Knight 80 User manual

Installation & Operation Manual
Models: 80 - 500
This manual must only be used by a
qualified heating installer / service
technician. Read all instructions,
including this manual and the
Knight Boiler Service Manual, before
installing. Perform steps in the order
given. Failure to comply could result
in severe personal injury, death, or
substantial property damage.

WARNING
Save this manual for future reference.

Installation & Operation Manual
2
Hazard definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Please read before proceeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
The Knight Boiler -- How it works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1. Determine boiler location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2. Prepare boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. General venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4. Sidewall direct venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5. Vertical direct venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6. Hydronic piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7. Gas connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8. Field wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
9. Condensate disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
10. Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
11. Operating information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
12. Notes page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
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.

Installation & Operation Manual
Please read before proceeding
Installer – Read all instructions,
including this manual and the Knight
Boiler Service Manual, before installing.
Perform steps in the order given.
User – This manual is for use only by a
qualified heating installer/service
technician. Refer to the User’s
Information Manual for your reference.
Have this boiler serviced/inspected by a
qualified service technician, at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
Failure to adhere to the guidelines on this
page can result in severe personal injury,
death, or substantial property damage.
When 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. 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 neighbor’s 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 Boiler - How it works...
1. Stainless steel heat exchanger
Allows system water to flow through specially designed
coils for maximum heat transfer, while providing
protection against flue gas corrosion. The coils are
encased in a jacket that contains the combustion process.
2. 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 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)
NPT water connection that supplies hot water to the
system, either 1", 1-1/4", or 1-1/2", depending on the
model.
14. Water inlet (system return)
NPT water connection that returns water from the
system to the heat exchanger, either 1", 1-1/4", or 1-1/2",
depending on the model.
15. Gas connection pipe
Threaded pipe connection, either 1/2", 3/4", or 1",
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 sensor
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 may be set at 30 psi or 50 psi depending on
model.
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.

Installation & Operation Manual
Figure 1 Front View - Models 80 - 210
Figure 3 Left Side (inside unit) - Models 80 - 210 Figure 4 Right Side (inside unit) - Models 80 - 210
The Knight Boiler - How it works... (continued)
Figure 2 Rear View - Models 80 - 210
5
Models 80 - 210

Installation & Operation Manual
6
The Knight Boiler - How it works...
Figure 5 Rear View - Models 285 - 399
Figure 7 Rear View - Model 500 Figure 8 Left Side (inside unit) - Model 500
Figure 6 Left Side (inside unit) - Models 285 - 399
Models 285 - 399
Model 500

Installation & Operation Manual
Ratings
Notes:
1. As an Energy Star Partner, Lochinvar has determined that
Knight boilers meet the Energy Star guidelines for energy
efficiency.
2. The ratings are based on standard test procedures
prescribed by the United States Department of Energy.
3. Net I=B=R ratings are based on net installed radiation of
sufficient quantity for the requirements of the building
and nothing need be added for normal piping and
pickup. Ratings are based on a piping and pickup
allowance of 1.15.
4. Knight boilers require special gas venting. Use only the
vent materials and methods specified in the Knight
Installation and Operation Manual.
5. Lochinvar’s Low Temperature Application Annual
Efficiency is based on ASHRAE 103 test method, using a
boiler return water temperature of 90°F, with a boiler
outlet water temperature of 110°F. This rating was
conducted by Lochinvar.
7
Maximum allowed working pressure is located on the rating plate.
6. The Knight boiler is equipped for operation up to
2000 feet. For operation at elevations above 2000 feet, the
appliance output ratings shall be reduced at a rate of 4%
for each 1000 feet above sea level. However, operation of
the Knight boiler between 2000 - 4000 feet elevation
requires no field adjustments. For operation above
4000 feet elevation, consult the manufacturer.
Model
Number
Note: Change
“N” to “L” for
L.P. gas
models.
CSA
Input Modulation
Btu/hr
DOE
Heating
Capacity
Btu/hr
Net
I=B=R
Ratings
Btu/hr
DOE
AFUE
%
Lochinvar
Low
Temperature
Application
Annual
Efficiency %
Boiler Water
Content
Gallons
Water
Connections
Gas
Connections Vent/Air Size
(Note 6) (Note 2, 9) (Note 3, 9) (Note 1, 9) (Note 5) (Note 4)
KBN080 16,000 - 80,000 73,000 63,000 93.0 98.0 0.6 1" 1/2" 3"
KBN105 21,000 - 105,000 95,000 83,000 93.0 98.0 0.7 1" 1/2" 3"
KBN150 30,000 - 150,000 136,000 118,000 93.0 98.0 1.3 1" 1/2" 3"
KBN210 42,000 - 210,000 191,000 166,000 93.0 98.0 1.7 1" 1/2" 3"
KBN285 57,000 - 285,000 259,000 225,000 93.0 98.0 2.4 1-1/4" 3/4" 4"
Model
Number
Note:
Change “N”
to “L” for L.P.
gas models.
CSA
Input Modulation
Btu/hr
Gross
Output,
Btu/hr
Net
I=B=R
Ratings
Btu/hr
Combustion
Efficiency %
Thermal
Efficiency %
Lochinvar Low
Temperature Efficiency
Combustion Thermal
% %
Boiler
Water
Content
Gallons
Water
Connections
Gas
Connections
Vent/Air
Size
(Note 6) (Note 6, 9) (Note 3, 9) (Note 7, 9) (Note 7, 9) (Note 8) (Note 8) (Note 4)
KBN399 80,000 - 399,000 360,000 313,000 92.2 90.3 95.4 94.5 3.4 1-1/2" 1" 4"
KBN500 100,000 - 500,000 451,000 392,000 92.2 90.3 95.4 94.5 4.2 1-1/2" 1" 4"
NOTICE

WARNING DO NOT install high altitude models
below 4000 feet.
7. Combustion and Thermal Efficiency based on I=B=R
testing and rating procedure BTS-2000.
8. Lochinvar's Low Temperature Efficiency is based on
I=B=R test method BTS-2000, using a boiler return water
temperature of 90°F, with boiler outlet water temperature
of 110°F. This rating was conducted by Lochinvar.
9. Ratings have been confirmed by the Hydronics Institute,
Division of GAMA.

Installation & Operation Manual
1 Determine boiler location
8
The Knight boiler gas manifold and
controls met safe lighting and other
performance criteria when the boiler
underwent tests specified in ANSI Z21.13
– latest edition.
Failure to keep boiler area clear and free of
combustible materials, gasoline, and other
flammable liquids and vapors can result in
severe personal injury, death, or
substantial property damage.
Installation must comply with:
• Local, state, provincial, and national codes, laws,
regulations, and ordinances.
• National Fuel Gas Code, ANSI Z223.1 – latest edition.
• Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD-1, when
required.
• National Electrical Code.
• For Canada only: B149.1 or B149.2 Installation Code, CSA
C22.1 Canadian Electrical Code Part 1 and any local codes.
Before locating the boiler, check:
1. Check for nearby connection to:
• System water piping
• Venting connections
• Gas supply piping
• Electrical power
2. Locate the appliance so that if water connections should
leak, water damage will not occur. When such locations
cannot be avoided, it is recommended that a suitable
drain pan, adequately drained, be installed under the
appliance. The pan must not restrict combustion air
flow. Under no circumstances is the manufacturer to be
held responsible for water damage in connection with
this appliance, or any of its components.
3. Check area around the boiler. Remove any combustible
materials, gasoline and other flammable liquids.
4. The Knight boiler must be installed so that gas control
system components are protected from dripping or
spraying water or rain during operation or service.
5. If a new boiler will replace an existing boiler, check for
and correct system problems, such as:
• System leaks causing oxygen corrosion or heat
exchanger cracks from hard water deposits.
• Incorrectly-sized expansion tank.
• Lack of freeze protection in boiler water causing system
and boiler to freeze and leak.

WARNING This appliance is certified as an indoor
appliance. Do not install the appliance
outdoors or locate where the appliance will
be exposed to freezing temperatures or to
temperatures that exceed 100°F.
Failure to install the appliance indoors
could result in severe personal injury,
death, or substantial property damage.
Provide clearances:
Clearances from combustible materials
1. Hot water pipes—at least 1" from combustible materials.
2. Vent pipe – at least 1" from combustible materials.
3. See FIG.’s 9 and 10 on page 9 for other clearance
minimums.
Clearances for service access
1. See FIG.’s 9 and 10 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 installations
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. 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.
Alcove installations
For alcove installations as shown in FIG. 10, PVC vent
material can be used with the required clearances and an
open front.
For closet installations as shown in FIG. 9,
CPVC vent material must be used (at least
in the closet structure). The two
ventilating air openings shown in FIG. 9
are required for this arrangement. Failure
to follow this warning could result in fire,
personal injury, or death.

WARNING

WARNING
NOTICE

WARNING

Installation & Operation Manual
1 Determine boiler location (continued)
9
Figure 10 Alcove Installation - Minimum Required Clearances
Figure 9 Closet Installation - Minimum Required Clearances

WARNING For closet installations, CPVC
material MUST BE used in a closet
structure. Failure to follow this
warning could result in fire,
personal injury, or death.

Installation & Operation Manual
1 Determine boiler location
10
Provide air openings to room:
Knight boiler alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Knight boiler are at
least equal to the SERVICE clearances shown in FIG.’s 9
and 10. For spaces that do NOT supply this clearance,
provide two openings as shown in FIG. 9. Each opening
must provide one square inch free area per 1,000 Btu/hr
of boiler input.
Knight boiler in same space with other gas or oil-
fired appliances
1. Follow the National Fuel Gas Code (U.S.) or CSA B149.1
and B149.2 (Canada) to size/verify size of the
combustion/ventilation air openings into the space.
The space must be provided with
combustion/ventilation air openings
correctly sized for all other appliances
located in the same space as the Knight
boiler.
Do not install the boiler in an attic.
Failure to comply with the above warnings
could result in severe personal injury,
death, or substantial property damage.
2. Size openings only on the basis of the other appliances in
the space. No additional air opening free area is needed
for the Knight boiler because it takes its combustion air
from outside (direct vent installation).
Do not install the boiler on carpeting even
if foundation is used. Fire can result,
causing severe personal injury, death, or
substantial property damage.
If flooding is possible, elevate the boiler sufficiently to prevent
water from reaching the boiler.
Flooring and foundation
Flooring
The Knight boiler is approved for installation on combustible
flooring, but must never be installed on carpeting.
Residential garage installation
Precautions
Take the following special precautions when installing the
boiler in a residential garage. If the boiler is located in a
residential garage, per ANSI Z223.1, paragraph 5.1.9:
• Mount the boiler with a minimum of 18 inches above
the floor of the garage to the bottom of the boiler to
ensure the burner and ignition devices will be no less
than 18 inches above the floor.
• Locate or protect the boiler so it cannot be damaged by
a moving vehicle.
Vent and air piping
The Knight boiler 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 boiler using any
other means.
Be sure to locate the boiler such that the vent and air piping
can be routed through the building and properly terminated.
The vent/air piping lengths, routing and termination method
must all comply with the methods and limits given in this
manual.
Prevent combustion air contamination
Install air inlet piping for the Knight boiler as described in
this manual. Do not terminate vent/air in locations that can
allow contamination of combustion air. Refer to Table 1, 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 1, 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
1 Determine boiler location (continued)
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 1 Corrosive Contaminants and Sources When removing a boiler from existing
common vent system:
Do not install the Knight boiler into a
common vent with any other appliance.
This will cause flue gas spillage or
appliance malfunction, resulting in
possible severe personal injury, death, or
substantial property damage.
Failure to follow all instructions can result
in flue gas spillage and carbon monoxide
emissions, causing severe personal injury
or death.
At the time of removal of an existing boiler, the following
steps shall be followed with each appliance remaining
connected to the common venting system placed in
operation, while the other appliances remaining connected to
the common venting system are not in operation.
a. Seal any unused openings in the common venting system.
b. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion, or other deficiencies,
which could cause an unsafe condition.
c. Test vent system – Insofar as is practical, close all building
doors and windows and all doors between the space in
which the appliances remaining connected to the
common venting system are located and other spaces of
the building. Turn on clothes dryers and any appliance
not connected to the common venting system. Turn on
any exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed. Do not
operate a summer exhaust fan. Close fireplace dampers.
d. Place in operation the appliance being inspected. Follow
the lighting instructions. Adjust thermostat so appliance
will operate continuously.
e. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a
match or candle, or smoke from a cigarette, cigar, or pipe.
f. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined herein, return
doors, windows, exhaust fans, fireplace dampers, and any
other gas-burning appliance to their previous conditions
of use.
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

Installation & Operation Manual
2 Prepare boiler
12
Figure 12 Installing Propane Orifice - Models 80 - 285
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. 11).
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. 11).
b. Detach the boiler from the lag bolts in the rear of the
unit, see FIG. 11.
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.
You must install the propane orifice to fire
the Knight boiler on propane. Verify when
installing that the orifice size marking
matches boiler size (Models 80 – 399,
Table 2). Failure to comply could result in
severe personal injury, death, or
substantial property damage.
Models 80 - 285
1. Remove the top and front access covers from the unit (no
tools required for removal).
2. Remove the three star-drive screws securing the gas valve
to the venturi (FIG. 12).
3. Locate the propane orifice disk from the conversion kit
bag. Verify that the stamping on the orifice disk matches
the boiler size (80 – 285) (see Table 2 above).
Place the orifice into the black rubber grommet in the
side of the gas valve and secure in the valve (FIG. 12).
4. Reposition the gas valve against the venturi and replace
the star-drive screws (FIG. 12) securing the valve to the
venturi.
5. After installation is complete, attach the propane
conversion label (in the conversion kit bag) next to the
boiler rating plate. Attach the LP caution label (in the
conversion kit bag) to the left side of the unit in the lower
left corner.
6. Replace the top and front access covers.
Figure 11 Boiler Mounted on Shipping Pallet
Gas conversions
LP Conversion Table
Model LP Orifice Stamping
80 80
105 105
150 150
210 210
285 285
399 7.2
NOTICE

WARNING
Table 2 LP Conversion Table

Installation & Operation Manual
13
2 Prepare boiler (continued)
Figure 13 Installing Propane Orifice - Model 399
Figure 14 Gas Valve Adjustment - Model 500
Figure 15 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. 15
below.
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. 13).
3. Remove the four star-drive screws securing the gas valve
to the venturi (FIG. 13).
4. Locate the propane orifice disk from the conversion kit
bag. Verify that the stamping on the orifice disk matches
the boiler size (399) (see Table 2 on page 12).
5. Remove the existing orifice from the black rubber
grommet 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. 13.
6. Reposition the gas valve against the venturi and replace
the star-drive screws (FIG. 13) 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. 13).
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.
Model 500
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. 14).
3. Turn the adjustment screw on top of the gas valve one
revolution counterclockwise (see FIG. 14).
4. Use a combustion analyzer to verify CO2is within the
range of 9.6 – 10.2%. If not, adjust the screw clockwise
incrementally to raise CO2and counterclockwise to lower
CO2(FIG. 14).
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.

DANGER Knight 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.

Installation & Operation Manual
3 General venting
14
Figure 16 Two-Pipe Vertical Termination - See page 24 for more
details
Figure 17 Two-Pipe Sidewall Termination - See page 18 for
more details
Figure 18 Concentric Vertical Termination - See page 26 for more
details
Figure 19 Concentric Sidewall Termination - See page 21 for more
details
Direct venting options

Installation & Operation Manual
3 General venting (continued)
15
Vent and air piping materials
Use only the materials listed in Table 3
below for vent, air 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 or B149.2 for
Canadian installations.
All combustion air and vent pipe materials and fittings must comply with the following:
Item Material Standards for installation in:
United States Canada
Vent or air pipe and
fittings
PVC schedule 40 ANSI/ASTM D1785
CSA or ULC certified only
PVC-DWV ANSI/ASTM D2665
CPVC schedule 40 ANSI/ASTM F441
ABS-DWV schedule 40 ANSI/ASTM D2661
Pipe cement/primer
PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493
ABS ANSI/ASTM D2235
NOTICE: DO NOT USE CELLULAR (FOAM) CORE PIPE
Table 3 Vent, Air Pipe, and Fittings
Install vent and combustion air
piping

DANGER The Knight boiler must be vented and
supplied with combustion and ventilation
air as described in this section. Ensure the
vent and air piping and the combustion
air supply comply with these instructions
regarding vent system, air system, and
combustion air quality. See also Section 1
of this manual.
Inspect finished vent and air piping
thoroughly to ensure all are airtight and
comply with the instructions provided
and with all requirements of applicable
codes.
Failure to provide a properly installed
vent and air system will cause severe
personal injury or death.
All 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 installations, CPVC material
MUST BE used in a closet structure.
Failure to follow this warning could result
in fire, personal injury, or death.
NOTICE

Installation & Operation Manual
3 General venting
16
Air intake/vent connections
1. Combustion Air Intake Connector (FIG.’s 20 and 21) -
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 20 and 21) - 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.
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
Figure 20 Near Boiler Venting Models 80 - 210
Figure 21 Near Boiler Venting Models 285 - 500
Maximum allowable combustion air and
vent piping lengths are as follows:
Combustion Air = 100 equivalent feet
Ve n t = 100 equivalent feet
When determining equivalent combustion air and vent
length, add 5 feet for each 90° elbow, 3 feet for each 45° elbow,
and 3 feet for the concentric vent kit, see example below.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit = 49 equivalent feet of
piping.
The Knight boiler uses model specific combustion air intake
and vent piping sizes as detailed in Table 4 below.
Model Air Intake Vent
80 - 210 3" 3"
285 - 500 4" 4"
Table 4 Air Intake/Vent Piping Sizes
Increasing or decreasing combustion air
or vent piping is not authorized.
NOTICE

Installation & Operation Manual
17
3 General venting (continued)
Vent, air piping and termination:
The Knight boiler vent and air piping can be installed through
the roof or through a sidewall. Follow the procedures in this
manual for the method chosen. Refer to the information in
this manual to determine acceptable vent and air piping
length.
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 1, 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 1, 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 or B149.2 for
Canadian installations.
You must also install air piping from outside to the boiler air
intake adapter. The resultant installation is direct vent (sealed
combustion).
You may use any of the vent/air piping methods covered in
this manual. Do not attempt to install the Knight boiler using
any other means.
DO NOT mix components from different
systems. The vent system could fail,
causing leakage of flue products into the
living space. Use only PVC, CPVC, or ABS
pipe and fittings, with primer and cement
specifically designed for the material used.
NOTICE

WARNING

WARNING

WARNING

Installation & Operation Manual
18
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 or B149.2 for
Canadian installations.
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
16 of this manual.
2. The air piping must terminate in a down-turned elbow as
shown in FIG. 22. This arrangement avoids recirculation
of flue products into the combustion air stream.
3. The vent piping must terminate in an elbow pointed
outward or away from the air inlet, as shown in FIG. 22.
Do not exceed the maximum lengths of
the outside vent piping shown in
FIG. 22. Excessive length exposed to the
outside could cause freezing of condensate
in the vent pipe, resulting in potential
boiler shutdown.
4. 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.
Figure 22 Sidewall Termination of Air and Vent
Figure 23 Alternate Sidewall Termination of Air and Vent if Space
Allows
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

WARNING
NOTICE

WARNING

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.

Installation & Operation Manual
19
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.
5. Maintain clearances as shown in FIG.’s 22 - 25, pages 18
and 19. Also maintain the following:
a. Vent must terminate:
• At least 6 feet from adjacent walls.
• No closer than 5 feet below roof overhang.
• At least 7 feet above any public walkway.
• At least 3 feet above any forced air intake within
10 feet.
• No closer than 12 inches below or horizontally
from any door or window or any other gravity air
inlet.
b. Air inlet must terminate at least 12 inches above
grade or snow line; at least 12 inches below the vent
termination; and the vent pipe must not extend
more than 24 inches vertically outside the building
as shown in FIG. 22.
c. Do not terminate closer than 4 feet horizontally
from any electric meter, gas meter, regulator, relief
valve, or other equipment. Never terminate above or
below any of these within 4 feet horizontally.
6. Locate terminations so they are not likely to be damaged
by foreign objects, such as stones or balls, or subject to
buildup of leaves or sediment.
Vent/air termination – sidewall
Figure 24 Clearance to Gravity Air Inlets
Figure 25 Clearance to Forced Air Inlets
Prepare wall penetrations
1. Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as
close as desired to the air pipe outside diameter.
2. Vent pipe penetration:
a. Cut a hole for the vent pipe. For either combustible
or noncombustible construction, size the vent pipe
hole at least 1/2 inch larger than the vent pipe
diameter:
• 4 inch hole for 3 inch vent pipe
• 5 inch hole for 4 inch vent pipe
b. Insert a galvanized metal thimble in the vent pipe
hole as shown in FIG. 26.
3. Use a sidewall termination plate as a template for correct
location of hole centers.
4. Follow all local codes for isolation of vent pipe when
passing through floors or walls.
5. Seal exterior openings thoroughly with exterior caulk.
4 Sidewall direct venting (continued)

Installation & Operation Manual
20
4 Sidewall direct venting
Vent/air termination – sidewall
Figure 26 Sidewall Termination Assembly
Termination and fittings
1. Prepare the vent termination elbow and the air
termination elbow (FIG. 26) by inserting the bird screens
provided with the boiler. Bird screens are provided for
either 3 inches (Knight 80 – 105 – 150 and 210) or
4 inches (Knight 285 – 399 and 500) fittings.
2. When completed, the air termination coupling must be
oriented at least 12 inches below the vent termination
and at least 12 inches above grade or snow line as shown
in FIG. 22, page 18.
3. Maintain the required dimensions of the finished
termination piping as shown in FIG. 22, page 18.
4. Do not extend exposed vent pipe outside of building
more than shown in this document. Condensate could
freeze and block vent pipe.
All vent pipes and air inlets must
terminate at the same height to avoid
possibility of severe personal injury, death,
or substantial property damage.
Multiple vent/air terminations
1. When terminating multiple Knight boilers terminate each
vent/air connection as described in this manual (FIG. 27).
2. Place wall penetrations to obtain minimum clearance of
12 inches between vent pipe and adjacent air inlet elbow,
as shown in FIG. 27 for U.S. installations. For Canadian
installations, provide clearances required by CSA B149.1
or B149.2 Installation Code.
3. The air inlet of a Knight boiler is part of a direct vent
connection. It is not classified as a forced air intake with
regard to spacing from adjacent boiler vents.
Figure 27 Multiple Vent Terminations (must also comply with FIG. 22)

WARNING