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

11
Installation & Operation Manual
Products to avoid:
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cements and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents
found in household laundry rooms
Adhesives used to fasten building products and other
similar products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garages with workshops
Table 1A Corrosive Contaminants and Sources
1 Determine boiler location (continued)
Failure to follow all instructions can result
in flue gas spillage and carbon monoxide
emissions, causing severe personal injury
or death.
WARNING
When using an existing vent system to
install a new boiler:
Check the following venting components before installing:
• Material - For materials listed for use with this appliance,
see Section 3 - General Venting, Table 3A. For stainless
steel venting, an adapter of the same manufacturer
(Table 3B) must be used at the flue collar connection.
• Size - To ensure proper pipe size is in place, see Table 3C.
Check to see that this size is used throughout the vent
system.
• Manufacturer - For a stainless steel application, you
must use only the listed manufacturers and their type
product listed in Table 3A for CAT IV positive pressure
venting with flue producing condensate.
• Supports - Non-combustible supports must be in place
allowing a minimum 1/4" rise per foot. The supports
should adequately prevent sagging and vertical slippage,
by distributing the vent system weight. For additional
information, consult the vent manufacturer’s
instructions for installation.
• Terminations - Carefully review Sections 3 through 5 to
ensure requirements for the location of the vent and air
terminations are met and orientation of these fit the
appropriate image from the Sidewall or Vertical
options listed in the General Venting Section. For
stainless steel vent, only use terminations listed in Table
3B for the manufacturer of the installed vent.
• Seal - With prior requirements met, the system should be
tested to the procedure listed in parts (c) through (f) of
the Removal of an Existing Boiler Section on page 12.
With stainless steel vent, seal and connect all pipe and
components as specified by the vent manufacturer used; with
PVC/CPVC vent, see the Installing Vent or Air Piping Section
on page 16.
WARNING If any of these conditions are not met,
the existing system must be updated or
replaced for that concern. Failure to
follow all instructions can result in flue gas
spillage and carbon monoxide emissions,
causing severe personal injury or death.

Installation & Operation Manual
12
When removing a boiler from existing
common vent system:
Do not install the Knight boiler into a
common vent with any other appliance.
This will cause flue gas spillage or appliance
malfunction, resulting in possible severe
personal injury, death, or substantial
property damage.
Failure to follow all instructions can result
in flue gas spillage and carbon monoxide
emissions, causing severe personal injury
or death.
At the time of removal of an existing boiler, the following steps
shall be followed with each appliance remaining connected
to the common venting system placed in operation, while
the other appliances remaining connected to the common
venting system are not in operation.
a. Seal any unused openings in the common venting system.
b. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage
or restriction, leakage, corrosion, or other deficiencies,
which could cause an unsafe condition.
c. Test vent system – Insofar as is practical, close all building
doors and windows and all doors between the space
in which the appliances remaining connected to the
common venting system are located and other spaces of
the building. Turn on clothes dryers and any appliance
not connected to the common venting system. Turn on
any exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed. Do not
operate a summer exhaust fan. Close fireplace dampers.
d. Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust thermostat so
appliance will operate continuously.
e. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a
match or candle, or smoke from a cigarette, cigar, or pipe.
f. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined herein, return
doors, windows, exhaust fans, fireplace dampers, and any
other gas-burning appliance to their previous conditions
of use.
DANGER
WARNING
g. Any improper operation of the common venting system
should be corrected so the installation conforms with the
National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or
CAN/CSA B149.1, Natural Gas and Propane Installation
Code. When resizing any portion of the common venting
system, the common venting system should be resized
to approach the minimum size as determined using the
appropriate tables in Part 11 of the National Fuel Gas Code,
ANSI Z223.1/NFPA and/or CAN/CSA B149.1, Natural Gas
and Propane Installation Code.
1 Determine boiler location

13
Installation & Operation Manual
Figure 2-2 Installing Propane Orifice
Remove boiler from wood pallet
1. After removing the outer shipping carton from the boiler,
remove the parts box.
2. Remove the front door to access the lag bolts in front of
the unit (FIG. 2-1).
3. To remove the boiler from the pallet (after removing the
front door):
a. Remove the two lag bolts from the wood pallet
inside the boiler (FIG. 2-1).
b. Detach the boiler from the lag bolts in the rear of the
unit, see FIG. 2-1.
Do not drop the boiler or bump the jacket
on the floor or pallet. Damage to the
boiler can result.
For a boiler already installed, you must
turn off gas supply, turn off power and
allow boiler to cool before proceeding.
You must also completely test the boiler
after conversion to verify performance
as described under Start-up, Section 10
of this manual. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
You must install a propane orifice to
operate the Knight boiler on propane gas.
Verify when installing that the orifice size
marking matches boiler size (Table 2A).
5. After installation is complete, attach the propane conversion
label (in the conversion kit bag) next to the boiler rating
plate. Attach the LP caution label (in the conversion kit
bag) to the left side of the unit in the lower left corner.
6. Replace the top and front access covers.
. 2
Figure 2-1 Boiler Mounted on Shipping Pallet
Gas conversions
NOTICE
WARNING
Figure 2-3 Leveling Legs on the Boiler
Leveling the boiler
1. Set the boiler in place and check level.
a) Adjust legs if necessary to level boiler, see FIG. 2-3
below.
WARNING After converting to LP, check combustion
per the Start-up procedure in Section 10
of this manual. Failure to check and verify
combustion could result in severe personal
injury, death, or substantial property damage.
LP Conversion Table
Model LP Orifice Stamping
81 80
106 105
151 150
211 210 / W150
286 285
Table 2A LP Conversion Table
1. Remove the top and front access covers from the unit (no
tools required for removal).
2. Remove the three screws securing the gas valve to the
venturi (FIG. 2-2).
3. Locate the propane orifice disk from the conversion kit
bag. Verify that the stamping on the orifice disk matches
the boiler size (see Table 2A).
Place the orifice into the black rubber grommet in the
side of the gas valve and secure in the valve (FIG. 2-2).
4. Reposition the gas valve against the venturi and replace
the screws (FIG. 2-2) securing the valve to the venturi.
2 Prepare boiler

14
Installation & Operation Manual
3 General venting
Figure 3-1 PVC/CPVC Two-Pipe Sidewall
Termination - See page 21 for more details
Figure 3-3 PVC/CPVC Concentric Sidewall
Termination - See page 25 for more details
Direct venting options - Sidewall Vent
Figure 3-2 Stainless Steel Two-Pipe - See page 22
for more details

15
Installation & Operation Manual
Figure 3-5 Stainless Steel Two-
Pipe Vertical Termination - See
page 28 for more details
Figure 3-6 PVC/CPVC Concentric
Vertical Termination - See page 30
for more details
Figure 3-8 Stainless Steel Vertical Vent, Sidewall Air
- See page 20 for more details
Figure 3-4 PVC/CPVC Two-Pipe
Vertical Termination - See page
28 for more details
Direct venting options - Vertical Vent
Direct venting options - Vertical Vent, Sidewall Air
Figure 3-7 PVC/CPVC Vertical Vent, Sidewall Air -
See page 20 for more details
3 General venting (continued)
Stainless steel vent/air design and terminations will vary slightly by manufacturer.
NOTICE

16
Installation & Operation Manual
3 General venting
PVC/CPVC vent piping materials
Use only the materials listed in Table
3A for vent pipe, and fittings. Failure to
comply could result in severe personal
injury, death, or substantial property
damage.
Installation must comply with local
requirements and with the National
Fuel Gas Code, ANSI Z223.1 for U.S.
installations or CSA B149.1 for Canadian
installations.
Install vent and combustion air piping
DANGER The Knight boiler must be vented and
supplied with combustion and ventilation
air as described in this section. Ensure the
vent and air piping and the combustion
air supply comply with these instructions
regarding vent system, air system, and
combustion air quality. See also Section 1
of this manual.
Inspect finished vent and air piping
thoroughly to ensure all are airtight and
comply with the instructions provided and
with all requirements of applicable codes.
Failure to provide a properly installed vent
and air system will cause severe personal
injury or death.
All PVC vent pipes must be glued, properly
supported, and the exhaust must be
pitched a minimum of a 1/4 inch per foot
back to the boiler (to allow drainage of
condensate).
WARNING
NOTICE
WARNING
WARNING For closet and alcove installations, CPVC
or stainless steel material MUST BE used in
a closet/alcove structure. Failure to follow
this warning could result in fire, personal
injury, or death.
NOTICE
Requirements for installation in
Canada
1. Installations must be made with a vent pipe system
certified to ULC-S636.
IPEX is an approved vent manufacturer in Canada
supplying vent material listed to ULC-S636.
2. The first three (3) feet of plastic vent pipe from the
appliance flue outlet must be readily accessible for visual
inspection.
3. The components of the certified vent system must not be
interchanged with other vent systems or unlisted
pipe/fittings. For concentric vent installations, the inner
vent tube must be replaced with field supplied certifiedvent
material to comply with this requirement.
4. The 3" Concentric Vent Kit available from Lochinvar (see
Section 4 – Sidewall Termination – Optional Concentric
Vent) and the 3" Concentric Vent Kit available from IPEX
are both approved for use on the Knight boiler. Both
kits are listed to the ULC-S636 standard for use in Canada.
This appliance requires a special venting
system. The vent connection to the
appliance must be made with the starter
CPVC pipe section provided with the
appliance if PVC/CPVC vent is to be used.
For stainless steel venting use an adapter
from Table 3B (page 19) that corresponds
with the intended vent manufacturer to
be used and discard the CPVC starter
piece. The field provided vent fittings must
be cemented to the CPVC pipe section
using an “All Purpose Cement” suitable for
PVC and CPVC pipe. 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.
Installing vent and air piping
Improper installation of PVC or CPVC
systems may result in injury or death.
CAUTION
Use only cleaners, primers, and solvents that
are approved for the materials which are
joined together.
NOTICE
1. Work from the boiler to vent or air termination. Do not
exceed the lengths given in this manual for the air or vent
piping.
2. Cut pipe to the required lengths and deburr the inside and
outside of the pipe ends.
3. Chamfer outside of each pipe end to ensure even cement
distribution when joining.
4. Clean all pipe ends and fittings using a clean dry rag.
(Moisture will retard curing and dirt or grease will prevent
adhesion.)
5. Dry fit vent or air piping to ensure proper fit up before
assembling any joint. The pipe should go a third to
two-thirds into the fitting to ensure proper sealing after
cement is applied.
WARNING Insulation should not be used on PVC
or CPVC venting materials. The use of
insulation will cause increased vent wall
temperatures, which could result in vent
pipe failure.

Installation & Operation Manual
Table 3A Vent Pipe, and Fittings
All vent pipe materials and fittings must comply with the following:
Item Material Standards for installation in:
United States Canada
Vent pipe and
fittings
PVC Plastic Pipe, Schedules 40, 80, & 120 ANSI/ASTM D1785 CPVC and PVC venting must be ULC-S636
Certified. IPEX is an approved manufacturer
in Canada supplying vent material listed to
ULC-S636.
PVC Plastic Pipe Fittings, Schedule 40 ANSI/ASTM D2466
PVC Plastic Pipe Fittings, Schedule 80 ANSI/ASTM D2467
PVC - DWV Pipe and Fittings ANSI/ASTM D2665
CPVC Plastic Pipe, Schedule 40 & 80 ANSI/ASTM F441
CPVC Plastic Pipe Fittings, Schedule 80 ANSI/ASTM F439
AL29-4C UL1738 ULC-S636
NOTICE: DO NOT USE CELLULAR (FOAM) CORE PIPE
Approved Stainless Steel Vent Manufacturers
Make Model
ProTech Systems (Simpson Dura-Vent Co.) FasNSeal Vent / FasNSeal Flex* Vent
Z-Flex (Nova Flex Group) Z-Vent
Heat Fab (Selkirk Corporation) Saf-T Vent
6. Priming and Cementing:
a. Handle fittings and pipes carefully to prevent
contamination of surfaces.
b. Apply a liberal even coat of primer to the fitting
socket.
c. Apply a liberal even coat of primer to the pipe end to
approximately 1/2" beyond the socket depth.
d. Apply a second primer coat to the fitting socket.
e. While primer is still wet, apply an even coat of
approved cement to the pipe equal to the depth of
the fitting socket.
f. While primer is still wet, apply an even coat of
approved cement to the fitting socket.
g. Apply a second coat of cement to the pipe.
h. While the cement is still wet, insert the pipe into the
fitting, if possible twist the pipe a 1/4 turn as you insert
it. NOTE: If voids are present, sufficient cement was
not applied and joint could be defective.
i. Wipe excess cement from the joint removing ring or
beads as it will needlessly soften the pipe.
3 General venting (continued)
PVC/CPVC air intake/vent connections
1. Combustion Air Intake Connector (FIG.’s 3-9 and 3-10) - Used to provide combustion air directly to the unit from
outdoors. A fitting is provided on the unit for final connection. Combustion air piping must be supported per guidelines
listed in the National Mechanical Code, Section 305, Table 305.4 or as local codes dictate.
2. Vent Connector (FIG.’s 3-9 and 3-10) - Used to provide a passageway for conveying combustion gases to the outside. A
transition fitting is provided on the unit for final connection. Vent piping must be supported per the National Building Code,
Section 305, Table 305.4 or as local codes dictate.
3” CPVC PIPE SUPPLIED WITH BOILER
MUST BE USED FOR VENT CONNECTION
NOTE: CPVC VENT PIPE AND VENT FITTINGS MUST BE USED IN CLOSET
AND ALCOVE INSTALLATIONS.
VENT
AIR
Figure 3-9 Near Boiler PVC/CPVC Venting Models
81 - 211
4” CPVC PIPE SUPPLIED WITH BOILER
MUST BE USED FOR VENT CONNECTION
NOTE: CPVC VENT PIPE AND VENT FITTINGS MUST BE USED IN CLOSET
AND ALCOVE INSTALLATIONS.
Figure 3-10 Near Boiler PVC/CPVC Venting Model 286
*Use of FasNSeal Flex smooth inner wall vent is to be used in vertical or near vertical sections only, taking precaution to ensure
no sagging occurs of the vent system. Connect to the FasNSeal rigid vent using specially designed adapters and sealing method,
see manufacturer’s instructions.
17

18
3 General venting
Air inlet pipe materials:
The air inlet pipe(s) must be sealed. Choose acceptable
combustion air inlet pipe materials from the following list:
PVC, CPVC or ABS
Dryer Vent or Sealed Flexible Duct (not recommended
for rooftop air inlet)
Galvanized steel vent pipe with joints and seams sealed as
specified in this section.
Type “B” double-wall vent with joints and seams sealed as
specified in this section.
AL29-4C, stainless steel material to be sealed to
specification of its manufacturer.
*Plastic pipe may require an adapter (not provided) to
transition between the air inlet connection on the appliance
and the plastic air inlet pipe.
WARNING Using vent or air intake materials other
than those specified, failure to properly
seal all seams and joints or failure to follow
vent pipe manufacturer’s instructions can
result in personal injury, death or property
damage. Mixing of venting materials will
void the warranty and certification of the
appliance.
NOTICE The use of double-wall vent or insulated
material for the combustion air inlet pipe is
recommended in cold climates to prevent
the condensation of airborne moisture in
the incoming combustion air.
Sealing of Type “B” double-wall vent material or galvanized
vent pipe material used for air inlet piping on a sidewall or
vertical rooftop Combustion Air Supply System:
a. Seal all joints and seams of the air inlet pipe using either
Aluminum Foil Duct Tape meeting UL Standard 723 or
181A-P or a high quality UL Listed silicone sealant such as
those manufactured by Dow Corning or General Electric.
b. Do not install seams of vent pipe on the bottom of
horizontal runs.
c. Secure all joints with a minimum of three sheet metal
screws or pop rivets. Apply Aluminum Foil Duct Tape or
silicone sealant to all screws or rivets installed in the vent
pipe.
d. Ensure that the air inlet pipes are properly supported.
The PVC, CPVC, or ABS air inlet pipe should be cleaned and
sealed with the pipe manufacturer’s recommended solvents
and standard commercial pipe cement for the material used.
The PVC, CPVC, ABS, Dryer Vent or Flex Duct air inlet pipe
should use a silicone sealant to ensure a proper seal at the
appliance connection and the air inlet cap connection. Dryer
vent or flex duct should use a screw type clamp to seal the vent
to the appliance air inlet and the air inlet cap. Proper sealing
of the air inlet pipe ensures that combustion air will be free of
contaminants and supplied in proper volume.
Stainless steel vent
This product has been approved for use with stainless steel
using the manufacturers listed in Table 3A.
Use only the materials, vent systems, and
terminations listed in Table 3B. DO
NOT mix vent systems of different types
or manufacturers, unless listed in this
manual. Failure to comply could result
in severe personal injury, death, or
substantial property damage.
WARNING
Installations must comply with applicable
national, state, and local codes. Stainless
steel vent systems must be listed as a
UL-1738 approved system for the United
States and a ULC-S636 approved system
for Canada.
NOTICE
Installation of a stainless steel vent system
should adhere to the stainless steel vent
manufacturer’s installation instructions
supplied with the vent system.
NOTICE
The installer must use a specific vent starter
adapter at the flue collar connection,
supplied by the vent manufacturer to
adapt to its vent system. See Table 3B for
approved vent adapters. Discard CPVC
starter piece.
NOTICE
When a sidewall or vertical rooftop combustion air supply
system is disconnected for any reason, the air inlet pipe must
be resealed to ensure that combustion air will be free of
contaminants and supplied in proper volume.
DANGER Failure to properly seal all joints and seams
as required in the air inlet piping may
result in flue gas recirculation, spillage
of flue products and carbon monoxide
emissions causing severe personal injury
or death.
Installation & Operation Manual

19
Installation & Operation Manual
3" S.S. ADAPTER
3" S.S. INTERMEDIATE
(FOR SAF-T VENT ONLY)
Figure 3-11 Near Boiler Stainless Steel Venting Model286
Stainless steel air intake/vent connections
1. Combustion Air Intake Connector (FIG. 3-11) - Used to
provide combustion air directly to the unit from
outdoors. A fitting is provided on the unit for final
connection. Combustion air piping must be supported
per guidelines listed in the National Mechanical Code,
Section 305, Table 305.4 or as local codes dictate.
2. Vent Connector (FIG. 3-11) - Used to provide a
passageway for conveying combustion gases to the
outside. A transition fitting is provided on the unit for
final connection. Vent piping must be supported per the
National Building Code, Section 305, Table 305.4 or as
local codes dictate.
The Knight boiler uses model specific combustion air intake
and vent piping sizes as detailed in Table 3C below.
Model Air Intake Vent
81 - 211 3 inches 3 inches
286 4 inches 4 inches
Table 3C Air Intake/Vent Piping Sizes
Increasing or decreasing combustion air
or vent piping is not authorized.
NOTICE
Minimum/Maximumallowablecombustion
air and vent piping lengths are as follows:
Combustion Air = 12 equivalent feet minimum / 100 equivalent
feet maximum
Vent = 12 equivalent feet minimum / 100 equivalent feet
maximum
When determining equivalent combustion air and vent length,
add 5 feet for each 90° elbow and 3 feet for each 45° elbow.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit (CVK3003) = 49 equivalent
feet of piping.
The appliance output rating will reduce by
up to 1.5% for each 25 feet of vent length.
NOTICE
3 General venting (continued)
Table 3B Approved Stainless Steel Terminations and Adapters
Model
ProTech Heat Fab Z Flex
FasNSeal Saf-T Vent Z-Vent
Boiler
Adapter Flue Termination
Intake
Air
Termination
Boiler
Adapter Intermediate Adapter Flue Termination
Intake
Air
Termination
Boiler
Adapter Flue Termination Intake Air Termination
81 - 211 300715 FSBS3
FSRC3(R.C) 303889 KB80210 9353BUREZ-1* 9392 5300CI 9314TERM 2SVSLA03 2SVSTP03 2SVSRCX03 2SVSTEX0390
286 F303759 FSBS4
FSRC4(R.C.) FSAIH04 303888 KB285600 9454BUREZ-1* 9492 5400CI 9414TERM 2SVSLA04 2SVSTP04 2SVSRCX04 2SVSTEX0490
* = This adapter must be used in addition to the boiler adapter for Saf-T vent pipe as shown in FIG. 3-11, unless approved vent
other than standard diameter is used. Consult a Heat Fab representative for questions.

20
Installation & Operation Manual
3 General venting
Air contamination
Pool and laundry products and common household and hobby
products often contain fluorine or chlorine compounds. When
these chemicals pass through the boiler, they can form strong
acids. The acid can eat through the boiler wall, causing serious
damage and presenting a possible threat of flue gas spillage or
boiler water leakage into the building.
Please read the information given in Table 1A, page 11,
listing contaminants and areas likely to contain them. If
contaminating chemicals will be present near the location of the
boiler combustion air inlet, have your installer pipe the boiler
combustion air and vent to another location, per this manual.
If the boiler combustion air inlet is located in
a laundry room or pool facility, for example,
these areas will always contain hazardous
contaminants.
To prevent the potential of severe personal
injury or death, check for areas and products
listed in Table 1A, page 11 before installing
the boiler or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
—OR—
• Relocate air inlet and vent terminations
to other areas.
Removing from existing vent
Follow the instructions in Section 1, page 12 of this manual
when removing a boiler from an existing vent system.
Vent and air piping
Vent and air system:
Installation must comply with local
requirements and with the National
Fuel Gas Code, ANSI Z223.1 for U.S.
installations or CSA B149.1 for Canadian
installations.
You must also install air piping from outside to the boiler air
intake adapter. The resultant installation is direct vent (sealed
combustion).
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.
NOTICE
WARNING
WARNING
WARNING
Model Kit Number Equivalent Vent
Length
81 - 211 CVK3003 3 feet
286 CVK3007 3 feet
Table 3D Concentric Vent Kit Equivalent Vent Lengths
Vent, air piping and termination:
The Knight boiler vent and air piping can be installed through
the roof or through a sidewall. Follow the procedures in this
manual for the method chosen. Refer to the information
in this manual to determine acceptable vent and air piping
length.
Optional room air
WARNING When utilizing the single pipe method,
provisions for combustion and ventilation
air must be in accordance with Air for
Combustion and Ventilation, of the latest
edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada, the latest edition
of CGA Standard B149 Installation Code for
Gas Burning Appliances and Equipment, or
applicable provisions of the local building
codes.
• There will be a noticeable increase in the noise level
during normal operation from the inlet air opening.
• Using the room air kit makes the unit vulnerable to
combustion air contamination from within the
building. Please review Section 1, Prevent Combustion
Air Contamination, to ensure proper installation.
• Vent system and terminations must comply with the
standard venting instructions set forth in this manual.
Model Kit Number
81 - 211 KIT30052
286 KIT30053
Table 3E Optional Room Air Kit
DO NOT mix components from different
systems. The vent system could fail,
causing leakage of flue products into the
living space. Use only approved stainless
steel, PVC or CPVC pipe and fittings. For
PVC/CPVC use with primer and cement
specifically designed for the material used.
Commercial applications utilizing the Knight boiler may
be installed with a single pipe carrying the flue products to
the outside while using combustion air from the equipment
room. In order to use the room air venting option the
following conditions and considerations must be followed.
• The unit MUST be installed with the appropriate
room air kit (Table 3E).
• The equipment room MUST be provided with
properly sized openings to assure adequate
combustion air. Please refer to instructions provided
with the room air kit.
NOTICE Optional room air is intended for
commercial applications. Combustion
air piping to the outside is recommended
for residential applications.