Lochinvar Knight 50-210 User manual

Service Manual
Models: 50 - 210
This manual must only be
used by a qualified heating
installer / service technician.
Read all instructions,
including this manual and the
Knight Wall Mount
Installation and Operation
Manual, before installing.
Perform steps in the order
given. Failure to comply
could result in severe personal
injury, death, or substantial
property damage.
WARNING
Save this manual for future reference.

2
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels
or to important information concerning the life of the product.
DANGER
WARNING
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Hazard Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
PLEASE READ BEFORE PROCEEDING . . . . . . . . . . . . 3
Handling Ceramic Fiber Materials . . . . . . . . . . . . . . . . . . . 3
When servicing boiler . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Boiler operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Boiler water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Freeze protection fluids . . . . . . . . . . . . . . . . . . . . . . . . 4
WHAT IS IN THIS MANUAL . . . . . . . . . . . . . . . . . . . . . . . 5
1. SERVICE
Near Boiler Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The Knight Wall Mount Display . . . . . . . . . . . . . . . . . . . . . 7
Control Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Control Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12
Display Panel Menu Access . . . . . . . . . . . . . . . . . . . . . . 13
Display Panel Parameter Access . . . . . . . . . . . . . . . . . . 14
Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-16
Viewable and Changeable Control Parameters . . . . . . . 17-22
2. MAINTENANCE
Maintenance and Annual Startup . . . . . . . . . . . . . . . . . . 23-27
3. TROUBLESHOOTING
Before Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Check Control Module Fuses . . . . . . . . . . . . . . . . . . . . . 28
Table 3A - Troubleshooting Chart - No Display . . . . . . . . 29
Checking Temperature Sensors . . . . . . . . . . . . . . . . . . . 30
Table 3E - Troubleshooting Chart - Noisy System . . . . . 31
Table 3F - Troubleshooting Chart - Fault Messages . . . . 32-39
Combustion Analysis Procedure . . . . . . . . . . . . . . . . . . . 40
Table 3G - Troubleshooting Chart - Combustion Levels 40
Table 3H - Flue Products . . . . . . . . . . . . . . . . . . . . . . . . . 40
Gas Valve Adjustment Procedure . . . . . . . . . . . . . . . . . . 41
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover
Contents

Service Manual
Please read before proceeding
Installer – Read all instructions,
including this manual and the Knight
Wall Mount Installation and Operation
Manual, before installing. Perform steps
in the order given.
User – This manual is for use only by a
qualified heating installer/service
technician. Refer to the Knight Wall
Mount 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.
When calling or writing about the boiler –
Please have the boiler model and serial
number from the boiler rating plate.
Consider piping and installation when
determining boiler location (see the Knight
Wall Mount Installation and Operation
Manual).
Any claims for damage or shortage in
shipment must be filed immediately against
the transportation company by the
consignee.
3
Handling ceramic fiber materials
REMOVAL OF COMBUSTION CHAMBER LINING
The combustion chamber door insulation in this product 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).”:
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
the NIOSH website at http://www.cdc.gov/niosh/homepage.html. NIOSH approved respirators,
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 boiler 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.
WARNING NOTICE
WARNING

4
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.

Service Manual
5
What is in this manual?
Service
Near boiler piping
• Typical system components
The Knight wall mount boiler display
• Display panel readout, buttons and their functions
Control module inputs
• Control module inputs and options
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
Control panel menu access
• Accessing programming mode and locating menus
(See separate guide covering the PC interface.)
Control panel parameter access
• Accessing and changing parameters from the display panel
Quick start information -- parameter
table
• An index of available adjustments and readouts, where to
access them and where to find detailed information.
Knight wall mount boiler operation
• A: General
• B: Temperature Setting
• C: Data Logging
• D: Functions
• E: DHW Settings
• F: Outdoor Air Reset Curve
• G: Anti-cycling
• H: Control Modes
• I: Circulation Pumps
• J: Service Notification
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
• Flue vent system and air piping
• Check water system
• Check expansion tank
• 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
• Review with owner
• Cleaning boiler heat exchanger
• Oiled bearing circulators
Troubleshooting
• Troubleshooting table - No display
• Checking temperature sensors
• Sensor tables
• Troubleshooting table - Fault messages displayed on
boiler interface
• Combustion analysis procedure
• Gas valve adjustment procedure

1 Service
6
Service Manual
Near boiler piping
This piping reference is included to specify the Near Boiler Piping specific to the Knight wall mount boiler. This piping scheme
is important for proper operation of the SMART SYSTEM control. See the Knight Wall Mount Installation and Operation
Manual for more detailed piping diagrams.

1 Service
Service Manual
7
1 Service (continued)
The Knight wall mount display

1 Service
8
Service Manual
1 Service
GAS PRESSURE SWITCH
DHW THERMOSTAT
ROOM THERMOSTAT /
ZONE CONTROL
FLOW SWITCH
SYSTEM SENSOR
OUTDOOR SENSOR
SEQUENCER / BUILDING
MANAGMENT SYSTEM
LOW VOLTAGE
CONNECTION
BOARD
INLET TEMPERATURE
SENSOR
OUTLET TEMPERATURE /
HIGH LIMIT SENSOR
FLUE GAS SENSOR
FLAME SENSOR
LOW WATER CUTOFF
BLOCKED DRAIN SWITCH
DISPLAY PANEL
PC INTERFACE
SMART CONTROL
MODULE
AIR PRESSURE SWITCH
Control inputs

1 Service
Service Manual
9
1 Service (continued)
Control outputs

1 Service
10
Service Manual
1 Service
General Operation
How the boiler operates
The Knight wall mount boiler 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.
How the control module operates
The Knight wall mount 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.
Sequence of operation
Table 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.
Access modes
User
The user can adjust space heating set point using the UP and
DOWN buttons at any time during normal operation. By
entering the USER code (0704), the user can also change
temperature units, time and date, and night setback settings.
In user mode, the following parameters can be viewed but not
changed: Boiler outlet water temperature in DHW mode;
boiler model number; software version; total operating hours,
and total cycles.
Installer
Most parameters are available only to the installer, accessible
only by entering the installer access code (5309).
Saving parameters
To save parameters:
Press the ENTER/RESET button.
To keep parameter settings only for a current operating cycle:
Press the MENU/EXIT button 1 time to return to the
parameter listings; press again to return to the menu listings.

1 Service
Service Manual
11
1 Service (continued)
Sequence of operation
Table 1A Sequence of operation - space heating and DHW
OPERATION DISPLAY
1. Upon a call for heat, the control turns on the appropriate pumps
(system and boiler pumps for space heating call; DHW pump
for DHW call).
BLR: Standby
OUT: 123.8F(129)
2. The control connects 120 vac to the blower. The blower does
not run at this time.
• If the unit is equipped with a flow switch or low water cutoff, it
must close before the control powers up the blower.
• If the unit is equipped with a manual reset high limit it must be
closed before the control powers up the blower.
• If the unit is equipped with a solenoid valve and/or a vent
valve, they will be energized along with the blower.
• If the unit is equipped with a gas pressure switch, it must close
at this time.
• If there is an auxiliary device connected to the unit, the unit
will then provide 24 vac to its enable relay. If the auxiliary
device has a proving switch, it must close before the
sequence continues.
BLR: Standby
OUT: 123.8F(129)
3. The control then starts a 10 second prepurge cycle. BLR: PREPURGE
OUT: 123.9F(129)
4. Once the prepurge cycle is complete, and the blocked drain
switch and auto-reset high limit are closed, the control starts
the 5 second trial for ignition by sending spark voltage to the
spark electrode and opening the gas valve.
BLR: IGNITION
OUT: 123.9F(129)
5. If the control does not detect flame by the end of the trial for
ignition, the control performs a 10 second postpurge, another
prepurge and tries to light the burner again. If the burner does
not light after 4 trials, the control locks out for 1 hour and then
tries another set of 4 trials.
BLR: POSTPURGE, PREPURGE
OUT: 123.9F(129)
6. If the control detects a flame before the trial for ignition ends, it
begins to modulate the burner in order to maintain the set point.
If the boiler lights due to a space heating call for heat, and the
ramp delay function is active (default is off), the modulation
will be held to a series of increasing limits after the burner has
lit.
BLR: SH 20% RATE
OUT: 124.8F(129)
7. If the space heating call for heat is active, and the DHW
thermostat closes, the control will turn on the DHW pump, wait
2 seconds, and then turn off the boiler pump. This will divert
the hot water away from the heating zone(s) and send it to the
DHW tank instead. The control will then modulate to maintain
the outlet temperature to the DHW boiler set point.
BLR: DHW 85% RATE
OUT: 177.8(180)

1 Service
12
Service Manual
1 Service
Sequence of operation (continued)
Table 1A (continued from previous page) Sequence of operation - space heating and DHW
OPERATION DISPLAY
8. If the DHW thermostat remains on for more than 30 minutes,
and the space heating call for heat is also on, then the control
will turn on the boiler pump, turn off the DHW pump after 2
seconds, and resume modulating based on the space heating
set point. As long as both the space heating and DHW calls for
heat remain active, the control will switch back and forth
between the two modes until one of them is satisfied.
BLR: SH 41% RATE
OUT: 123.0F(129)
9. Once both calls for heat are satisfied, the control will turn off the
burner. The blower will remain on for the 10 second postpurge
cycle. Any pumps that are running will continue to run for their
respective pump delay times, then turn off.
BLR: POSTPURGE
OUT: 127.4F(129)
10. Boiler pump off, system pump continues its delay if longer. BLR: Standby
OUT: 124.7F(129)
11. System pump off. BLR: Standby
OUT: 122.9F(129)

1 Service
Service Manual
13
1 Service (continued)
Display panel menu access
Table 1B Use this procedure to access menus from the display panel

1 Service
14
Service Manual
1 Service
Display panel parameter access
Table 1C This is a typical example of accessing a parameter, shown for parameter I2, boiler pump delay

1 Service
Service Manual
15
1 Service (continued)
Parameter table
Table 1D This table lists SMART SYSTEM control module parameters and where to access them
MENU SUB ITEM DESCRIPTION SEE
PAGE
USER ACCESS INSTALLER ACCESS
DISPLAY MODIFY DISPLAY MODIFY
A
1Boiler Model 17 Yes No Yes No
2User Code 17 Yes Yes Yes Yes
3Date and Time 17 Yes Yes Yes Yes
4Software Version 17 Yes No Yes No
5Temperature Units 17 Yes Yes Yes Yes
6Night Setback Temperature 17 Yes Yes Yes Yes
7Night Setback Times 17 Yes Yes Yes Yes
GENERAL
B
1SH Set Point User 17 Yes Yes Yes Yes
2SH Minimum Set Point 17 No No Yes Yes
3SH Maximum Set Point 17 No No Yes Yes
4SH Offset 17 No No Yes Yes
5SH Differential 18 No No Yes Yes
C
1Hours Running SH 18 Yes No Yes No
2Hours Running DHW 18 Yes No Ye s No
3Ignition Attempts 18 Yes No Yes No
4Show Last 10 Errors 18 Yes No Yes No
D
1Reset Last 10 Errors 18 No No Yes Yes
2Service Mode Delay 18 No No Ye s Yes
DATA
FUNCTIONS
E
1DHW Boiler Set Point 18 Yes Yes Yes Yes
2SH/DHW Switching Time 18 Yes Yes Yes Yes
F
1Minimum Air Temperature 18 No No Yes Yes
2Maximum Air Temperature 18 No No Yes Yes
3Maximum SH Set Point 19 No No Ye s Yes
4Minimum SH Set Point 19 No No Yes Yes
5Outdoor Air Shutdown 19 Yes Yes Yes Ye s
6Outdoor Air Shutdown
Differential 19 Yes Yes Ye s Yes
7Shift Air Reset 19 No No Yes Yes
8Boost Temperature 20 Yes Yes Yes Ye s
9Boost Time 20 Yes Yes Yes Ye s
TEMPERATURE
SETTING
LOGGING
DHW
SETTINGS
OUTDOOR AIR RESET

1 Service
16
Service Manual
1 Service
Parameter table (continued)
Table 1D (continued from previous page) This table lists SMART SYSTEM control module parameters and
where to access them
The parameters for Building Management System operation are not listed in this table. They are only
accessible using the PC interface software. See separate documentation for access information. See page 21
of this manual for a brief discussion.
NOTICE
MENU SUB ITEM DESCRIPTION SEE
PAGE
USER ACCESS INSTALLER ACCESS
DISPLAY MODIFY DISPLAY MODIFY
G
1Anti-cycling Time 20 No No Yes Yes
2Return Temperature Differential for
Ending Anti-Cycling 20 No No Yes Yes
3Ramp Delay On/Off 20 No No Yes Ye s
ANTI-CYCLING
H
1SH Controlling Sensor
(Outlet/System, Inlet) 21 No No Yes Ye s
2SH Source (Thermostat, BMS, and
Cascade) 21 No No Yes Ye s
3Boiler Cascade Address 21 No No Yes Ye s
4Max. Cascade Set Point 21 No No Yes Ye s
5Cascade Offset 22 No No Yes Ye s
6Cascade Differential 22 No No Yes Ye s
CONTROL
MODES
I
1System Pump Delay 22 No No Yes Yes
2SH Pump Delay 22 No No Yes Yes
3DHW Pump Delay 22 No No Yes Yes
CIRCULATION
PUMPS
J
1Service Notification in Month 22 No No Yes Yes
2Service Notification Running Hours 22 No No Yes Yes
3Service Notification Boiler Cycles 22 No No Yes Yes
4Reset Service Notification Counter 22 No No Yes Yes
SERVICE
NOTIFICATION

1 Service
Service Manual
17
Viewable and changeable control parameters
A: General
Boiler model
The control will display “Knight Boiler” as the model number
because the same control is used on several models. This will be
displayed when parameter A1 has been accessed. This parameter
is not changeable.
User code
The User Code allows the user to access and change a limited
number of control parameters. The access code can be changed
by the user or the installer to a code of their choosing. To change
the code, parameter A2 must be accessed. The default code is
0704. The code can be changed one digit at a time by using the
arrow keys on the display.
Date and time
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 30 days. To set the
clock, parameter A3 must be accessed. The date and time are
displayed as “YY:MM:DD W hh:mm”. YY = year, MM = month,
DD = date, W = day (1 = Sunday, 2 = Monday, etc.), hh = hour
(24 hour time; 2:00 PM = 14:00), mm = minutes.
Night setback times
If parameter A6 is set to anything other than 32°F, the night
setback feature becomes active. This will require start and stop
times to be programmed for the days that reduced temperatures
are required. These times can be changed by the user or the
installer by accessing parameter A7. Each day of the week
(Sunday through Saturday) will have an on and off time.
Example: Monday ON: 22:30, Tuesday OFF: 6:45. If you wish
to skip a day and have no night setback, leave the on and off
times the same. The default times for each day will be 00:00
(midnight).
B: Temperature settings
SH set point user
The SH set point user sets the water temperature set point for
fixed operation or the maximum temperature set point when
the outdoor air sensor is used. This parameter can be changed
by the user or the installer by accessing parameter B1. The
temperature range of this parameter is 50°F to 190°F. The
default value is 125°F.
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 parameter B2. The
temperature range of this parameter is 32°F to 190°F. The
default value is 70°F.
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 parameter B3. The temperature range of
this parameter is 32°F to 190°F. The default value is 190°F.
SH Offset
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
parameter B4. The temperature range of this parameter is 0°F
to 86°F. The default value is 10°F.
CAUTION Before changing parameters, note the settings so that the unit can be returned to its original operating
parameters.
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.
Temperature units
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 parameter A5. The default is °F.
Night setback temperature
Once the internal clock has been set correctly, the night setback
feature can be used to program a lower water temperature set
point for space heating. This parameter can be changed by the
user or the installer by accessing parameter A6. The
temperature range for this parameter is 32°F to 140°F. The
feature is turned off with a setting of 32°F. The default value is
32°F.
NOTICE The internal clock does not adjust for
Daylight Savings Time and therefore, will
require a manual adjustment.

1 Service
18
Service Manual
1 Service
SH Differential
The SH differential sets how many degrees below the turn off
temperature the temperature has to go before the boiler will
turn on. This parameter can only be changed by the installer
by accessing parameter B5. The temperature range of this
parameter is 0°F to 86°F. The default value is 20°F.
C: Data logging
Hours running SH
The hours running SH parameter shows the total number of
hours the boiler has been in the SH firing position. This
parameter can be viewed by the user and the installer by
accessing parameter C1.
Hours running DHW
The hours running DHW parameter shows the total number
of hours the boiler has been in the DHW firing position. This
parameter can be viewed by the user and the installer by
accessing parameter C2.
Ignition attempts
The ignition attempts parameter shows the total number of
times the boiler has attempted to fire. This parameter can be
viewed by the user and the installer by accessing parameter
C3.
Show last 10 errors
The control will log the 10 most current errors with the date
and time the error occurred. This parameter can be viewed
by the user and the installer by accessing parameter C4.
D: Functions
Reset last 10 errors
The reset last 10 errors parameter allows the error counter to
be reset to 0. This parameter can only be cleared by the
installer by accessing parameter D1. Once accessed, press the
RESET key to clear the counter.
Service mode delay
By pressing the pin button on the front of the display for five
(5) seconds, the control will be placed in Service Mode. This
will override all other heat demands. The Service Mode
allows the installer to set the unit to either maximum firing
rate or minimum firing rate for the purpose of combustion
analysis. The delay sets the length of time the boiler will stay
in the Service Mode if no keys have been pressed before going
back to its original state. This parameter can only be changed
by the installer by accessing parameter D2. The time range of
this parameter is 0 to 40 minutes. The default value is
20 minutes.
E: DHW settings
DHW boiler set point
When a DHW call for heat becomes active, the control will
use the DHW boiler set point to determine the firing rate of
the boiler based on the actual water temperature. This
parameter can be changed by the installer by accessing
parameter E1. The temperature range of this parameter is
50°F to 190°F. The default value is 180°F.
SH/DHW switching time
The SH/DHW switching time parameter sets the length of
time the control will stay in DHW Mode when a SH call has
been received. After this time period has expired the control
will revert to SH Mode. If a DHW call is still active the timer
will reset. After the time period has expired the control will
revert back to DHW Mode. This will continue until one of
the demands has been satisfied. This parameter can be
changed by the installer by accessing parameter E2. The time
range of this parameter is 10 minutes to 240 minutes. The
default value is 30 minutes.
F: Outdoor air reset
Outdoor air reset operation
When the outdoor air sensor is installed, the control will
calculate the water temperature set point based on the
outdoor air temperature. As the outdoor air temperature
drops the water temperature set point increases. This feature
allows the boiler to be more efficient in periods of mild
weather, see FIG. 1-1 on page 19.
Minimum air temperature
When the outdoor air temperature drops to or below this
point, the water temperature will be at its maximum setting
(FIG. 1-1). However, if the user set point is set lower, the
water temperature will be limited by the user set point
instead. This parameter can be changed by the installer by
accessing parameter F1. The temperature range of this
parameter is -30°F to 90°F. The default value is 25°F.
Maximum air temperature
When the outdoor air temperature rises to or above this
point, the water temperature will be at its minimum setting
(FIG. 1-1). This parameter can be changed by the installer by
accessing parameter F2. The temperature range of this
parameter is -30°F to 90°F. The default value is 70°F.

1 Service
Service Manual
19
1 Service (continued)
Figure 1-1 Outdoor Air Reset Curve
Maximum SH set point
When the outdoor temperature drops to or below its
minimum setting (F1) the water temperature will be at this
point, if the SH set point is set higher (FIG. 1-1). This
parameter can be changed by the installer by accessing
parameter F3. The temperature range of this parameter is 0°F
to 190°F. The default value is 180°F.
Minimum SH set point
When the outdoor temperature rises to or above its
maximum setting (F2) the water temperature will be at this
point (FIG. 1-1). This parameter can be changed by the
installer by accessing parameter F4. The temperature range of
this parameter is 0°F to 190°F. The default value is 70°F.
Outdoor air shutdown
When the outdoor temperature rises above this point, the
control will block all SH demands (DHW demands will still
be active). This parameter can be changed by the user or the
installer by accessing parameter F5. The temperature range of
this parameter is 0°F to 120°F. The default value is 80°F.
Outdoor air shutdown differential
The outdoor air shutdown differential parameter is the
number of degrees below parameter F5 the outdoor air
temperature must go before the boiler will respond to a SH
demand. This parameter can be changed by the user or the
installer by accessing parameter F6. The temperature range of
this parameter is 0°F to 90°F. The default value is 10°F.
Shift reset curve
The shift reset curve parameter shifts the actual set point
above the calculated set point the number of degrees in this
parameter. This parameter can be changed by the installer by
accessing parameter F7. The temperature range of this
parameter is -27°F to 27°F. The default value is 0°F. This
feature will be active if this parameter is set to anything other
than 0°F.

1 Service
20
Service Manual
1 Service
Boost temperature
If a SH demand lasts longer than the programmed time delay
setting (F9) 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 the 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 parameter F8. The temperature range of this
parameter is 0°F to 45°F. The default value is 0°F. This feature
will be active if this parameter is set to anything other than
0°F.
Boost time
The boost time parameter sets the amount of time that must
elapse with a SH demand before the water temperature set
point will be increased. This parameter can be changed by the
installer by accessing parameter F9. The time range for this
parameter is 1 minute to 60 minutes. The default value is 20
minutes.
G: Anti-cycling
Anti-cycling time
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 parameter G2.
This parameter can be changed by the installer by accessing
parameter G1. The time range for this parameter is 0 minutes
to 40 minutes. The default value is 1 minute.
Inlet temperature differential for ending anti-cycling
The control will bypass the anti-cycling time if the water
temperature drops too quickly. The control will use the water
temperature the boiler was at when it shut off as the starting
point. If the 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 parameter G2. The temperature range of this
parameter is 0°F to 86°F. The default value is 10°F.
Ramp delay on/off
When the ramp delay on/off parameter is active, the ramp
delay limits the boiler firing rate when a SH cycle has started.
There are six (6) limiting steps used to limit temperature
overshoot and short cycles, see FIG. 1-2 on page 21 of this
manual. This feature can be turned on or off depending on
the installation. This parameter can be changed by the
installer by accessing parameter G3. The control range of this
parameter is 0 = Off, 1 = Ramp Up Only, and 2 = Ramp Up
and Ramp Down. The default value is 0.
When ramp delay is active, additional parameters for ramp
delay operation will have to be adjusted. These can only be
accessed by the optional PC software. See the Knight Wall
Mount Smart System PC Program Instructions Manual for
additional ramp delay parameter information.