Lochinvar Knight WH 55 User manual

WH-I-O Rev H
Installation & Operation Manual
Models: WH 55 - 399
This manual must only be used by
a qualified heating installer / service
technician. Read all instructions,
including this manual and the Knight
Wall Mount Service Manual, before
installing. Perform steps in the order
given. Failure to comply could result
in severe personal injury, death, or
substantial property damage.
WARNING
Save this manual for future reference.

2
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
DANGER
WARNING
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
HAZARD DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 2
PLEASE READ BEFORE PROCEEDING . . . . . . . . . . . . 3
THE KNIGHT WALL MOUNT BOILER--HOW IT WORKS . 4-5
RATINGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1. DETERMINE BOILER LOCATION
Provide Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Provide Air Openings to Room . . . . . . . . . . . . . . . . . . . . . 9
Wall Mounting Location . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Residential Garage Installation . . . . . . . . . . . . . . . . . . . . . 9
Vent and Air Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Prevent Combustion Air Contamination. . . . . . . . . . . . . . . 9
Corrosive Contaminants and Sources . . . . . . . . . . . . . . . 10
Using an Existing Vent System to Install a New Boiler . . 10
Removing a Boiler from Existing Common Vent . . . . . . . 11
2. PREPARE BOILER
Remove Boiler from Wood Pallet. . . . . . . . . . . . . . . . . . . 12
Gas Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Mounting the Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3. GENERAL VENTING
Direct Venting Options ..................................................... 14
Install Vent and Combustion Air Piping ........................... 15
Requirements for Installation in Canada.......................... 16
Sizing ............................................................................... 16
Materials............................................................................ 17
Optional Room Air............................................................ 18
PVC/CPVC ....................................................................... 19
Polypropylene................................................................... 20
Stainless Steel Vent ......................................................... 21
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall................................... 22-28
Determine Location................................................ 22-24
Prepare Wall Penetrations.......................................... 24
Multiple Vent/Air Terminations ......................................... 25
Sidewall Termination - Optional Concentric Vent ....... 26-28
5. VERTICAL DIRECT VENTING
Vent/Air Termination - Vertical .................................... 29-30
Determine Location..................................................... 29
Prepare Roof Penetrations ......................................... 29
Multiple Vent/Air Terminations.................................... 30
Vertical Termination - Optional Concentric Vent ... 30-31
Alternate Vertical Concentric Venting......................... 32
6. HYDRONIC PIPING
System Water Piping Methods. . . . . . . . . . . . . . . . . . . . . 33
Low Water Cutoff Device . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chilled Water System. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Freeze Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
General Piping Information . . . . . . . . . . . . . . . . . . . . . . . 33
Near Boiler Piping Components. . . . . . . . . . . . . . . . . . . . 34
Near Boiler Piping Connections . . . . . . . . . . . . . . . . . . . . 35
Circulator Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Variable Speed Pump Option . . . . . . . . . . . . . . . . . . . . . 37
7. GAS CONNECTIONS
Connecting Gas Supply Piping . . . . . . . . . . . . . . . . . . . . 48
Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Pipe Sizing for Natural Gas . . . . . . . . . . . . . . . . . . . . 49
Natural Gas Supply Pressure Requirements . . . . . . . 49
Propane Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Pipe Sizing for Propane Gas . . . . . . . . . . . . . . . . . . . 49
Propane Supply Pressure Requirements . . . . . . . . . . 49
Check Inlet Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Gas Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . 51
8. FIELD WIRING
Line Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . . 52
Low Voltage Connections . . . . . . . . . . . . . . . . . . . . . . . . 52
Wiring of the Cascade . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9. CONDENSATE DISPOSAL
Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10. STARTUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57-63
11. OPERATING INFORMATION
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Cascade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . 68-69
Knight Wall Mount Boiler Control Module . . . . . . . . . . . . 70
Status Display Screens . . . . . . . . . . . . . . . . . . . . . . . 71-73
12. MAINTENANCE
Maintenance and Annual Startup. . . . . . . . . . . . . . . . 74-77
13. DIAGRAMS
Ladder Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Wiring Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover
Contents

Installation & Operation Manual
Please read before proceeding
Installer – Read all instructions,
including this manual and the Knight
Wall Mount Service Manual, before
installing. Perform steps in the order
given.
User – This manual is for use only
by a qualified heating installer/
service technician. Refer to the User’s
Information Manual for your reference.
Have this boiler serviced/inspected by
a qualified service technician, at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
Failure to adhere to the guidelines on this
page can result in severe personal injury,
death, or substantial property damage.
When servicing boiler –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
Boiler water –
• Thoroughly flush the system (without boiler
connected) to remove sediment. The high-efficiency
heat exchanger can be damaged by build-up or
corrosion due to sediment.
• Continual fresh make-up water will reduce boiler life.
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger,
and causes failure. Addition of oxygen carried in by
makeup water can cause internal corrosion in system
components. Leaks in boiler or piping must be repaired
at once to prevent makeup water.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited
propylene glycol solutions, which are specifically
formulated for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used in hydronic
systems.
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
Consider piping and installation when
determining boiler location.
Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by
the consignee.
Factory warranty (shipped with unit)
does not apply to units improperly
installed or improperly operated.
3
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
This appliance MUST NOT be installed
in any location where gasoline or
flammable vapors are likely to be present.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a near by phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
• Installation and service must be
performed by a qualified installer,
service agency, or the gas supplier.
WARNING
NOTICE
WARNING
WARNING
Do not use petroleum-based cleaning or
sealing compounds in the boiler system.
Gaskets and seals in the system may be
damaged. This can result in substantial
property damage.
CAUTION
CAUTION Do not use “homemade cures” or “boiler
patent medicines”. Serious damage to
the boiler, personnel, and/or property
may result.

Installation & Operation Manual
4
The Knight Wall Mount Boiler - How it works...
1. Stainless steel heat exchanger
Allows system water to flow around specially designed
tubes for maximum heat transfer, while providing
protection against flue gas corrosion.
2. Combustion chamber access cover
Allows access to the combustion side of the heat
exchanger.
3. Blower
The blower pulls in air and gas through the venturi (item
5). Air and gas mix inside the blower and are pushed into the
burner, where they burn inside the combustion chamber.
4. Gas valve
The gas valve senses the negative pressure created by the
blower, allowing gas to flow only if the gas valve is
powered and combustion air is flowing.
5. Venturi
The venturi controls air and gas flow into the burner.
6. Flue gas sensor (limit rated)
This sensor monitors the flue gas exit temperature. The control
module will modulate and shut down the boiler if flue gas
temperature gets too hot. This protects the flue pipe from
overheating.
7. Boiler outlet temperature sensor (housed with high
limit sensor)
This sensor monitors boiler outlet water temperature (system
supply). If selected as the controlling sensor, the control
module adjusts boiler firing rate so the outlet temperature is
correct.
8. Boiler inlet temperature sensor
This sensor monitors return water temperature (system
return). If selected as the controlling sensor, the control
module adjusts the boiler firing rate so the inlet temperature is
correct.
9. Temperature and pressure gauge (field installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
10. Electronic LCD display
The electronic display consists of 4 buttons, a navigation dial
and a multiple line liquid crystal display.
11. Flue pipe adapter
Allows for the connection of the PVC vent pipe system to the
boiler.
12. Burner (not shown)
Made with metal fiber and stainless steel construction,
the burner uses pre-mixed air and gas and provides a
wide range of firing rates.
13. Water outlet (system supply)
The water outlet is the water connection for water leaving the
boiler and entering the system.
14. Water inlet (system return)
The water inlet is the water connection for water entering the
boiler from the system.
15. Gas connection pipe
Threaded pipe connection. This pipe should be
connected to the incoming gas supply for the purpose of
delivering gas to the boiler.
16. SMART SYSTEM Control Module
The SMART SYSTEM Control responds to internal and
external signals and controls the blower, gas valve, and pumps
to meet the heating demand.
17. Air intake adapter
Allows for the connection of the PVC air intake pipe to
the boiler.
18. High voltage junction box
The junction box contains the connection points for the line
voltage power and all pumps.
19. Low voltage connection board
The connection board is used to connect external low voltage
devices.
20. Low voltage wiring connections (knockouts)
Conduit connection points for the low voltage
connection board.
21. Condensate drain connection
Connects the condensate drain line.
22. Access door
Provides access to all internal components.
23. Ignition electrode
Provides direct spark for igniting the burner.
24. Flame inspection window
The quartz glass window provides a view of the burner
surface and flame.
25. Gas shutoff switch
An electrical switch designed to cut power to the gas valve to
prevent releasing any gas.
26. High limit sensor (housed with outlet sensor)
Device that monitors the outlet water temperature. If the
temperature exceeds its setting, it will break the control circuit,
shutting the boiler down.
27. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 30 psi.
28. Flame sensor
Used by the control module to detect the presence of burner
flame.
29. Line voltage wiring connections (knockouts)
Conduit connection points for the high voltage junction box.
30. Transformer
The transformer provides 24V power to the integrated control.
31. ModBus
The optional ModBus option provides intelligent building
system communications.
32. On/Off switch
The On/Off switch is used to turn 120 VAC on and off to the
unit.
33. Manual air vent
Allows for removal of trapped air from the heat exchanger.

Installation & Operation Manual
17
11
28
22
10
Front View
IMG00161
11
17
4
3
24
2
6
8
7
26
1
33
Left Side (inside unit)
IMG00162
27
23
28
16
19 31
30
18
25
5
33
Right Side (inside unit)
The Knight Wall Mount Boiler - How it works... (continued)
IMG00117
21
13
14
20
15
29
FRONT OF UNIT
32
Bottom View
5
Models 55 - 399

6
Installation & Operation Manual
Ratings
Notes:
1. As an Energy Star Partner, Lochinvar has determined that
Knight wall mount boilers meet the Energy Star guidelines
for energy efficiency.
2. The ratings are based on standard test procedures prescribed
by the United States Department of Energy.
3. Net 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.
4. Knight wall mount boilers require special gas venting. Use
only the vent materials and methods specified in the Knight
Wall Mount Installation and Operation Manual.
5. Standard Knight wall mount boilers are equipped to operate
from sea level to 4,500 feet only with no adjustments. The
boiler will de-rate by 4% for each 1,000 feet above sea level
up to 4,500 feet.
6. High altitude Knight wall mount boilers are equipped
to operate from 3,000 to 12,000 feet only with no field
adjustments. The boiler will de-rate by 2% for each 1,000
feet above 3,000 feet. High altitude models are manufactured
with a different control module for altitude operation, but
the operation given in this manual remains the same as the
standard boilers. A high altitude label (as shown in FIG. A)
is also affixed to the unit.
Maximum allowed working pressure is located on the rating plate.
NOTICE
Knight Wall Mount Boiler
AHRI Rating
Model Number
Note: Change
“N” to “L” for
L.P. gas models.
Input
MBH
(Note 5)
Min Max
Heating
Capacity
MBH
(Note 2, 8)
Net
AHRI
Ratings
Water,
MBH
(Note 3, 8)
AFUE
%
(Note 1, 8)
WHN055 11 55 51 44 96
WHN085 17 85 79 69 96
WHN110 22 110 102 89 96
WHN155 31 155 144 125 96
WHN199 40 199 186 162 96
WHN285 57 285 265 230 96
WHN399 80 399 379 330 95
7. The Knight Wall Mount boiler input rate, on some models,
is reduced for vent lengths beyond the minimum. Two inch
vent will reduce Models WH(N,L) 055, WH(N,L) 085 and
WH(N,L)110 by 0.6%, 0.94%, and 1.2% for every 10 feet
of vent. Three inch vent will reduce Models WH(N,L)155,
WH(N,L)199 and WH(N,L) 285 by 0.3%, 0.5%, and 0.6%
for every 10 feet of vent. Four inch vent will reduce Model
WH(N,L) 399 by 0.4% for every 10 feet of vent.
8. Ratings have been confirmed by the Hydronics Section of
AHRI. Model 399 has a thermal efficiency rating.
9. Knight wall mount boilers comply with the requirements
of CSD-1 Section CW-400 requirements as a temperature
operation control. The manual reset high limit provided
with the Knight wall mount boiler is listed to UL353.
Other Specifications
Boiler Water
Content
Gallons
Water
Connections
Gas
Connections
Vent/Air
Size
(Note 4)
2.5 1" 1/2" 2"
2.5 1" 1/2" 2"
3.5 1" 1/2" 3"
3.5 1" 1/2" 3"
5.0 1 1/4" 1/2" 3"
5.0 1 1/4" 1/2" 3"
6.5 1 1/2" 3/4" 4"
Figure A High Altitude Label Location
UNIT EQUIPPED FOR
HIGH ALTITUDE
3,000FT TO 12,000FT
ASME
H

Installation & Operation Manual
The Knight wall mount boiler gas
manifold and controls met safe lighting
and other performance criteria when the
boiler underwent tests specified in ANSI
Z21.13 – latest edition.
Failure to keep boiler area clear and free
of combustible materials, gasoline, and
other flammable liquids and vapors can
result in severe personal injury, death, or
substantial property damage.
Installation must comply with:
• Local, state, provincial, and national codes, laws,
regulations, and ordinances.
• National Fuel Gas Code, ANSI Z223.1 – latest edition.
• Standard for Controls and Safety Devices for Automatically
Fired Boilers, ANSI/ASME CSD-1, when required.
• National Electrical Code.
• For Canada only: B149.1 Installation Code, CSA C22.1
Canadian Electrical Code Part 1 and any local codes.
Before locating the boiler, check:
1. Check for nearby connection to:
• System water piping
• Venting connections
• Gas supply piping
• Electrical power
2. Locate the appliance so that if water connections should
leak, water damage will not occur. When such locations
cannot be avoided, it is recommended that a suitable
drain pan, adequately drained, be installed under the
appliance. The pan must not restrict combustion air
flow. Under no circumstances is the manufacturer to be
held responsible for water damage in connection with
this appliance, or any of its components.
3. Check area around the boiler. Remove any combustible
materials, gasoline and other flammable liquids.
4. The Knight wall mount boiler must be installed so
that gas control system components are protected from
dripping or spraying water or rain during operation or
service.
5. If a new boiler will replace an existing boiler, check for
and correct system problems, such as:
• System leaks causing oxygen corrosion or heat exchanger
cracks from hard water deposits.
• Incorrectly-sized expansion tank.
• Lack of freeze protection in boiler water causing system
and boiler to freeze and leak.
WARNING
NOTICE
1 Determine boiler location
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.
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.
Provide clearances:
Clearances from combustible materials
1. Hot water pipes—at least 1/4" from combustible materials.
2. Vent pipe – at least 1" from combustible materials.
3. See FIG.’s 1-1 and 1-2 on page 8 for other clearance
minimums.
Clearances for service access
1. See FIG.’s 1-1 and 1-2 on page 8 for recommended
service clearances. If you do not provide the minimum
clearances shown, it may not be possible to service the
boiler without removing it from the space.
Closet and alcove installations
This appliance requires a special venting
system. The vent connection to the
appliance is made of CPVC. Field supplied
vent fittings must be cemented to the CPVC
fitting on the boiler. Use only the vent
materials, primer, and cement specified in
the manual to make the vent connections.
Failure to follow this warning could result
in fire, personal injury, or death.
For closet and alcove installations as shown
in FIG.’s 1-1 and 1-2, CPVC or stainless
steel vent material must be used inside
the structure. The two ventilating air
openings shown in FIG. 1-1 are required
for this arrangement. Failure to follow
this warning could result in fire, personal
injury, or death.
WARNING
WARNING
A closet is any room the boiler is installed in which the room
volume is less than the room volume listed in the table below.
An alcove is any room which meets the criteria for a closet,
but it does not have a door.
Model Room Volume
(in cubic feet)
55 - 85 90
110 - 285 108
399 178
Example: Room dimensions = 4 feet long, 4 feet wide, and
9 foot ceiling = 4 x 4 x 9 = 144 cubic feet. This would be
considered a closet for the WHN399 model.
7

1/4" MINIMUM CLEARANCE
AROUND HOT WATER PIPES
1" MINIMUM CLEARANCE
A
ROUND VENT PIPE
OPEN FRONT
LEFT
0" MINIMUM
RIGHT
0" MINIMUM
FRONT
6" MINIMUM
BOTTOM
0" MINIMUM
TOP
6" MINIMUM
RECOMMENDED SERVICE CLEARANCES:
FRONT: 24”
BOTTOM: 24”
LEFT SIDE: 12”
Figure 1-2 Alcove Installation - Minimum Required Clearances
1/4" MINIMUM CLEARANCE
AROUND HOT WATER PIPES
1" MINIMUM CLEARANCE
AROUND VENT PIPE
CLOSED DOOR
6"
6"
VENTILATING
AIR OPENING*
*AREAOF EACH OPENING:
1 SQ. INCH PER 1000 BTU PER HOUR INPUT
WITH A MINIMUM OF 100 SQ. INCHES.
VENTILATING
AIR OPENING*
TOP
6" MINIMUM
LEFT
0" MINIMUM
BOTTOM
0" MINIMUM
RIGHT
0" MINIMUM
FRONT
6" MINIMUM
RECOMMENDED SERVICE CLEARANCES:
FRONT: 24”
BOTTOM: 24”
LEFT SIDE: 12”
Figure 1-1 Closet Installation - Minimum Required Clearances
WARNING
Note: Service clearances are recommendations only.
Note: Service clearances are recommendations only.
WARNING
8
1 Determine boiler location
Installation & Operation Manual
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.
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.

Installation & Operation Manual
Provide air openings to room:
Knight wall mount boiler alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Knight wall mount
boiler are at least equal to the SERVICE clearances
shown in FIG.’s 1-1 and 1-2. For spaces that do NOT
supply this clearance, provide two openings as shown
in FIG. 1-1. Each opening must provide one square
inch free area per 1,000 Btu/hr of boiler input.
Knight wall mount boiler in same space with other
gas or oil-fired appliances
1. Follow the National Fuel Gas Code (U.S.) or CSA
B149.1 (Canada) to size/verify size of the combustion/
ventilation air openings into the space.
The space must be provided with
combustion/ventilation air openings
correctly sized for all other appliances
located in the same space as the Knight
wall mount boiler.
Do not install the boiler in an attic.
Failure to comply with the above
warnings could result in severe personal
injury, death, or substantial property
damage.
2. Size openings only on the basis of the other appliances
in the space. No additional air opening free area is
needed for the Knight wall mount boiler because it
takes its combustion air from outside (direct vent
installation).
Wall mounting location
Ensure the wall for which the boiler is intended to be
mounted is comprised of either, cement, brick, block, or
wooden studs spaced 16" apart from center. Ensure the
wall is capable of supporting at least 250 pounds for Models
55 - 285 and 300 pounds for the 399 Models.
If flooding is possible, elevate the boiler sufficiently to
prevent water from reaching the boiler.
Ensure the boiler is installed in a location that minimizes
the risk of water damage due to valves, pumps, etc.
Residential garage installation
Precautions
Take the following precautions when installing the appliance in
a residential garage. If the appliance is located in a residential
garage, it should be installed in compliance with the latest
edition of the National Fuel Gas Code, ANSI Z223.1 and/or
CAN/CGA-B149 Installation Code.
• Appliances located in residential garages and in
adjacent spaces that open to the garage and are not part
of the living space of a dwelling shall be installed so that
all burners and burner ignition devices are located not
less than 18 inches (46 cm) above the floor.
• The appliance shall be located or protected so that it is
not subject to physical damage by a moving vehicle.
Vent and air piping
The Knight wall mount boiler requires a special vent system,
designed for pressurized venting.
The boiler is to be used for either direct vent installation or for
installation using indoor combustion air. When room air is
considered, see Section 3, General Venting. Note prevention of
combustion air contamination below when considering vent/
air termination.
Vent and air must terminate near one another and may be
vented vertically through the roof or out a side wall, unless
otherwise specified. You may use any of the vent/air piping
methods covered in this manual. Do not attempt to install the
Knight wall mount boiler using any other means.
Be sure to locate the boiler such that the vent and air piping can
be routed through the building and properly terminated. The
vent/air piping lengths, routing and termination method must
all comply with the methods and limits given in this manual.
Prevent combustion air contamination
Install air inlet piping for the Knight wall mount boiler as
described in this manual. Do not terminate vent/air in locations
that can allow contamination of combustion air. Refer to
Table 1A, page 10 for products and areas which may cause
contaminated combustion air.
You must pipe combustion air to the boiler
air intake. Ensure that the combustion air will
not contain any of the contaminants in Table
1A, page 10. Contaminated combustion air
will damage the boiler, resulting in possible
severe personal injury, death or substantial
property damage. Do not pipe combustion
air near a swimming pool, for example. Also,
avoid areas subject to exhaust fumes from
laundry facilities. These areas will always
contain contaminants.
WARNING
WARNING
1 Determine boiler location (continued)
9

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
10
1 Determine boiler location
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:
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.
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 11.
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 page 19.

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

Installation & Operation Manual
2 Prepare boiler
12
Remove boiler from wood pallet
1. After removing the outer shipping carton from the boiler,
remove the parts box.
2. To remove the boiler from the pallet:
a. Remove the two (2) lag bolts securing the bottom
of the unit to the pallet.
b. Lift the boiler off the wall bracket mounted to
the pallet.
3. Remove the two (2) lag bolts securing the wall bracket to
the wood pallet. Be certain not to lose the wall bracket
as it will be needed for securing the boiler to the wall
(FIG. 2-1).
Do not drop the boiler or bump the jacket
on the floor or pallet. Damage to the
boiler can result.
The gas conversion procedure should
be accomplished BEFORE the boiler is
installed. For a boiler already installed,
you must turn off gas supply, turn off
power, and allow the boiler to cool before
proceeding. You must also completely
test the boiler after conversion to verify
performance as described under Start-up,
Section 10 of this manual.
You must install the propane orifice to fire
the Knight wall mount boiler on propane.
Verify when installing that the orifice size
marking matches boiler size (Table 2A).
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
DO NOT DISCARD-
WILL BE NEEDED TO
SECURE THE BOILER
TO THE WALL
REMOVE SHIPPING
[WALL] BRACKET
Figure 2-1 Boiler Mounted on Shipping Pallet
Gas conversions
LP Conversion Table
Model LP Orifice Stamping
55 055
85 085
110 110
155 155
199 199
285 H285
399 8.0
NOTICE
WARNING
Table 2A LP Conversion Table
Figure 2-2 Gas Valve Power Switch & Venturi Removal
REMOVE THE SCREWS SECURING
THE GAS VALVE VENTURI TO THE
INLET OF THE COMBUSTION
BLOWER
7. Using an Allen wrench, remove the screws securing the gas
pipe to the gas valve. Remove the gas valve venturi assembly
from the unit (FIG. 2-3).
8. Using an Allen wrench, remove the venturi from the gas
valve.
9. Locate the propane orifice disk from the conversion kit bag.
Verify that the stamping on the orifice disk matches the
boiler size (see Table 2A).
10. Place the orifice into the black rubber grommet in the side of
the gas valve and secure inside the gas valve (see FIG. 2-3).
11. Reattach the venturi to the gas valve and reposition the gas
valve venturi assembly inside the unit. Secure the venturi
back to the gas valve (FIG. 2-3).
12. Reattach the gas pipe to the gas valve. Reattach the air intake
and coupler and tighten down on the band clamp.
1. Remove the front access cover from the unit (no tools
required for removal).
2. Models 55 - 285 only, locate the power switch on the gas
valve and turn the power switch to the “OFF” position
(FIG. 2-2).
3. Model 399 only, shut off power at the source.
4. Disconnect the Molex plug from the gas valve.
5. Using a 5/16" nut driver, loosen the band clamp securing the
air intake coupler to the gas valve venturi. Remove the air
intake pipe and coupler from the gas valve venturi.
6. Using an Allen wrench, remove the screws securing the
gas valve venturi to the inlet of the combustion blower
(FIG. 2-2).

Installation & Operation Manual
2 Prepare boiler (continued)
FASTENERS
APPROPRIATE
FOR WALL TYPE
QTY: 4
MOUNTING BRACKET
(FACTORY SUPPLIED)
WALL:
WOOD OR METAL STUDS ON
16" CENTERS -OR-
MASONRY / POURED CONCRETE
Figure 2-4 Mounting the Boiler
VENTURI
GAS VALVE
GROMMET
BRASS ORIFICE
SCREWS
Figure 2-3 Installing Propane Orifice
13. Reattach the Molex plug to the gas valve.
14. Models 55 - 285 only, turn the gas valve power switch to
the “ON” position.
15. Model 399 only, turn on power at the source.
16. After the installation is complete, fill out the gas conversion
label (in the conversion kit bag) and affix it to the unit
under the boiler rating plate inside the unit. Attach the
LP caution label (in the conversion kit bag) to the left side
of the unit in the lower left corner.
17. Replace the front access cover.
2. Mount the wall bracket using the 2 1/4" lag bolts
provided. Make sure the top edge of the bracket is away
from the wall. Ensure the bracket is level when mounted.
Extreme care is needed to ensure the bolts are secured in
the center of the studs.
3. Hang the boiler on the bracket and secure the bottom of
the boiler with two (2) additional lag bolts provided.
Mounting to a metal studded wall:
1. The wall mount bracket is designed for a stud spacing of
16 inches from center. For other stud spacing a solid
mounting surface must be provided by the installer.
WARNING The boiler is too heavy for a single person
to lift. A minimum of two people is needed
for mounting the boiler onto the bracket.
2. Mount the wall bracket using two (2) field supplied toggle
bolts capable of supporting 100 pounds each. Ensure the
top edge of the bracket is away from the wall. Ensure the
bracket is level when mounted. Extreme care is needed to
ensure the bolts are secured in the center of the studs.
3. Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) field supplied toggle bolts.
WARNING Do not mount the boiler to a hollow wall. Be
sure to mount the boiler to the studs only.
Mounting the boiler
See page 9 of this manual for boiler mounting location
instructions.
NOTICE The Knight Wall Mount boiler is not
intended for floor installation.
Mounting to a wood studded wall:
1. The wall mount bracket is designed for a stud spacing of
16 inches from center. For other stud spacing a solid
mounting surface must be provided by the installer.
WARNING Do not mount the boiler to a hollow wall.
Be sure to mount the boiler to the studs
only.
Mounting to a concrete wall:
1. Mount the wall bracket using the two (2) wedge anchor
bolts provided with the bracket. To mount the wedge
anchor bolts, drill a 1/4" diameter hole 1 1/8" deep and
insert anchor. Hang the bracket from the anchor and secure
with the two nuts provided. Make sure the top edge of the
bracket is away from the wall. Ensure bracket is level when
mounted. Extreme care is needed to ensure the bolts are
secured in the center of the studs.
Note: If wall thickness does not allow a 1 1/8" deep hole,
field supplied hardware suitable for the application should be
provided.
2. Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) remaining anchors, following the
instructions above.
WARNING The boiler is too heavy for a single person to
lift. A minimum of two people is needed for
mounting the boiler onto the bracket.
WARNING After converting to LP, check combustion
per the Start-up procedure in Section 10
of this manual. Failure to check and
verify combustion could result in severe
personal injury, death, or substantial
property damage.
WARNING The boiler is too heavy for a single person to
lift. A minimum of two people is needed for
mounting the boiler onto the bracket.
13

3 General venting
14
Installation & Operation Manual
Figure 3-1 Two-Pipe Sidewall Termination - See page
22 for more details Figure 3-2 PVC/CPVC Concentric Sidewall Termination - See page 26 for more details
Direct venting options - Sidewall Vent
Figure 3-3 Two-Pipe Vertical
Termination - See page 29 for
more details
Figure 3-4 PVC/CPVC Concentric
Vertical Termination - See page 30
for more details
Figure 3-5 Vertical Vent, Sidewall Air
- See page 18 for more details

15
Installation & Operation Manual
3 General venting
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 wall mount boiler must be
vented and supplied with combustion and
ventilation air as described in this section.
Ensure the vent and air piping and the
combustion air supply comply with these
instructions regarding vent system, air
system, and combustion air quality. See
also Section 1 of this manual.
Inspect finished vent and air piping
thoroughly to ensure all are airtight and
comply with the instructions provided and
with all requirements of applicable codes.
Failure to provide a properly installed vent
and air system will cause severe personal
injury or death.
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. 3-6) - 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 3-7 thru 3-9) - Used to provide a
passageway for conveying combustion gases to the
outside. A transition fitting is provided on the unit for
final connection. Vent piping must be supported per the
National Building Code, Section 305, Table 305.4 or as
local codes dictate.
The Knight wall mount boiler vent and air piping can be
installed through the roof or through a sidewall. Follow the
procedures in this manual for the method chosen. Refer to the
information in this manual to determine acceptable vent and
air piping length.
You may use any of the vent/air piping methods covered in
this manual. Do not attempt to install the Knight wall mount
boiler using any other means.
You must also install air piping from outside to the boiler
air intake adapter unless following the Optional Room
Air instructions on page 18 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
11 of this manual when removing a boiler
from an existing vent system.
NOTICE
AIR
Figure 3-6 Near Boiler Air Piping

3 General venting
Installation & Operation Manual
16
Model 2" Max Vent/
Air 3" Max Vent/ Air 4" Max Vent/ Air
55 *80 feet 100 feet N/A
85 *50 feet 100 feet N/A
110 *40 feet 100 feet N/A
155 N/A 100 feet N/A
199 N/A 100 feet N/A
285 N/A *50 feet 100 feet
399 N/A N/A 100 feet
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 2" and 3" Concentric Vent Kits available from
Lochinvar (see Section 4 – Sidewall Termination – Optional
Concentric Vent) and the 2" and 3" Concentric Vent Kits
available from IPEX are approved for use on the Knight
wall mount boiler. Both kits are listed to the ULC-S636
standard for use in Canada.
When determining equivalent combustion air and vent
length, add 5 feet for each 90° elbow and 3 feet for each
45° elbow.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2)
45° elbows + (1) concentric vent kit (CVK3003) = 49
equivalent feet of piping.
The appliance output rating will reduce
by up to 1.5% for each 25 feet of vent
length.
NOTICE
Model Kit Number Equivalent Vent
Length
55 - 110 CVK3008 3 feet
155 - 199 CVK3003 3 feet
285 - 399 CVK3007 3 feet
Table 3B Concentric Vent Kit Equivalent Vent Lengths
Sizing
The Knight boiler uses model specific combustion air intake and
vent piping sizes as detailed in Table 3A below.
Table 3A Air Intake/Vent Piping Sizes
Increasing or decreasing combustion air or
vent piping sizes is not authorized.
NOTICE
For Models 55, 85, and 110 using 2"
venting and Model 285 using 3" venting,
the first seven (7) equivalent feet of vent
must be CPVC (field supplied). This
includes any transition piece used to
increase or decrease the vent diameter.
*WARNING
Note: The minimum combustion air and vent piping
length is 12 equivalent feet.

17
Installation & Operation Manual
3 General venting (continued)
Materials
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.
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.
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.

3 General venting
18
Installation & Operation Manual
Air contamination
Pool and laundry products and common household and hobby
products often contain fluorine or chlorine compounds.
When these chemicals pass through the boiler, they can form
strong acids. The acid can eat through the boiler wall, causing
serious damage and presenting a possible threat of flue gas
spillage or boiler water leakage into the building.
If the boiler combustion air inlet is located
in a laundry room or pool facility, for
example, these areas will always contain
hazardous contaminants.
To prevent the potential of severe personal
injury or death, check for areas and
products listed in Table 1A, page 10 before
installing the boiler or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
—OR—
• Relocate air inlet and vent
terminations to other areas.
WARNING
WARNING
Optional room air
Commercial applications utilizing the Knight wall mount
boiler may be installed with a single pipe carrying the flue
products to the outside while using combustion air from
the equipment room. In order to use the room air venting
option the following conditions and considerations must be
followed.
• The unit MUST be installed with the appropriate
room air kit (Table 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.
WARNING When utilizing the single pipe method,
provisions for combustion and ventilation
air must be in accordance with Air for
Combustion and Ventilation, of the latest
edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada, the latest edition
of CGA Standard B149 Installation Code for
Gas Burning Appliances and Equipment, or
applicable provisions of the local building
codes.
Model Vent Size Kit Number
55 - 110 2" KIT30051
55 - 285 3" KIT30052
199 - 399 4" KIT30053
Table 3C Optional Room Air Kit
NOTICE Optional room air is intended for
commercial applications. Combustion air
piping to the outside is recommended for
residential applications.
Please read the information given in Table 1A, page 10,
listing contaminants and areas likely to contain them. If
contaminating chemicals will be present near the location of
the boiler combustion air inlet, have your installer pipe the
boiler combustion air and vent to another location, per this
manual.

3 General venting (continued)
19
Installation & Operation Manual
Installing vent and air piping
Use only cleaners, primers, and solvents
that are approved for the materials which
are joined together.
NOTICE
1. Work from the boiler to vent or air termination. Do not
exceed the lengths given in this manual for the air or vent
piping.
2. Cut pipe to the required lengths and deburr the inside
and outside of the pipe ends.
3. Chamfer outside of each pipe end to ensure even
cement distribution when joining.
4. Clean all pipe ends and fittings using a clean dry rag.
(Moisturewillretardcuringanddirtorgreasewillprevent
adhesion.)
5. Dry fit vent or air piping to ensure proper fit up before
assembling any joint. The pipe should go a third to
two-thirds into the fitting to ensure proper sealing after
cement is applied.
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
approved cement to the pipe equal to the depth of
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 cement was not applied and joint could
be defective.
g. Wipe excess cement from the joint removing ring
or beads as it will needlessly soften the pipe.
PVC/CPVC
Table 3D PVC/CPVC Vent Pipe, and Fittings
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 piece 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.
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
Figure 3-7 Near Boiler PVC/CPVC Venting
This product has been approved for use with the PVC/CPVC
vent materials listed in Table 3D.
NOTE: In Canada, CPVC and PVC vent pipe, fittings and cement/
primer must be ULC-S636 certified.
CPVC STARTER PIECE

3 General venting
20
Installation & Operation Manual
The installer must use a specific vent starter
adapter at the flue collar connection.
The adapter is supplied by the vent
manufacturer to adapt to its vent system.
See Table 3F for approved vent adapters.
NOTICE
All vent connections MUST be secured by
the vent manufacturer's joint connector
(FIG. 3-8).
NOTICE
IMG00130
JOINT CONNECTOR REQUIRED
AT ALL COMPONENT CONNECTIONS
OF VENT SYSTEM
POLYPROPYLENE ADAPTER
W/FLUE CLAMP
Figure 3-8 Near Boiler Polypropylene Venting
Model
Centrotherm InnoFlue SW Duravent Polypro
Polypropylene
Adapter Joint Connector
Sidewall
Retaining
Bracket* Sidewall Adapter* Polypropylene Adapter Joint
Connector Sidewall Kit*
55 - 85 ISAG0202 w/
IAFC02 IANS02 IATP0202 ISTAGL0202 2PPS-AD w/PPS-PAC 2PPS-LB 2PPS-HLK
110 - 285 ISAG0303 w/
IAFC03 IANS03 IATP0303 ISTAGL0303 3PPS-AD w/PPS-PAC 3PPS-LB 3PPS-HLK
399 ISAG0404 w/
IAFC04 IANS04 IATP0404 ISTAGL0404 4PPS-AD w/PPS-PAC 4PPS-LB 4PPS-HLK
* These parts are only needed if the sidewall termination assembly is used (see FIG. 4-4B on page 24).
Table 3F Approved PolypropyleneTerminations
Polypropylene
This product has been approved for use with polypropylene
vent with the manufacturers listed in Table 3E.
All terminations must comply with listed options in this manual
and be a single-wall vent offering.
For use of flex pipe, it is recommended to have the vent material
in 32°F or higher ambient space before bending at installation.
No bends should be made to greater than 45° and ONLY
installed in vertical or near vertical installations.
For support and special connections required, see the
manufacturer's instructions. All vent is to conform to standard
diameter and equivalent length requirements established.
Use only the adapters and vent system listed
in Tables 3E and 3F. DO NOT mix vent
systems of different types or manufacturers.
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
WARNING
Installations must comply with applicable
national, state, and local codes. For
Canadian installation, polypropylene vent
must be listed as a ULC-S636 approved
system.
NOTICE
Installation of a polypropylene vent system
should adhere to the vent manufacturer’s
installation instructions supplied with the
vent system.
NOTICE
Approved Polypropylene Vent Manufacturers
Make Model
Centrotherm Eco Systems InnoFlue SW/Flex
Duravent (M & G Group) PolyPro Single-Wall / PolyPro Flex
Table 3E Polypropylene Vent Pipe and Fittings
WARNING Insulation should not be used on
polypropylene venting materials. The use
of insulation will cause increased vent wall
temperatures, which could result in vent
pipe failure.