Lochinvar KNIGHT 400 - 801 User manual

Installation & Operation Manual
Models: 400 - 801
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.
KBXII-I-O Rev H

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
Using an Existing Vent System to Install a New Boiler ... 11
Removing a Boiler from Existing Common Vent.............. 12
2. PREPARE BOILER
Remove Boiler from Wood Pallet..................................... 13
Gas Conversions.............................................................. 13
Model 400................................................................... 13
Model 501................................................................... 14
Models 601 - 801........................................................ 14
Leveling the Boiler............................................................ 14
3. GENERAL VENTING
Direct Venting Options..................................................... 15
Install Vent and Combustion Air Piping ........................... 16
Requirements for Installation in Canada.......................... 17
Sizing ............................................................................... 17
Min./Max. Combustion Air & Vent Piping Lengths............17
Materials............................................................................18
Optional Room Air............................................................ 19
PVC/CPVC.................................................................. 19-20
Polypropylene................................................................... 21
Stainless Steel Vent......................................................... 22
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall................................... 23-26
Determine Location................................................ 23-25
Prepare Wall Penetrations..................................... 25-26
Multiple Vent/Air Terminations......................................... 26
Sidewall Termination - Optional Concentric Vent....... 27-29
5. VERTICAL DIRECT VENTING
Vent/Air Termination - Vertical.................................... 30-31
Determine Location..................................................... 30
Prepare Roof Penetrations......................................... 31
Multiple Vent/Air Terminations......................................... 31
Vertical Termination - Optional Concentric Vent......... 32-33
Alternate Vertical Concentric Venting......................... 34-35
6. HYDRONIC PIPING
System Water Piping Methods......................................... 36
Low Water Cutoff Device................................................. 36
Chilled Water System....................................................... 36
Freeze Protection............................................................. 36
General Piping Information .............................................. 36
Flow Switch and Relief Valve Installation ....................... 37
Flow Switch Adjustment.............................................. 38
Near Boiler Piping Components.................................. 38-39
Circulator Sizing............................................................... 39
Near Boiler Piping Connections....................................... 39
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 XL Control Module........................................... 67-68
Status Display Screens............................................... 69-71
12. MAINTENANCE
Maintenance and Annual Startup................................ 72-76
13. DIAGRAMS
Wiring Diagram........................................................... 77
Ladder Diagram......................................................... 78
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.
• 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.

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. 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 the
flue gas temperature gets too hot. This protects the flue pipe from
overheating.
7. Boiler outlet temperature sensor (housed with the
high limit sensor)
This sensor monitors boiler outlet water temperature (system
supply). If selected as the controlling sensor, the control
module adjusts boiler firing rate so the outlet temperature is
correct.
8. Boiler inlet temperature sensor
This sensor monitors return water temperature (system
return). If selected as the controlling sensor, the control
module adjusts the boiler firing rate so the inlet temperature is
correct.
9. Temperature and pressure gauge (field installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
10. Electronic LCD display
The electronic display consists of 4 buttons, a navigation dial
and a multiple line liquid crystal display.
11. Flue pipe adapter
Allows for the connection of the PVC vent pipe system to the
boiler.
12. Burner (not shown)
Made with metal fiber and stainless steel construction, the
burner uses pre-mixed air and gas and provides a wide range of
firing rates.
13. Water outlet (system supply)
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 of 1". This pipe should be connected
to the incoming gas supply for the purpose of delivering gas to
the boiler.
16. SMART SYSTEM Control Module
The SMART SYSTEM Control responds to internal and
external signals and controls the blower, gas valve, and pumps
to meet the heating demand.
17. Manual air vent
Designed to remove trapped air from the heat exchanger
coils.
18. Air intake adapter
Allows for the connection of the PVC air intake pipe to the
boiler.
19. High voltage junction box
The junction box contains the connection points for the line
voltage power and all pumps.
20. Boiler drain port
Location from which the heat exchanger can be drained.
21. Low voltage connection board
The connection board is used to connect external low voltage
devices.
22. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage connection
board.
23. Condensate drain connection
Connects the condensate drain line to a 1/2" PVC union.
24. Access cover - front
Provides access to the gas train and the heat exchanger.
25. Ignition electrode
Provides direct spark for igniting the burner.
26. Flame inspection window
The quartz glass window provides a view of the burner surface
and flame.
27. Gas shutoff valve (Models 501 - 801 only)
Manual valve used to isolate the gas valve from the gas supply.
28. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 50 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. Top panel
Removable panel to gain access to the internal components.
32. Power switch
Turns 120 VAC ON/OFF to the boiler.
33. 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.
34. Air shroud (Model 501 only)
The air shroud controls air and gas flow into the burner.
35. Air pressure switch
The air pressure switch detects blocked flue/inlet conditions.
break the control circuit, shutting the boiler down.
36. Pump relay board
The pump relay board is used to connect the boiler, system and
DHW pumps.
37. Transformer
The transformer provides 24V power to the integrated control.
38. High limit sensor (housed with the outlet temperature
sensor)
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, the integrated control will break
the control circuit, shutting the boiler down.
39. Over-temp switch (located underneath access cover)
An electrical switch designed to shut down boiler operation in
the event the outer back of the heat exchanger, directly above the
flue connection exceeds 604°F (318°C). This is a one time
switch and could warrant a heat exchanger replacement. Check
the integrity of the rear refractory at the back of the upper coil if
the switch opens.
Installation & Operation Manual

Front View - Model 400
27
35
8
7
20
13
28
23
14
29
25
4
5
37
38
Left Side (inside unit) - Model 400
19
21
36
16
1
3
17
33
26
2
Right Side (inside unit) - Model 400
The Knight XL - How it works... (continued)
Rear View - Model 400
5
Model 400
10
31
24
30
22
11
15
32
6
18
39
Installation & Operation Manual

6
The Knight XL - How it works...
18
15
27
39
Rear View - Model 501
27
15
18
39
Rear View - Models 601 - 801 Left Side (inside unit) - Models 601 - 801
Left Side (inside unit) - Model 501
Model 501
Models 601 - 801
34
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 AHRI 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 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.
5. High altitude Knight XL 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.
6. Ratings have been confirmed by the Hydronics Section of
AHRI.
7
Maximum allowed working pressure is located on the rating plate.
NOTICE
Knight XL Boiler
AHRI 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
AHRI
Ratings
Water,
MBH
(Note 2)
KBN400 80 399 373 324
KBN501 100 500 467 406
KBN601 120 600 567 493
KBN701 140 700 660 574
KBN801 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
3000 FT. TO 12,000 FT.
HIGH ALTITUDE
7. Knight XL 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 XL is listed to UL353.
Installation & Operation Manual

8
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
Provide clearances:
Clearances from combustible materials
1. Hot water pipes—at least 1/4" (6 mm) from combustible
materials.
2. Vent pipe – at least 1" (25 mm) from combustible materials.
3. See FIG.’s 1-1 and 1-2 on page 9 for other clearance
minimums.
Clearances for service access
1. See FIG.’s 1-1 and 1-2 on page 9 for recommended
service clearances. If you do not provide the minimum
clearances shown, it may not be possible to service the
boiler without removing it from the space.
Closet and alcove installations
This appliance requires a special venting
system. 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 KBN400 models, 193 cubic feet for KBN501
models, 223 cubic feet for KBN601 models, 247 cubic feet for
KBN701 models and 278 cubic feet for KBN801 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.
Installation & Operation Manual
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.
Do not install the appliance where the
relative humidity may exceed 93%. Do not
install the appliance where condensation
may form on the inside or outside of the
appliance, or where condensation may fall
onto the appliance.
Failure to install the appliance indoors
could result in severe personal injury,
death, or substantial property damage.

9
1 Determine boiler location (continued)
ALCOVE INSTALLATION
OPEN
FRONT
1/4" (6 MM) MINIMUM CLEARANCE
AROUND HOT WATER PIPES
1” (25 MM) MINIMUM CLEARANCE
AROUND VENT PIPE
18" (457 MM)
FRONT
0"
RIGHT
13" (330)
TOP
12"
(305 MM)
LEFT
14" (356 MM)
REAR
RECOMMENDED SERVICE CLEARANCES:
FRONT - 30” (762 mm)
TOP - 24” (610 mm)
LEFT SIDE - 24” (610 mm)
REAR - 24” (610 mm)
Figure 1-2 Alcove Installation - Minimum Required Clearances
CLOSET INSTALLATION
CLOSED DOOR
VENTILATING
AIR OPENING*
*
*AREAOF EACH OPENING:
1 SQ. INCH PER 1000 BTU PER HOUR INPUT
WITH A MINIMUM OF 100 SQ. INCHES.
1/4" (6 MM) MINIMUM CLEARANCE
A
ROUND HOT WATER PIPES
1” (25 MM) MINIMUM CLEARANCE
A
ROUND VENT PIPE
6" (152 MM)
FRONT
6"
13"
TOP
0"
RIGHT
12"
(305 MM)
LEFT
14" (356 MM)
REAR
VENTILATING
AIR OPENING
RECOMMENDED SERVICE CLEARANCES:
FRONT - 30” (762 mm)
TOP - 24” (610 mm)
LEFT SIDE - 24” (610 mm)
REAR - 24” (610 mm)
Figure 1-1 Closet Installation - Minimum Required Clearances
WARNING
WARNING
Installation & Operation Manual
For alcove installations, CPVC,
polypropylene 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.
For closet installations, CPVC,
polypropylene 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.

10
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.
The boiler is to be used for either direct vent installation or
for installation using indoor combustion air. When room
air is considered, see the General Venting Section. 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 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
Installation & Operation Manual

11
Products to avoid:
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cements and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents
found in household laundry rooms
Adhesives used to fasten building products and other
similar products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garages with workshops
Table 1A Corrosive Contaminants and Sources
1 Determine boiler location (continued)
Installation & Operation Manual
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. For polypropylene or
stainless steel venting, an adapter of the same
manufacturer must be used at the flue collar connection.
• Size - To ensure proper pipe size is in place, see Table 3A.
Check to see that this size is used throughout the vent
system.
• Manufacturer - For a stainless steel or polypropylene
application, you must use only the listed manufacturers
and their type product listed in Tables 3E and 3G 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
3H for the manufacturer of the installed vent.
• Seal - With prior requirements met, the system should be
tested to the procedure listed in parts (c) through (f) of
the Removal of an Existing Boiler Section on page 12.
With polypropylene and 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 pages 19 and 20.
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.

1 Determine boiler location
12
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.
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 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.
Installation & Operation Manual

2 Prepare boiler
13
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 400 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 400 - 8.0 LP orifice stamping).
Models 501 - 801 do not require an orifice
installation for propane operation, but
they will require a valve adjustment.
. 2
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 400
Model 400
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 400 - 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 400: 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.
Installation & Operation Manual

2 Prepare boiler
14
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 501
Model 501
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 601 - 801
Models 601 - 801
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 601 Model, one
and a half (1 1/2) turns on the 701 Model, and one turn on
the 801 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.
Installation & Operation Manual

15
Two Pipe Sidewall
See page 23 for more details
PVC/CPVC Concentric Sidewall
Models 400 - 601 Only
See page 27 for more details
Direct venting options - Sidewall Vent
3 General venting
Installation & Operation Manual
Two Pipe Vertical
See page 30 for more details Vertical Vent, Sidewall Air
See page 19 for more details
PVC/CPVC
Concentric Vertical
Models 400 - 601 Only
See page 32 for more details
Direct venting options - Vertical Vent

16
3 General venting
Installation & Operation Manual
This appliance requires a special venting
system. Use only approved stainless steel,
PVC, CPVC or polypropylene pipe and
fittings listed in Tables 3D, 3E, and 3G 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 XL 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.
WARNING
NOTICE
WARNING For closet and alcove installations, CPVC,
polypropylene 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.
Air intake/vent connections
1. Combustion Air Intake Connector (FIG. 3-1) - 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 3-2 thru 3-6) - Used to provide a
passageway for conveying combustion gases to the
outside. A transition fitting is provided on the unit for
final connection. Vent piping must be supported per the
National Building Code, Section 305, Table 305.4 or as
local codes dictate.
The Knight XL 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.
You may use any of the vent/air piping methods covered in this
manual. Do not attempt to install the Knight XL boiler using
any other means.
You must also install air piping from outside to the boiler
air intake adapter unless following the Optional Room Air
instructions on page 19 of this manual. The resultant installation
is direct vent (sealed combustion).
WARNING DO NOT mix components from different
systems. The vent system could fail,
causing leakage of flue products into the
living space. Mixing of venting materials
will void the warranty and certification of
the appliance.
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.
Improper installation of venting systems
may result in injury or death.
CAUTION
Follow the instructions in Section 1, page
12 of this manual when removing a boiler
from an existing vent system.
NOTICE
T
AIR
Figure 3-1 Near Boiler Air Piping

17
3 General venting (continued)
Installation & Operation Manual
Requirements for installation in
Canada
1. Installations must be made with a vent pipe system
certified to ULC-S636.
2. The first three (3) feet of plastic vent pipe from the
appliance flue outlet must be readily accessible for visual
inspection.
3. The components of the certified vent system must not be
interchanged with other vent systems or unlisted
pipe/fittings. For concentric vent installations, the inner
vent tube must be replaced with field supplied certifiedvent
material to comply with this requirement.
4. The 4" Concentric Vent Kit available from Lochinvar (see
Section 4 – Sidewall Termination – Optional Concentric
Vent) and the 4" Concentric Vent Kit available from IPEX
are both approved for use on the Knight XL (400 - 601
models only) boiler. Both kits are listed to the ULC-S636
standard for use in Canada.
The appliance output rating will reduce
by up to 1.5% for each 25 feet of vent
length.
NOTICE
Sizing
Increasing or decreasing combustion air
or vent piping sizes is not authorized.
NOTICE
Model Air Intake Vent
400 - 601 4 inches (102 mm) 4 inches (102 mm)
701 - 801 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 3A below.
Table 3A Air Intake/Vent Piping Sizes Model Kit Number Equivalent
Vent Length
400 CVK3007 5 Feet (1.5 m)
501 CVK3007 30 Feet (9 m)
601 CVK3007 30 Feet (9 m)
Table 3B Concentric Vent Kit Equivalent Vent Lengths
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
Vent = 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.

18
3 General venting
Air inlet pipe materials:
The air inlet pipe(s) must be sealed. Choose acceptable
combustion air inlet pipe materials from the following list:
PVC, CPVC, Polypropylene 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.
Installation & Operation Manual
WARNING Using air intake materials other than
those specified can result in personal
injury, death or property damage.
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 (3) 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.
Follow the polypropylene manufacturer’s instructions when
using polypropylene material as an inlet pipe.
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.

19
3 General venting (continued)
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.
Please read the information given in Table 1A, page 11,
listing contaminants and areas likely to contain them. If
contaminating chemicals will be present near the location of the
boiler combustion air inlet, have your installer pipe the boiler
combustion air and vent to another location, per this manual.
If the boiler combustion air inlet is located in
a laundry room or pool facility, for example,
these areas will always contain hazardous
contaminants.
To prevent the potential of severe personal
injury or death, check for areas and products
listed in Table 1A, page 11 before installing
the boiler or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
—OR—
• Relocate air inlet and vent terminations
to other areas.
WARNING
WARNING
Optional room air
WARNING When utilizing the single pipe method,
provisions for combustion and ventilation
air must be in accordance with Air for
Combustion and Ventilation, of the latest
edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada, the latest edition
of CGA Standard B149 Installation
Code for Gas Burning Appliances and
Equipment, or applicable provisions of
the local building codes.
Table 3C Optional Room Air Kit
Commercial applications utilizing the Knight XL 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 3C).
• 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.
NOTICE Optional room air is intended for
commercial applications. Combustion
air piping to the outside is recommended
for residential applications.
Model Description Kit Number
400 - 801 Filter Box Assembly KIT30022
90° Elbow with Screen KIT30053
Installing vent and air piping
Use only cleaners, primers, and solvents
that are approved for the materials which
are joined together.
NOTICE
PVC/CPVC
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).
NOTICE
WARNING 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. 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 Table 3D to make
the vent connections. Failure to follow
this warning could result in fire, personal
injury, or death.
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.
This product has been approved for use with the PVC/CPVC
vent materials listed in Table 3D on page 20.

20
3 General venting
Installation & Operation Manual
5. Dry fit vent or air piping to ensure proper fit up before
assembling any joint. The pipe should go a third to
two-thirdsintothefittingtoensurepropersealingafter
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 and to the pipe end to approximately 1/2"
beyond the socket depth.
c. Apply a second primer coat to the fitting
socket.
d. While primer is still wet, apply an even coat of
approvedcementtothepipeequaltothedepthof
the fitting socket along with an even coat of
approved cement to the fitting socket.
e. Apply a second coat of cement to the pipe.
f. 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 cementwas not appliedandjoint could
be defective.
g. Wipe excess cement from the joint removing
ring or beads as it will needlessly soften the
pipe.
Table 3D PVC/CPVC Vent Pipe, and Fittings
Approved PVC/CPVC Vent Pipe and Fittings
Item Material Standard
Vent pipe PVC Schedule 40, 80 ANSI/ASTM D1785 PVC - DWV ANSI/ASTM D2665
CPVC Schedule 40, 80 ANSI/ASTM F441
Vent fittings PVC Schedule 40 ANSI/ASTM D2466 PVC Schedule 80 ANSI/ASTM D2467
CPVC Schedule 80 ANSI/ASTM F439
Pipe Cement /
Primer PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493
NOTICE: DO NOT USE CELLULAR (FOAM) CORE PIPE
NOTE: In Canada, CPVC and PVC vent pipe, fittings and cement/
primer must be ULC-S636 certified.
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.)
6” COUPLING
(FIELD SUPPLIED)
6” CPVC
STARTER
PIECE
(FACTORY SUPPLIED)
VENT
THE 6” STAINLESS STEEL ADAPTER SUPPLIED
WITH THE BOILER MUST BE USED FOR VENT
CONNECTION TO PVC/CPVC. THE 6” CPVC
STARTER PIECE MUST BE USED FOR PVC ONLY.
Figure 3-3 Near Boiler PVC/CPVC Venting - Models
701 - 801
VENT
4" CPVC PIPE SUPPLIED WITH
BOILER MUST BE USED FOR VENT CONNECTION
NOTE: CPVC VENT OR STAINLESS STEEL PIPE AND
VENT FITTINGS MUST BE USED IN CLOSET AND
A
LCOVE INSTALLATIONS.
*
* 4” CPVC STREET ELBOW
MAY BE SUBSTITUTED
Figure 3-2 Near Boiler PVC/CPVC Venting - Models 400 - 601