U.S. Boiler Company K2 User manual

1
105337-03 - 5/15 Price - $5.00
WARNING: Improper installation, adjustment, alteration, service or maintenance can cause property damage,
injury, or loss of life. For assistance or additional information, consult a qualied installer, service agency or the
gas supplier. This boiler requires a special venting system. Read these instructions carefully before installing.
9700609
As an ENERGY STAR®Partner, U.S. Boiler Company has determined that the K2™ Series meets the ENERGY
STAR® guidelines for energy efciency established by the United States Environmental Protection Agency (EPA).
OPERATING INSTRUCTIONS
FOR
K2™
CONDENSING HIGH EFFICIENCY
DIRECT VENT
GAS - FIRED HOT WATER BOILER

2105337-03 - 5/15
IMPORTANT INFORMATION - READ CAREFULLY
NOTE: The equipment shall be installed in accordance with those installation regulations enforced in the area where the
installation is to be made. These regulations shall be carefully followed in all cases. Authorities having jurisdiction
shall be consulted before installations are made.
All wiring on boilers installed in the USA shall be made in accordance with the National Electrical Code and/or local
regulations.
All wiring on boilers installed in Canada shall be made in accordance with the Canadian Electrical Code and/or local
regulations.
The following terms are used throughout this manual to bring attention to the presence of hazards of various risk levels,
or to important information concerning product life.
The City of New York requires a Licensed Master Plumber supervise the installation of this product.
The Massachusetts Board of Plumbers and Gas Fitters has approved the K2™ Series boiler. See the Massachusetts Board of
Plumbers and Gas Fitters website, http://license.reg.state.ma.us/pubLic/pl_products/pb_pre_form.asp for the latest Approval
Code or ask your local Sales Representative.
The Commonwealth of Massachusetts requires this product to be installed by a Licensed Plumber or Gas Fitter.
DANGER
Indicates an imminently hazardous situation
which, if not avoided, will result in death, serious
injury or substantial property damage.
CAUTION
Indicates a potentially hazardous situation which,
if not avoided, may result in moderate or minor
injury or property damage.
WARNING
Indicates a potentially hazardous situation which,
if not avoided, could result in death, serious injury
or substantial property damage.
NOTICE
Indicates special instructions on installation,
operation, or maintenance which are important
but not related to personal injury hazards.
DANGER
Explosion Hazard. DO NOT store or use gasoline or other ammable vapors or liquids in the vicinity of this
or any other appliance.
If you smell gas vapors, NO NOT try to operate any appliance - DO NOT touch any electrical switch or use
any phone in the building. Immediately, call the gas supplier from a remotely located phone. Follow the gas
supplier’s instructions or if the supplier is unavailable, contact the re department.

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WARNING
Asphyxiation Hazard. This boiler requires regular maintenance and service to operate safely. Follow
the instructions contained in this manual.
Improper installation, adjustment, alteration, service or maintenance can cause property damage,
personal injury or loss of life. Read and understand the entire manual before attempting installation,
start-up operation, or service. Installation and service must be performed only by an experienced,
skilled, and knowledgeable installer or service agency.
This boiler must be properly vented.
This boiler needs fresh air for safe operation and must be installed so there are provisions for
adequate combustion and ventilation air.
Asphyxiation Hazard. The interior of the venting system must be inspected and cleaned before the
start of the heating season and should be inspected periodically throughout the heating season for
any obstructions. A clean and unobstructed venting system is necessary to allow noxious fumes
that could cause injury or loss of life to vent safely and will contribute toward maintaining the boiler’s
efciency.
Installation is not complete unless a safety relief valve is installed into the tapping located on left
side of appliance or the supply piping. - See the Water Piping and Trim Section of the K2 Installation
manual for details.
This boiler is supplied with safety devices which may cause the boiler to shut down and not re-start
without service. If damage due to frozen pipes is a possibility, the heating system should not be left
unattended in cold weather; or appropriate safeguards and alarms should be installed on the heating
system to prevent damage if the boiler is inoperative.
Burn Hazard. This boiler contains very hot water under high pressure. Do not unscrew any pipe
ttings nor attempt to disconnect any components of this boiler without positively assuring the water
is cool and has no pressure. Always wear protective clothing and equipment when installing, starting
up or servicing this boiler to prevent scald injuries. Do not rely on the pressure and temperature
gauges to determine the temperature and pressure of the boiler. This boiler contains components
which become very hot when the boiler is operating. Do not touch any components unless they are
cool.
Respiratory Hazard. Boiler materials of construction, products of combustion and the fuel contain
alumina, silica, heavy metals, carbon monoxide, nitrogen oxides, aldehydes and/or other toxic or
harmful substances which can cause death or serious injury and which are known to the state of
California to cause cancer, birth defects and other reproductive harm. Always use proper safety
clothing, respirators and equipment when servicing or working nearby the appliance.
Failure to follow all instructions in the proper order can cause personal injury or death. Read all
instructions, including all those contained in component manufacturers manuals which are provided
with the boiler before installing, starting up, operating, maintaining or servicing.
All cover plates, enclosures and guards must be in place at all times.

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Table of Contents
I. Operation 5
II. Troubleshooting 33

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5. Built-in Safety Control
The Control includes safety controls designed to ensure safe
and reliable operation. In addition to ame safety controls
the Control includes supply water temperature, differential
water temperature, and stack temperature safety limits
and stepped modulation responses. Boiler modulation is
adjusted when required to help avoid loss of boiler operation
due to exceeding limits. Additionally, the Control accepts
the eld installation of optional auxiliary safety limits.
6. Outdoor Air Reset
When selected the modulation rate setpoint is automatically
adjusted based on outside air temperature, time of day and
length of demand (boost) settings. Outdoor air “reset”
setpoint saves fuel by adjusting the water temperature of a
heating boiler lower as the outside air temperature increases.
7. Warm Weather Shutdown (WWSD)
Some boilers are used primarily for heating buildings, and
the boilers can be automatically shutdown when the outdoor
air temperature is warm. When outside air temperature is
above the WWSD setpoint, this function will shut down
the boiler, boiler and system pump.
8. Energy Management System (EMS) Interface
The control accepts a 4-20mAdc input from the EMS system
for either direct modulation rate or setpoint.
A factory congured RS485 Modbus interface is available
for Energy Management System(EMS)monitoring when not
used for Multiple Boiler Sequencer Peer-To-Peer Network.
Consult factory for points list or if this interface must be
used in addition to the boiler Peer-to-Peer Network.
9. Circulator Control
The Control may be used to sequence the domestic hot
water, boiler and system circulators. Service rated relay
outputs are wired to a line voltage terminal block for easy
eld connection. Simple parameter selections allow all
three pumps to respond properly to various hydronic piping
arrangements including either a boiler or primary piped
indirect water heater. Circulators are automatically run for
a 20 second exercise period after not being used for longer
than 7 days. Circulator exercise helps prevent pump rotor
seizing.
10. Multiple Boiler Sequencer Peer-To-Peer Network
The Control includes state-of-the-art modulating lead-lag
sequencer for up to eight (8) boilers capable of auto rotation,
outdoor reset and peer-to-peer communication. The peer-
peer network is truly “plug and play”. Communication
is activated by simply connecting a RJ45 ethernet cable
between boilers. The Control provides precise boiler
coordination by sequencing boilers based on both header
water temperature and boiler modulation rate. For example,
the lead boiler can be congured to start a lag boiler after
operating at 50% modulation rate for longer than an
adjustable time. The boilers are modulated in “unison”
(parallel) modulation rate to ensure even heat distribution.
I. Operation
A. Overview
1. Sage2.2 Controller
The Sage2.2 Controller (Control) contains features and
capabilities which help improve heating system operation,
and efciency. By including unique capabilities, the Control
can do more, with less eld wiring, and fewer aftermarket
controls and components – improving the operation of both
new and replacement boiler installations.
2. Advanced Touch Screen Display
Home Screen
Boiler status and setup selections are available from an easy
to use, dual color, LCD Touch Screen Display. Over one
hundred helpful information screens are provide to explain
status information and setup functions. In the event of a fault
condition the user is guided by “blinking” touch buttons to
Help screens that explain the problem cause and corrective
action. Operation evaluation and problem-solving is enhanced
by historical capability including graphic trends, lockout
history records as well as boiler and circulator cycle counts
and run time hours.
3. Advanced Modulating Control
The Control modulates the boiler input by varying the fan
speed. As the fan speed increases, so does the amount of
fuel gas drawn into the blower. As a result, a fairly constant
air-fuel ratio is maintained across all inputs. The Control
determines the input needed by looking at both current and
recent differences between the measured temperature and the
setpoint temperature. As the measured temperature approaches
the setpoint temperature, the fan will slow down and the input
will drop. The Control also utilizes boiler return water and
ue gas temperatures to adjust fan speed.
4. HeatMatchTM Software
When the boiler is installed with a Sage Zone Control Panel
(Zone Control) into a multiple zone home the Control uses
a patent pending HeatMatch Software to improve home
comfort, increase component life and save energy. The Sage2.2
Controller with the Zone Control detects active (turned “on”)
zones, totals btu/hrs expected and limits the boiler ring rate
to “match” actual home demand. Instead of simply ring
to 100% in response to a cold supply water temperature the
Control combinesheat matchingwith supply watertemperature
control. The result is longer run times, dramatic reduction
in boiler excessive cycling and higher operating efciency.
Avoiding extra cycling saves customer fuel dollars (pre and
post purge sends heat up stack) and saves wear and tear on
the boiler. Lowering the boiler’s ring rate saves fuel dollars
by increasing the amount of ue gas condensation, always
the goal of condensing boiler installations.

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I. Operation
B. Supply Water Temperature Regulation
1. Priority Demand
The Control accepts a call for heat (demand) from
multiple places and responds according to it’s “Priority”.
When more than 1 demand is present the higher priority
demand is used to determine active boiler settings. For
example, when Domestic Hot Water (DHW) has priority
the setpoint, “Diff Above”, “Diff Below” and pump
settings are taken from DHW selections.Active “Priority”
is displayed on the “Boiler Status” screen.
Priority Status Screen
Display Boiler Responding to:
1st Sequencer
Control
The boiler is connected to the peer-
to-peer network. The boiler accepts
demand from the Sequencer Master.
2nd Domestic Hot
Water
DHW call for heat is on and selected
as the priority demand. DHW is always
higher priority than Central Heat. It also
has higher priority than the Sequencer
Control when DHW priority is “enabled”
and “Boiler Piped” IWH is selected.
3rd Central Heat Central Heat call for heat is on and
there is no DHW demand or DHW
priority time has expired.
4th Auxiliary Heat Auxiliary Heat call for heat is on and
there is no Central Heat or DHW
demand. (NOTE: May be user
selected to be higher priority than
Central Heat.)
5th Frost
Protection
Frost Protection is active and there is
no other call for heat. Frost protection
will be a higher priority than Sequencer
Control if the Sequence Master has no
active call for heat.
6th Warm
Weather
Shutdown
(WWSD)
WWSD is active and the boiler will
not respond to central heat demands.
DHW demand is not blocked by
WWSD.
7th Standby There is no demand detected.
Table 1: Order of Priority
2. Setpoint Purpose
The Control starts and stops the boiler and modulates
the boiler input from minimum (MBH) to maximum
(MBH) in order to heat water up to the active setpoint.
The setpoint is determined by the priority (Central Heat
or Domestic Hot Water) and as described in the following
paragraphs.
3. Central Heat Setpoint
Upon a Central Heat call for heat the setpoint is either the
user entered Central Heat Setpoint, or is automatically
adjusted by a thermostat’s “Sleep” or “Away” modes
and/or Outdoor Air Reset or, an Energy Management
System (EMS) supplied 4-20mAdc setpoint.
4. Auxiliary Heat Setpoint
Auxiliary Heat is a second heating demand that may
be used to serve either lower temperature radiation or
warmer heat demands such as fan coils. Upon anAuxiliary
Heat call for heat the setpoint is either the user entered
Auxiliary Heat Setpoint or is automatically adjusted as
a thermostat’s “sleep” or, Away Modes or, Outdoor Air
Reset.
5. Outdoor Air Reset
If an outdoor temperature sensor is connected to the boiler
and Outdoor Reset is enabled, the Central Heat setpoint
will automatically adjust downwards as the outdoor
temperature increases. When the water temperature is
properly matched to heating needs there is minimal chance
of room air temperature overshoot. Excessive heat is
not sent to the room heating elements by “overheated”
(supply water temperature maintained too high a setting)
water. Reset control saves energy by reducing room
over heating, reducing boiler temperature & increasing
combustion efciency and, reducing standby losses as a
boiler and system piping cool down to ambient following
room over heating.
6. Boost Time
When the Central Heat Setpoint is decreased by Outdoor
Air Reset settings the Boost function can be enabled to
increase the setpoint in the event that central heat demand
is not satised for longer than the Boost Time minutes. The
Boost feature increases the operating temperature setpoint
by 10°F (5.6°C) every 20 minutes (eld adjustable) the
central heat demand is not satised. This process will
continue until heat demand is satised (indoor air is at
desired temperature). Once the heat demand is satised,
the operating setpoint reverts to the value determined by
the Outdoor Air Reset settings. If Boost Time is zero,
then the boost function is not used.
7. Domestic Hot Water (DHW) Setpoint
Upon a DHW call for heat the setpoint is either the user
entered DHW setpoint or the Thermostat’s “Sleep” or
“Away” DHW setpoint. The optimal value of this setpoint
is established based on the requirements of the indirect
water heater.
8. Domestic Hot Water Priority (DHWP)
When domestic hot water priority is selected and there is
a DHW call for heat, the system pump will be turned off
(when “System Pump Run Pump for” parameter is set for
“Central Heat Optional Priority”) and the DHW pump will
be turned on. Additionally, if outdoor reset is active, the
active setpoint is adjusted to the DHW Setpoint. Priority
protection is provided to ensure central heat supply in the
case of excessively long DHW call for heat.
9. “Setback” Setpoints
User adjustable Thermostat “Sleep” or “Away” Setback
Setpoints are provided for Central Heat, Auxiliary Heat
and DHW demands. The Setback setpoint is used when
the EnviraCOM thermostat is in “leave” or “sleep” modes.
When setback is “on” the thermostat setback setpoint shifts
the reset curve to save energy while the home is in reduced
room temperature mode. The Honeywell VisionPro IAQ
(part number TH9421C1004) is a “setback” EnviraCOM
enabled thermostat.

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I. Operation
Table 2: Frost Protection
C. Boiler Protection Features
1. Supply Water Temperature High Limit
The control is equipped with internal operating
control and high limit features. The control monitors
a dual element temperature sensor that is mounted in
the supply water manifold and provides UL353 and
UL1998 internal safety algorithms. If supply water
temperature increases above the active setpoint plus diff
above, default 190°F (87.7°C) the boiler is cycled off.
If the temperature exceeds 210°F (98.9°C), a manual
reset hard lockout results. If the boiler is responding to
the internal Multiple Boiler Control Sequencer, Header
Sensor or an External EMS demand and the supply
water temperature increases above 190°F (87.7°C) the
control begins to reduce the blower maximum speed
setting and if the temperature increases to 200°F (93°C)
a forced recycle results. Additionally, if the supply
temperature rises faster than the degrees Fahrenheit
per second limit a soft lockout is activated.
2. High Differential Temperature Limit
The Control monitors the temperature difference
between the return and supply sensors. If this difference
exceeds 43°F (23.9°C) the control begins to reduce the
maximum blower speed. If temperature difference
exceeds 53°F (29.4°C) a forced boiler recycle results.
If the temperature difference exceeds 63°F (35°C) the
control will shut the unit down. The unit will restart
automatically once the temperature difference has
decreased and the minimum off time has expired.
3. Return Temperature Higher Than Supply
Temperature (Inversion Limit)
The Control monitors the supply and return temperature
sensors. If the return water temperature exceeds the
supply water temperature for longer than a limit time
delay the Control shuts down the boiler and delays
restart. If the inverted temperature is detected more
than ve times the boiler manual reset Hard Lockout is
set. This condition is the result of incorrectly attaching
the supply and return piping.
4. External Limit
An external limit control can be installed on the low
voltage terminal strip. Be sure to remove the jumper
when adding an external limit control to the system. If
the external limit opens, the boiler will shut down and
an open limit indication and error code are provided.
If the limit installed is a manual reset type, it will need
to be reset before the boiler will operate.
5. Boiler Mounted Limit Devices
The control monitors individual limit devices: ow
switch, thermal fuse and sump pressure switch. If
any of these limits open the boiler will shut down and
an open limit indication is provided. Additionally,
the control monitors an air proving switch. During
the boiler start sequence the control requires the air
proving switch to be in the “open” position before
the blower starts and in the “closed” position after
the blower starts. If the air proving switch is not in
the required position the start sequence is halted or
the boiler is shut down and the open limit indication
is provided. The air proving switch is only required
to be closed during pre-purge. It is normal for the air
proving switch to be open during run mode.
6. Stack High Limit
The Control monitors the ue gas temperature sensor
located in the vent connector. If the ue temperature
exceeds 194°F (90°C), the control begins to reduce
the maximum blower speed. If the ue temperature
exceeds 204°F (96°C), a forced boiler recycle results.
If the ue temperature exceeds 214°F (101°C), the
control activates a manual reset Hard Lockout.
7. Ignition Failure
The Control monitors ignition using a burner mounted
ame sensor. In the event of an ignition failure, the
control retries 5 times and then goes into soft lockout
for one hour.
8. Central Heating System Frost Protection
When enabled, Frost Protection starts the boiler and
system pump and res the boiler when low outside air
and low supply water temperatures are sensed. The
Control provides the following control action when
frost protection is enabled:
Device
Started
Start
Temperatures
Stop
Temperatures
Boiler Pump Outside Air < 0°F (-18°C)
Supply Water < 45°F (7.2°C)
Outside Air > 4°F (-16°C)
Supply Water > 50°F (10°C)
Boiler Supply Water < 38°F (3.3°C) Supply Water > 50°F (10°C)
FROST PROTECTION NOTE
The Control helps provide freeze protection for the boiler
water. Boiler ue gas condensate drain is not protected from
freezing. Since the Control only controls the system and
boiler circulators individual zones are not protected. It is
recommended that the boiler be installed in a location that is
not exposed to freezing temperatures.

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I. Operation
D. Multiple Boiler Control Sequencer
1. “Plug &Play”Multiple BoilerControlSequencer
When multiple boilers are installed, the Control’s
Sequencer may be used to coordinate and optimize
the operation of up to eight (8) boilers. Boilers are
connected into a “network” by simply “plugging in”
standard ethernet cables into each boiler’s “Boiler-To-
Boiler Communication” RJ45 connection.
2. Sequencer Master
Asingle Control is parameter selected to be the Sequencer
Master. The call for heat, outdoor and header sensors,
and common pumps are wired to the Sequencer Master
“enabled” Control.
3. Lead/Slave Sequencing & Equalized Run Time
One boileris a“Lead” boilerand theremaining networked
boilers are “Slaves”. When demand is increasing, the
Lead boiler is the rst to start and the Slave boilers are
started in sequential order (1,2,3,…) until the demand
is satised. When demand is decreasing, the boilers are
stopped in reverse order with the Lead boiler stopped
last (…,3,2,1). To equalize the run time the sequencer
automatically rotates the Lead boiler after 24 hours of
run time.
4. Improved Availability
The following features help improve the heat availability:
a. Backup Header Sensor: In the event of a header
sensor failure the lead boiler’s supply sensor is
used by the Sequence Master to control ring
rate. This feature allows continued coordinated
sequencer control even after a header sensor
failure.
b. “Stand Alone” Operation Upon Sequence Master
Failure: If the Sequence Master Control is
powered down or disabled or if communication
is lost between boilers, individual boilers may be
setup to automatically resume control as a “stand
alone” boiler.
c. Slave Boiler Rate Adjustment: Each slave boiler
continues to monitor supply, return and ue gas
temperatures and modies the Sequence Master’s
ring rate demand to help avoid individual boiler
faults, minimize boiler cycling and provide heat to
the building efciently.
d. Slave Boiler Status Monitoring: The Sequence
Master monitors slave boiler lockout status and
automatically skip over disabled boilers when
starting a new slave boiler.
5. Customized Sequences
Normally, boilers are started and stopped in numerical
order. However, custom sequences may be established
to optimize the heat delivery. For example, in order to
minimize boiler cycling, a large boiler may be selected
to run rst during winter months and then selected to
run last for the remainder of the year.
6. Multiple Demands
The Sequence Master responds to Central Heat,Auxiliary
Heat, DHW and frost protection demands similar to the
stand alone boiler. For example, when selected and DHW
priority is active, the sequence master uses DHW setpoint,
“Diff Above”, “Diff Below” and pump settings.
7. Shared or Isolated DHW Demand
When the Indirect Water Heater (IWH) parameter is set
to “Primary Piped” the Sequence Master sequences all
required boilers to satisfy the DHW setpoint (default
180°F (82.2°C). When “Boiler Piped” is selected only
the individual slave boiler, with the wired DHW demand
and pump, res to satisfy the DHW setpoint.
8. DHW Two boiler Start
When the Indirect Water Heater (IWH) parameter is set to
“Primary Piped” and the DHWTwo Boiler Start parameter
is set to “Enabled” two boilers are started without delay
in response to a DHW call for heat. This feature allows
rapid recovery of large IWH’s and multiple IWH’s.
9. Optimized Boiler Modulation
Boiler ring rate is managed to increase smoothly as
boilers are started. For example, when a second boiler is
started the initial ring rate is 100%/2 or 50%, when the
third boiler is started the ring rate starts at 200%/3 or
66%. After the initial start, the Sequence Master develops
a unison ring rate demand based on it’s setpoint and
sensed header temperature.
10. Innovative Condensing Boiler Control
During low loads, the Sequence Master limits ring rates
to a ‘Base Load Common Rate” to ensure modulating
condensing boiler peak operating efciency. Lower ring
rates boost efciency by helping increase the amount of
ue gas water vapor condensation. The Control maintains
a “Base Load Common Rate” until the last lag boiler is
started. At this point, the “Base Load Common Rate” is
released to allow boilers to modulated as required to meet
heat load.
11. Advanced Boiler Sequencing
After there is a Call For Heat input, both header water
temperature and boiler ring rate percent are used to start
and stop the networked boilers. The control starts and stops
boilers when the water temperature is outside the user
selected “Diff Above” and “Diff Below” settings. Also,
in order to minimize temperature deviations, the control
adjusts the number of boilers running based on the ring
rate. This combination allows the boilers to anticipate
slow load changes before they disrupt water temperature
yet still respond quickly to sudden load changes. These
special sequencer features help reduce energy wasting
system temperature swings and the resulting unnecessary
boiler cycling.
12. Stop All Boilers
All boilers are stopped without delay if the Call for Heat
input is removed or if the header temperature is higher
than 195°F (90.6°C) (eld adjustable).

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X. Operation
E. Boiler Sequence of Operation
1. Normal Operation
Table 3: Boiler Sequence of Operation
Status Screen Display Description
Priority:
Standby
Status:
Standby
(burner Off, circulator(s) Off)
Boiler is not ring and there is no call for heat, priority equals standby. The boiler
is ready to respond to a call for heat.
Priority:
Central Heat
Status:
Standby
(burner Off, circulator(s) On)
Boiler is not ring. There is a Central Heat call for heat and the Supply temperature
is greater than setpoint minus the “Diff Below”.
Priority:
Central Heat
Status:
Prepurge
When supply temperature drops burner demand continues with following Status
shown:
Safe Startup: Flame circuit is tested.
Drive purge: The blower is driven to the fan purge speed.
Prepurge: After the blower reaches the fan purge speed setting the
combustion chamber purge is conducted.
Priority:
Central Heat
Status:
Direct
ignition
After purge time is complete the following Status is shown:
Drive light-off: The blower is driven to light-off rate.
Pre-Ignition Test: After the blower reaches light-off rate a safety relay test is
conducted.
Pre-ignition: Spark is energized and it is conrmed that no ame is present
Direct Ignition: Spark and Main fuel valve are energized.
Priority:
Central Heat
Status:
Running
(burner On, circulator(s) On)
After ame is proven the sequence continues with run stabilization and low
re hold time. Once the eld adjustable low re hold time is completed normal
boiler operation begins, modulation rate depending on temperature and setpoint
selections.
Supply 132 F
180 F
Rate 100%
Status:
Setpoint
Boiler 1
>
<
Priority:Domestic Hot Water
i
Running
Priority:
Domestic
Hot Water
Status:
Running
If the Central Heat call for heat is active and a Domestic Hot Water (DHW) call for
heat received the DHW demand becomes the “priority” and the modulation rate,
setpoint, “Diff Above” and “Diff Below” are based on DHW settings.
Priority:
Standby
Status:
Post-purge
(burner Off, circulator(s) Off)
If there is no call for heat the main fuel valve is closed and the blower is driven
to the fan post-purge speed. After the blower reaches the fan post-purge speed
setting the combustion chamber purge is conducted.
Priority:
Standby
Status:
Standby
Delay
Standby delay status is entered when a delay is needed before allowing the burner
control to be available. For example, when Anti-Short Cycle time is selected
Standby delay is entered after the Central Heat call for heat ends. Select “Help”
button from the “Home Screen” to determine the cause of the Standby Delay.
Priority:
Standby
Status:
Lockout
A lockout status is entered to prevent the boiler from running due to a detected
problem. Select “Help” button from the “Home Screen” to determine the cause of
the Lockout. The last 10 Lockouts are recorded in the Lockout History.
Supply 132 F
140 F
Rate 100%
Status:
Setpoint
Boiler 1
>
<
Priority:Central Heat
i
Running

10 105337-03 - 5/15
I. Operation E. Boiler Sequence Of Operation (continued)
2. Using The Display
The Control includes a touch screen LCD display. The user monitors and adjusts boiler operation by selecting screen
navigation “buttons” and symbols. The “Home Screen” and menu selections are shown below. When no selection is
made, while viewing any screen, the display reverts to the “Home Screen” after 4 minutes. The “Home Screen” provides
boiler temperature, ring rate in BTU/hr, boiler status, efciency information and page links.
Menu Buttons
The Home Screen Menu Buttons
connect the displays four main
display groups:
Information Symbol
“Information” symbol links most
screens to screen content
explanations. New terminology used
in status and adjustment screens are
explained in plain words.
Fault Indication
In the event of a boiler fault the
screen color turns red and the user
is guided by “blinking” touch buttons
to Help screens that explain the
problem cause and corrective action.
Figure 1: Home Screen Details
(see Figure 4) (see bottom of Page 13) (see Figure 9) (see Figure 6)
Close Symbol
The “Close” symbol returns to the display to previous menu or screen.
Repeatedly pressing the “Close” symbol will always return the display
to the “Home” screen.
Arrow Symbol
The “Arrow” symbol links together all screens in the selected group.
For example, repeated pressing the right “Arrow” symbol will rotate
the display around all the screens in the Status group. Using this
feature the user can review all the boiler status and adjustment mode
screens.
Fault Symbols
“Active Fault” and “Rate Limit” symbols provide a link to the cause
of a boiler fault or ring rate limit. The rst boiler status screen
provides an overview of boiler operation including fault status.
Status Screen
Figure 2: Screen Navigation
Boiler number and Tankless indication shows
“Tankless” when congured for K2 Combi Kit
Rate
Firing rate is displayed as kbtu/hr input.
Demand Status
The reason or cause of the boiler demand is
displayed; Central Heat, Auxiliary Heat, Domestic
Hot Water, Sequencer Control (peer-to-peer
Demand) or Frost Protection. Warm Weather
Shutdown status is shown. “Standby’ is shown
when no demand is present.
Energy Save On Indication
Outdoor Air Reset, DHW or setback have lowered
boiler water setpoint.
High Efciency On Indication
Return temperature is low enough to allow energy
saving ue gas condensation.

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105337-03 - 5/15
Figure 3: Status Screen Overview
3. Status Screens
Boiler Status screens are the primary boiler monitoring screens. The user may simply “walk” though boiler
operation by repeatedly selecting the right or left “arrow” symbol. These screens are accessed by selected the
“Status” button from the “Home” screen.
NOTE
Only visible if Zone Panel is
connected. Zone Panel 1 and 2
shown typical for 1 through 4.
Active fault:
A hard lockout will cause the active
fault indication to appear. When
visible the text becomes a screen link
to the “Help” Menu.
Rate Limit:
The “6” symbol appears to the
right of the Rate % when ring rate
is limited or overridden in any way.
During the start-up and shutdown
sequence it is normal for the rate to
be overridden by the purge, light-
off and low re hold requirements.
When a rate limit is the result of
boiler protection logic the “6” symbol
blinks and becomes a screen link.
Rate:
The rate % value is equal to the actual kbtu/hr
input divided by the boiler rated input.
Priority:
The selected Priority is shown. Available
Priorities are: Standby (no call for heat is present),
Sequencer Control, Central Heat, Auxiliary Heat,
Domestic Hot Water, Frost Protection or Warm
Weather Shutdown.
Setpoint:
This is the active setpoint. This temperature
setpoint determined based on active priority;
Central Heat, Auxiliary Heat or Domestic Hot
Water. The setpoint may be the result of Outdoor
Air Reset and Setback selections.
Supply:
Measured supply water temperature. This is the
temperature being used to start/stop and re boiler
when there is a call-for- heat. Header temperature
is shown when selected.
Figure 4: Boiler Status Screen Denitions
Status:
Information found at the
bottom of the Status screen
and on the Home screen.
Table 28 shows each status
and the action the control
takes during the condition.
I. Operation E. Boiler Sequence Of Operation (continued)

12 105337-03 - 5/15
3. Status Screens (continued)
Bargraph Screen
Bargraph Screen
The bargraph screen presents measured values for easy comparison.
Data Logging
Real time graphic trends allow users to observe process changes over
time providing valuable diagnostic information. For example, ame
current performance over start up periods and varying loads can be
an indication of gas supply issues. Additionally, supply and return
temperature dual pen trends brings a focused look at heat exchanger
and pump performance. For example, studying a differential temperature
trend may indicate pump speed settings need to be changed.
Trend Screens
NOTE
Firing Rate Trend shows fan demand and
feedback.
Burner Status Screen
Cycles and Hours
Boiler cycles and hours are used to monitor
the boilers overall compatibility to the
heating load. Excessive cycling compared
to run time may be an indication of
pumping, boiler sizing or adjustment issues.
NOTE
“Boiler Cycle” and “Run Time Hours” are
resettable by selecting the “Reset Counts”
button located on the information screen.
The “Controller Cycles” and “Controller
Run Time” data is not resettable and
remains for the life of the control.
I. Operation E. Boiler Sequence Of Operation (continued)

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I. Operation E. Boiler Sequence Of Operation (continued)
Pumping is a major part of any hydronic system. This screen provides the
status of the boiler’s demand to connected pumps as well as the status of Frost
Protection and pump Exercise functions.
This screen provides the status of the boilers ve (5) possible heat demands.
When demand is off the Control has not detected the call-for-heat. This screen
allows the user to determine which demands are present when more than one
demand is present.
Circulator Status Screen
NOTE
Only visible if Zone Panel is
connected. Zone Panel 1 and 2
shown typical for 1 through 4.
Zone Control Status Screens
NOTE
Zone cycles are resettable by selecting
the “Reset Cycle Counts” button
located on the information screen.
Zone Control Status
Screen provides status and a page links
for up to four zone panels. Individual
zone “on” status is shown by a bold zone
number with a solid underscore. “Press”
the zone control “button” to view individual
zone .
Zone Panel 1 (typical for 2 through 4)
Zone panel screens show individual zone
status, cycle counts and individual zone
expected heat rate in kbtu/hr. Individual
zone expected heat rate may be adjusted
under the Adjust “Modulation” menu. Also
zone descriptions may be modied using
the “Zone Control Description Setup”
menu.
Detail screens are accessed by selecting the “Detail” button from the “Home” screen. These screens provide in depth operating
parameter status such as “On Point”, “Off Point” and “Setpoint Source” information. Demand-specic details are provided for
Central Heat, Auxiliary Heat, Domestic Hot Water and the Sequence Master demands. Detail screens also provide details on
outdoor air reset and Sequencer network status. Sequencer screens are only shown when the Sequence Master is enabled.
Demand Detail Display
(Central Heat shown, Typical for
Auxiliary Heat, Domestic Hot Water
and Sequencer Master)
Outdoor Reset Display
(Central Heat shown,
Typical for Auxiliary Heat)
Head Demand Screen
4. Detail Screens

14 105337-03 - 5/15
5. Multiple Boiler Sequencer Screens
When the Sequence Master is enabled the following screens are available:
I. Operation E. Boiler Sequence Of Operation (continued)
Header:
measured header water
temperature. This is the
temperature being used to start,
stop and re boiler when there is a
call-for-heat.
Setpoint:
this is the active setpoint. This
temperature is the result of Outdoor
Air Reset, Setback and Domestic Hot
Water (DHW) selections.
Networked Boiler Status:
Provides connected, start sequence and ring rate status information for all connected boiler addresses. The boiler number is
underlined if the boiler is running and blinks if the boiler has the start sequence in progress. For example the status for boiler
address 1 is provided as follows:
1 - Boiler 1 is connected to the network
1 - “Blinking underline” - boiler 1 is starting
1 - “Solid underline” - boiler 1 is running
Rate:
The rate % value is equal to the
Sequence Master demand to the
individual boiler. Actual boiler ring
rate is found on the individual boiler
status pages.
Priority:
The selected Sequencer Priority
is shown. Available Priorities are:
Standby (no call for heat is present),
Central Heat, Auxiliary Heat,
Domestic Hot Water, Frost Protection
or Warm Weather Shutdown.
The Sequencer Status screen is selected by “pressing” “Status” button from the “Home” screen when Sequence Master is
enabled.
The “Networked Boilers” screen is selected by “pressing” the “Detail” button from the “Home” screens and “pressing” Networked
Boilers” from the “Detail” screen.
Sequence Status:
Slave boiler status is provide as follows:
Available:
Add Stage:
Running:
On Leave:
Recovering:
Disabled:
Boiler is ready and waiting to be started by the Sequencer
Master.
Boiler has begun the start sequence but has not yet reached
the boiler running status.
Boiler is running.
Boiler has left the network to service a DHW demand.
Boiler is in the process of returning to the network. For
example, the slave boiler is in the Postpurge state.
Note: The recovery time is normally 30 seconds. However,
if the slave boiler fails to start the recovery time increases
from 30 seconds to 5, 10 and 15 minutes.
Boiler has a lockout condition and is unable to become
available to the Sequencer Master.
Boiler Number:
Up to eight (8) boiler’s status is
shown
Lead Boiler:
Upon power up the lowest
numbered boiler becomes the lead
boiler. The lead boiler is the rst
to start and last to stop. The lead
boiler is automatically rotated after
24 hours of run time.
Additionally, the lead is rotated if
there is a lead boiler fault.
Firing Rate:
Actual ring rate is
provided.

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I. Operation
1. Entering Adjust Mode
The Control is factory programmed
to include basic modulating boiler
functionality. These settings are password
protected to discourage unauthorized or
accidental changes to settings. User login is
required to view or adjust these settings:
- Press the “Adjust” button on the “Home”
screen.
- Press the “Adjust” button on the Adjust
Mode screen or Press “Service Contact”
for service provider contact information.
- Press “Login” button to access password
screen.
- Press 5-digit display to open a keypad.
Enter the password (Installer Password
is 86) and press the return arrow to close
the keypad. Press the “Save” button.
- Press the “Adjust” button to enter
Adjustment mode.
F. Changing Adjustable Parameters
Figure 5: Adjust Mode Screens
2. Adjusting Parameters
Editing parameters is accomplished as follows:

16 105337-03 - 5/15
I. Operation F. Changing Adjustable Parameters (continued)
2. Adjusting Parameters (continued)
The following pages describe the Control’s adjustable parameters. Parameters are presented in the order they appear on
the Control’s Display, from top to bottom and, left to right. From the “Home” screen select the Adjust button to access the
adjustment mode screens show below (if required, refer to the previous page to review how to enter Adjustment mode):
“Press”
System
Setup
button to access the following parameters:
Factory
Setting
Range /
Choices Parameter and Description
Fahrenheit Fahrenheit,
Celsius
Temperature Units
The Temperature Units parameter determines whether temperature is represented in units of Fahrenheit
or Celsius degrees.
20-14 Display Brightness
Display brightness is adjustable from 0 to 14.
70-14 Display Contrast
Display contrast is adjustable from 0 to 14.
Wired
Not Installed,
Wired
Wireless
Outdoor Sensor Source
Not Installed Outdoor Sensor is not connected to the boiler, the sensor is not monitored for faults.
Wired Outdoor Sensor is installed directly on the boiler terminal Strip-TB2.
Wireless Outdoor sensor is installed and wireless.
0-100 to 100
tenths of degree
Outdoor Air Sensor Calibration
Outdoor Air Sensor Calibration offset allows a single point calibration. Using a reliable source (reference)
for outdoor temperature measure outdoor air temperature. Set the offset equal to the difference between
the controller reading and the reference. The result will be the Control’s measurement matching the
reference reading.
Not
Connected
Connected,
Not Connected
Zone Control Status Connected
When the Zone Control is connected adjustable settings are automatically shown under the Adjust
“Modulation”, “Auxiliary Heat” and “Zone Control Description Setup” menus. This feature allows these
adjustments to be made before the zone panel is connected. When the user selects “Show As If
Connected” Zone Control related parameters are made visible and may be adjusted.
Enabled Enable/Disable
Frost Protection
Disable Frost Protection is not used.
Enable Boiler and system circulators start and boiler res when low outside air, supply and return
temperatures are sensed as follows:
0 Secs 0-900 Secs
Anti-Short Cycle Time
Anti-short cycle is a tool that helps prevent excessive cycling resulting from a fast cycling Thermostat or
Zone valves. It provides a minimum delay time before the next burner cycle. DHW demand is serviced
immediately, without any delay.
Disabled Enable/Disable
Warm Weather Shutdown Enable
Disable Warm Weather Shutdown (WWSD) is not used.
Enable The boiler and pumps will not be allowed to start in response to a central heat call for heat if
the outside temperature is greater than the WWSD setpoint. WWSD is initiated as soon as
outside air temperature is above WWSD Setpoint. The control does not require call for heat
to be satised.
The boiler will still start in response to a Domestic Hot Water call for heat.
70°F 0-100°F
Warm Weather Shutdown Setpoint
The Warm Weather Shutdown (WWSD) Setpoint used to shutdown the boiler when enabled by the
“WWSD Enable” parameter.
Device Started Start Temperatures Stop Temperatures
Boiler & System Outside Air < 0° (-18°C)°F Outside Air > 4°F (-16°C)

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2. Adjusting Parameters (continued)
WARNING
Asphyxiation Hazard. Boiler type is factory set and must match the boiler model. Only change the boiler
type setting if you are installing a new or replacement Control. The boiler type setting determines minimum
and maximum blower speeds. Incorrect boiler type can cause hazardous burner conditions and improper
operation that may result in PROPERTY LOSS, PHYSICAL INJURY OR DEATH.
“Press”
Modulation
Setup
button to access the following parameters:
Factory
Setting Range / Choices Parameter and Description
See Table
4See Table 4
Boiler Type
Boiler Size Setup
To verify the boiler size selection, a qualied technician should do the following:
1. Check boiler’s label for actual boiler size.
2. Set “Boiler Type” to match actual boiler size.
3. Select “Conrm”.
The Boiler Type parameter changes the minimum and maximum modulation settings. This
parameter is intended to allow a user to set the parameters in a spare part Control to a particular
boiler type.
100%
Minimum to
Maximum
Heat Rate
Central Heat Maximum Expected Heat Rate
This parameter denes the highest modulation rate the Control will go to during a central heat
call for heat. If the rated input of the installed home radiation is less than the maximum output of
the boiler, change the Central Heat Maximum Expected Heat Rate (fan speed) setting to limit the
boiler output accordingly.
80%
Minimum to
Maximum
Heat Rate
Domestic Hot Water (DHW) Max Expected Heat Rate
This parameter denes the highest modulation rate the Control will go to during a Domestic Hot
Water call for heat. If the rated input of the indirect water heater is less than the maximum output
of the boiler, change the DHW Maximum Expected Heat Rate (fan speed) setting to limit the boiler
output accordingly.
100%
Minimum to
Maximum
Heat Rate
Auxiliary Maximum Expected Heat Rate
This parameter denes the highest modulation rate the Control will go to during the auxiliary heat
call for heat. If the rated input of the Auxiliary Heat Zones is less than the maximum output of the
boiler, change the Auxiliary Heat Maximum Expected Heat Rate (fan speed) setting to limit the
boiler output accordingly.
40%
Minimum to
Maximum
Heat Rate
Zone 1 Expected Heat Rate (typical for zone 1 through 16)
This parameter denes the highest modulation rate the Control will go to during the Zone 1 call for
heat. If the rated input of the installed home radiation in zone 1 is less than the maximum output
of the boiler, change the Zone 1 Expected Heat Rate (fan speed) setting to limit the boiler output
accordingly.
30
Minutes 0 to 60 Minutes
Zone Release Time
After the Zone Release Time minutes and a zone has not been satised (thermostat opens) the
measured heat loss will be released to increase to the Central Heat Maximum Heat Rate.
See Table
4
Minimum
- 100 to
Maximum
Minimum Modulation
This parameter is the lowest modulation rate the Control will go to during any call for heat.
See Table
4See Table 4 Lightoff Rate This is the blower speed during ignition and ame stabilization periods.
I. Operation F. Changing Adjustable Parameters (continued)

18 105337-03 - 5/15
I. Operation F. Changing Adjustable Parameters (continued)
Control Repair Part Kit Part Number 106194-01
Altitude 0 - 2000 Ft.
Parameter K2-80-02 K2-100-02 K2-120-02 K2-150-02 K2-180-02
Maximum Heat Rate (RPM) 5100 5500 5100 5400 6000
Minimum Heat rate (RPM) 1600 1650 1600 2000 1800
Absolute Maximum Heat Rate (RPM) 5400 6900 5700 6300 6700
Minimum Light-off (RPM) 3500 3500 3500 3500 3500
Maximum Light-off rate (RPM) 4000 4000 4000 4000 4000
Altitude 2001 - 4500 Ft.
Parameter K2-80-24 K2-100-24 K2-120-24 K2-150-24 K2-180-24
Maximum Heat Rate (RPM) 6000 7450 6900 7200 7050
Minimum Heat rate (RPM) 1600 1850 1750 2000 1800
Absolute Maximum Heat Rate (RPM) 7565 7620 6984 7200 7150
Minimum Light-off (RPM) 3500 3500 3500 3500 3500
Maximum Light-off rate (RPM) 4000 4000 4000 4000 4000
Altitude 4501 - 7800 Ft.
Parameter K2-80-57 K2-100-57 K2-120-57 K2-150-57 K2-180-57
Maximum Heat Rate (RPM) 6200 7500 7050 7300 7200
Minimum Heat rate (RPM) 1800 2000 1800 2000 1900
Absolute Maximum Heat Rate (RPM) 7720 7680 7132 7300 7385
Minimum Light-off (RPM) 3500 3500 3500 3500 3500
Maximum Light-off rate (RPM) 4000 4000 4000 4000 4000
Altitude 7801 - 10100 Ft.
Parameter K2-80-80 K2-100-80 K2-120-80 K2-150-80 K2-180-80
Maximum Heat Rate (RPM) 7000 7900 7240 7450 7500
Minimum Heat rate (RPM) 1900 2000 1800 2000 1900
Absolute Maximum Heat Rate (RPM) 7950 7975 7360 7450 7760
Minimum Light-off (RPM) 3500 3500 3500 3500 3500
Maximum Light-off rate (RPM) 4000 4000 4000 4000 4000
Table 4: Parameters Changed Using the Boiler Type Parameter Selections:

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I. Operation F. Changing Adjustable Parameters (continued)
The Control is shipped with defaults that will provide improved operation. Adjustment is only required to optimize
setup.
The expected heat rate adjustment is used to better match boiler output to the home heating needs. After receiving
a "call for heat" the Control rst uses the expected heat rate value to set a maximum heat rate. The maximum heat
rate is the highest heat rate that the boiler can re to at that moment. The maximum heat rate is the summation of
the expected heat rates for the active (turned on) zones. After establishing the maximum heat rate the Control then
measures water temperature and res the boiler only as hard as required for the heat demand.
Expected Heat Rate Adjustment Screens (HeatMatch Software)
Figure 6: Four Zone House (with Zone Control Connected)
Figure 7: Expected Heat Rate Adjustment (with Zone Control Connected)
Example “call for heat”
durations for a four zone
house.
Maximum heat rate limits
ring rate and prevents
the Control from ring to
100% in response to a
smaller zone demands.
Maximum modulation
numbers are shown in both
RPM and kbtu/hr to allow for
easier understanding of boiler
heat rate.
NOTE
This feature requires Zone
Control to be connected.
Refer to Electrical section
for Zone Control connection
information.
The sum of Zone Expected
Heat Rates plus DHW
Maximum Expected Heat Rate
(if DHW is active) is used to
calculate the active maximum
modulation rate.
Maximum Heat Rate:
Automatically adjusted
by the Control based on
the size and number of
zones calling for heat.
Actual Heat Rate:
Boiler is free to
modulate based on
temperature from
minimum to maximum
heat rate.

20 105337-03 - 5/15
“Press”
Pump Setup
button to access the following parameters:
Factory Setting Range / Choices Parameter and Description
Central Heat,
Optional Priority
Never,
Any Demand,
Central Heat,
No Priority,
Central Heat,
Optional Priority
System Pump run pump for:
Activates the system pump output according to selected function.
Never: Pump is disabled and not shown on status screen.
Any Demand: Pump Runs during any call for heat.
Central Heat, No Priority: Pump Runs during central heat and frost protection call for
heat. Pump does not start for a DHW call for heat and
continues to run during Domestic Hot Water Priority.
Central heat, Optional
Priority: Pump Runs during central heat and frost protection call for
heat. Pump does not start for a DHW call for heat and will be
forced off if there is a DHW call for heat and Domestic Hot
Water Priority is active.
Any Demand Any Demand,
Header Sensor
Demand
Boiler Pump run pump for:
Activates the boiler pump output according to selected function.
Any Demand: Pump Runs during any call for heat.
Header Sensor Demand: Pump Runs when boiler is ring and when there is DHW
demand. Selected when Header Sensor is selected as
modulation sensor and boiler is a stand alone boiler.
Primary
Loop Pipe
IWH
Never,
Primary Loop
Piped IWH,
Domestic Pump run pump for:
Activates the Domestic pump output according to selected function.
Never: Pump is disabled and not shown on status screen.
Primary Loop Piped IWH: Pump Runs during domestic hot water call for
heat. Domestic Hot Water Priority enable/disable
does not affect pump operation.
I. Operation F. Changing Adjustable Parameters (continued)
Explanation:
This piping arrangement only
services central heat. When
there is any demand both
boiler and system pumps turn
on.
Example Pump Parameter selections:
Single boiler with no Indirect Water Heater
Parameter Selection:
System pump = “Central Heat,
Optional Priority”
Boiler pump = “any demand”
DHW pump = “never”