Lochinvar KNIGHT 51 User manual

WBII-I-O Rev C
Installation & Operation Manual
Models: 51 - 211
This manual must only be used by a
qualified heating installer / service
technician. Read all instructions,
including this manual and the Knight
Wall Mount 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 WALL MOUNT BOILER--HOW IT WORKS . . . 4-5
RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1. DETERMINE BOILER LOCATION
Provide Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Provide Air Openings to Room . . . . . . . . . . . . . . . . . . . . . 9
Wall Mounting Location . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Residential Garage Installation . . . . . . . . . . . . . . . . . . . . . 9
Vent and Air Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Prevent Combustion Air Contamination . . . . . . . . . . . . . . . 9
Corrosive Contaminants and Sources . . . . . . . . . . . . . . . 10
Using an Existing Vent System to Install a New Boiler . . 10
Removing a Boiler from Existing Common Vent . . . . . . . 11
2. PREPARE BOILER
Remove Boiler from Wood Pallet . . . . . . . . . . . . . . . . . . 12
Gas Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Mounting the Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3. GENERAL VENTING
Direct Venting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-15
Install Vent and Combustion Air Piping . . . . . . . . . . . . . . 16
PVC/CPVC Vent Piping Materials . . . . . . . . . . . . . . . 16
Requirements for Installation in Canada . . . . . . . . . . . . . 16
PVC/CPVC Air Intake/Vent Connections . . . . . . . . . . . . . 17
Air Inlet Pipe Materials . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Stainless Steel Vent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Max. Allowable Vent Piping Lengths . . . . . . . . . . . . . . . . 19
Vent and Air Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Optional Room Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall . . . . . . . . . . . . . . . . . . . . 21-24
Determine Location . . . . . . . . . . . . . . . . . . . . . . . . . . 21-22
Prepare Wall Penetrations . . . . . . . . . . . . . . . . . . . . . 23
Termination and Fittings . . . . . . . . . . . . . . . . . . . . . . . 23
Multiple Vent/Air Terminations . . . . . . . . . . . . . . . . . . . . . 23-24
Sidewall Termination - Optional Concentric Vent . . . . . . 24-26
5. VERTICAL DIRECT VENTING
Vent/Air Termination - Vertical . . . . . . . . . . . . . . . . . . . . . 27-28
Determine Location . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Prepare Roof Penetrations . . . . . . . . . . . . . . . . . . . . . 28
Termination and Fittings . . . . . . . . . . . . . . . . . . . . . . . . . 28
Multiple Vent/Air Terminations . . . . . . . . . . . . . . . . . . . . . 28
Vertical Termination - Optional Concentric Vent . . . . . . . 29-30
Optional Vertical Concentric Venting . . . . . . . . . . . . . . . . 31-32
6. HYDRONIC PIPING
System Water Piping Methods . . . . . . . . . . . . . . . . . . . . 33
Low Water Cutoff Device . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chilled Water System . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
General Piping Information . . . . . . . . . . . . . . . . . . . . . . . 33
Near Boiler Piping Components . . . . . . . . . . . . . . . . . . . 34
Near Boiler Piping Connections . . . . . . . . . . . . . . . . . . . 35
Circulator Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Variable Speed Pump Option . . . . . . . . . . . . . . . . . . . . . 37
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 Wall Mount Boiler Control Module . . . . . . . . . . . . 67
Status Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . 68-70
12. MAINTENANCE
Maintenance and Annual Startup . . . . . . . . . . . . . . . . . . 71-74
13. DIAGRAMS
Ladder Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover
Contents

Installation & Operation Manual
Please read before proceeding
Installer – Read all instructions,
including this manual and the Knight
Wall Mount 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 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.
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.
3
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 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.

Installation & Operation Manual
4
The Knight Wall Mount 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 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)
The water outlet is the water connection for water leaving the
boiler and entering the system. Boiler connection is 1".
14. Water inlet (system return)
The water inlet is the water connection for water entering the
boiler from the system. Boiler connection is 1".
15. Gas connection pipe
Threaded pipe connection of 1/2". 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. Air intake adapter
Allows for the connection of the PVC air intake pipe to
the boiler.
18. High voltage junction box
The junction box contains the connection points for the line
voltage power and all pumps.
19. Manual air vent
Designed to remove trapped air from the heat exchanger
coils.
20. Low voltage connection board
The connection board is used to connect external low voltage
devices.
21. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage
connection board.
22. Condensate drain connection
Connects the condensate drain line to a 1/2" pipe.
23. Access door
Provides access to all internal components.
24. Ignition electrode
Provides direct spark for igniting the burner.
25. Flame inspection window
The quartz glass window provides a view of the burner
surface and flame.
26. Gas shutoff switch
An electrical switch designed to cut power to the gas valve to
prevent releasing any gas.
27. High limit sensor (housed with outlet sensor)
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, it will break the control circuit,
shutting the boiler down.
28. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 30 psi.
29. Flame sensor
Used by the control module to detect the presence of burner
flame.
30. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
31. Air pressure switch
The air pressure switch detects blocked inlet conditions.
32. Transformer
The transformer provides 24V power to the integrated control.

Installation & Operation Manual
11
17
19
23
10
28
Front View
16
32
20
29
31
3
13
14
7
27
8
6
Left Side (inside unit)
2
25
24
5
4
26
22
18
1
Right Side (inside unit)
The Knight Wall Mount Boiler - How it works... (continued)
FRONT
OF UNIT
14
13
30
21
15
22
Bottom View
5
Models 51 - 211

6
Installation & Operation Manual
Ratings
Notes:
1. As an Energy Star Partner, Lochinvar has determined that
Knight wall mount 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 wall mount boilers require special gas venting. Use
only the vent materials and methods specified in the Knight
Wall Mount Installation and Operation Manual.
5. Standard Knight wall mount 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 wall mount 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.
Maximum allowed working pressure is located on the rating plate.
NOTICE
Knight Wall Mount Boiler
I=B=R Rating
Model
Number
Note: Change
“N” to “L” for L.P.
gas models.
Input
MBH
(Note 5)
Min Max
Heating
Capacity
MBH
(Note 2, 8
Net
I=B=R
Ratings
Water,
MBH
(Note 3, 8)
AFUE
%
(Note 1, 8)
WBN051 10 50 45 39 95.3
WBN081 16 80 72 63 95.3
WBN106 21 105 94 82 95.4
WBN151 30 150 135 119 95.5
WBN211 42 210 190 165 95.7
7. The Knight Wall Mount boiler input rate, on some
models, is reduced for vent lengths beyond the
minimum. Models WB(N,L)081 and WB(N,L)106 with
2" vent will reduce 1% for every 10 feet of vent. Models
WB(N,L)151 and WB(N,L)211 with 3" vent will reduce
0.5% for every 10 feet of vent.
8. Ratings have been confirmed by the Hydronics Institute,
Section of AHRI.
9. Knight wall mount 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.
Other Specifications
Boiler Water
Content
Gallons
Water
Connections
Gas
Connections
Vent/Air Size
(Note 4)
0.6 1" 1/2" 2"
0.6 1" 1/2" 2"
0.7 1" 1/2" 2"
1.3 1" 1/2" 3"
1.7 1" 1/2" 3"
Figure A High Altitude Label Location
UNIT EQUIPPED FOR
HIGH ALTITUDE
3,000 FT. TO 12,000 FT.

The Knight wall mount 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 wall mount 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" from combustible materials.
2. Vent pipe – at least 1" from combustible materials.
3. See FIG.’s 1-1 and 1-2 on page 8 for other clearance
minimums.
Clearances for service access
1. See FIG.’s 1-1 and 1-2 on page 8 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. The vent connection to the
appliance is made of CPVC. Field supplied
vent fittings must be cemented to the
CPVC fitting on the boiler. Use only the
vent materials, primer, and cement
specified in the 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 two ventilating
air openings shown in FIG. 1-1 are
required for this arrangement. Failure to
follow this warning could result in fire,
personal injury, or death.
WARNING
WARNING
NOTICE
WARNING
A closet is any room the boiler is installed in which is less than
79 cubic feet for WBN051 through WBN106 models,
104 cubic feet for WBN151 models, and 125 cubic feet for
WBN211 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, 4 feet wide, and
9 foot ceiling = 4 x 4 x 9 = 144 cubic feet. This would be
considered a closet for a Knight wall mount boiler.
7
1 Determine boiler location
Installation & Operation Manual

TOP
6" MINIMUM
LEFT
24" SERVICE
0" MINIMUM
FRONT
24" SERVICE
6" MINIMUM
BOTTOM
24" SERVICE
0" MINIMUM
1" MINIMUM CLEARANCE
AROUND HOT WATER PIPES
1" MINIMUM CLEARANCE
A
ROUND VENT PIPE OPEN FRONT
RIGHT
0" MINIMUM
Figure 1-2 Alcove Installation - Minimum Required Clearances
TOP
6" MINIMUM
LEFT
24" SERVICE
0" MINIMUM
BOTTOM
24" SERVICE
0" MINIMUM
1" MINIMUM CLEARANCE
AROUND HOT WATER PIPES
1" MINIMUM CLEARANCE
A
ROUND VENT PIPE CLOSED DOOR
FRONT
24" SERVICE
6" MINIMUM
6"
6"
VENTILATING
AIR OPENING*
*AREAOF EACH OPENING:
1 SQ. INCH PER 1000 BTU PER HOUR INPUT
WITH A MINIMUM OF 100 SQ. INCHES.
VENTILATING
AIR OPENING*
RIGHT
0" MINIMUM
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.
Note: Service clearances are recommendations only.
Note: Service clearances are recommendations only.
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.
8
1 Determine boiler location
Installation & Operation Manual

Provide air openings to room:
Knight wall mount boiler alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Knight wall mount
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 wall mount 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
wall mount 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 wall mount boiler because it
takes its combustion air from outside (direct vent
installation).
Wall mounting location
Ensure the wall for which the boiler is intended to be
mounted is comprised of either, cement, brick, block, or
wooden studs spaced 16" apart from center. Ensure the wall
is capable of supporting at least 200 pounds.
If flooding is possible, elevate the boiler sufficiently to
prevent water from reaching the boiler.
Ensure the boiler is installed in a location that minimizes
the risk of water damage due to valves, pumps, etc.
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 wall mount 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 wall mount 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 wall mount 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 10 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 10. 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
1 Determine boiler location (continued)
9
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
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 11.
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.
10
1 Determine boiler location
Installation & Operation Manual

When removing a boiler from existing
common vent system:
Do not install the Knight wall mount 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.
11
1 Determine boiler location
Installation & Operation Manual

Installation & Operation Manual
2 Prepare boiler
12
Remove boiler from wood pallet
1. After removing the outer shipping carton from the boiler,
remove the parts box.
2. To remove the boiler from the pallet:
a. Remove the two (2) lag bolts securing the bottom
of the unit to the pallet.
b. Lift the boiler off the wall bracket mounted to
the pallet.
3. Remove the two (2) lag bolts securing the wall bracket to
the wood pallet. Be certain not to lose the wall bracket as
it will be needed for securing the boiler to the wall
(FIG. 2-1).
Do not drop the boiler or bump the jacket
on the floor or pallet. Damage to the
boiler can result.
The gas conversion procedure should be
accomplished BEFORE the boiler is
installed. For a boiler already installed,
you must turn off gas supply, turn off
power, and allow the 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.
You must install the propane orifice to fire
the Knight wall mount boiler on propane.
Verify when installing that the orifice size
marking matches boiler size (Table 2A).
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
1. Remove the front access cover from the unit (no tools
required for removal).
2. Disconnect the ribbon cable from the control board.
Remove the four (4) screws securing the bezel to the front of
the unit and remove the bezel.
3. Locate the power switch on the gas valve and turn the power
switch to the “OFF” position (FIG. 2-2).
4. Disconnect the Molex plug from the wiring connector
located on the gas valve.
5. Using a 5/16" nut driver, loosen the band clamp securing the
air intake coupler to the gas valve venturi. Remove the air
intake pipe and coupler from the gas valve venturi.
6. Using a 4mm Allen wrench, remove the two (2) screws
securing the gas valve venturi to the inlet of the combustion
blower (FIG. 2-2). Remove the gas valve venturi assembly
from the unit.
DO NOT DISCARD-
WILL BE NEEDED TO
SECURE THE BOILER
TO THE WALL
REMOVE SHIPPING
[WALL] BRACKET
Figure 2-1 Boiler Mounted on Shipping Pallet
Gas conversions
LP Conversion Table
Model LP Orifice Stamping
51 50
81 80
106 105
151 210 / W150
211 210 / W150
NOTICE
WARNING
Table 2A LP Conversion Table
Figure 2-2 Gas Valve Power Switch & Venturi Removal
DETAIL
POWER SWITCH
REMOVE THE TWO (2) SCREWS
SECURING THE GAS VALVE VENTURI
TO THE INLET OF THE COMBUSTION BLOWER
7. Using a 4mm Allen wrench, remove the four (4) screws
securing the gas valve to the venturi (FIG. 2-3).
8. Locate the propane orifice disk from the conversion kit bag.
Verify that the stamping on the orifice disk matches the
boiler size (51 - 211, see Table 2A).
9. Place the orifice into the black rubber grommet in the side of
the gas valve and secure inside the gas valve (see FIG. 2-3).
10. Reposition the gas valve against the venturi and replace the
four (4) screws removed in Step 7, securing the valve to the
venturi (FIG. 2-3).
11. Reposition the gas valve venturi assembly inside the unit.
Secure the gas valve venturi to the combustion blower by
replacing the two (2) screws removed in Step 6 (FIG. 2-2).
12. Reattach the air intake pipe and coupler to the gas valve
venturi. Tighten the band clamp to secure.

Installation & Operation Manual
13
2 Prepare boiler (continued)
FASTENERS
APPROPRIATE
FOR WALL TYPE
QTY: 4
MOUNTING BRACKET
(FACTORY SUPPLIED)
WALL:
WOOD OR METAL STUDS ON
16" CENTERS
-OR-
MASONRY / POURED CONCRETE
Figure 2-4 Mounting the Boiler
Figure 2-3 Installing Propane Orifice
13. Reattach the wiring connector to the gas valve. Tighten
the screw on the wiring connector to secure to the gas
valve.
14. Turn the gas valve power switch to the “ON” position.
15. Reattach the bezel to the unit. Reconnect the ribbon cable
to the control board.
16. After installation is complete, fill out the gas conversion
label (in the conversion kit bag) and affix it to the unit
under the boiler rating plate inside the unit. Attach the LP
caution label (in the conversion kit bag) to the left side of
the unit in the lower left corner.
17. Replace the front access cover.
2. Mount the wall bracket using the 2 1/4" lag bolts
provided. Make sure the top edge of the bracket is away
from the wall. Ensure the bracket is level when mounted.
Extreme care is needed to ensure the bolts are secured in
the center of the studs.
3. Hang the boiler on the bracket and secure the bottom of
the boiler with two (2) additional lag bolts provided.
Mounting to a metal studded wall:
1. The wall mount bracket is designed for a stud spacing of
16 inches from center. For other stud spacing a solid
mounting surface must be provided by the installer.
WARNING The boiler is too heavy for a single person to
lift. A minimum of two people is needed for
mounting the boiler onto the bracket.
2. Mount the wall bracket using two (2) field supplied toggle
bolts capable of supporting 100 pounds each. Ensure the
top edge of the bracket is away from the wall. Ensure the
bracket is level when mounted. Extreme care is needed to
ensure the bolts are secured in the center of the studs.
3. Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) field supplied toggle bolts.
WARNING Do not mount the boiler to a hollow wall. Be
sure to mount the boiler to the studs only.
Mounting the boiler
See page 9 of this manual for boiler mounting location
instructions.
NOTICE The Knight Wall Mount boiler is not
intended for floor installation.
Mounting to a wood studded wall:
1. The wall mount bracket is designed for a stud spacing of
16 inches from center. For other stud spacing a solid
mounting surface must be provided by the installer.
WARNING Do not mount the boiler to a hollow wall.
Be sure to mount the boiler to the studs
only.
Mounting to a concrete wall:
1. Mount the wall bracket using the two (2) wedge anchor
bolts provided with the bracket. To mount the wedge
anchor bolts, drill a 1/4" diameter hole 1 1/8" deep and
insert anchor. Hang the bracket from the anchor and secure
with the two nuts provided. Make sure the top edge of the
bracket is away from the wall. Ensure bracket is level when
mounted. Extreme care is needed to ensure the bolts are
secured in the center of the studs.
Note: If wall thickness does not allow a 1 1/8" deep hole, field
supplied hardware suitable for the application should be
provided.
2. Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) remaining anchors, following the
instructions above.
WARNING The boiler is too heavy for a single person to
lift. A minimum of two people is needed for
mounting the boiler onto the bracket.
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.
WARNING The boiler is too heavy for a single person to
lift. A minimum of two people is needed for
mounting the boiler onto the bracket.

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 24 for more details
Direct venting options - Sidewall Vent
Figure 3-2 Stainless Steel Two-Pipe Sidewall
Termination - See page 22 for more details
14
Installation & Operation Manual

Figure 3-4 PVC/CPVC Two-Pipe
Vertical Termination - See page 27
for more details
Figure 3-5 Stainless Steel Two-Pipe
Vertical Termination - See page 27
for more details
Figure 3-7 PVC/CPVC Vertical Vent, Sidewall Air Figure 3-8 Stainless Steel Vertical Vent, Sidewall Air
Direct venting options - Vertical Vent
Direct venting options - Vertical Vent, Sidewall Air
Stainless steel vent/air design and terminations will vary slightly by manufacturer.
NOTICE
Figure 3-6 PVC/CPVC Concentric
Vertical Termination - See page 29
for more details
15
3 General venting (continued)
Installation & Operation Manual

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 wall mount 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.
4. The 2" and 3" Concentric Vent Kits available from
Lochinvar (see Section 4 – Sidewall Termination – Optional
Concentric Vent) and the 2" and 3" Concentric Vent Kits
available from IPEX are approved for use on the Knight
wall mount boiler. Both kits are listed to the ULC-S636
standard for use in Canada.
For models 50 - 105 when transitioning
from 2 to 3 inch vent diameter, a 2" pipe
section and 2" to 3" increaser are required
to be CPVC when PVC/CPVC vent is used.
For installations using 2" vent, the first
seven (7) equivalent feet of vent must be
CPVC (field supplied). See examples below.
WARNING
Examples: 1. Seven (7) feet vertical
2. Connector + 90° elbow + 2 feet horizontal
3. One (1) foot vertical + 90° elbow + 1 foot
horizontal
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 18) 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.)
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.

3 General venting (continued)
Table 3A Vent Pipe, and Fittings
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.
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.
PVC/CPVC air intake/vent connections
1. Combustion Air Intake Connector (FIG. 3-9) - 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. 3-9) - 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.
VENT
AIR
Figure 3-9 Near Boiler PVC/CPVC 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.
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 schedule 40 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-DWV ANSI/ASTM D2665
CPVC schedule 40/80 ANSI/ASTM F441
AL29-4C UL1738 ULC-S636
Pipe cement/primer PVC ANSI/ASTM D2564 IPEX System 636
Cements & Primers
CPVC ANSI/ASTM F493
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
17
*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.
Installation & Operation Manual

18
Installation & Operation Manual
3 General venting
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.
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.
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
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
51 - 211
300716
(Vent)
300715
(Intake Air)
FSBS3
FSRC3(R.C) 303889
WB50210
(Vent)
KB80210
(Intake Air)
9353BUREZ-1* 9392
5300CI 9314TERM
2SVSLPVC3
(Vent)
2SVSLA03
(Intake Air)
2SVSTP03
2SVSRCX03 2SVSTEX0390
* = This adapter must be used in addition to the boiler adapter for Saf-T vent pipe as shown in FIG. 3-10, unless approved vent
other than standard diameter is used. Consult a Heat Fab representative for questions.
**The stainless steel venting option is only available in 3" vent diameters.
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.

3 General venting (continued)
Removing from existing vent
Follow the instructions in Section 1, page 11 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 wall mount boiler
using any other means.
NOTICE
WARNING
VENT
3" S.S. INTERMEDIATE
(FOR SAF-T VENT ONLY)
3" S.S. ADAPTER
Figure 3-10 Near Boiler Stainless Steel Venting
Stainless steel air intake/vent
connections
1. Combustion Air Intake Connector (FIG. 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. 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.
Maximum allowable combustion air and
vent piping lengths are as follows:
Model 2" Max Vent/Air 3" Max Vent/Air
51 40 feet 100 feet
81 40 feet 100 feet
106 40 feet 100 feet
151 N/A 100 feet
211 N/A 100 feet
Increasing or decreasing the size of the
combustion air or vent piping beyond the
sizes listed in Table 3C is not authorized.
NOTICE
When determining equivalent combustion air and vent length,
add 5 feet for each 90° elbow, 3 feet for each 45° elbow, and 3 feet
for the concentric vent kit, see example below.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit = 49 equivalent feet of piping.
Table 3C Maximum Combustion Air and Vent Piping
Lengths
Note: The minimum combustion air and vent piping length is
12 equivalent feet.
For 2" vent / air lengths greater than 40 feet,
consult the factory.
NOTICE
The Knight wall mount boiler uses model specific
combustion air intake and vent piping sizes as detailed in
Table 3C below.
Vent, air piping and termination:
The Knight wall mount 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.
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.
19
Installation & Operation Manual

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.
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 10 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.
WARNING
WARNING
Optional room air
Commercial applications utilizing the Knight wall mount
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 3D).
• 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.
• 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.
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.
Model Kit Number
51 - 211 KIT30051
Table 3D Optional Room Air Kit
NOTICE Optional room air is intended for
commercial applications. Combustion air
piping to the outside is recommended for
residential applications.
Please read the information given in Table 1A, page 10, 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.
20
3 General venting
Installation & Operation Manual