Lochinvar KBN399 User manual

Installation & Operation Manual
Models: 399 - 800
This manual must only be used by a
qualified heating installer / service
technician. Read all instructions,
including this manual and the
Knight XL 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.
KBX-I-O Rev D

2
Contents
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 XL -- HOW IT WORKS . . . . . . . . . . . . . . . 4-6
RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1. DETERMINE BOILER LOCATION
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
Removing a Boiler from Existing Common Vent . . . . . . . 11
2. PREPARE BOILER
Remove Boiler from Wood Pallet . . . . . . . . . . . . . . . . . . 12
Gas Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Model 399 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Model 500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Models 600 - 800 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Leveling 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 and Air Piping . . . . . . . . . . . . . . . . . 18
Min./Max. Combustion Air & Vent Piping Lengths . . . . . . 19
Removing from Existing Vent . . . . . . . . . . . . . . . . . . . . . 19
Vent and Air Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall . . . . . . . . . . . . . . . . . . . . 20-23
Determine Location . . . . . . . . . . . . . . . . . . . . . . . . . . 20-21
Prepare Wall Penetrations . . . . . . . . . . . . . . . . . . . . . 22-23
Termination and Fittings . . . . . . . . . . . . . . . . . . . . . . . 23
Multiple Vent/Air Terminations . . . . . . . . . . . . . . . . . . 23
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 Room Air . . . . . . . . . . . . . 29
Vertical Termination - Optional Concentric Vent . . . . . . . 30-31
6. HYDRONIC PIPING
System Water Piping Methods . . . . . . . . . . . . . . . . . . . . 32
Low Water Cutoff Device . . . . . . . . . . . . . . . . . . . . . . . . . 32
Chilled Water System . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
General Piping Information . . . . . . . . . . . . . . . . . . . . . . . 32
Flow Switch and Relief Valve Installation . . . . . . . . . . . . 33
Flow Switch Adjustment . . . . . . . . . . . . . . . . . . . . . . . 33
Circulator Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Near Boiler Piping Connections . . . . . . . . . . . . . . . . . . . 34
Near Boiler Piping Components . . . . . . . . . . . . . . . . . . . 36
7. GAS CONNECTIONS
Connecting Gas Supply Piping . . . . . . . . . . . . . . . . . . . . 39
Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Pipe Sizing for Natural Gas . . . . . . . . . . . . . . . . . . . . 40
Natural Gas Supply Pressure Requirements . . . . . . . 40
Propane Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Pipe Sizing for Propane Gas . . . . . . . . . . . . . . . . . . . 40
Propane Supply Pressure Requirements . . . . . . . . . . 40
Check Inlet Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Gas Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . 42
8. FIELD WIRING
Line Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . . 43
Low Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . . 44
Wiring of the Cascade . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9. CONDENSATE DISPOSAL
Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10. STARTUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-53
11. OPERATING INFORMATION
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Cascade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56-57
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Knight XL Control Module . . . . . . . . . . . . . . . . . . . . . . . . 59-60
Status Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . 61-64
12. MAINTENANCE
Maintenance and Annual Startup . . . . . . . . . . . . . . . . . . 65-69
13. DIAGRAMS
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Ladder Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover

Installation & Operation Manual
Please read before proceeding
Installer – Read all instructions,
including this manual and the Knight XL
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.
• Do not use petroleum-based cleaning or sealing
compounds in the boiler system. Gaskets and seals in
the system may be damaged. This can result in
substantial property damage.
• Do not use “homemade cures” or “boiler patent
medicines”. Serious damage to the boiler, personnel,
and/or property may result.
• Continual fresh make-up water will reduce boiler life.
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger,
and causes failure. Addition of oxygen carried in by
makeup water can cause internal corrosion 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

Installation & Operation Manual
4
The Knight XL - 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. Heat exchanger 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
This sensor monitors the flue gas exit temperature. The control
module will modulate and shut down the boiler if the flue gas
temperature gets too hot. This protects the flue pipe from
overheating.
7. Boiler outlet temperature 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 display
The electronic display consists of 7 buttons and a dual line 32-
character 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)
A 1-1/2" or 2" NPT (depending on the model) water
connection that supplies hot water to the system.
14. Water inlet (system return)
A 1-1/2" or 2" NPT (depending on the model) water
connection that returns water from the system to the heat
exchanger.
15. Gas connection pipe
Threaded pipe connection, either 1" or 1-1/2", 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 Control Module
The SMART Control responds to internal and external signals
and controls the blower, gas valve, and pumps to meet the
heating demand.
17. Automatic 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. Gas shutoff valve
Manual valve used to isolate the gas valve from the gas supply.
28. High limit
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, it will break the control circuit,
shutting the boiler down.
29. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve will be set at 50 PSI.
30. Flame sensor
Used by the control module to detect the presence of burner
flame.
31. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
32. Top panel
Removable panel to gain access to the internal components.
33. Power switch
Turns 120 VAC ON/OFF to the boiler.
34. 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.
35. Air shroud (Model 500 only)
The air shroud controls air and gas flow into the burner.

Installation & Operation Manual
Front View - Model 399
4
5
25
30
23
20
28
13
29
14
8
7
27
36
Left Side (inside unit) - Model 399
19
21
16
1
3
34
17
26
2
37
Right Side (inside unit) - Model 399
The Knight XL - How it works... (continued)
Rear View - Model 399
5
Model 399
10
24
32
18
11
6
15
33
22
31
36. Air pressure switch
The air pressure switch detects blocked flue/inlet conditions.
37. Pump relay board
The pump relay board is used to connect the boiler, system and
DHW pumps.

Installation & Operation Manual
6
The Knight XL - How it works...
18
15
27
Rear View - Model 500
27
15
18
Rear View - Models 600 - 800 Left Side (inside unit) - Models 600 - 800
Left Side (inside unit) - Model 500
Model 500
Models 600 - 800
35
4
5
4

Installation & Operation Manual
Ratings
Notes:
1. The ratings are based on standard test procedures
prescribed by the United States Department of Energy.
2. 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.
3. Knight XL boilers require special gas venting. Use only the
vent materials and methods specified in the Knight XL
Installation and Operation Manual.
4. Standard Knight XL boilers are equipped for operation up
to 4,500 feet with no field adjustments. Output ratings will
be reduced by 4% for each 1,000 feet above sea level up to
4,500 feet only.
5. High altitude Knight XL boilers will have a high altitude
label affixed to the unit (as shown in FIG. A) and are
equipped for operation of 4,501 feet to 12,000 feet only
with no field adjustments. For high altitude models,
output ratings will be reduced by 2% for each 1,000 feet
above sea level.
High altitude models have a different control module for
altitude operation, but the operation given in this manual
for standard models remains the same.
6. Ratings have been confirmed by the Hydronics Institute,
Division of AHRI.
7
Maximum allowed working pressure is located on the rating plate.
NOTICE
Knight XL Boiler
I=B=R Rating
Model Number
Note: Change “N” to
“L” for L.P. gas models.
Input
MBH
(Note 4)
Min Max
Gross
Output
MBH
(Note 1)
Net
I=B=R
Ratings
Water,
MBH
(Note 2)
KBN399 80 399 373 324
KBN500 100 500 467 406
KBN600 120 600 567 493
KBN700 140 700 660 574
KBN800 160 800 752 654
Other Specifications
Boiler
Water
Content
Gallons
Water
Connections
Gas
Connections
Air
Size
Vent
Size
(Note 3)
3.4 1-1/2" 1" 4" 4"
4.2 1-1/2" 1" 4" 4"
4.2 2" 1" 4" 4"
5.0 2" 1" 4" 6"
5.7 2" 1" 4" 6"
Figure A High Altitude Label Location
UNIT EQUIPPED FOR
3,000 FT. TO 12,000 FT.
HIGH ALTITUDE

8
Installation & Operation Manual
The Knight XL 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 XL 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 (37.8°C).
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" (25 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. The vent connection to the
appliance must be made with the starter
CPVC/stainless steel pipe section provided
with the appliance. The field provided PVC
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
171 cubic feet for KBN399 models, 193 cubic feet for KBN500
models, 223 cubic feet for KBN600 models, 247 cubic feet for
KBN700 models and 278 cubic feet for KBN800 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 = 5 feet long, 4 feet wide, and
8 foot ceiling = 5 x 4 x 8 = 160 cubic feet. This would be
considered a closet for a Knight XL Boiler.

9
Installation & Operation Manual
1 Determine boiler location (continued)
12"
(305 MM)
LEFT
13" (330 MM)
TOP
1" (25 MM) MINIMUM CLEARANCE
AROUND HOT WATER
PIPES AND VENT PIPE
14" (356 MM)
REAR
18" (457 MM)
FRONT
0"
RIGHT
OPEN
FRONT
ALCOVE INSTALLATION
Figure 1-2 Alcove Installation - Minimum Required Clearances
6" (152 MM)
13" (330 MM)
TOP
CLOSET INSTALLATION
1" (25 MM) MINIMUM CLEARANCE
AROUND HOT WATER
PIPES AND VENT PIPE
VENTILATING*
AIR OPENING
CLOSED DOOR
VENTILATING*
AIR OPENING
0"
RIGHT
6" (152 MM)
F RONT
14" (356 MM)
REAR
12" (305 MM)
LEFT
*AREA OF EACH OPENING:
1 SQ. INCH PER 1000 BTU PER HOUR INPUT
WITH A MINIMUM OF 100 SQ. INCHES
Figure 1-1 Closet Installation - Minimum Required Clearances
WARNING For closet installations, CPVC or
stainless steel 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.
RECOMMENDED SERVICE CLEARANCES:
Front - 30" (762 mm)
Top - 24" (610 mm)
Left Side - 24" (610 mm)
Rear - 24" (610 mm)
RECOMMENDED SERVICE CLEARANCES:
Front - 30" (762 mm)
Top - 24" (610 mm)
Left Side - 24" (610 mm)
Rear - 24" (610 mm)
WARNING For alcove installations, CPVC or
stainless steel 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 XL alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Knight XL 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 XL 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 XL.
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 XL 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 XL 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 XL requires a special vent system, designed for
pressurized venting.
You must also install air piping from outside to the boiler air
intake adapter. The resultant installation is direct vent (sealed
combustion). 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. You may
use any of the vent/air piping methods covered in this
manual. Do not attempt to install the Knight XL 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 XL 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 When removing a boiler from existing
common vent system:
Do not install the Knight XL 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.
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.
DANGER
WARNING
1 Determine boiler location (continued)

Installation & Operation Manual
12
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.
For the 399 Model you must install a propane
orifice to operate the Knight XL on propane
gas. Verify when installing that the orifice size
marking matches boiler size (Model 399 - 8.0
LP orifice stamping).
Models 500 - 800 do not require an orifice
installation for propane operation, but they
will require a valve adjustment.
Figure 2-1 Boiler Mounted on Shipping Pallet
Gas conversions
NOTICE
WARNING
BLOWER
O-RING VENTURI
SCREWS
QTY. 3
GAS VALVE
BRASS ORIFICE
O-RING
SCREWS
QTY. 4
Figure 2-2 Installing Propane Orifice - Model 399
Model 399
1. Remove the top and front access covers from the unit (no
tools required for removal).
2. Remove the three screws securing the venturi to the blower.
Note: When separating the venturi from the blower, take
care not to damage the O-ring inside the blower (FIG. 2-2).
3. Remove the four star-drive screws securing the gas valve to
the venturi (FIG. 2-2).
4. Locate the propane orifice disk from the conversion kit bag.
Verify that the stamping on the orifice disk matches the
boiler size (Model 399 - 8.0 LP orifice stamping).
5. Remove the existing orifice from the O-ring in the side of the
gas valve and replace it with the orifice from the kit. Position
and secure the orifice in the valve as shown in FIG. 2-2.
6. Reposition the gas valve against the venturi and replace the
star-drive screws (FIG. 2-2) securing the valve to the venturi.
7. Inspect the O-ring inside the blower. Handle the O-ring
with care, do not damage. Reposition the venturi against the
blower and replace the screws securing the venturi to the
blower (FIG. 2-2).
8. 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.
9. Replace the top and front access covers.
DANGER Model 399: Inspect the O-ring when the
blower is disassembled. The O-ring must be
in good condition and must be installed.
Failure to comply will cause a gas leak,
resulting in severe personal injury or death.
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.
2 Prepare boiler

SCREWDRIVER
SLOT
LOWER
RAISE
Figure 2-5 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. 2-5
below.
ALLEN WRENCH
ADJUSTMENT SCREW
Figure 2-3 Gas Valve Adjustment - Model 500
Model 500
1. Remove the top access cover from the unit (no tools
required for removal).
2. Turn the adjustment screw on the gas valve clockwise until
it stops. Then turn the adjustment screw counterclockwise
four and three quarter (4 3/4) turns (see FIG. 2-3).
3. Use a combustion analyzer to verify CO2is within the range
of 9.6 – 10.5%. If not, adjust the screw counterclockwise
incrementally to raise CO2and clockwise to lower CO2
(FIG. 2-3).
4. After adjustment 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.
5. Replace the top access cover.
COVER
A
LLEN WRENCH
ADJUSTMENT SCREW
Figure 2-4 Gas Valve Adjustment - Models 600 - 800
Models 600 - 800
1. Remove the top access cover from the unit (no tools
required for removal).
2. Remove the cover on top of the gas valve (FIG. 2-4).
3. Turn the adjustment screw on top of the gas valve clockwise
one and three quarter (1 3/4) turns on the 600 Model, one
and a half (1 1/2) turns on the 700 Model, and one turn on
the 800 Model (see FIG. 2-4).
4. Use a combustion analyzer to verify CO2is within the range
of 9.6 – 10.5%. If not, adjust the screw counterclockwise
incrementally to raise CO2and clockwise to lower CO2
(FIG. 2-4).
5. After adjustment 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 gas valve cover along with the top access cover.
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 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.
2 Prepare boiler (continued)
Installation & Operation Manual
13

14
Installation & Operation Manual
PVC/CPVC Two Pipe
See Figure 4-1A
Models 399 - 600 Only
PVC/CPVC Alternate
Two Pipe
See Figure 4-2A
Stainless Steel
Alternate Two Pipe
See Figure 4-2B
Stainless Steel
Two Pipe
See Figure 4-1C
Models 399 - 600 Only
PVC/CPVC Concentric
See Figure 4-7
Models 399 - 600 Only
Direct venting options - Sidewall Vent
3 General venting

15
Installation & Operation Manual
Direct venting options - Vertical Vent Optional Room Air
3 General venting (continued)
Direct venting options - Vertical Vent
PVC/CPVC
Two Pipe
See Figure 5-1A
Stainless Steel
Two Pipe
See Figure 5-1B
PVC/CPVC
Concentric
See Figure 5-5
PVC/CPVC
Room Air
See Figure 5-4
Stainless Steel
Room Air
See Figure 5-4

3 General venting
PVC/CPVC vent piping materials
Use only the materials listed in Table 3A
below 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.
Table 3A PVC, Vent Pipe, and Fittings
Install vent and combustion air piping
DANGER The Knight XL 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).
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. 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.
WARNING
NOTICE
WARNING
WARNING For closet and alcove installations, CPVC
material MUST BE used in a closet/alcove
structure. Failure to follow this warning
could result in fire, personal injury, or death.
NOTICE
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 ANSI/ASTM F441
Pipe cement/primer PVC ANSI/ASTM D2564 IPEX System 636
Cements & Primers
CPVC ANSI/ASTM F493
NOTICE: DO NOT USE CELLULAR (FOAM) CORE PIPE
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.
16
Installation & Operation Manual

17
Installation & Operation Manual
3 General venting (continued)
Combustion air piping to the outside MUST
BE used. Use of combustion air from the
room via louvers, plenums, or any other
device is not authorized.
NOTICE
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. Transition fittings are provided
with 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.
6” COUPLING
(FIELD SUPPLIED)
6” CPVC
STARTER
PIECE
(FACTORY SUPPLIED)
VENT
AIR
BOTH THE 6” STAINLESS STEEL ADAPTER
AND THE 6” CPVC STARTER PIECE
SUPPLIED WITH THE BOILER MUST BE
USED FOR VENT CONNECTION TO PVC/CPVC
Figure 3-10 Near Boiler PVC/CPVC Venting -
Models 700 - 800
VENT
AIR
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.
*
* 4” CPVC STREET ELBOW
MAY BE SUBSTITUTED
Figure 3-9 Near Boiler PVC/CPVC Venting - Models 399 - 600
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.
*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.

Installation & Operation Manual
18
3 General venting
Stainless steel air intake/vent
connections
1. Combustion Air Intake Connector (FIG.’s 3-11 and
3-12) - 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 3-11 and 3-12) - 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.
4” PVC TO 4” STAINLESS
STEEL ADAPTER
Figure 3-12 Near Boiler Stainless Steel Venting
Models 700 - 800
VENT
AIR
4” PVC TO 4” STAINLESS
STEEL ADAPTER
Figure 3-11 Near Boiler Stainless Steel Venting
Models 399 - 600
Stainless steel vent
This product has been approved for use with stainless steel FasNseal
vent systems manufactured by Protech.
Use only the materials, vent systems, and
terminations listed in Table 3B. DO NOT mix
vent systems. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
WARNING
Installations must comply with 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 installation instructions supplied
with the vent system.
NOTICE
The installer must use a specific vent starter
adapter supplied by the vent manufacturer to
adapt to different vent systems. See Table 3B for
approved vent adapters.
NOTICE
Model Description Lochinvar
Part Number
Vendor and Part
Number
399 - 600
4" SS Adapter** (2) MSC2761 FasNseal - F303759
4" Flue Termination** MSC2198 FasNseal - FSBS4
4" Air Intake
Termination** MSC2764 FasNseal - FSAIH04
700 - 800
4" SS Adapter** MSC2761 FasNseal - F303759
4" Air Intake
Termination** MSC2764 FasNseal - FSAIH04
6" Flue Termination** MSC2763 FasNseal - FSBS6
*Note: Part is supplied with the unit.
**Note: Part is supplied in the Kit.
Table 3B Approved Stainless Steel Terminations and Adapters
Table 3C Stainless Steel Vent Termination Kits
Model Kit Number
399 - 600 KIT3136
700 - 800 KIT3137
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
Model Kit Number Equivalent
Vent Length
399 CVK3007 5 Feet (1.5 m)
500 CVK3007 30 Feet (9 m)
600 CVK3007 30 Feet (9 m)
3 General venting (continued)
Vent, air piping and termination:
The Knight XL 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.
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 products permanently.
—OR—
• Relocate air inlet and vent
terminations to other areas.
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 XL using any
other means.
DO NOT mix components from different
systems. The vent system could fail, causing
leakage of flue products into the living
space. Use only PVC or CPVC pipe and
fittings, with primer and cement specifically
designed for the material used.
NOTICE
WARNING
WARNING
WARNING
Table 3E Concentric Vent Kit Equivalent Vent Lengths
The appliance output rating will reduce by
up to 1.5% for each 25 feet (68 m) of vent
length.
NOTICE
Minimum / Maximum allowable
combustion air and vent piping lengths are
as follows:
Combustion Air = 12 equivalent feet (3.7 m) minimum / 100
equivalent feet (30.5 m) maximum
Ve n t = 12 equivalent feet (3.7 m) minimum / 100 equivalent
feet (30.5 m) maximum
When determining equivalent combustion air and vent length,
add 5 feet (1.5m) for each 90° elbow and 3 feet (.9 m) for each
45° elbow.
EXAMPLE: 20 feet (6 m) of PVC pipe + (3) 90° elbows + (3)
45° elbows + (1) concentric vent kit (CVK3007) = 49 equivalent
feet (15 m) of piping.
Model Air Intake Vent
399 - 600 4 inches (102 mm) 4 inches (102 mm)
700 - 800 4 inches (102 mm) 6 inches (152 mm)
The Knight XL uses model specific combustion air intake and
vent piping sizes as detailed in Table 3D below.
Table 3D Air Intake/Vent Piping Sizes
Increasing or decreasing combustion air or
vent piping is not authorized.
NOTICE

Installation & Operation Manual
20
4 Sidewall direct venting
Vent/air termination – sidewall
Follow instructions below when determining
vent location to avoid possibility of severe
personal injury, death, or substantial
property damage.
A gas vent extending through an exterior wall
shall not terminate adjacent to a wall or
below building extensions such as eaves,
parapets, balconies, or decks. 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.
WARNING
WARNING
NOTICE
WARNING Do not connect any other appliance to the
vent pipe or multiple boilers to a common
vent pipe. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
Determine location
Locate the vent/air terminations using the following guidelines:
1. The total length of piping for vent or air must not exceed the
limits given in the General Venting Section on page 19 of
this manual.
2. You must consider the surroundings when terminating the
vent and air:
a. Position the vent termination where vapors will
not damage nearby shrubs, plants or air
conditioning equipment or be objectionable.
b. The flue products will form a noticeable plume as
they condense in cold air. Avoid areas where the
plume could obstruct window views.
c. Prevailing winds could cause freezing of
condensate and water/ice buildup where flue
products impinge on building surfaces or plants.
d. Avoid possibility of accidental contact of flue
products with people or pets.
e. Do not locate the terminations where wind eddies
could affect performance or cause recirculation,
such as inside building corners, near adjacent
buildings or surfaces, window wells, stairwells,
alcoves, courtyards, or other recessed areas.
WARNING Sidewall vent and air inlet terminations
must terminate in the same pressure zone.
f. Do not terminate above any door or window.
Condensate can freeze, causing ice formations.
g. Locate or guard vent to prevent condensate damage
to exterior finishes.
TO BOILER
INTAKE AIR
CONNECTION
FROM BOILER
VENT PIPE
CONNECTION
VENT / AIR
TERMINATION
GRADE OR
SNOW LINE
12"
MIN
12"
MIN
TO
OVER-
HANG
POSSIBLE ORIENTATIONS
Figure 4-1A PVC/CPVC Sidewall Termination of Air and
Vent
Model Kit Number Vent Size
399 - 600 KIT30046 4 inch vent
700 - 800 KIT30048 6 inch vent
Table 4A Sidewall Vent Kits
Do not exceed the maximum lengths of the
outside vent piping shown in FIG. 4-1B.
Excessive length exposed to the outside could
cause freezing of condensate in the vent pipe,
resulting in potential boiler shutdown.
WARNING
If using the alternate sidewall termination:
3. The air piping must terminate in a down-turned elbow as
shown in FIG. 4-1B. This arrangement avoids recirculation
of flue products into the combustion air stream.
4. The vent piping must terminate in an elbow pointed
outward or away from the air inlet, as shown in FIG. 4-1B.
Figure 4-1B Alternate PVC/CPVC Sidewall Termination
of Air and Vent w/Field Supplied Fittings