Lochinvar 81 - 286 User manual

KBII-I-O Rev D
Installation & Operation Manual
Models: 81 - 286
This manual must only be used by
a qualified heating installer / service
technician. Read all instructions,
including this manual and the
Knight Boiler Service 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.
HAZARD DEFINITIONS .................................................... 2
PLEASE READ BEFORE PROCEEDING ........................ 3
THE KNIGHT BOILER -- HOW IT WORKS................... 4-6
RATINGS........................................................................... 7
1. DETERMINE BOILER LOCATION
Provide Clearances............................................................ 8
Provide Air Openings to Room ........................................ 10
Flooring and Foundation................................................. 10
Residential Garage Installation........................................ 10
Vent and Air Piping.......................................................... 10
Prevent Combustion Air Contamination........................... 10
Corrosive Contaminants and Sources............................. 11
Using an Existing Vent System to Install a New Boiler ... 11
Removing a Boiler from Existing Common Vent.............. 12
2. PREPARE BOILER
Remove Boiler from Wood Pallet..................................... 13
Gas Conversions.............................................................. 13
Leveling the Boiler...................................................... 13
3. GENERAL VENTING
Direct Venting Options................................................ 14-15
Install Vent and Combustion Air Piping ........................... 16
PVC/CPVC Vent and Air Piping Materials.................. 16
Requirements for Installation in Canada.......................... 16
Installing Vent and Air Piping........................................... 16
PVC/CPVC Air Intake/Vent Connections......................... 17
Air Inlet Pipe Materials..................................................... 18
Stainless Steel Vent......................................................... 18
Stainless Steel Air Intake/Vent Connections.................... 19
Min./Max. Combustion Air & Vent Piping Lengths........... 19
Vent and Air Piping.......................................................... 20
Optional Room Air............................................................ 20
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall................................... 21-24
Determine Location................................................ 21-23
Prepare Wall Penetrations.......................................... 23
Termination and Fittings............................................. 24
Multiple Vent/Air Terminations......................................... 24
Sidewall Termination - Optional Concentric Vent....... 25-27
5. VERTICAL DIRECT VENTING
Vent/Air Termination - Vertical.................................... 28-29
Determine Location..................................................... 28
Prepare Roof Penetrations......................................... 29
Termination and Fittings................................................... 29
Multiple Vent/Air Terminations......................................... 29
Vertical Termination - Optional Concentric Vent......... 30-31
Alternate Vertical Concentric Venting......................... 32-33
6. HYDRONIC PIPING
System Water Piping Methods......................................... 34
Low Water Cutoff Device................................................. 34
Chilled Water System....................................................... 34
Freeze Protection............................................................. 34
General Piping Information .............................................. 34
Relief Valve / T & P Installation ....................................... 35
Near Boiler Piping Components.................................. 35-36
Near Boiler Piping Connections....................................... 36
Circulator Sizing............................................................... 36
Variable Speed Pump Option .......................................... 38
7. GAS CONNECTIONS
Connecting Gas Supply Piping........................................ 46
Natural Gas...................................................................... 47
Pipe Sizing for Natural Gas........................................ 47
Natural Gas Supply Pressure Requirements ............. 47
Propane Gas.................................................................... 47
Pipe Sizing for Propane Gas...................................... 47
Propane Supply Pressure Requirements................... 47
Check Inlet Gas Supply ................................................... 48
Gas Pressure ................................................................... 49
Gas Valve Replacement .................................................. 49
8. FIELD WIRING
Line Voltage Connections................................................ 50
Low Voltage Connections ................................................ 50
Wiring of the Cascade...................................................... 52
9. CONDENSATE DISPOSAL
Condensate Drain............................................................ 54
10. STARTUP ............................................................. 55-60
11. OPERATING INFORMATION
General............................................................................. 61
Cascade........................................................................... 64
Sequence of Operation............................................... 65-66
Knight Boiler Control Module...................................... 67-68
Status Display Screens............................................... 69-71
12. MAINTENANCE
Maintenance and Annual Startup................................ 72-76
13. DIAGRAMS
Ladder Diagram ............................................................... 77
Wiring Diagram................................................................. 78
Revision Notes.................................................. Back Cover
Contents

3
Installation & Operation Manual
Please read before proceeding
Installer – Read all instructions, including
this manual and the Knight Boiler Service
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 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.
Failure to adhere to the guidelines on this
page can 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.
Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by
the consignee.
Factory warranty (shipped with unit) does
not apply to units improperly installed or
improperly operated.
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
This appliance MUST NOT be installed in
any location where gasoline or flammable
vapors are likely to be present.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a near by phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
• Installation and service must be
performed by a qualified installer,
service agency, or the gas supplier.
WARNING
NOTICE
WARNING
WARNING
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.
• 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 in system
components. Leaks in boiler or piping must be repaired
at once to prevent 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.
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.
CAUTION
CAUTION Do not use “homemade cures” or “boiler
patent medicines”. Serious damage to
the boiler, personnel, and/or property
may result.

The Knight Boiler - How it works...
1. Stainless steel heat exchanger
Allows system water to flow through specially designed
coils for maximum heat transfer, while providing
protection against flue gas corrosion. The coils are
encased in a jacket that contains the combustion process.
2. Combustion chamber access cover
Allows access to the combustion side of the heat
exchanger coils.
3. Blower
The blower pulls in air and gas through the venturi (item
5). Air and gas mix inside the blower and are pushed into the
burner, where they burn inside the combustion chamber.
4. Gas valve
The gas valve senses the negative pressure created by the
blower, allowing gas to flow only if the gas valve is
powered and combustion air is flowing.
5. Venturi
The venturi controls air and gas flow into the burner.
6. Flue gas sensor (limit rated)
This sensor monitors the flue gas exit temperature. The control
module will modulate and shut down the boiler if flue gas
temperature gets too hot. This protects the flue pipe from
overheating.
7. Boiler outlet temperature sensor (housed with the
high limit sensor)
This sensor monitors boiler outlet water temperature (system
supply). If selected as the controlling sensor, the control
module adjusts boiler firing rate so the outlet temperature is
correct.
8. Boiler inlet temperature sensor
This sensor monitors return water temperature (system
return). If selected as the controlling sensor, the control
module adjusts the boiler firing rate so the inlet temperature is
correct.
9. Temperature and pressure gauge (field installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
10. Electronic LCD display
The electronic display consists of 4 buttons, a navigation dial
and a multiple line liquid crystal display.
11. Flue pipe adapter
Allows for the connection of the PVC vent pipe system to the
boiler.
12. Burner (not shown)
Made with metal fiber and stainless steel construction,
the burner uses pre-mixed air and gas and provides a
wide range of firing rates.
13. Water outlet (system supply)
NPT water connection that supplies hot water to the
system, either 1" or 1-1/4", depending on the
model.
14. Water inlet (system return)
NPT water connection that returns water from the
system to the heat exchanger, either 1" or 1-1/4",
depending on the model.
15. Gas connection pipe
Threaded pipe connection, either 1/2" or 3/4",
depending on the model. This pipe should be connected
to the incoming gas supply for the purpose of delivering
gas to the boiler.
16. SMART SYSTEM Control Module
The SMART SYSTEM Control responds to internal and
external signals and controls the blower, gas valve, and pumps
to meet the heating demand.
17. Manual air vent
Designed to remove trapped air from the heat exchanger
coils.
18. Air intake adapter
Allows for the connection of the PVC air intake pipe to
the boiler.
19. High voltage junction box
The junction box contains the connection points for the line
voltage power and all pumps.
20. Boiler drain port
Location from which the heat exchanger can be drained.
21. Low voltage connection board
The connection board is used to connect external low voltage
devices.
22. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage
connection board.
23. Condensate drain connection
Connects the condensate drain line to a 1/2" PVC union.
24. Access cover - front
Provides access to the gas train and the heat exchanger.
25. Ignition electrode
Provides direct spark for igniting the burner.
26. Flame inspection window
The quartz glass window provides a view of the burner
surface and flame.
27. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 30 psi.
28. Flame sensor
Used by the control module to detect the presence of burner
flame.
29. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
30. Top panel
Removable panel to gain access to the internal components.
31. Power switch
Turns 120 VAC ON/OFF to the boiler.
32. Leveling legs
Used to allow the heat exchanger to be leveled. This is needed
for the proper draining of the condensate from the combustion
chamber.
33. Air pressure switch
The air pressure switch detects blocked inlet conditions.
34. Transformer
The transformer provides 24V power to the integrated control.
35. High limit sensor (housed with the outlet
temperature sensor)
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, the integrated control will
break the control circuit, shutting the boiler down.
36. Gas shutoff switch
An electrical switch designed to cut power to the gas valve to
prevent releasing any gas.
37. Over-temp switch (Model 286 Only) (located underneath
access cover)
Used to detect excessive temperatures on the upper coil of the heat
exchanger.
4
Installation & Operation Manual

5
Installation & Operation Manual
10
30
24
Front View - Models 81 - 211
33
18
15
8
14
27
13
20
32
23
10
25
12
28
Left Side (inside unit) - Models 81 - 211 Right Side (inside unit) - Models 81 - 211
The Knight Boiler - How it works... (continued)
29
31
11
22
6
Rear View - Models 81 - 211
Models 81 - 211
19
21
16
3
1
17
4
5
7
2
26
35
36
34

6
Installation & Operation Manual
The Knight Boiler - How it works...
18
15
37
Model 286
Left Side (inside unit) - Model 286 Right Side (inside unit) - Model 286
Front View - Model 286 Rear View - Model 286
10
24
33
4
34

7
Ratings
Notes:
1. As an Energy Star Partner, Lochinvar has determined that
Knight boilers meet the Energy Star guidelines for energy
efficiency.
2. The ratings are based on standard test procedures prescribed
by the United States Department of Energy.
3. Net I=B=R ratings are based on net installed radiation of
sufficient quantity for the requirements of the building
and nothing need be added for normal piping and pickup.
Ratings are based on a piping and pickup allowance of 1.15.
4. Knight boilers require special gas venting. Use only
the vent materials and methods specified in the Knight
Installation and Operation Manual.
5. Standard Knight boilers are equipped to operate from sea
level to 4,500 feet only with no adjustments. The boiler
will de-rate by 4% for each 1,000 feet above sea level up to
4,500 feet.
6. High altitude Knight boilers are equipped to operate
from 3,000 to 12,000 feet only with no field adjustments.
The boiler will de-rate by 2% for each 1,000 feet above
3,000 feet. High altitude models are manufactured with
a different control module for altitude operation, but the
operation given in this manual remains the same as the
standard boilers. A high altitude label (as shown in FIG. A)
is also affixed to the unit.
7. Ratings have been confirmed by the Hydronics Institute,
Section of AHRI.
Maximum allowed working pressure is located on the rating plate.
NOTICE
Knight Boiler
I=B=R Rating
Model Number
Note: Change “N” to
“L” for L.P. gas models.
Input
MBH
(Note 5)
Min Max
Gross
Output
MBH
(Note 2,7)
Net
I=B=R
Ratings
Water,
MBH
(Note 3,7)
KBN081 16 80 72 63
KBN106 21 105 94 82
KBN151 30 150 135 117
KBN211 42 210 190 165
KBN286 57 285 260 226
Other Specifications
Boiler
Water
Content
Gallons
Water
Connections Gas Connections
Air
Size
Vent
Size
(Note 4)
0.6 1" 1/2" 3" 3"
0.7 1" 1/2" 3" 3"
1.3 1" 1/2" 3" 3"
1.7 1" 1/2" 3" 3"
2.4 1-1/4" 3/4" 4" 4"
Figure A High Altitude Label Location
3,000 FT. TO 12,000 FT.
HIGH ALTITUDE
UNIT EQUIPPED FOR
8. Knight boilers comply with the requirements of CSD-1
Section CW-400 requirements as a temperature operation
control. The manual reset high limit provided with the
Knight is listed to UL353.
Installation & Operation Manual

8
Installation & Operation Manual
The Knight boiler gas manifold and
controls met safe lighting and other
performance criteria when the boiler
underwent tests specified in ANSI Z21.13
– latest edition.
Failure to keep boiler area clear and free
of combustible materials, gasoline, and
other flammable liquids and vapors can
result in severe personal injury, death, or
substantial property damage.
Installation must comply with:
• Local, state, provincial, and national codes, laws,
regulations, and ordinances.
• National Fuel Gas Code, ANSI Z223.1 – latest edition.
• Standard for Controls and Safety Devices for Automatically
Fired Boilers, ANSI/ASME CSD-1, when required.
• National Electrical Code.
• For Canada only: B149.1 Installation Code, CSA C22.1
Canadian Electrical Code Part 1 and any local codes.
Before locating the boiler, check:
1. Check for nearby connection to:
• System water piping
• Venting connections
• Gas supply piping
• Electrical power
2. Locate the appliance so that if water connections should
leak, water damage will not occur. When such locations
cannot be avoided, it is recommended that a suitable
drain pan, adequately drained, be installed under the
appliance. The pan must not restrict combustion air
flow. Under no circumstances is the manufacturer to be
held responsible for water damage in connection with
this appliance, or any of its components.
3. Check area around the boiler. Remove any combustible
materials, gasoline and other flammable liquids.
4. The Knight boiler must be installed so that gas control
system components are protected from dripping or
spraying water or rain during operation or service.
5. If a new boiler will replace an existing boiler, check for
and correct system problems, such as:
• System leaks causing oxygen corrosion or heat exchanger
cracks from hard water deposits.
• Incorrectly-sized expansion tank.
• Lack of freeze protection in boiler water causing system
and boiler to freeze and leak.
WARNING This appliance is certified as an indoor
appliance. Do not install the appliance
outdoors or locate where the appliance will
be exposed to freezing temperatures or to
temperatures that exceed 100°F.
Failure to install the appliance indoors
could result in severe personal injury,
death, or substantial property damage.
Provide clearances:
Clearances from combustible materials
1. Hot water pipes—at least 1/4" (6 mm) from combustible
materials.
2. Vent pipe – at least 1" (25 mm) from combustible
materials.
3. See FIG.’s 1-1 and 1-2 on page 9 for other clearance
minimums.
Clearances for service access
1. See FIG.’s 1-1 and 1-2 on page 9 for recommended
service clearances. If you do not provide the minimum
clearances shown, it may not be possible to service the
boiler without removing it from the space.
Closet and alcove installations
This appliance requires a special venting
system. If using PVC the vent connection
to the appliance must be made with the
starter CPVC pipe section provided with
the appliance. The field provided vent
fittings must be cemented to the CPVC
pipe section. Use only the vent materials,
primer and cement specified in this manual
to make the vent connections. Failure to
follow this warning could result in fire,
personal injury, or death.
For closet and alcove installations as
shown in FIG.’s 1-1 and 1-2, CPVC or
stainless steel vent material must be used
inside the structure. The ventilating air
openings shown in FIG.’s 1-1 and 1-2 are
required for this arrangement. Failure to
follow this warning could result in fire,
personal injury, or death.
WARNING
WARNING
NOTICE
WARNING
1 Determine boiler location
A closet is any room the boiler is installed in which is less
than 67 cubic feet for KBN081 and KBN106 models, 86 cubic
feet for KBN151 models, 107 cubic feet for KBN211 models,
and 120 cubic feet for KBN286 models.
An alcove is any room which meets the criteria for a closet
with the exception that it does not have a door.
Example: Room dimensions = 4 feet long, 3 feet wide, and
8 foot ceiling = 4 x 3 x 8 = 96 cubic feet. This would be
considered a closet for a Knight Boiler.

9
Installation & Operation Manual
1 Determine boiler location (continued)
ALCOVE INSTALLATION
OPEN
FRONT
1/4" (6 MM) MINIMUM CLEARANCE
A
ROUND HOT WATER PIPES
1” (25 MM) MINIMUM CLEARANCE
A
ROUND VENT PIPE
0”
RIGHT
18”
FRONT
14”
REAR
12”
LEFT
13”
TOP
RECOMMENDED SERVICE CLEARANCES:
FRONT - 24”
TOP - 24”
LEFT SIDE - 24”
REAR - 24”
Figure 1-2 Alcove Installation - Minimum Required Clearances
CLOSET INSTALLATION
CLOSED DOOR
VENTILATING*
AIR OPENING
VENTILATING*
AIR OPENING
*AREA OF EACH OPENING:
1 SQ. INCH PER 1000 BTU PER HOUR INPUT
WITH A MINIMUM OF 100 SQ. INCHES.
6"
6"
1" MINIMUM CLEARANCE
AROUND HOT WATER
PIPES AND VENT PIPE
0"
RIGHT
6"
FRONT
14"
REAR
12"
LEFT
13”
TOP
RECOMMENDED SERVICE CLEARANCES:
FRONT - 24”
TOP - 24”
LEFT SIDE - 24”
REAR - 24”
Figure 1-1 Closet Installation - Minimum Required Clearances
WARNING For closet installations, CPVC or
stainless steel vent material MUST
BE used in a closet structure due to
elevated temperatures. Failure to
follow this warning could result in
fire, personal injury, or death.
WARNING For alcove installations, CPVC or
stainless steel vent material MUST
BE used in an alcove structure
due to elevated temperatures.
Failure to follow this warning
could result in fire, personal
injury, or death.

10
Installation & Operation Manual
1 Determine boiler location
Provide air openings to room:
Knight boiler alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Knight boiler are
at least equal to the SERVICE clearances shown in
FIG.’s 1-1 and 1-2. For spaces that do NOT supply this
clearance, provide two openings as shown in FIG. 1-1.
Each opening must provide one square inch free area per
1,000 Btu/hr of boiler input.
Knight boiler in same space with other gas or oil-
fired appliances
1. Follow the National Fuel Gas Code (U.S.) or CSA B149.1
(Canada) to size/verify size of the combustion/ventilation
air openings into the space.
The space must be provided with
combustion/ventilation air openings
correctly sized for all other appliances
located in the same space as the Knight
boiler.
Do not install the boiler in an attic.
Failure to comply with the above warnings
could result in severe personal injury,
death, or substantial property damage.
2. Size openings only on the basis of the other appliances in
the space. No additional air opening free area is needed
for the Knight boiler because it takes its combustion air
from outside (direct vent installation).
Do not install the boiler on carpeting even
if foundation is used. Fire can result,
causing severe personal injury, death, or
substantial property damage.
If flooding is possible, elevate the boiler sufficiently to prevent
water from reaching the boiler.
Flooring and foundation
Flooring
The Knight boiler is approved for installation on combustible
flooring, but must never be installed on carpeting.
Residential garage installation
Precautions
Take the following precautions when installing the appliance
in a residential garage. If the appliance is located in a
residential garage, it should be installed in compliance with
the latest edition of the National Fuel Gas Code, ANSI Z223.1
and/or CAN/CGA-B149 Installation Code.
• Appliances located in residential garages and in
adjacent spaces that open to the garage and are not part
of the living space of a dwelling shall be installed so that
all burners and burner ignition devices are located not
less than 18 inches (46 cm) above the floor.
• The appliance shall be located or protected so that it is
not subject to physical damage by a moving vehicle.
Vent and air piping
The Knight boiler requires a special vent system, designed for
pressurized venting.
The boiler is to be used for either direct vent installation or
for installation using indoor combustion air. When room
air is considered, see Section 3, General Venting. Note
prevention of combustion air contamination below when
considering vent/air termination.
Vent and air must terminate near one another and may be
vented vertically through the roof or out a side wall, unless
otherwise specified. You may use any of the vent/air piping
methods covered in this manual. Do not attempt to install
the Knight boiler using any other means.
Be sure to locate the boiler such that the vent and air piping
can be routed through the building and properly terminated.
The vent/air piping lengths, routing and termination method
must all comply with the methods and limits given in this
manual.
Prevent combustion air contamination
Install air inlet piping for the Knight boiler as described in this
manual. Do not terminate vent/air in locations that can allow
contamination of combustion air. Refer to Table 1A, page
11 for products and areas which may cause contaminated
combustion air.
You must pipe combustion air to the boiler
air intake. Ensure that the combustion air
will not contain any of the contaminants
in Table 1A, page 11. Contaminated
combustion air will damage the boiler,
resulting in possible severe personal
injury, death or substantial property
damage. Do not pipe combustion air near
a swimming pool, for example. Also,
avoid areas subject to exhaust fumes from
laundry facilities. These areas will always
contain contaminants.
WARNING
WARNING
WARNING