time of day.
General
Time and Date
The control uses an internal clock for the night setback
feature and for logging of events. For these features to
work correctly, the clock must be set when the boiler is first
installed or anytime the boiler has been powered off for more
than four (4) hours. This parameter must be accessed to set
the clock.
The internal clock does not adjust for
Daylight Savings Time and therefore,
will require a manual adjustment.
NOTICE
Please note that the brackets ([]) denote
NOTICE
screen status.
The clock is automatically updated whenever a PC is
connected and the Win_Pro-Installer program is started.
1. When the screen is first accessed, start trigger number 1
is shown. If a different trigger number is desired, the
installer can rotate the NAVIGATION dial until the
desired trigger number is displayed. Once the desired trigger
number is selected, the installer can press the NAVIGATION
dial and the day of the week will start to flash.
2. The installer can adjust the day of the week to the one he
wishes to set. Once the day is set, the installer can press the
NAVIGATION dial and the hour will begin to flash.
3. After setting the hour, the installer can press the
NAVIGATION dial and the minutes will flash. Once all
settings have been made, the installer can press the RIGHT
SELECT [SAVE] key. The installer can now select a
different trigger and adjust the settings for that trigger.
4. Once all adjustments are made, the installer can press the
RIGHT SELECT [SAVE] key to save all of the new settings
and return to the General menu, or press the LEFT SELECT
[EXIT] key to return to the General menu without saving the
changes.
Software Version
The software version allows the user to view the software
version in use by the control. This software controls the
operation of the boiler. When a new software version
becomes available, the existing control can be replaced with a
new control to update the software.
Software version is read only.
Temperature units (°C / °F)
The control can be configured to display temperature in
either °C or °F. This parameter can be changed by the user
or the installer by accessing the Temperature Units parameter.
The default is °F.
Space Heating (SH) and Domestic Hot Water (DHW)
Night Setback Offset
Once the unit’s internal clock has been set correctly, the
Night Setback feature can be used to program a lower set
point during unoccupied times. Both the space heating and
DHW can be programmed for night setback. When in night
setback, the control reduces the set point by a fixed amount.
For space heating, it subtracts the space heating night setback
offset from each of the SH user set points (SH1, 2, and 3 Set
point parameters), or the calculated outdoor reset set point (if
lower). For DHW, it subtracts the DHW night setback offset
from the tank set point (Tank Set point parameter).
Space Heating (SH) and Domestic Hot Water (DHW)
Night Setback Off Times
The corresponding space heating night setback stop triggers are
set by accessing the SH Night Setback Off Times parameter. The
stop triggers for the DHW night setback feature can be adjusted
by accessing the DHW Night Setback Off Times parameter. The
adjustment procedure for these parameters is identical to the
space heating start triggers described above.
Night Setback Override
NOTE: The DHW night setback will not work without a tank
sensor installed.
Any Night Setback On trigger currently active or scheduled
within the next seven (7) days can be skipped. To skip a trigger,
rotate the NAVIGATION dial until the arrow (>) is next to the
trigger you wish to skip. Press the NAVIGATION dial once.
“SK” will appear next to that trigger to indicate that it will be
skipped. You can restore an upcoming trigger by selecting that
trigger, and pressing the NAVIGATION dial again. The “SK”
next to that trigger will disappear.
The installer may adjust the space heating night setback
offset by accessing the SH Night Setback Offset parameter and
the DHW night setback offset by accessing the DHW Night
Setback Offset parameter. The minimum setting is 0°F (0°C)
and the maximum setting is 90°F (50°C).
18
Service Manual
1 Service
(continued)
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.
3-Way Valve Time
The optional Lochinvar Multi-Temperature Loop Control
Board(MTLCB)canbeusedtocontrolthesupplytemperature
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.
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 (SH1, SH2, SH3) Set Point
Mixing valves are required for the
protection of any low temperature loops.
CAUTION
Data Logging
Reset log errors
The reset log errors function clears the last 10 errors log.
There are three (3) individual user set points for better zone
control. These are listed as SH1 Set Point through SH3 Set
Point. If multiple set points are calling for heat the highest set
point has priority. The range is SH Minimum Set point to SH
Maximum Set point. The default is 125°F (52°C).
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.
Space Heating (SH) Minimum Set Point
The SH minimum set point sets the minimum water
temperature set point that can be used for space heating
operation. 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 Minimum SH
Set point parameter. The temperature range of this parameter
is 32°F (0°C) to the space heating maximum set point. The
default value is 32°F (21°C).
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).
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 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 (82°C).
SH1 - SH3 Offset Set Point
Never put the Freeze Protection Pump
on a setting lower than the Freeze
Protection Burner On setting.
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
parameters 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.
NOTICE
Freeze Protection Burner On
If running the pumps does not prevent the inlet temperature
from falling closer to freezing, the SMART SYSTEM control
will fire the burner at low fire. The installer can adjust the
temperature at which the burner fires by adjusting the Freeze
Protection Burner On parameter. The minimum setting is
-3°F (-19°C), and the maximum setting is 45°F (7.2°C). The
default setting is 37°F (2.8°C).
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.
Never put the Freeze Protection Pump
on a setting lower than the Freeze
Protection Burner On setting.
NOTICE
19
Service Manual
1 Service
Freeze Protection Burner Differential
Once this timer expires, it will switch back to the DHW demand.
The installer can adjust the length of time the boiler will service
the space heating demand by accessing SH/DHW Switching
Time parameter. The minimum setting is 0 minutes and the
maximum setting is 50 minutes. The default time is 30 minutes.
Once the burner has started firing due to a low inlet
temperature, the inlet temperature must increase by this
amount before the burner turns back off. The installer can
adjust this differential by accessing the Freeze Protection
Burner Differential parameter. The minimum setting is 0°F,
and the maximum is 20°F. The default setting is 5°F (2.8°C).
DHW/SH Switching Time
When a boiler has a DHW demand and it receives a space
heating demand, the SMART SYSTEM control will start a
timer. Once the timer expires, it will stop the DHW demand
and service the space heating demand. The installer can adjust
the length of time the boiler will service the DHW demand
by accessing the DHW/SW Switching Time parameter. The
minimum setting is 0 minutes and the maximum setting is 50
minutes. The default setting is 30 minutes.
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 boiler outlet water temperature, or
system temperature when DHW is programmed as a zone.
This parameter can be changed by the installer by accessing
the DHW Boiler Set point parameter. The temperature range
of this parameter is 68°F (20°C) to 180°F (82°C). The default
value is 180°F (82°C).
Tank Minimum Set Point
This setting controls the minimum tank set point for the tank
temperature. The installer can adjust this by accessing the Tank
Minimum Set point parameter. The minimum setting is 60°F
(16°C) and the maximum setting is the maximum tank set point
(Tank Maximum Set point parameter). The default value is 60°
(16°C).
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 below the tank set point differential (Tank Set point
Differential parameter), and finishes the call for heat when
the tank temperature reaches tank set point + offset. This
parameter can be changed by the installer by accessing the
DHW Tank Set point parameter. The temperature range of
this parameter tank minimum set point to tank maximum set
point. The default value is 125°F (52°C).
Tank Maximum Set Point
This setting controls the maximum tank set point for the tank
temperature. The installer can adjust this by accessing the Tank
Maximum Set point parameter. The minimum setting is the
minimum tank set point (Tank Minimum Set point parameter)
and the maximum setting is 190°F (88°C). The default value is
140°F (60°C).
DHW Type
Tank Set Point Differential
This parameter determines whether the Knight XL boiler treats
the indirect DHW tank as a separate load, or as a zone on the
primary loop. When programmed as a separate load, the boiler
will turn on the DHW pump and then turn off the boiler pump
when an indirect DHW demand begins. When programmed as
a zone, the boiler will turn on the DHW pump, leave the boiler
pump on and change the system set point to the DHW boiler set
point (DHW Boiler Set point parameter).
When a tank sensor is installed, the tank temperature must
drop this amount below the tank set point (DHW Tank
Set point parameter) before the boiler turns back on. The
installer can adjust this setting by accessing the Tank Set point
Differential parameter. The minimum setting is 0° (0°C), and
the maximum is 40°F (22°C). The default setting is 6°F (3°C).
DHW Boiler Offset
This parameter reflects the degrees above DHW boiler set
point the temperature has to go before the boiler will shut off.
The range is 0°F (0°C) to 40°F (22°C). The default setting is
10°F (6°C).
This setting may be changed by the installer by accessing the
DHW Type parameter. The choices are NORMAL and ZONE.
The default setting is NORMAL.
Fan Speed Limiting for Indirect DHW Tank
DHW Boiler Differential
This parameter determines the maximum fan speed (and
therefore the maximum rate) to be used when heating an
indirect DHW tank when the DHW Type is set to Normal.
This setting may be used when the tank is unable to accept all
of the BTU’s available from the boiler. This parameter may be
adjusted by the installer by accessing the Fan Speed Limiting
for Indirect DHW Tank parameter. The default value is the
maximum fan speed for that model.
This parameter reflects the degrees below DHW boiler set
point the temperature has to go before the boiler turns back
on. The range is 0°F (0°C) to 60°F (33°C). The default setting
is 20°F (13°C).
SH/DHW Switching Time
When a boiler has a space heating demand and it receives
a DHW demand, it will immediately switch to the DHW
demand and start a timer. Once the timer has expired, the
boiler will switch back to the space heating demand and start
another timer.
20
Service Manual
1 Service
(continued)
Set Point (1 - 3) at Low Outdoor Temperature
Outdoor Reset
When the outdoor air temperature drops to the Outdoor
(1 - 3) Low parameters, the calculated set point will be at
this setting (FIG. 1-1). If the outdoor air temperature drops
further, the set point will continue to increase above this
setting. However, if SH1, SH2, and SH3 are set lower, the
water temperature will be limited by these set points instead.
These parameters can be changed by the installer by accessing
the Set point 1 at Low Outdoor Temp 1, Set point 2 at Low
Outdoor Temp 2 and Set point 3 at Low Outdoor Temp 3
parameters. The temperature range of this parameter is 68°F
(20°C) to 180°F (82°C). The default value is 180°C (82°C).
The option of controlling up to three (3) different outdoor
resets for low outdoor temperatures is available.
Outdoor (1 - 3) Low
When the outdoor air temperature drops to this point, the
water temperature will be at the Set point 1 at Low Outdoor
Temp 1, Set point 2 at Low Outdoor Temp 2 and Set point
3 at Low Outdoor Temp 3 parameters (FIG. 1-1). If the
outdoor air temperature drops further, the set point will
continue to increase above this setting. This parameter can
be changed by the installer by accessing the Outdoor (1-3)
Low parameter. The temperature range of this parameter is
-39°F (-39°C) to high outdoor temperature set point. The
default value is 25°F (-4°C).
Set Point (1 - 3) at High Outdoor Temperature
When the outdoor air temperature rises to or above Outdoor
(1 - 3) High parameters, the calculated set point will be at this
setting (FIG. 1-1). These parameters can be changed by the
installer by accessing the Set point 1 at High Outdoor Temp 1,
Set point 2 at High Outdoor Temp 2 and Set point 3 at High
Outdoor Temp 3 parameters. The temperature range of this
parameter is 68°F (20°C) to 190°F (88°C). The default value
is 70°F (21°C).
Outdoor (1 - 3) High
When the outdoor air temperature rises to or above this
point, the water temperature will be at the Set point 1 at High
Outdoor Temp 1, Set point 2 at High Outdoor Temp 2 and
Set point 3 at High Outdoor Temp 3 parameters (FIG. 1-1).
This parameter can be changed by the installer by accessing
the Outdoor (1-3) High parameter. The temperature range
of this parameter is low outdoor temperature set point to
104°F (40°C). The default value is 70°F (21°C).
Outdoor Air Shutdown (SH1 - SH3)
When the outdoor temperature rises above this point, the
control will block all SH demands (DHW demands will still
be active). These parameters can be changed by the installer
by accessing the Outdoor Air Shutdown SH1, SH2, and SH3
parameters. The temperature range of this parameter is 32°F
(0°C) to 104°F (40°C). The default value is 70°F (21°C).
Figure 1-1 Outdoor Air Reset Curve
SET POINT AT
LOW OUTDOOR
TEMPERATURE
(SH)
SET POINT
SET POINT AT
HIGH OUTDOOR
TEMPERATURE
HIGH OUTDOOR
TEMPERATURE
LOW OUTDOOR
TEMPERATURE
21
Service Manual
1 Service
Outdoor Air Shutdown Differential (SH1 - SH3)
Boost Time
The outdoor air shutdown differential parameter is the
number of degrees below Outdoor Air Shutdown SH1, SH2,
and SH3 parameters the outdoor air temperature must go
before the boiler will respond to a SH demand. These
parameters can be changed by the installer by accessing
the Outdoor Air Shutdown Differential SH1, SH2, and SH3
parameters The temperature range of this parameter is 0°F
(0°C) to 54°F (30°C). The default value is 10°F (6°C).
The boost time parameter sets the amount of time that must
elapse with a SH demand before the water temperature calculated
set point will be increased. This parameter can be changed by
the installer by accessing the Boost Time parameter. The time
range for this parameter is 0 minute to 50 minutes. The default
value is 0 minutes.
Anti-Cycling
Anti-Cycling Time
Shift Reset Curve (SH1 - SH3)
Once a SH demand has been satisfied, a set amount of time must
elapse before the control will respond to a new SH demand. The
control will block the new heat demand and anti-cycling will
be shown in the display until the time has elapsed or the water
temperature drops below the Anti-Cycling Override Differential
parameter. This parameter can be changed by the installer by
accessing the Anti-Cycling Time parameter. The time range for
this parameter is 1 minute to 10 minutes. The default value is
1 minute.
There is a shift reset curve for each outdoor reset. The shift
reset curve parameter shifts the actual set point above or
below the calculated set point by the number of degrees in
this parameter. These parameters can be changed by the
installer by accessing the Shift Reset Curve SH1, SH2, and
SH3 parameters. The temperature range of this parameter
is -17°F (-10°C) to 18°F (10°C). The default value is 0°F
(0°C). This feature will be active if this parameter is set to
anything other than 0°F (0°C).
Anti-Cycling Override Differential
Boost Temperature
The control will bypass the anti-cycling time if the inlet
water temperature drops too much. The control will use the
inlet water temperature the boiler was at when it shut off as
the starting point. If the inlet temperature drops below the
temperature parameter the control will abort anti-cycling and
allow the boiler to fire. This parameter can be changed by
the installer by accessing the Anti-Cycling Override Differential
parameter. The temperature range of this parameter is 0°F (0°C)
to 54°F (30°C). The default value is 10°F (6°C).
If a SH demand lasts longer than the programmed time
delay setting and there have been no DHW demands, the
control will increase the water temperature set point by the
amount in this parameter. If the SH demand continues
through another time period, the set point will be increased
again. This will continue until either the SH demand ends,
a maximum of 20 increases has occurred, or SH1, SH2,
SH3 maximum set point has been reached. Once the SH
demand has been satisfied the set point will revert back
to its calculated setting. The boost temperature can be
changed by the installer by accessing the Boost Temperature
parameter. The temperature range of this parameter is 0°F
(0°C) to 25°F (14°C). The default value is 0°F (0°C). This
feature will be active if this parameter is set to anything
other than 0°F (0°C).
Ramp Delay (Enable / Disable)
This parameter allows the installer to enable or disable the SH
ramp delay. The default setting is disabled.
Figure 1-2 Ramp Delay Interval
22
Service Manual
1 Service
(continued)
BMS
Ramp Settings
The set point or modulation of the boiler may be controlled
through the 0 - 10V BMS input or through ModBus. When the
BMS parameter is set to INACTIVE, the 0 - 10V input will be
ignored. When set to ACTIVE, the set point or modulation will
be controlled by the voltage on the 0 - 10V input (in the case
of 0 - 10V BMS control), or the 0 - 10V input value received
through ModBus. The default value is INACTIVE.
Please note that the brackets ([]) denote
screen status.
NOTICE
The SMART SYSTEM control can be programmed to limit the
firing rate for a fixed period of time at the start of a space heating
demand. There are six (6) possible limits, each with their own
time delay. The first limit applies as soon as the burner starts.
Once its time delay expires, the second limit is applied and its
timer begins. The control steps through these limits until the
6th (sixth) limit expires. Note, however, that the 6th limit will
also limit the rate for the rest of that heat demand. The installer
can adjust the firing limits and time delays by accessing the
Ramp Settings parameter. Once this parameter is selected, the
screen will show the step number, the time delay for that step
and the limit value corresponding with that step. If the installer
wishes to adjust one of the values in that step, he can press
the NAVIGATION dial until the value he wishes to change is
flashing. The installer can then rotate the NAVIGATION dial
to adjust that value. If the installer presses the RIGHT SELECT
[SAVE] key while the limit value is flashing, the step value will
flash again. The installer can then select the next step and adjust
the delay and limit values corresponding with that step.
ModBus
When BMS is set to ACTIVE (see BMS Active / Inactive) and
the boiler is being controlled through ModBus, set ModBus
parameter to ACTIVE. Otherwise, set the ModBus parameter
to INACTIVE. Note that the boiler can still be monitored by
ModBus with this parameter set to INACTIVE. The default
value is INACTIVE.
ModBus T/O
The amount of time the unit controls will wait to receive
a communication string from the BMS controller before
reverting back to its own internal parameters. This parameter
is adjustable by the installer by accessing the ModBus T/O
parameter. The adjustment range of this parameter is 5 seconds
to 2 minutes. The default value is 10 seconds.
When finished, the installer can press the RIGHT SELECT
[SAVE] key to store the new settings, or the LEFT SELECT
[EXIT] key to return to the Anti-Cycling parameter list
without saving the changes. The delay value can be set between
0 minutes and 20 minutes. The limit value can be set between
0% and 100%.
Cascade Address
The boiler designated as the Leader needs to be programmed
with address 0. All the Member boilers require addresses from
1 to 7, and the addresses must be different for each Member.
The addresses can be in any order, regardless of the order in
which the units are wired together. This parameter is adjustable
by the installer by accessing the Cascade Address parameter.
The outdoor air (if used) and system supply sensor must be
connected to the Leader boiler. The default address is 1.
Control modes
Controlling Sensor
The SH controlling sensor parameter selects the sensor the
control will use to regulate the boiler firing rate. This parameter
is adjustable by the installer by accessing the Controlling Sensor
parameter. The sensor selections are as follows: The outlet
sensor regulates the firing rate based on the outlet water
temperature of the boiler and the inlet sensor regulates the
firing rate based on the inlet water temperature of the boiler.
If the outlet sensor is selected, and the optional system supply
sensor is connected, the control will regulate the firing rate
based on the system supply sensor temperature. The default
sensor is the Outlet Sensor.
If installing the boilers in an existing system, the new boilers
should be programmed as the Leader and/or the higher number
addresses.
Cascade Type (L/L / EFF)
There are two (2) options for the way a Cascade divides the load
between its heaters. The first is Lead/Lag, designated as L/L in
the menu. This method is used when it is desired to have the
least amount of total flow through the boilers. This method
will modulate the last two (2) boilers. This provides for smooth
transitions when a boiler turns on or off. When the last boiler
reaches 100% and the calculated load is still increasing, it will
start the next boiler at 20% and reduce the previous boiler
to 80%, thus eliminating the sudden jump in total output
of the Cascade. When the calculated load is decreasing and
the last boiler gets down to 20% fire, it will hold it there and
start lowering the firing rate on the next-to-last boiler. When
the next-to-last boiler reaches 20%, it will turn the last boiler
off and raise the rate of the next-to-last boiler to 40%, thus
eliminating the sudden drop in total output of the Cascade.
BMS Thermostat Input
When controlling the boiler through the 0 - 10V BMS input or
through ModBus, the boiler can be enabled one of two ways.
With the BMS Thermostat Input parameter set to ACTIVE,
the boiler will be enabled by closing the Heat/Loop Demand 1
input. When set to INACTIVE, the boiler will be enabled by
the voltage level on the 0 - 10V input (in the case of 0 - 10V
BMS control), or the 0 - 10V input value received through
ModBus. The default value is INACTIVE.
23
Service Manual
1 Service
The other Cascade divider method is Efficiency
Optimization, designated as EFF in the menu. This
method is used, as the name implies, when it is desired
to have the most efficient system. When the first boiler
reaches a certain rate (default = 90%), it lowers its rate
to 45% and turns on the next boiler at 45%. The two (2)
boilers then modulate at the same rate.
Minimum On/Off Time
In order to prevent units in a Cascade from short cycling,
this parameter defines the minimum ON and OFF time for
each unit. The installer can adjust this time by accessing the
Minimum On/Off Time parameter. The minimum setting is 0
seconds and the maximum setting is 10 minutes. The default
is 30 seconds.
Minimum Next On Time
As the calculated load increases further and both boilers
ramp up to 90%, it lowers the rate of the first two (2)
boilers to 60% and brings the next boiler on at 60%.
The three (3) boilers then modulate together. As the
calculated load decreases, the boilers will reach a lower
threshold (default = 30%), at which time the last boiler
(the third in our example) will turn off and the Cascade
will increase the rates of the remaining boilers to provide
the equivalent total output as before ((3 x 30%) / 2 = 45%
in our example).
In order to reduce the risk of temperature overshoot with
a Cascade, this parameter defines the minimum time delay
from starting one unit until the next unit may be started. The
installer can adjust this time delay by accessing the Minimum
Next On Time parameter. The minimum setting is 0 minutes
and the maximum setting is 10 minutes. The default is 60
seconds.
Boiler Size
When boilers of different sizes are connected together in a
Cascade, the Leader boiler has to know the size of each boiler
in that Cascade. The Boiler Size parameters allow the installer
to program the size based on the Cascade address. This screen
shows the Cascade address and the size of the boiler with that
address (in BTU/hr):
Efficiency optimization is automatically selected when
boilers of different sizes are programmed into the Leader
control (see Boiler Size on this page).
Maximum Cascade Set Point
This parameter determines the set point used by the
individual boilers in a Cascade when a system sensor
is connected to the Leader boiler. When a boiler is
commanded to fire by the Leader boiler, it will attempt to
achieve this temperature at its outlet. The Leader boiler
will limit the modulation of the last boiler to fire in order
to hold the temperature at the system supply sensor to
the user set point. If any of the boiler outlet temperatures
reach the maximum cascade set point, the boiler will
then modulate down on its own in order to keep its
outlet temperature within the maximum cascade set point.
Therefore, this parameter can be used to limit the outlet
temperatures of all the boilers in a Cascade. Note that
this parameter does not apply when the boiler is heating
an indirect DHW tank. This parameter is adjustable by
the installer by accessing the Maximum Cascade Set Point
parameter. The temperature range of this parameter is 32°
(0°C) to 190°F (88°C). The default maximum cascade set
point is 185°F (85°C).
1. When the Boiler Size screen is first accessed, Cascade
Address 0 (Leader) is shown.
2. Press the NAVIGATION dial to access the first digit of the
boiler size. Rotate the NAVIGATION dial to adjust the
first digit. To access the next digit, press the NAVIGATION
dial again. Continue this process until the correct boiler
size (to the nearest 1000 BTU/hr) is shown. Press the
RIGHT SELECT [SAVE] key.
3. Rotate the NAVIGATION dial to select the address of the
next boiler in the Cascade. Repeat Step 2.
4. Once the size of the last boiler in the Cascade has been
entered and saved, press the LEFT SELECT [EXIT] key to
return to the Control Modes menu.
5. If no other parameters are to be adjusted, press the RIGHT
SELECT [HOME] key to save the new settings and return
to the Status screens.
The SMART SYSTEM control automatically uses the Efficiency
Optimization Cascade type when controlling boilers of different
sizes.
Cascade Offset
This parameter determines how much the temperature
must go above set point before the lead boiler will turn off.
This parameter can be adjusted by the installer by accessing
the Cascade Offset parameter. The temperature range of
this parameter is 0° to 20°F (11°C) The default value is
10°F (6°C).
Circulation pumps
System Pump Delay
The system pump delay parameter sets the length of time the
system pump (if connected) will run after a SH demand has
been satisfied. This parameter is adjustable by the installer by
accessing the System Pump Delay parameter. The time range
for this parameter is 1 second to 40 minutes. The default time
is 30 seconds.
Cascade Differential
This parameter determines how much the temperature
must go below the turn off temperature (Set point +
Offset) before the lead boiler turns on. This parameter
can be adjusted by the installer by accessing the Cascade
Differential parameter. The temperature range of this
parameter is 0°F to 60°F (33°C) The default value is 20°F
(11°C).
24
Service Manual
1 Service
The SH pump delay parameter sets the length of time the
boiler pump will run after a SH demand has been satisfied.
Setting the delay time to 0 will disable the pump. This
parameter is adjustable by the installer by accessing the Boiler
Pump Delay parameter. The time range for this parameter is
1 second to 40 minutes. The default time is 30 seconds.
(continued)
DHW Blocks Sys Pump
Boiler Pump Delay
When the indirect DHW tank is connected as a zone on the
primary loop, the DHW Blocks Sys Pump parameter tells the
system pump if it is allowed to run during a DHW demand.
To force the system pump to turn off during a DHW demand,
set the DHW Blocks Sys Pump parameter to YES. The default
setting is NO.
DHW Pump Anti-Seize Delay
DHW Pump Delay
If the boiler pump does not run for 24 hours, it will be turned
on briefly to prevent it from seizing. The length of time it runs
is determined by the DHW Pump Anti-Seize Delay parameter.
The range of this setting is 0 seconds to 50 minutes. The default
setting is 20 seconds.
The DHW pump delay parameter sets the length of time the
DHW pump (if connected) will run after a DHW demand has
been satisfied. This parameter is adjustable by the installer by
accessing the DHW Pump Delay parameter. The time range
for this parameter is 10 seconds to 40 minutes. The default
time is 1 minute.
System Pump Anti-Seize Delay
If the boiler pump does not run for 24 hours, it will be turned
on briefly to prevent it from seizing. The length of time it runs
is determined by the System Pump Anti-Seize Delay parameter.
The range of this setting is 0 seconds to 50 minutes. The default
setting is 20 seconds.
Boiler Pump Anti-Seize Delay
If the boiler pump does not run for 24 hours, it will be
turned on briefly to prevent it from seizing. The length of
time it runs is determined by the Boiler Pump Anti-Seize
Delay parameter. The range of this setting is 0 seconds to 50
minutes. The default setting is 20 seconds.
BMS
BMS Type
Boiler Pump Minimum Voltage
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus, the 0 - 10V signal can be interpreted
as either a modulation command or a set point. When the BMS
Type parameter is set to POWER, the 0 - 10V signal will control
the modulation. When set to SETPOINT, the 0 - 10V signal
will control the SH set point. The default setting is SETPOINT.
The speed of the boiler pump can be controlled by the
SMART SYSTEM control in order to maintain a minimum
T through the heat exchanger. Thus, as the firing rate
decreases, the speed of the boiler pump can decrease as well.
The SMART SYSTEM control outputs a 0 - 10V signal to the
boiler pump to control its speed. The Boiler Pump Minimum
Voltage parameter determines the minimum voltage given to
the boiler pump, thereby setting its minimum speed. The
range of this setting is 2.5V to 10V. The default setting is
3.5V.
Volts at Minimum
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus, the Volts at Minimum parameter
should be set to the minimum voltage signal sent to the
SMART SYSTEM control. The range of this parameter is 0.0V
to the Volts at Maximum value. The default setting is 2.0V.
System Pump Type
The system pump can be programmed to operate in response
to any of the Room Thermostat inputs, or to run continuously
until the boiler goes into Outdoor Shutdown. To program
the system pump to operate only with a space heating call
for heat, set the System Pump Type parameter to CFH. To
program the system pump to run continuously until outdoor
shutdown starts, set the System Pump Type parameter to
WWSD. The default setting is CFH.
Volts at Maximum
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus, the Volts at Maximum parameter
should be set to the maximum voltage signal sent to the
SMART SYSTEM control. The range of this parameter is the
Volts at Minimum value to 10.0V. The default value is 10.0V.
Rate at Minimum Volts
DHW Forces Sys Pump
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Type is programmed as
POWER, the modulation percentage represented by the Volts
at Minimum parameter is set by the Rate at Minimum Volts
parameter. The minimum value is 0% and the maximum is
the Rate at Maximum Volts setting. The default value is 20%.
When the indirect DHW tank is connected as a zone on the
primary loop, the DHW Forces Sys Pump parameter tells the
system pump if it must run when there is a DHW demand.
To have the system pump constantly running during a DHW
demand, set the DHW Forces Sys Pump parameter to YES (the
parameter DHW Blocks Sys Pump must be set to NO). If this
parameter and the DHW Blocks Sys Pump parameter are both
set to NO, the system pump operation will be based strictly on
the System Pump Type parameter setting. The default setting
of this parameter is YES.
Rate at Maximum Volts
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Type is programmed as
POWER, the modulation percentage represented by the Volts
at Maximum parameter is set by the Rate at Maximum Volts
parameter. The minimum value is the Rate at Minimum Volts
setting and the maximum is 100%. The default value is 100%.
25
Service Manual
1 Service
Set Point at Minimum Volts
Service Notification Cycles
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Type is programmed as
SETPOINT, the set point represented by the Volts at Minimum
parameter is set by the Set Point at Maximum Volts parameter.
The minimum value is 32°F (0°C) and the maximum is the
Set Point at Maximum Volts setting. The default value is 70°F
(21°C).
When the boiler control determines that a scheduled
service is due based on the number of boiler cycles, the
boiler display will alternate the standard boiler display
text with the message SERVICE DUE every 5 seconds.
This parameter is adjustable by the installer by accessing
the Service Notification Cycles parameter. The range for
this parameter is 0 cycles to 100,000 cycles. The default is
50,000 cycles.
Set Point at Maximum Volts
Reset Maintenance Reminder
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Type is programmed as
SETPOINT, the set point represented by the Volts at Maximum
parameter is set by the Set Point at Maximum Volts parameter.
The minimum value is the Set Point at Minimum Volts setting
and the maximum is 190°F (88°C). The default value is 180°F
(82°C).
Once servicing has been completed, the service notification
counter should be reset. This parameter can be reset by
the installer by accessing the Reset Maintenance Reminder
parameter. Once accessed, press the RESET key to reset the
service notification counter.
Service Name and Phone Number
On Volts
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Thermostat Input is set
to INACTIVE, the On Volts parameter determines the 0 - 10V
BMS input voltage at which the boiler is enabled. The minimum
value is 0.5V and the maximum is 10.0V. The default value is
2.0V.
Please note that the brackets ([]) denote
screen status.
NOTICE
When a Maintenance Reminder timer or counter has
expired, a Maintenance Reminder screen will appear on the
display. By programming the installer’s name and phone
number, this information will appear on the Maintenance
Reminder Screen at that time. This can be programmed by
accessing the Service Name and Phone Number parameter.
When selected, another menu will appear with PHONE
and NAME.
Off Differential Volts
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus and the BMS Thermostat Input is set
to INACTIVE, the Off Differential Volts parameter determines
how far below the On Volts setting the 0 - 10V BMS input
voltage must be in order to disable the boiler. The minimum
value is 0.2V and the maximum is the On Volts setting. The
default value is 1.0V.
1. Rotate the NAVIGATION dial to point to the
name/phone number to program and press the
NAVIGATION dial. The screen will now display the
selected item (either PHONE or NAME).
Service Notification
Service Notification in Months
2. Press the NAVIGATION dial again. A cursor will
appear at the bottom of the screen. By rotating the
NAVIGATION dial, various numbers and characters
will appear. When the desired number/character is
found, press the NAVIGATION dial. The cursor will
move to the next position.
When the boiler control determines that a scheduled service is
due based on days of installation, the boiler display will alternate
the standard boiler display text with the message SERVICE DUE
every 5 seconds. This parameter is adjustable by the installer by
accessing the Service Notification in Months parameter. The time
range for this parameter is 0 months to 100 months. The default
time is 12 months.
3. Repeat this procedure until the entire message is
entered. If you make a mistake and wish to back up
one character, rotate the NAVIGATION dial until
the back arrow () character is displayed and press the
NAVIGATION dial.
This feature has been disabled by the manufacturer. To enable
this feature change parameter K1 to the desired time range.
4. When finished, press the RIGHT SELECT [SAVE] key
to return to the previous menu.
Service Notification Running Time
When the boiler control determines that a scheduled service is
due based on the hours of actual operation, the boiler display
will turn yellow and a new status screen will appear informing
the installer that maintenance is required. This parameter is
adjustable by the installer by accessing the Service Notification
Running Time parameter. The time range for this parameter is
0 hours to 17,500 hours. The default time is 8,760 hours.
26
Service Manual
2 Maintenance
Maintenance and annual startup
Table 2-1 Service and Maintenance Schedules
Owner maintenance
Service technician
(see the Knight XL User’s Information Manual for
instructions)
(see the following pages for instructions)
General:
• Address reported problems
• Check boiler area
• Inspect interior; clean and vacuum if
necessary;
• Check pressure/temperature
gauge
Daily
• Clean condensate trap and fill with fresh
water
• Check for leaks (water, gas, flue,
condensate)
• Verify flue and air lines in good condition
and sealed tight
• Check vent piping
• Check air piping
• Check system water pressure/system
piping/expansion tank
Monthly
• Check air and vent termination
screens
• Check control settings
• Check ignition and flame sense
electrodes (sand off any deposits; clean
and reposition)
• Check relief valve
• Check condensate drain system
• Check air vents
• Check wiring and connections
•
Perform start-up checkout and
performance verification per Section 10
in the Knight XL Installation and
Operation Manual.
•Test low water cutoff (if used)
Periodically
• Reset button (low water cutoff)
• Flame inspection (stable, uniform)
• Flame signal (at least 10 microamps at
high fire)
• Check boiler piping (gas and
water) for leaks
Every
6 months
• Clean the heat exchanger if flue
temperature is more than 54°F (30°C)
above return water temperature.
• Operate relief valve
If combustion or performance
indicate need:
•Shut boiler down (unless boiler
used for domestic hot water)
End
of season
• Clean heat exchanger
• Remove and clean burner using
compressed air only
months
• Clean the blower wheel
27
Service Manual
2 Maintenance
Follow the Service and maintenance procedures given throughout this manual and in component literature
shipped with the boiler. Failure to perform the service and maintenance could result in damage to the boiler
or system. Failure to follow the directions in this manual and component literature could result in severe
personal injury, death, or substantial property damage.
ƽ WARNING
The boiler should be inspected annually only by a qualified service technician. In addition, the maintenance
and care of the boiler designated in Table 2-1 and explained on the following pages must be performed to
assure maximum boiler efficiency and reliability. Failure to service and maintain the boiler and system could
result in equipment failure.
ƽ WARNING
Electrical shock hazard – Turn off power to the boiler before any service operation on the boiler except
as noted otherwise in this instruction manual. Failure to turn off electrical power could result in electrical
shock, causing severe personal injury or death.
ƽ WARNING
Address reported problems
Figure 2-1 Condensate Trap
1. Inspect any problems reported by the owner and correct
before proceeding.
RETAINING
SCREW
2” PVC CAP WITH
BLOCKED DRAIN SWITCH
Inspect boiler area
1. Verify that boiler area is free of any combustible materials,
gasoline and other flammable vapors and liquids.
PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
2. Verify that air intake area is free of any of the contaminants
listed in Section 1 of the Knight XL Installation and
Operation Manual. If any of these are present in the
boiler intake air vicinity, they must be removed. If
they cannot be removed, reinstall the air and vent lines
per this manual and the Knight XL Installation and
Operation Manual.
CONDENSATE FROM
HEAT EXCHANGER
TO FLOOR
DRAIN
Inspect boiler interior
The condensate trap must be filled with
water during all times of boiler operation
to avoid flue gas emission from the
condensate drain line. Failure to fill the
trap could result in severe personal injury
or death.
1. Remove the front access cover and inspect the interior of
the boiler.
ƽ WARNING
2. Vacuum any sediment from inside the boiler and
components. Remove any obstructions.
Clean condensate trap
Check all piping for leaks
1. Inspect the condensate drain line, condensate PVC
fittings, and condensate trap.
Eliminate all system or boiler leaks.
ƽ WARNING
Continual fresh makeup water will
reduce boiler life. Minerals can build
up in sections, reducing heat transfer,
overheating heat exchanger, and causing
heat exchanger failure. Leaking water may
also cause severe property damage.
2. Remove the PVC cap retaining screw from the PVC cap
(FIG. 2-1).
3. Remove the 2 inch PVC cap with the switch located at the
top of the trap (FIG. 2-1).
4. Remove any sediment in the trap.
1. Inspect all water and gas piping and verify to be leak free.
5. Fill with fresh water until the water begins to pour out of
the drain.
2. Look for signs of leaking lines and correct any problems
found.
6. Replace the cap. Press the cap onto the trap until the cap
makes contact with the drain.
3. Check gas line using the procedure found in Section 7
-
Gas Connections of the Knight XL Installation and
Operation Manual.
7. Replace the retaining screw.
28
Service Manual
2 Maintenance
(continued)
Safety relief valves should be re-inspected
AT LEAST ONCE EVERY THREE YEARS,
by a licensed plumbing contractor or
authorized inspection agency, to ensure
that the product has not been affected by
corrosive water conditions and to ensure
that the valve and discharge line have not
been altered or tampered with illegally.
Certain naturally occurring conditions
may corrode the valve or its components
over time, rendering the valve inoperative.
Such conditions are not detectable unless
the valve and its components are physically
removed and inspected. This inspection
must only be conducted by a plumbing
contractor or authorized inspection
agency – not by the owner. Failure to
re-inspect the boiler relief valve as directed
could result in unsafe pressure buildup,
which can result in severe personal injury,
death, or substantial property damage.
Flue vent system and air piping
ƽ WARNING
1. Visually inspect the entire flue gas venting system and air
piping for blockage, deterioration or leakage. Repair any
joints that show signs of leakage. Verify that air inlet pipe
is connected and properly sealed.
2. Verify that boiler vent discharge and air intake are clean
and free of obstructions.
Failure to inspect for the above conditions
and have them repaired can result in
severe personal injury or death.
ƽ WARNING
Check water system
1. Verify all system components are correctly installed and
operational.
2. Check the cold fill pressure for the system. Verify it is
correct (must be a minimum of 12 psi (82.7 kPa)).
3. Watch the system pressure as the boiler heats up (during
testing) to ensure pressure does not rise too high.
Excessive pressure rise indicates expansion tank sizing or
performance problem.
Following installation, the valve lever
must be operated AT LEAST ONCE
A YEAR to ensure that waterways are
clear. Certain naturally occurring
mineral deposits may adhere to the valve,
rendering it inoperative. When manually
operating the lever, water will discharge
and precautions must be taken to avoid
contact with hot water and to avoid water
damage. Before operating lever, check
to see that a discharge line is connected
to this valve directing the flow of hot
water from the valve to a proper place of
disposal. Otherwise severe personal injury
may result. If no water flows, valve is
inoperative. Shut down the boiler until a
new relief valve has been installed.
ƽ WARNING
4. Inspect automatic air vents and air separators. Remove
air vent caps and briefly press push valve to flush vent.
Replace caps. Make sure vents do not leak. Replace any
leaking vents.
Check expansion tank
1. Expansion tanks provide space for water to move in
and out as the heating system water expands due to
temperature increase or contracts as the water cools.
Tanks may be open, closed or diaphragm or bladder
type. See Section 6 - Hydronic Piping of the Knight XL
Installation and Operation Manual for suggested best
location of expansion tanks and air eliminators.
2. After following the above warning directions, if the relief
valve weeps or will not seat properly, replace the relief
valve. Ensure that the reason for relief valve weeping is
the valve and not over-pressurization of the system due
to expansion tank waterlogging or undersizing.
Check boiler relief valve
1. Inspect the relief valve and lift the lever to verify flow.
Before operating any relief valve, ensure that it is piped
with its discharge in a safe area to avoid severe scald
potential. Read Section 6 - Hydronic Piping of the
Knight XL Installation and Operation Manual before
proceeding further.
29
Service Manual
2 Maintenance
Inspect ignition and flame sense
electrodes
Figure 2-2 Burner Assembly - Model 400
1. Remove the ignition and flame sense electrodes from the
boiler heat exchanger access cover.
2. Remove any deposits accumulated on the ignition/flame
sense electrode using sandpaper. If the electrodes cannot
be cleaned satisfactorily, replace with new ones.
AIR / GAS ARM
3. Replace ignition/flame sense electrode, making sure
gasket is in good condition and correctly positioned.
Check ignition ground wiring
1. Inspect boiler ground wire from the heat exchanger
BURNER
GASKET
access cover to ground terminal strip.
2. Verify all wiring is in good condition and securely
attached.
SCREWS
(QTY. 5)
3. Check ground continuity of wiring using continuity
meter.
Figure 2-3 Burner Assembly - Model 501
4. Replace ground wires if ground continuity is not
satisfactory.
Check all boiler wiring
1. Inspect all boiler wiring, making sure wires are in good
AIR / GAS ARM
condition and securely attached.
Check control settings
1. Set the SMART SYSTEM control module display to
Parameter Mode and check all settings. See Section 1 of
this manual. Adjust settings if necessary. See Section 1 of
this manual for adjustment procedures.
BURNER
GASKET
2. Check settings of external limit controls (if any) and
adjust if necessary.
SCREWS
(QTY. 5)
Perform start-up and checks
Figure 2-4 Burner Assembly - Models 601 - 801
1. Start boiler and perform checks and tests specified in
Section 10 - Start-up of the Knight XL Installation and
Operation Manual.
2. Verify cold fill pressure is correct and that operating
pressure does not go too high.
AIR ARM
Check burner flame
1. Inspect flame through observation window.
2. If the flame is unsatisfactory at either high fire or low fire,
turn off boiler and allow boiler to cool down. Remove the
burner and clean it thoroughly using a vacuum cleaner
or compressed air. Do not use compressed air to clean
burner if performed inside a building.
BURNER
GASKET
SCREWS
(QTY. 5)
3. Remove the burner, reference FIG.’s 2-2 thru 2-4.
4. When replacing the burner, ensure gasket is in good
condition and positioned correctly (FIG.’s 2-2 thru 2-4).
30
Service Manual
2 Maintenance
(continued)
7. Brush the heat exchanger while dry using a nylon bristle
brush. Caution: DO NOT use a metal brush. Re-vacuum
the heat exchanger.
Check flame signal
1. At high fire the flame signal shown on the display should
be at least 10 microamps.
8. Finish cleaning using a clean cloth dampened with warm
water. Rinse out debris with a low pressure water supply.
2. A lower flame signal may indicate a fouled or damaged
flame sense electrode. If cleaning the flame sense electrode
does not improve, ground wiring is in good condition,
and ground continuity is satisfactory, replace the flame
sense electrode.
9. Allow the heat exchanger to thoroughly dry.
10. Remove the field supplied rear refractory cover from the
back of the combustion chamber of the heat exchanger and
reassemble.
3. See Section 3 - Troubleshooting in this manual for other
procedures to deal with low flame signal.
11. Close isolation valves on piping to isolate boiler from
system. Attach a hose to the boiler drain and flush boiler
thoroughly with clean water by using purging valves to
allow water to flow through the water make-up line to the
boiler.
Review with owner
1. Review the Knight XL User’s Information Manual with
the owner.
2. Emphasize the need to perform the maintenance schedule
specified in the Knight XL User’s Information Manual
(and in this manual as well).
12. Perform start-up and check-out procedures in the Check
Flame and Combustion - Section 10 - Startup of the
Installation and Operation Manual.
3. Remind the owner of the need to call a licensed contractor
should the boiler or system exhibit any unusual behavior.
13. Replace the access cover and restore boiler to operation.
4. Remind the owner to follow the proper shutdown
procedure and to schedule an annual start-up at the
beginning of the next heating season.
Table 2-2 Heat Exchanger Cleaning Kits
Kit
Part
Component
Description
Model
Cleaning boiler heat exchanger
Number Number
For recommended materials; including brush, appropriate
extension(s), refractory cover, and detailed instructions see
Table 2-2 - Heat Exchanger Cleaning Kits.
CTN20005
Rear Refractory Cover
Nylon 4" Wheel Brush*
MSC20083*
400
KIT30063
MSC20084
3mm Allen Wrench
1/4" x 24" Drill Extension
Rear Refractory Cover
Nylon 4" Wheel Brush*
1/4" x 12" Drill Extension
1/4" x 24" Drill Extension
1. Shut down boiler:
MSC20086
CTN20005
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup of the Installation
and Operation Manual.
• Do not drain the boiler unless it will be exposed to
freezing temperatures. If using freeze prevention fluid
in system, do not drain.
MSC20083*
KIT30064
501 - 801
MSC20085
MSC20086
* Do NOT use a metal brush. Only use
the kit provided brush or an equivalent
replacement nylon brush.
ƽ CAUTION
2. Allow time for the boiler to cool to room temperature if
it has been firing.
3. Remove the nuts securing the heat exchanger access cover
to the heat exchanger and set aside.
Figure 2-5 Rope Gasket - Heat Exchanger Door
4. Remove the heat exchanger access cover, burner, and
gas/air arm assembly.
ROPE GASKET
The boiler contains ceramic fiber
ƽ WARNING
materials. Use care when handling these
materials per instructions on page 3 of
this manual. Failure to comply could
result in severe personal injury.
5. Remove the condensate hose from the heat exchanger
end. Connect a field supplied 3/4” diameter hose to
a drain pan. Using field supplied means, cover the
refractory in the back of the combustion chamber of the
heat exchanger.
CAUTION: IF GASKET IS DAMAGED
DO NOT REUSE, THE HEAT EXCHANGER DOOR
MUST BE REPLACED.
Rope gasket is intended for sealing combustion
(FIG. 2-5). If damaged DO NOT reuse, the
heat exchanger door must be replaced. Consult
factory for replacement heat exchanger door
(kit WTR3080 and WTR3086).
31
NOTICE
6. Use a vacuum cleaner to remove any accumulation on the
boiler heating surfaces. Do not use any solvent.
Service Manual
2 Maintenance
Test low water flow conditions
9. When the ꢀT reaches 60°F, the control module will turn
off the burner. If the control module shuts down, the test
was successful.
This test is to be carried out once the
NOTICE
Knight XL boiler is completely piped
10. Disconnect the jumper wire from the low voltage terminal
strip connected in Step 2.
in with adequate gas and water flow.
Once the test is completed, ensure
that the isolation valve is opened up to
allow full water flow.
11. Completely open the isolation valve on the outlet piping of
the boiler.
12. Resume operation.
Test procedure
NOTE: This lockout is a soft lockout. Once the ꢀ T has
decreased to an acceptable level and there is a call for heat,
the unit will fire again to meet the demand.
1. Set the [SH1 SETPOINT:] set point to the max user set
point (reference Section 10 of the Knight XL Installation
and Operation Manual). Max user set point will allow
the boiler to operate without reaching this set point. The
boiler will require a load large enough to dissipate a large
portion of the heat it is generating.
Figure 2-6 Low voltage terminal strip and enable contacts
LOW VOLTAGE CONNECTION BOARD
2. Simulate a call for heat by placing a jumper wire across
the enable contacts #19 and 20 on the low voltage
terminal strip located at the rear of the unit (FIG. 2-6).
3. Allow the unit to progress through its normal diagnostics
and pre-purge programming.
4. Locate the pinhole button below the RESET button on
the display board (see page 7). Insert a thin wire (such as
a paper clip) into the hole and press the button once and
hold for 5 seconds to place the boiler into Service Mode.
In Service Mode the boiler will fire at ignition speed and
will then modulate up to full fire.
ENABLE
CONTACTS
IMG00103
5. Allow the unit to fire and operate until the temperatures
stabilize. This occurs when the inlet and outlet
temperatures are rising together and the Delta T (ꢀ T)
is maintained.
Figure 2-7 Adjust outlet isolation valve
ADJUST OUTLET
ISOLATION VALVE
ONLY
6. When the unit stabilizes, begin to slowly shut off the
isolation valve on the outlet piping of the boiler (see
FIG. 2-7). This will begin to restrict the flow and
simulate a low flow condition.
7. While slowly shutting off the isolation valve, refer to the
Status Screens to watch the behavior of the boiler. These
screens allow you to monitor the inlet temperature,
outlet temperature, and ꢀT.
8. When the ꢀ T reaches 55˚F, the control will attempt to
modulate the firing rate down to protect it from low flow
conditions.
IMG00098
32
Service Manual
3 Troubleshooting
Label all wires prior to disconnection
Check control module fuses
ƽ WARNING
when servicing controls. Wiring errors
can cause improper and dangerous
operation. Always disconnect power
to the boiler before servicing. Failure
to comply could result in severe
personal injury, death, or substantial
property damage.
ALWAYS check control module fuses before
NOTICE
replacing control module or any major
components (blower, etc.). If one of these
fuses is blown, it can prevent the control
module or other components from operating.
1. Turn OFF the power to the boiler at the external line
switch.
Never jumper (bypass) any device
except for momentary testing as
outlined in the Troubleshooting
chart. Severe personal injury, death,
or substantial property damage can
result.
ƽ WARNING
2. Remove top access cover.
3. Remove the control module cover.
4. Inspect fuses F1, F2, and F3, see FIG 3-1 below.
Figure 3-1 Control Module Fuses
Before troubleshooting:
1. Have the following items:
a. Voltmeter that can check 120 VAC, 24 VAC, and
12 VDC.
b. Continuity checker.
c. Contact thermometer.
F3 - .80 AMP FUSE
24V DC POWER SUPPLY
2. Check for 120 VAC (minimum 102 VAC to maximum
132 VAC) to boiler.
F1 - 5 AMP FUSE
PUMPS
F2 - 3.15 AMP FUSE
BLOWER
3. Make sure thermostat is calling for heat and contacts
(including appropriate zone controls) are closed.
Check for 24 VAC between thermostat wire nuts and
ground.
5. The boiler is shipped with three (3) spare fuses in a plastic
bag attached to the control module cover.
4. Make sure all external limit controls are installed and
operating.
6. If necessary, replace open fuse (F3 is .80 amps, F2 is 3.15
amps and F1 is 5 amps).
Check the following:
Note: Fuses F1, F2, and F3 are all slow blow fuses.
1. Wire connectors to control module are securely
plugged in at the module and originating control.
Do not jumper fuse or replace with any fuse
ƽ WARNING
except as specified. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
2. Gas pressures:
• Maximum: 14 inches w.c. (3.5 kPa) (natural and
LP) with no flow (lockup) or with boiler on
• Minimum: 4 inches w.c. (1.0 kPa) (natural),
8 inches w.c. (2.0 kPa) (LP) with gas flowing (verify
during boiler startup)
7. Install control module cover and top access cover after fuse
inspection.
8. Restore power to the boiler at the external line switch and
verify boiler operation (Section 10 - Start-up in the Knight
XL Installation and Operation Manual) after completing
boiler service.
33
Service Manual
3 Troubleshooting
Table 3-1 Troubleshooting Chart - No Display
FAULT
CAUSE
CORRECTIVE ACTION
• Check external line switch, fuse, or breaker.
- No 120 vac supplied to unit.
• Check position of ON/OFF switch. Turn switch to the
ON position.
• Check 120 vac through the ON/OFF switch.
• Check wiring harness connection between display
board and main control board. Connect
harness at both points.
No Display
- No voltage through the switch.
- Bad display board.
• Replace switch.
• Replace board.
- Bad main control board.
• Replace the main control board.
• Replace fuse F3 on the main control board, see
page 33 of this manual.
- Blown fuse.
- Main control board temperature set point
satisfied.
• Review temperature setting.
- Remote thermostat satisfied.
• Review remote thermostat setting.
- Outside air temperature above Warm • Check location of outside air sensor.
Check
No Burner
Operation
Weather Shutdown (WWSD) set point for
main control board.
resistance of outdoor air sensor and compare to Table
3-2B on page 35 of this manual.
• Consult display for specific fault. Refer to fault
descriptions on page 37 of this manual for corrective
actions.
- Unit locked out on fault.
- Unit in Shutdown Mode.
• Take unit out of Shutdown Mode.
• Check ramp delay parameter settings. Optional PC
software required.
- Ramp delay active.
• Turn ramp delay feature off. See page 22 of this
manual for instructions on how to turn this feature off.
Unit Does
• Check BMS parameter settings.
software required.
Optional PC
Not Modulate - Boiler controlled by BMS.
Above 50%
• Verify that the flue sensor is located in the flue outlet.
• Check wiring connections at the flue sensor.
- Flue sensor open.
• Check the resistance of the flue sensor and compare
to Table 3-2D on page 35 of this manual.
34
Service Manual
3 Troubleshooting
(continued)
Checking temperature sensors
The boiler temperature sensors (inlet water, outlet water, system water, flue, and outdoor air) are all resistance type devices. The
following tables show the correct values for the sensors at various temperatures. Use an ohmmeter to read the resistance of the
sensor at a known temperature. If the resistance of the sensor does not closely match its corresponding table, replace the sensor
It is important to note that the flue and outlet water sensors have two temperature sensing devices in one housing. These
devices are designated as S1a/S1b, outlet sensor and S3a/S3b, flue sensor. Please reference the wiring diagram in the Knight XL
Installation and Operation Manual for correct terminal location.
Table 3-2A - Inlet Water/System Sensor Resistance vs.
Table 3-2B - Outdoor Air Sensor Resistance vs.
Temperature
Temperature
Temperature Resistance Temperature Resistance
Temperature Resistance Temperature Resistance
-50
-40
-30
-20
10
490,813
336,606
234,196
165,180
118,018
85,362
20
30
40
50
60
70
80
46,218
34,558
26,099
19,900
15,311
11,883
9,299
50
68
18,780
12,263
8,194
5,592
3,893
2,760
158
176
194
212
1,990
1,458
1,084
817
86
104
122
140
0
10
62,465
Table 3-2C - Outlet Water Sensor Resistance vs. Temperature
S1a
S1b
(Wire Color - R/BK and Y)
(Wire Color - G and Y)
Temperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance
50
68
19,553
12,690
8,406
5,715
3,958
2,786
158
176
194
212
2,004
1,464
1,084
816
50
68
40,030
25,030
16,090
10,610
7,166
158
176
194
212
3,478
2,492
1,816
1,344
86
86
104
122
140
104
122
140
4,943
Table 3-2D - Flue Sensor Resistance vs. Temperature
S3a
S3b
(Wire Color - W/B and Y)
(Wire Color - PR and Y)
Temperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance
50
68
40,030
25,030
16,090
10,610
7,166
158
176
194
212
3,478
2,492
1,816
1,344
50
68
258,500
125,500
80,220
52,590
35,270
24,160
158
176
194
212
16,870
12,000
8,674
86
86
104
122
140
104
122
140
6,369
4,943
35
Service Manual
3 Troubleshooting
Table 3-3 Troubleshooting Chart - Noisy System
FAULT
CAUSE
CORRECTIVE ACTION
-
Supply gas problem. Natural gas • Refer to Section 7 - Gas Connections of the Knight
pressures should be between 4 inches XL Installation and Operation Manual for detailed
w.c. and 14 inches w.c. LP gas pressures information concerning the gas supply.
should be between 8 inches w.c. and 14
inches w.c.
- Gas/air mixture problem.
• Refer to the Gas Valve Adjustment Procedure on
page 47 of this manual for the proper gas valve setting.
Verify that the vent/air intake lengths do not exceed the
maximum listed in the General Venting section of the
Knight XL Installation and Operation Manual.
- Dirty/damaged burner.
• Refer to page 31 in this manual for the burner removal
and inspection procedure. Clean or replace the burner
as necessary.
Noisy
Operation
- Low water flow through the heat exchanger. • Refer to Section
6
-
Hydronic Piping of the
Knight XL Installation and Operation Manual for
minimum flow rates. Verify that the boiler is piped in a
primary/secondary fashion and that the boiler and
system pump are running on a call for heat.
- Air in the piping system.
• Properly purge all air from the piping system.
• Verify system pressure is a minimum of 12 psi.
- Low system water pressure.
- Blown fuse.
No Pump
Operation -
Boiler Pump
System Pump
or
• Replace fuse F1 on the control board, see page 33 of
this manual.
Note: Make sure pump amperage does not exceed
1.8 amps.
DHW Pump
• Replace pump.
- Faulty pump.
- Internal fault on control board.
• Replace main control board.
- System pressure exceeds relief valve • Lower the system pressure below the 30 psi rating of
setting.
the supplied relief valve or replace the standard relief
valve with a higher rated valve up to the maximum
pressure of the heat exchanger.
Relief Valve
Opening
• Improperly sized expansion tank.
36
Service Manual
3 Troubleshooting
(continued)
Table 3-4 Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Reset the pressure switches.
• Measure the supply gas pressure to determine cause
of failure. Natural gas pressures should be between
4
-
14 inches w.c. and LP gas pressures
should be between 8 - 14 inches w.c.
- Either the optional manual reset low gas
pressure switch or the optional manual reset • Refer to Section 7 - Gas Connections of the Knight
Gas Pressure SW
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
high gas pressure switch tripped.
XL Installation and Operation Manual for detailed
information concerning the gas supply.
• Correct the supply gas pressure if necessary.
• Check for a loose or misplaced jumper if pressure
switches are not installed.
• Check for a loose or misplaced jumper on the Low
Voltage Connection Board.
- The gas pressure switch contacts on the
Low Voltage Connection Board are open.
• Check for the addition of a device wired across the
gas pressure switch terminals on the Low Voltage
Connection Board.
• Check boiler pump operation on a call for heat.
• Check for closed valves or obstructions in the boiler
piping.
Flow Switch/
LWCO
- Either the optional flow switch or the optional
low water cutoff is not making.
• Verify system is full of water and all air has been
purged from the system.
(will require a manual
reset once condition has
been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Check for loose or misplaced jumpers if flow switch or
LWCO is not installed.
• Replace fuse F3 on the control board, see page 33
of this manual.
- Blown fuse.
• Check condensate tube from unit to floor drain for
proper installation and obstructions.
Blocked Drain SW
(will require a manual
reset once condition has
been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Inspect condensate trap for blockage. Clean if
necessary.
The blocked drain switch has detected
excessive condensate build up inside the
unit.
• Check for loose wiring connection at wire harness
plug.
• Bad blocked drain switch. Replace switch.
37
Service Manual
3 Troubleshooting
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
APS:
• Check the wiring connections to switch. Wires should
be connected to the common and normally closed
terminals.
• Air intake lengths exceed the maximum allowed
lengths. Refer to Section 3 - General Venting of the
Knight XL Installation and Operation Manual for
proper lengths.
• Check for obstruction or blockage in the air
intake pipes or at terminations.
APS / HEX
Temp Sw
• Check reference hoses connected to the air pressure
switch for blockage or obstruction.
Open
• Inspect the burner. Reference page 31 of this manual
for removal and cleaning procedures. Replace if
necessary.
Either the air pressure switch contacts are
open, or the O-temp heat exchanger switch
has opened.
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the SMART SYSTEM
display to reset.)
• Inspect the heat exchanger. Reference page 32 of
this manual for removal and cleaning procedures.
Replace if necessary.
• Faulty air pressure switch. Replace switch.
O-TEMP HEX SWITCH
• Inspect the back of the inner combustion chamber at
burner level for refractory breakdown / missing.
Replace heat exchanger if refractory is broken and unit
has fired.
• Check continuity across two contacts. Wires should be
connected at both poles of the normally closed switch.
• Faulty O-Temp HEX Switch. Replace switch.
• The control board will release the call for heat after a
set time period.
The main control board has received a call
for heat too quickly after the previous call for
heat has ended.
Anti-cycling
• The control board will release the call for heat if the
outlet temperature drops too quickly.
• Inspect spark electrode and associated wiring for
damage and connection. Reference page 31 of this
manual for removal and cleaning procedures.
Replace if necessary.
Flame Fail Ign
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the SMART SYSTEM
display to reset.)
• Check for proper electrical grounding of the unit.
The unit has failed to prove main burner
ignition after four (4) attempts.
• Check incoming supply gas pressure. Natural gas
pressures should be between 4 - 14 inches w.c. and
LP gas pressures should be between 8 - 14 inches w.c.
Refer to Section 7 - Gas Connections of the Knight
XL Installation and Operation Manual for detailed
information concerning the gas supply.
38
Service Manual
3 Troubleshooting
(continued)
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
The unit has failed to prove main burner • Verify that the plastic hose from the gas valve to the air
ignition after four (4) attempts.
inlet is connected and is not damaged.
• Verify that the vent/air intake pipes are correctly
installed and that there are no obstructions.
• Check for 24 vac to the gas valve at the 2-pin
connection on the side of the main control board during
the ignition attempt. If no voltage is present, replace
the main control board.
• If 24 vac is present at the main control board, check
the wiring between the main control board and the gas
valve. Replace the wiring if necessary. Do not
disconnect the wiring from the gas valve and attempt to
measure voltage at that point. The main control board
can detect if the gas valve is not connected and will
display the Gas Valve or Gas Valve Fail fault.
Flame Fail Ign
(cont’d)
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the SMART SYSTEM
display to reset.)
• If 24 vac is present, check the outlet of the valve to
ensure the valve is flowing gas. With a manometer
connected to the outlet tap of the gas valve, when the
unit is in the prepurge period, there should be a
negative pressure present.
When the valve is
energized a change in pressure should occur. If the
pressure change does not occur, the gas valve is not
opening. Replace the gas valve.
• Inspect flame sensor and associated wiring.
Reference page 31 of this manual for removal and
cleaning procedures. Replace if necessary.
• Inspect and clean the heat exchanger as necessary.
Reference page 32 of this manual for cleaning
procedures.
• Inspect the burner. Reference page 31 of this manual
for removal and cleaning procedures. Replace if
necessary.
• Replace the main control board.
Flame Sequence
(will require a manual
reset once the condition
has been corrected.
Press the RESET button
on the SMART SYSTEM
display to reset.)
• Check supply voltage for proper polarity.
• Check external wiring for voltage feedback.
• Check the flame rod and make sure it is clean.
• Check the internal wiring for bad connections.
• Replace main control board.
The flame detector circuit is seeing a flame
signal while no flame is present.
39
Service Manual
3 Troubleshooting
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Adjust the set point of the auto reset limit to a higher
setting up to a maximum of 200°F. Reference the
Knight XL Installation and Operation Manual for
adjusting procedures.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
Knight XL Installation and Operation Manual
for the proper piping methods for the Knight XL boiler.
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
The outlet water temperature has exceeded
the setting of the automatic reset high limit.
• Replace the main control board if necessary.
Outlet ARHL
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• If the system pump is a variable speed pump, ensure
that the system flow is not less than the boiler flow.
• If operating on something other than an outlet sensor,
check temperature setting of the main control board.
• If the optional manual reset high limit has tripped,
check setting of the device.
• Check resistance of water sensors and compare to
Table 3-2A on page 35 of this manual. Replace
sensor if necessary.
• Replace high limit.
• Adjust the set point of the manual reset limit to a higher
setting up to a maximum of 210°F. Reference the
Knight XL Installation and Operation Manual for
adjusting procedures.
Outlet MRHL
(will require a manual
reset once the condition
has been corrected.
Press the RESET
button on the SMART
SYSTEM display to
reset.)
• Verify that the system is full of water and that all air
has been properly purged from the system.
The outlet water temperature has exceeded
the setting of the manual reset high limit.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
Knight XL Installation and Operation Manual
for the proper piping methods for the Knight XL boiler.
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
40
Service Manual
3 Troubleshooting
(continued)
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Replace the main control board if necessary.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
Outlet MRHL
(cont’d)
• If the system pump is a variable speed pump, ensure
that the system flow is not less than the boiler flow.
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• If operating on something other than an outlet sensor,
check temperature setting of the main control board.
The outlet water temperature has exceeded
the setting of the manual reset high limit.
• If the optional manual reset high limit has tripped,
check setting of the device.
• Check resistance of water sensors and compare to
Table 3-2A on page 35 of this manual. Replace
sensor if necessary.
• Replace high limit.
• Vent/air intake lengths exceed the maximum allowed
lengths. Refer to Section 3 - General Venting of the
Knight XL Installation and Operation Manual for
proper lengths.
Fan Low/High
OR
• Check for obstruction or blockage in the vent/air
intake pipes or at terminations.
Fan Speed Low/ The actual fan RPM is 30% lower than what
is being called for.
High
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Check the wiring connections at the fan and at the
main control board.
• Replace the fan.
• Replace the main control board.
• Replace fuse F2 on the control board, see page 33
of this manual.
Blown fuse.
• Check wiring harness connection at the gas valve and
at the main control board.
GV/Relay
Fail
(will require a manual
• Replace the gas valve wire harness.
• Replace the gas valve.
The main control board did not detect the
gas valve.
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Replace the main control board.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
Sensor Open
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
Either the inlet water or outlet water • Measure the resistance of the sensors and compare
temperature sensor has been disconnected.
the resistance to the tables on page 35 of this
manual.
• Replace the sensor if necessary.
41
Service Manual
3 Troubleshooting
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
Sensor Shorted
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
Either the inlet water or outlet water • Measure the resistance of the sensors and compare
temperature sensor has been shorted.
the resistance to the tables on page 35 of this
manual.
SYSTEM display to reset.)
• Replace the sensor if necessary.
Louver Proving
Sw
• Check function of remote devices.
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
SYSTEM display to reset.)
An optional remote proving switch is not
making.
• Check for loose or misplaced jumper if auxiliary
proving switch is not installed.
• Check wiring to sensor.
connected and not damaged. Reconnect / repair
wiring if necessary.
Make sure wiring is
Inlet Sensor
Fault
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
SYSTEM display to reset.)
The control reads the inlet sensor as open
or shorted.
• Measure the resistance of the sensor and compare to
the resistance in Table 3-2A on page 35 of this manual.
Replace sensor if necessary.
• Replace control module.
• Check wiring to sensor.
connected and not damaged. Reconnect / repair
wiring if necessary.
Make sure wiring is
Outlet Sensor
Fault
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
SYSTEM display to reset.)
The control reads the inlet sensor as open
or shorted.
• Measure the resistance of the sensor and compare to
the resistance in Table 3-2C on page 35 of this manual.
Replace sensor if necessary.
• Replace control module.
• Check wiring to sensor.
Make sure wiring is
connected and not damaged. Reconnect / repair
wiring if necessary.
Outlet Temp Diff
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
• Measure the resistance of the sensor and compare to
the resistance in Table 3-2C on page 35 of this manual.
Replace sensor if necessary.
The control module reads an excessive
temperature difference between the two
sensors.
• Restore control parameter defaults from optional PC
software.
SYSTEM display to reset.)
• Replace control module.
42
Service Manual
3 Troubleshooting
(continued)
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Check wiring to sensor. Make sure wiring is
connected and not damaged. Reconnect / repair
wiring if necessary.
Flue Sensor Fault
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
The control reads the flue sensor as open
or shorted.
• Measure the resistance of the sensor and compare
to the resistance in Table 3-2D on page 35 of this
manual. Replace the sensor if necessary.
SYSTEM display to reset.)
• Replace control module.
• Check wiring to sensor. Make sure wiring is
connected and not damaged. Reconnect / repair
wiring if necessary.
Flue Temp Diff
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
• Measure the resistance of the sensor and compare to
the resistance in Table 3-2D on page 35 of this
manual. Replace sensor if necessary.
The control module reads an excessive
temperature difference between the two
sensors.
• Restore control parameter defaults from optional PC
software.
SYSTEM display to reset.)
• Replace control module.
• Inspect the heat exchanger. Reference page 32 of
this manual for the procedure on how to clean the flue
side of the heat exchanger.
Flue Temp Limit
(will require a manual reset
once the condition has been
corrected. Press the RESET
button on the SMART
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 3-2D on page 35 of this manual.
Replace the sensor if necessary.
The stack temperature has exceeded the
Flue Temp Limit set parameters.
SYSTEM display to reset.)
• Verify that the vent/air intake pipes are properly
installed and that there are no obstructions.
• Replace the main control board.
• Restore the parameter defaults from the optional PC
software.
The control module has detected parameter
settings that are out of range.
Fatal Error
• Replace control module.
A lockout occurs at the same time as a
power outage.
• Reset control module.
Memory Error
43
Service Manual
3 Troubleshooting
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Inspect the heat exchanger. Reference page 32 of
this manual for the procedure on how to clean the flue
side of the heat exchanger.
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 3-2D on page 35 of this manual.
Replace the sensor if necessary.
The stack temperature has exceeded the set
parameters for the boiler.
Flue Temp High
• Verify that the vent/air intake pipes are properly
installed and that there are no obstructions.
• Replace the main control board.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
Knight XL Installation and Operation Manual
for the proper piping methods for the Knight XL boiler.
• Check for 120 vac to the boiler pump motor on a call
for heat. If voltage is not present, check the wiring
back to the main control board. Replace the main
control board if necessary.
Delta T High
The temperature rise across the heat
exchanger has exceeded the set parameters
for the boiler.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• Verify that the boiler pump is set to the proper speed
or that the pump is the proper size. Reference
Section
6
-
Hydronic Piping of the Knight
XL Installation and Operation Manual for boiler
pump specifications.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
Knight XL Installation and Operation Manual
for the proper piping methods for the Knight XL boiler.
• Check for 120 vac to the boiler pump motor on a call
for heat. If voltage is not present, check wiring back
to the main control board. Replace the main control
board if necessary.
Outlet Temp
High
Outlet water temperature has exceeded the
maximum outlet water temperature.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• Verify that the boiler pump is set to the proper speed
or that the boiler pump is the proper size. Reference
Section 6 - Hydronic Piping of the Knight XL
Installation and Operation Manual for boiler pump
specifications.
• Replace the main control board.
44
Service Manual
3 Troubleshooting
(continued)
Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Check set point of the external control.
• Check the wiring between the external control and the
unit.
Rem Ctrl Flt
External control is cycling too often.
• Replace the control.
Parameters
Progr
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Press the ENTER/RESET button on the SMART
SYSTEM display panel.
After downloading parameters from a laptop,
the main control board must be reset.
• Establish a heating load to remove the heat from the
boiler loop.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping of the
Knight
XL
Installation
and
Operation
Manual for the proper piping methods for the Knight
XL boiler.
While the unit is in Service Mode, the outlet
temperature has exceeded 185°F.
• Check 120 vac to the boiler pump motor on a call for
heat. If voltage is not present, check the wiring back
to the main control board. Replace the main control
board if necessary.
Service Blk
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• Verify that the boiler pump is set to the proper speed
or that the boiler pump is the proper size. Reference
Section
6
-
Hydronic Piping of the Knight
XL Installation and Operation Manual for boiler
pump specifications.
• Check 120 vac supply to the transformer.
• Check wiring connections at the low voltage
terminal strip.
120 vac input to the main control board has
dropped below 80 vac.
Low 24 vac
• Check the wire size/length to remote devices.
• Replace the transformer.
The main control board has detected an
internal fault.
• Replace the main control board.
• Replace the main control board.
Watch Dog Error
The main control board has detected an
internal fault.
Write EEProm
The main control board has detected an
internal fault.
• Replace the main control board.
CRC Parameters
The main control board has detected an
internal fault.
• Replace the main control board.
No Error Stored
45
Service Manual
3 Troubleshooting
Combustion Analysis Procedure
Table 3-5 Flue Products
Natural Gas
CO2 O2
8.0% - 10% 3.0% - 6.5% 9.0% - 11%
1. Turn the main power off to the boiler by placing the “On/
Off” switch in the OFF position.
Propane
CO2
O2
2. Remove the flue temperature sensor from the flue pipe
connection. Note: Combustion measurements will be
made at this point.
4.1% - 6.9%
8. Once the combustion analysis is complete, test the safety
shutoff device by turning the manual shutoff valve to the
OFF position and ensuring that the boiler shuts down
and registers an alarm. Open the manual shutoff valve,
reset the control, and return to Service Mode.
3. Turn the main power on to the boiler by placing the
“On/Off” switch in the ON position.
4. Place the boiler into the active position by pressing the
RIGHT SELECT [ON] key (see page 7).
9. Turn the main power off to the boiler and replace the flue
temperature sensor into the flue pipe connection.
5. Locate the pinhole button below the RESET button on
the display board (see page 7). Insert a thin wire (such as
a paper clip) into the hole and press the button once and
hold for 5 seconds to place the boiler into Service Mode.
In Service Mode the boiler will fire at ignition speed and
will then modulate up to full fire.
10. Place the boiler back into normal operation.
You must replace the flue gas temperature
ƽ WARNING
sensor to prevent flue gas spillage into
the room. Failure to comply could result
in severe personal injury, death, or
substantial property damage.
6. Remove the flue temperature sensor. Insert the probe
from a combustion analyzer into the hole left by the
removal of the flue temperature sensor.
7. Once the boiler has modulated up to full fire, measure
the combustion. The values should be in the range listed
in Table 3-5 above. The CO levels should be less than
150 ppm for a properly installed unit.
If the combustion is not within the specified range,
reference the chart below for possible causes and
corrective actions.
Table 3-6 Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
CORRECTIVE ACTION
• Refer to Section 3 - General Venting of the Knight XL Installation and Operation Manual
for the proper venting and air intake methods for the Knight XL boiler.
Vent/Air Intake Length
or Obstruction
• Check for obstructions at the vent/air intake terminals.
• Refer to Section 7 - Gas Connections of the Knight XL Installation and Operation
Manual for the proper gas supply for the Knight XL boiler.
Gas Supply Pressure
• Refer to page 31 of this manual for burner removal and cleaning procedures.
• Replace burner if necessary.
Dirty/Damaged Burner
Gas Valve Adjustment
• Refer to page 47 of this manual for the gas valve adjustment procedure.
46
Service Manual
3 Troubleshooting
(continued)
Gas valve adjustment procedure
Figure 3-3 Gas Valve Adjustment: Model 501
If adjustment of the gas valve is deemed necessary, use the
following procedures: (Note: The procedures below are
model specific.)
Under normal operating conditions this
valve should not need adjusting.
CAUTION
Model 400
Locate the throttle adjustment screw on the top of the gas
valve, see FIG. 3-2. Using a screwdriver, turn the screw 1/8
turn counterclockwise to increase CO2 levels or 1/8 turn
clockwise to decrease CO2 levels. After one adjustment on
the valve, follow the Combustion Analysis Procedure on
page 46 of this manual to measure the combustion.
If combustion is still not within the specified range,
repeat the procedure. This procedure SHOULD NOT
be performed more than four (4) times. If after four (4)
adjustments and the combustion is still not within the
specified range, revisit the possible causes in Table 3-6 on
page 46 or replace the gas valve.
Models 601 - 801
Locate the throttle adjustment screw on top of the gas valve,
see FIG. 3-4. Using an Allen wrench, turn the screw a 1/4
turn counterclockwise to increase CO2 levels or a 1/4 turn
clockwise to decrease CO2 levels. After one adjustment on the
valve, follow the Combustion Analysis Procedure on page 46
of this manual to measure the combustion.
Figure 3-2 Gas Valve Adjustment: Model 400
THROTTLE ADJUSTMENT
SCREW
If combustion is still not within the specified range, repeat
the procedure. This procedure SHOULD NOT be performed
more than four (4) times. If after four (4) adjustments and
the combustion is still not within the specified range, revisit
the possible causes in Table 3-6 on page 46 or replace the gas
valve.
Figure 3-4 Gas Valve Adjustment: Models 601 - 801
Model 501
THROTTLE
ADJUSTMENT
SCREW
Locate the throttle adjustment screw on top of the gas valve,
see FIG. 3-3. Using a screwdriver, turn the screw a 1/4 turn
counterclockwise to increase CO2 levels or a 1/4 turn
clockwise to decrease CO2 levels. After one adjustment on
the valve, follow the Combustion Analysis Procedure on
page 46 of this manual to measure the combustion.
(REMOVE BLUE CAP)
If combustion is still not within the specified range,
repeat the procedure. This procedure SHOULD NOT
be performed more than four (4) times. If after four (4)
adjustments and the combustion is still not within the
specified range, revisit the possible causes in Table 3-6 on
page 46 or replace the gas valve.
47
Revision Notes: Revision A (ECO #C05747) initial release. Reflects
the new model numbers for the Knight XL upgrade.
Revision B (ECO #C06234) reflects changes made to the Service
Notification parameter.
Revision C (ECO #C07981) reflects changes made to the parameter
table, parameter descriptions, updates to the troubleshooting chart, and
the addition of the O-temp HEX switch.
Revision D (ECO #C09197) reflects updates made to the SMART
SYSTEM control (ECR #R04523).
Revision E (ECO #C09840) reflects the addition of the Test Procedure
for low water flow conditions on page 32.
Revision F (ECO #C10143) reflects updates made to the ignition timing
information.
KBXII-SER Rev F
04/12
|