HydroTherm KN-2 User manual

is manual is intended only for use by a qualied heating installer/technician. Read and follow this manual, all supplements and related
instructional information provided with the boiler. Install, start and service the boiler only in the sequence and methods given in these
instructions. Failure to do so can result in severe personal injury, death or substantial property damage.
Do not use the boiler during construction. Construction dust and particulate, particularly drywall dust, will cause contamination of
the burner, resulting in possible severe personal injury, death or substantial property damage. e boiler can only be operated with a dust-
freeairsupply.Follow the instruction manualprocedurestoductairtotheboilerairintake.Iftheboiler has been contaminatedbyoperation
with contaminated air, follow the instruction manual guidelines to clean, repair or replace the boiler if necessary.
Ax these instructions near to the boiler/water heater. Instruct the building owner to retain the instructions for future use by a qualied
service technician, and to follow all guidelines in the User’s Information Manual.
P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Cast iron condensing boilers
Models KN
- 2 and KN - 4
Vent/air manual
Installation instructions
for vent and air piping
Also read and follow:
KNBoiler manual
KNControl manual
KN-2/4 VAM2-1012
KN
Series

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 2 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
The Hydrotherm KN boiler —Vent and air piping options
Vent and air piping, general
Pages 2, 3 and 4 are a brief overview of the options for vent and air piping congurations. Page 3 and 4
gives a summary and brief list of requirements for each of the vent/air conguration options.
When air is taken from the boiler room (no air pipe connected to the boiler air inlet ing), follow the
instructions in the KNBoiler manual to ensure the boiler room has proper openings for combustion air
and ventilation.
Vent piping
Category II & IV venting only
Category IV Individual Vent: All KNboilers require vent piping listed for use in pressurized,
condensing operation. Use only the materials specied in this manual. Category II Common Vent:
Cosult factory when common venting multiple boilers and/or use an engineered venting system
solution.
Vent pipe options
Use only Heat-fab Saf-T Vent® EZ Seal vent pipe and components. You will nd specic component
information for each conguration in this manual.
Vent pipe joint assembly
EZ Seal vent piping use a silicon rubber ring-style gasket in each joint. Joints are secured using metal tabs
that wrap around a ring on the adjacent piping component for Heat-fab vent pipe, or gear clamps for vent
pipe. Never use screws in the vent piping. Screws are only applied to the air piping portion of Heat-fab SC
concentric vent, used for concentric vent/air sidewall terminations.
Air piping
Air options
Combustion air can be piped through the side wall or through the roof of the building. Sidewall air intake
can be done with either through-the-roof or sidewall venting. See the next page for a summary of each
conguration.
Air piping materials
e best choices for air piping are PVC, CPVC or ABS. ese materials are easy to work with and yield
a clean nal appearance. Joint sealing is easier than other methods because it only requires use of the
standard joint sealant for the type of plastic pipe used. And there are not horizontal seams requiring
sealing like on metal air piping.
Other materials suitable for combustion air venting are galvanized pipe, aluminum pipe and exible
aluminum pipe. All joints, including the seams, of these piping materials must be sealed with silicone
adhesive sealant, such as Dow Corning 732.
Terminations
Through-the-roof terminations
Both vent and air piping must terminate with a Heat-fab rain cap.
Sidewall terminations
Vent and air pipes can be individually terminated using Heat-fab termination elbows with built-in screen,
or concentrically terminated using Heat-fab type SC concentric vent/air pipe (only when using Heat-fab
vent piping) termination components as given in this manual.
Heat-fab
EZ Seal
Joint
Assembly

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 3KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
3 Vent & air piped through the roof
(separate vent and air terminations)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
4-inch
Rain cap vent termination 5300CI Rain cap vent termination 5400CI
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Air components Heat-Fab
Rain cap termination
Termination pipe section (3 ft)*
5300CI
9307
Rain cap termination
Termination pipe section (3 ft)*
5400CI
9407
*Note: Standard air piping termination pipe section is 3 feet. A longer
length can be used if needed.
*Note: Standard air piping termination pipe section is 3 feet. A longer
length can be used if needed.
Air piping/components
(incl. supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
Air piping/components
(incl. supports, thimbles, etc.)
4-inch PVC, CPVC, ABS,
galvanized or aluminum
1 Vent piped through the roof
(combustion air from the boiler room)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
4-inch
Rain cap vent termination 5300CI Rain cap vent termination 5400CI
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
See pages 5 – 6
2 Vent piped through the roof
(air piped through side wall)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
4-inch
Rain cap vent termination 5300CI Rain cap vent termination 5400CI
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Air components Heat-Fab
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9414TERM
9402
9493S
4-inch clamp
Air piping/components
(also supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
Air piping/components
(also supports, thimbles, etc.)
4-inch PVC, CPVC, ABS,
galvanized or aluminum
See pages 7 – 10
See pages 11 – 14
The Hydrotherm KN boiler —Vent and air piping options

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 4 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
4 Vent piped through a side wall
(combustion air from the boiler room)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
4-inch
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9414TERM
9402
9493S
4-inch clamp
See pages 15 – 18
5 Vent & air piped through a side wall
(separate vent and air terminations)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
4-inch
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9414TERM
9402
9493S
4-inch clamp
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Air components Heat-Fab
Termination elbow Same as vent termination Termination elbow Same as vent termination
Air piping/components
(also supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
Air piping/components
(also supports, thimbles, etc.)
4-inch PVC, CPVC, ABS,
galvanized or aluminum
6 Vent & air piped through a side wall
(concentric vent/air termination)
KN-2 Vent components Heat-Fab KN-4 Vent components Heat-Fab
Ventpiping/components
(incl.supports, thimbles, etc.)
EZ-Seal, 3-inch piping
Saf-TVent SC ttings for
termination assembly
Ventpiping/components
(incl.supports, thimbles, etc.)
EZ-Seal, 4-inch piping
Saf-TVent SC ttings for
termination assembly
Termination assembly:
• Single-wall adapter
• Air intake tee
• 6-inch straight section
• 12-inch straight section
• Wall plate (2 required)
• Termination adapter
• Mitered termination
SC03ADEZ
SC03TAD3
SC0366
SC03L12
SC03FS
SC03HT
9390
Termination assembly:
• Single-wall adapter
• Air intake tee
• 6-inch straight section
• 12-inch straight section
• Wall plate (2 required)
• Termination adapter
• Mitered termination
SC04ADEZ
SC04TAD3
SC0466
SC04L12
SC04FS
SC04HT
9490
Joint sealant, required GE RTV106 or equivalent Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Air components Heat-Fab
Air piping/components
(also supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
Air piping/components
(also supports, thimbles, etc.
4-inch PVC, CPVC, ABS,
galvanized or aluminum
See pages 19 – 22
See pages 23 – 26
The Hydrotherm KN boiler —Vent and air piping options

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 5KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (combustion air from the boiler room)1
Figure 1 Vertical venting
Vent piping (see Figure 1)
1 — Boiler vent connection
❑e vent connection at the boiler is for Heat-Fab EZ-Seal vent piping only.
EZ-Seal vent aachment
EZ-Seal connection: Insert EZ-Seal pipe male end into the boiler connection
(Do not cover combustion test port). Make sure the locking tabs slide under
the EZ-Seal locking ring. Bend back locking tabs to complete the joint. Follow EZ-
Seal instructions to complete the vent piping installation.
Read before proceeding
The vent piping operates with positive pressure. e vent
piping must be completely sealed and securely supported.
Use only the vent components listed in this manual. Use
of any other materials could result in vent system failure.
Exposed vent pipe poses a potential burn hazard to people and
pets. Insulate or shield the pipe where necessary to prevent
risk.
Never drill through, or install screws into, the vent pipe or
vent components.
Seal test hole with high temperature silicone aer each
combustion test and annual inspection to prevent gases and
condensation from leaking during appliance operation.
Failure to properly install the vent piping could result in ue
gas leakage, causing possible severe personal injury, death or
substantial property damage.
Code compliance — Follow all applicable local codes when
installing the vent system. Where codes dier from this
manual, follow code requirements. Contact Hydrotherm if you
have any questions regarding the installation.
Terminate the vent following the guidelines in this manual.
Avoid vent termination locations likely to be aected by
winds, snowdris, people and pets. Protect building materials
and vegetation from degradation caused by the ue gases and
condensation.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 6 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (combustion air from the boiler room) (cont.)1
Table 1 Vent system components
Figure 2 Vent termination minimum clearances
❑Slope horizontal runs toward the boiler. All horizontal runs of vent pipe
must slope continuously at least 1/4 inch per foot (21 mm per meter) to ensure
condensate drains completely back to the boiler. DO NOT install the vent piping
with any sections that could trap condensate.
2 — Vent piping components
❑See Table1 for acceptable vent components. NO OTHER vent materials are
acceptable.
❑Carefully follow the instructions supplied by the vent piping manufacturer.
❑e vent joints seal with elastomer rings in the pipe and ings. Avoid damaging
these seals.
❑Adjustable lengths of EZ-Seal pipe —Lengthadjustmentswith EZ-Seal piping
are made with slip-t adjustable length sections, not by cuing the pipe. Make sure
the adjustable length does not jut into elbows or terminations. is could block
ue gas and condensate ow.
❑Maximum vent piping length — See the table in Figure 3 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
❑Insulate the vent piping where it passes through unheated areas to prevent
condensate freeze-up.
❑If the pipe passes through an occupied space, install a chase around the pipe,
following the vent pipe instructions and applicable codes.
❑Clearance from combustible materials — Provide minimum clearance to all
combustible materials of at least 2 inches (51 mm).
❑Using an existing chimney as a chase —event piping can beroutedthrough
an existing UNUSED and STRAIGHT chimney. DO NOT vent directly into the
chimney. Install the vent piping so it can be inspected aer installation. Follow vent
pipe manufacturer’s instructions for chimney-as-chase installations.
3 & 4 — Support the vent piping completely
❑DO NOT use the boiler vent connection to support the vent piping. Provide
support straps from the ceiling and pedestal supports from the oor; utilize
noncombustible saddle. is is required on ALL installations, regardless of the
length of the horizontal piping connected to the boiler.
❑Ventpipingcannotbesupportedfromabove(suchasrelyingonroofjacksections).
You must install supports on the horizontal piping before the vent turns upward.
Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
❑Install at least one support on every horizontal run. For horizontal runs
longer than 5 feet (1.5 m), install a support every 3 feet (0.9 m).
❑Follow the vent pipe manufacturer’s instructions for placement and installation of
supports.
5 — Floor and wall penetrations
❑Followapplicablecodesand the ventpipe instructionstoinstallrestops,thimbles
or other devices at all oor and wall penetrations.
❑Provide minimum 2 inches (51 mm) clearance to all combustible construction.
6 — Roof penetrations
❑Followapplicablecodesandtheventpipeinstructions toinstallaroofjack, ashing
and support. Long extensions of vent pipe above the roof may require the use of
guy supports as specied in the vent pipe instructions.
7 — Rain cap termination
❑Use only the rain caps listed in Table 1.
❑e rain cap exhaust opening must be at least 2 feet (0.6 m)
above the highest roof point within 10 feet, as shown in
Figure 1. See the National Fuel Gas Code, ANSI/NFPA 54
for details on pitched roof applications.
❑See Figure 2 for additional minimum clearances.
Combustion air openings
❑Combustion air must be supplied from the boiler room as
shown in Figure 1. Make sure the installation provides air
openings as required by applicable codes and the Boiler
manual.
Multiple boiler installations
❑Install multiple vents through the roof following all guide-
lines for single-vent installations.
❑Install the vents so they are no closer than 12 inches on
centers.
KN-2 KN-4
Vent components Heat-Fab Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
EZ-Seal
4-inch
Rain cap vent termination 5300CI 5400CI
Joint sealant, required GE RTV106 or equivalent GE RTV106 or equivalent

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 7KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (air piped through side wall)2
Figure 3 Vertical venting/sidewall air
Read before proceeding
The vent piping operates with positive pressure. e vent
piping must be completely sealed and securely supported.
Use only the vent components listed in this manual. Use
of any other materials could result in vent system failure.
Exposed vent pipe poses a potential burn hazard to people and
pets. Insulate or shield the pipe where necessary to prevent
risk.
Never drill through, or install screws into, the vent pipe or
vent components.
Seal test hole with high temperature silicone aer each
combustion test and annual inspection to prevent gases and
condensation from leaking during appliance operation.
Failure to properly install the vent piping could result in ue
gas leakage, causing possible severe personal injury, death or
substantial property damage.
Code compliance — Follow all applicable local codes when
installing the vent system. Where codes dier from this
manual, follow code requirements. Contact Hydrotherm if you
have any questions regarding the installation.
Terminate the vent and air piping following the guidelines
in this manual. Avoid vent termination locations likely to be
aected by winds, snowdris, people and pets. Protect building
materials and vegetation from degradation caused by the ue
gases and condensation.
Vent piping (see Figure 3)
1 — Boiler vent connection
❑e vent connection at the boiler is for Heat-Fab EZ-Seal vent piping only.
EZ-Seal vent aachment
EZ-Seal connection: Insert EZ-Seal pipe male end into the boiler connection
(Do not cover combustion test port). Make sure the locking tabs slide under
the EZ-Seal locking ring. Bend back locking tabs to complete the joint. Follow EZ-
Seal instructions to complete the vent piping installation.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 8 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (air piped through side wall) (continued)2
Table 2 Vent and air system components
Figure 4 Vent termination minimum clearances
❑Slope horizontal runs toward the boiler. All horizontal runs of vent pipe
must slope continuously at least 1/4 inch per foot (21 mm per meter) to ensure
condensate drains completely back to the boiler. DO NOT install the vent piping
with any sections that could trap condensate.
2 — Vent piping components
❑SeeTable2foracceptableventcomponents.NO OTHER ventmaterialsareacceptable.
❑Carefully follow the instructions supplied by the vent piping manufacturer.
❑e vent joints seal with elastomer rings in the pipe and ings. Avoid damaging
these seals.
❑Adjustable lengths of EZ-Seal pipe —Lengthadjustmentswith EZ-Seal piping
are done with slip-t adjustable length sections, not by cuing the pipe. Make sure
the adjustable length does not jut into elbows or terminations. is could block
ue gas and condensate ow.
❑Maximum vent piping length — See the table in Figure 3 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
❑Insulate the vent piping where it passes through unheated areas to prevent
condensate freeze-up.
❑If the pipe passes through an occupied space, install a chase around the pipe,
following the vent pipe instructions and applicable codes.
❑Clearance from combustible materials — Provide minimum clearance to all
combustible materials of at least 2 inches (51 mm).
❑Using an existing chimney as a chase —event piping can beroutedthrough
an existing STIGHT chimney. DO NOT vent directly into the chimney.
Install the vent piping so it can be inspected aer installation. Follow vent pipe
manufacturer’s instructions for chimney-as-chase installations.
3 & 4 — Support the vent piping completely
❑DO NOT use the boiler vent connection to support the vent piping. Provide
support straps from the ceiling and pedestal supports from the oor; utilizing
noncombustible saddle. is is required on ALL installations, regardless of the
length of the horizontal piping connected to the boiler.
❑Install at least one support on every horizontal run. For horizontal runs
longer than 5 feet (1.5 m), install a support every 3 feet (0.9 m).
❑Ventpipingcannotbesupportedfromabove(suchasrelyingonroofjacksections).
You must install supports on the horizontal piping before the vent turns upward.
Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
❑Follow the vent pipe manufacturer’s instructions for placement and installation of
supports.
5 — Floor and wall penetrations
❑Followapplicablecodesand the ventpipe instructionstoinstallrestops,thimbles
or other devices at all oor and wall penetrations.
❑Provide minimum 2 inches (51 mm) clearance to all combustible construction.
6 — Roof penetrations
❑Followapplicablecodesandtheventpipeinstructions toinstallaroofjack, ashing
and support. Long extensions of vent pipe above the roof may require the use of
guy supports as specied in the vent pipe instructions.
7 — Rain cap termination
❑Use only the rain caps listed in Table 2.
❑e rain cap exhaust opening must be at least 2 feet (0.6 m)
above the highest roof point within 10 feet, as shown in
Figure 3. See the National Fuel Gas Code, ANSI/NFPA 54
for details on pitched roof applications.
❑See Figure 4 for additional minimum clearances.
KN-2 KN-4
Vent components Heat-Fab Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
EZ-Seal
4-inch
Rain cap vent termination 5300CI 5400CI
Joint sealant, required GE RTV106 or equivalent GE RTV106 or equivalent
Air components Heat-Fab Heat-Fab
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
9414TERM
9402
9493S
4-inch clamp
Air piping/components
(also supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
4-inch PVC, CPVC, ABS,
galvanized or aluminum

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 9KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (air piped through side wall) (continued)2
Figure 3 (partially repeated from page 6)
Figure 5 Sidewall air pipe termination assembly
Combustion air must be uncontaminated
Construction dust: If the boiler is operated while the building
isunderconstructionitmustbeprotectedfromwood,concrete,
sheet rock and other types of dust. Failure to properly protect
the boiler from construction dust will damage the boiler.
Combustion air contaminated with uorocarbons or
other halogenated compounds, such as laundry products,
cleaning solvents and refrigerants will result in the formation of
acids in the combustion chamber and vent piping. ese acids
will cause premature failure of the boiler and vent, causing
possible severe personal injury, death or substantial property
damage.
If the boiler room, or any room through which the air piping
travels, may contain contaminants as listed above, you MUST
sealair pipejoints withsiliconeRTVtopreventcontaminants
from entering the boiler combustion air. e nished air piping
installation must be air-tight and water-tight.
Air piping (see Figure 3)
8 — Air pipe connection
❑Before installing the air piping, install the air pipe sidewall termination assembly
(item 10, Figure 3). See instructions following.
❑Construct the air piping from PVC, CPVC or ABS plastic, or galvanized or
aluminum metallic pipe (including exible aluminum duct if desired).
When using metallic piping — seal all of the longitudinal seam joints in
addition to the component joints.
❑Aach the air piping to the boiler air connection, requiring use of silicone RTV
to seal the connection. If the boiler room air is free of contaminants you can use
metallic duct tape to seal the joints. With age, however, duct tape adhesives can
loosen, so duct tape is not as reliable as silicone RTV.
❑Iftheinstallationisrequiredtomeetdirectvent(sealedcombustion)requirements,
seal all joints with silicone RTV. e air pipe installation must be air-tight and
water-tight.
❑Maximum air piping length — See the table in Figure 3, for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
9 — Supporting air piping
❑DO NOT use the boiler air connection to support the air piping. Provide
support straps from the ceiling or install wall brackets.
❑Provide at least one support on all air pipe installations.
❑Provide a support every 3 feet for air pipe lengths greater than 5 feet horizontally.
❑Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
10 —Air pipe termination (see Figure 5)
❑See Table 2 for part numbers of the sidewall termination components required
for EZ-Seal air pipe installations. e air piping termination must be constructed
using the stainless steel vent materials listed in Table 2 to ensure the conguration
is correct. DO NOT terminate the air piping with any other method.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 10 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through the roof (air piped through side wall) (continued)2
Figure 6 Minimum clearances to air termination
Figure 7 Using external piping to raise the termination
❑Termination assembly components:
A. Wall thimble — Use only the thimble listed in Table 2. e hole in the
thimble will prevent the pipe length (B) from being pushed inward. e
raised portion of the pipe female end is too large to pass through the hole in
the thimble. Follow the vent pipe manufacturer’s instructions supplied with
the thimble. If the wall thimble isn’t long enough for the application, follow the
vent manufacturer’s instructions to add an extension.
Alternate construction — e air pipe can be inserted through a hole
without using a thimble. For this option, attach a storm collar on both the
inside and outside walls at the penetration. Before aaching the collars,
seal around the air pipe thoroughly with silicone RTV to prevent air leakage
or insect access. e storm collar tightens around the vent pipe with a gear
clamp. is prevents movement of the nished assembly. You will still need to
use the length of vent pipe and the termination elbow described below.
B. Length of vent pipe — Use a 1-foot length of vent pipe as listed in Table 2
unless the wall penetration requires a longer length. If a longer length is
required, use a length of EZ-Seal long enough for the application.
Insert the pipe from OUTSIDE, male end rst. e pipe will stop at the raised
section of the female end.
C. Gear clamp — Use a hose clamp or a gear clamp manufactured by the vent
manufacturer (see Table 2).
Slide the clamp over the male end of the pipe aer the pipe has been inserted
from outside.
From the inside, pull the pipe so it is rmly against the outside plate.
Push the gear clamp against the inside plate and tighten securely. is will
prevent the termination assembly from being pushed outward.
D. Termination elbow — Use only the termination elbow listed in Table 2. e
elbow must be pointed downward.
Before inserting the male end of the elbow into the pipe, apply a bead of
silicone RTV and spread around the end.
Insert the termination elbow and secure using the vent pipe manufacturer’s
joint assembly procedure.
Termination location — Install the air pipe termination where it meets the
minimum clearances shown in Figure 6.
Appliance exhaust outlets — Install the air intake at least 2 feet below and 5
feet horizontally from any appliance vent outlet.
Exiting below grade or minimum height — See Figure 7. When the air
pipe must exit the building below grade or below the minimum height for
the termination elbow, install vertical piping as necessary for the termination
elbow to be high enough to meet the minimum clearances of Figure 6. Make
sure to support the piping using wall brackets available from the vent pipe
manufacturer.
Multiple boiler installations
Venting multiple boilers
❑Install multiple vents through the roof following all guidelines for single-vent
installations.
❑Install the vents so they are no closer than 12 inches on centers.
Air piping for multiple boilers
❑Air for each boiler must be individually piped. DO NOT use
combined air piping.
❑Install multiple air pipes through the side wall following all
guidelines for single-air pipe installations.
❑Install the terminations so they are no closer than 12 inches
on centers.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 11KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent and air piped through the roof (separate terminations)3
Figure 8 Vertical venting/sidewall air
Read before proceeding
The vent piping operates with positive pressure. e vent
piping must be completely sealed and securely supported.
Use only the vent components listed in this manual. Use
of any other materials could result in vent system failure.
Exposed vent pipe poses a potential burn hazard to people and
pets. Insulate or shield the pipe where necessary to prevent
risk.
Never drill through, or install screws into, the vent pipe or
vent components.
Seal test hole with high temperature silicone aer each
combustion test and annual inspection to prevent gases and
condensation from leaking during appliance operation.
Failure to properly install the vent piping could result in ue
gas leakage, causing possible severe personal injury, death or
substantial property damage.
Code compliance — Follow all applicable local codes when
installing the vent system. Where codes dier from this
manual, follow code requirements. Contact Hydrotherm if you
have any questions regarding the installation.
Terminate the vent and air piping following the guidelines
in this manual. Avoid vent termination locations likely to be
aected by winds, snowdris, people and pets. Protect building
materials and vegetation from degradation caused by the ue
gases and condensation.
Vent piping (see Figure 8)
1 — Boiler vent connection
❑e vent connection at the boiler is for Heat-Fab EZ-Seal vent piping only.
EZ-Seal vent aachment
EZ-Seal connection: Insert EZ-Seal pipe male end into the boiler connection
(Do not cover combustion test port). Make sure the locking tabs slide under
the EZ-Seal locking ring. Bend back locking tabs to complete the joint. Follow EZ-
Seal instructions to complete the vent piping installation.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 12 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent and air piped through the roof (separate terminations) (continued)3
Table 3 Vent and air system components
Figure 9 Termination minimum clearances
❑Slope horizontal runs toward the boiler. All horizontal runs of vent pipe
must slope continuously at least 1/4 inch per foot (21 mm per meter) to ensure
condensate drains completely back to the boiler. DO NOT install the vent piping
with any sections that could trap condensate.
2 — Vent piping components
❑See Table 3 for acceptable vent components. NO OTHER vent materials are
acceptable.
❑Carefully follow the instructions supplied by the vent piping manufacturer.
❑e vent joints seal with elastomer rings in the pipe and ings. Avoid damaging
these seals.
❑Adjustable lengths of EZ-Seal pipe —Lengthadjustmentswith EZ-Seal piping
are done with slip-t adjustable length sections, not by cuing the pipe. Make sure
the adjustable length does not jut into elbows or terminations. is could block
ue gas and condensate ow.
❑Maximum vent piping length — See the table in Figure 8 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
❑Insulate the vent piping where it passes through unheated areas to prevent
condensate freeze-up.
❑If the pipe passes through an occupied space, install a chase around the pipe,
following the vent pipe instructions and applicable codes.
❑Clearance from combustible materials — Provide minimum clearance to all
combustible materials of at least 2 inches (51 mm).
❑Using an existing chimney as a chase — e vent piping and air piping can
be routed through an existing UNUSED and STRAIGHT chimney. DO NOT
vent directly into the chimney. Install the vent piping so it can be inspected aer
installation. Follow vent pipe manufacturer’s instructions for chimney-as-chase
installations.
3 & 4 — Support the vent piping completely
❑DO NOT use the boiler vent connection to support the vent piping. Provide
support straps from the ceiling and pedestal supports from the oor; utilizing
noncombustible saddle. is is required on ALL installations, regardless of the
length of the horizontal piping connected to the boiler.
❑Install at least one support on every horizontal run. For horizontal runs
longer than 5 feet (1.5 m), install a support every 3 feet (0.9 m).
❑Ventpipingcannotbesupportedfromabove(suchasrelyingonroofjacksections).
You must install supports on the horizontal piping before the vent turns upward.
Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
❑Follow the vent pipe manufacturer’s instructions for placement and installation of
supports.
5 — Floor and wall penetrations
❑Followapplicablecodesand the ventpipe instructionstoinstallrestops,thimbles
or other devices at all oor and wall penetrations.
❑Provide minimum 2 inches (51 mm) clearance to all combustible construction.
6 — Roof penetrations
❑Followapplicablecodesandtheventpipeinstructions toinstallaroofjack, ashing
and support. Long extensions of vent pipe above the roof may require the use of
guy supports as specied in the vent pipe instructions.
7 — Rain cap termination
❑Use only the rain caps listed in Table 3.
❑e rain cap exhaust opening must be at least 2 feet (0.6 m)
above the highest roof point within 10 feet, as shown in
Figure 8. See the National Fuel Gas Code, ANSI/NFPA 54
for details on pitched roof applications.
❑See Figure 9 for additional minimum clearances. e vent
must always terminate at least 4 feet (1.2 m) above the air
intake termination.
KN-2 KN-4
Vent components Heat-Fab Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
EZ-Seal
4-inch
Rain cap vent termination 5300CI 5400CI
Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Heat-Fab
Rain cap termination
Termination pipe section (3 ft)*
5300CI
9307
5400CI
9407
*Note: Standard air piping termination pipe section is 3 feet. A longer length can be used if needed.
Air piping/components
(incl. supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
4-inch PVC, CPVC, ABS,
galvanized or aluminum

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 13KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Figure 8 (repeated from page 10)
Combustion air must be uncontaminated
Construction dust: If the boiler is operated while the building
isunderconstructionitmustbeprotectedfromwood,concrete,
sheet rock and other types of dust. Failure to properly protect
the boiler from construction dust will damage the boiler.
Combustion air contaminated with uorocarbons or
other halogenated compounds, such as laundry products,
cleaning solvents and refrigerants will result in the formation of
acids in the combustion chamber and vent piping. ese acids
will cause premature failure of the boiler and vent, causing
possible severe personal injury, death or substantial property
damage.
If the boiler room, or any room through which the air piping
travels, may contain contaminants as listed above, you MUST
sealair pipejoints withsiliconeRTVtopreventcontaminants
from entering the boiler combustion air. e nished air piping
installation must be air-tight and water-tight.
Air piping (see Figure 3)
8 — Air pipe connection
❑Construct the air piping from PVC, CPVC or ABS plastic, or galvanized or
aluminum metallic pipe (including exible aluminum duct if desired).
When using metallic piping — seal all of the longitudinal seam joints in
addition to the component joints.
❑Aach the air piping to the boiler air connection, requiring use of silicone RTV
to seal the connection. If the boiler room air is free of contaminants you can use
metallic duct tape to seal the joints. With age, however, duct tape adhesives can
loosen, so duct tape is not as reliable as silicone RTV.
❑Iftheinstallationisrequiredtomeetdirectvent(sealedcombustion)requirements,
seal all joints with silicone RTV. e air pipe installation must be air-tight and
water-tight.
❑e air piping connects to the stainless steel pipe section aached to the air intake
rain cap termination (item 10, Figure 8). See instructions following.
❑Maximum air piping length — See the table in Figure 8 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
9 — Supporting air piping
❑DO NOT use the boiler air connection to support the air piping. Provide
support straps from the ceiling or install wall brackets.
❑Provide at least one support on all air pipe installations.
❑Provide a support every 3 feet for air pipe lengths greater than 5 feet horizontally.
❑Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
Vent and air piped through the roof (separate terminations)3

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 14 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
10 —Air pipe termination (see Figure 8)
❑See Table 3 for part numbers of the vertical termination components required
for EZ-Seal air pipe installations. e air piping termination must be constructed
using the stainless steel vent materials listed in Table 3 to ensure the conguration
is correct. DO NOT terminate the air piping with any other method.
❑Termination assembly components:
A. Rain cap — Use only the rain cap listed in Table 3, the same cap as used on
the vent termination.
Install the rain cap so it meets the minimum clearances shown in Figure 9,
page 11.
B. Length of vent pipe — Use a 3-foot length of vent pipe as listed in Table 3
unless the roof penetration requires a longer length to meet minimum
clearances. If a longer length is required, use a length of EZ-Seal long enough
for the application.
Aach the air piping to the male end (boom end) of the stainless steel pipe.
C. Roof penetration components — Use the same components as used for
the vent penetration.
Multiple boiler installations
Venting multiple boilers
❑Install multiple vents through the roof following all guidelines for single-vent
installations.
❑Install the vents so they are no closer than 12 inches on centers.
❑Provide minimum 5 feet between the center line of any vent termination and any
air intake termination.
Air piping for multiple boilers
❑Air for each boiler must be individually piped. DO NOT use combined air piping.
❑Install multiple air pipes through the side wall following all guidelines for single-air
pipe installations.
❑Install the terminations so they are no closer than 12 inches on centers.
❑Provide minimum 5 feet between the center line of any vent termination and any
air intake termination.
Vent and air piped through the roof (separate terminations) (continued)3

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 15KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through a side wall (combustion air from the boiler room)4
Figure 10 Vertical venting/sidewall air
Table 4 Vent system components
Read before proceeding
The vent piping operates with positive pressure. e vent
piping must be completely sealed and securely supported.
Use only the vent components listed in this manual. Use
of any other materials could result in vent system failure.
Exposed vent pipe poses a potential burn hazard to people and
pets. Insulate or shield the pipe where necessary to prevent
risk.
Never drill through, or install screws into, the vent pipe or
vent components.
Seal test hole with high temperature silicone aer each
combustion test and annual inspection to prevent gases and
condensation from leaking during appliance operation.
Failure to properly install the vent piping could result in ue
gas leakage, causing possible severe personal injury, death or
substantial property damage.
Code compliance — Follow all applicable local codes when
installing the vent system. Where codes dier from this
manual, follow code requirements. Contact Hydrotherm if you
have any questions regarding the installation.
Terminate the vent and air piping following the guidelines
in this manual. Avoid vent termination locations likely to be
aected by winds, snowdris, people and pets. Protect building
materials and vegetation from degradation caused by the ue
gases and condensation.
Vent piping (see Figure 10)
1 — Boiler vent connection
❑e vent connection at the boiler is for Heat-Fab EZ-Seal vent piping only.
EZ-Seal vent aachment
EZ-Seal connection: Insert EZ-Seal pipe male end into the boiler connection
(Do not cover combustion test port). Make sure the locking tabs slide under
the EZ-Seal locking ring. Bend back locking tabs to complete the joint. Follow EZ-
Seal instructions to complete the vent piping installation.
KN-2 KN-4
Vent components Heat-Fab Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
EZ-Seal
4-inch
Joint sealant, required GE RTV106 or equivalent
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
9414TERM
9402
9493S
4-inch clamp

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 16 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through a side wall (combustion air from the boiler room) (cont.)4
❑Slope horizontal runs toward the boiler. All horizontal runs of vent pipe
must slope continuously at least 1/4 inch per foot (21 mm per meter) to ensure
condensate drains completely back to the boiler. DO NOT install the vent piping
with any sections that could trap condensate.
2 — Vent piping components
❑See Table 4 for acceptable vent components. NO OTHER vent materials are
acceptable.
❑Carefully follow the instructions supplied by the vent piping manufacturer.
❑e vent joints seal with elastomer rings in the pipe and ings. Avoid damaging
these seals.
❑Adjustable lengths of EZ-Seal pipe —Lengthadjustmentswith EZ-Seal piping
are done with slip-t adjustable length sections, not by cuing the pipe. Make sure
the adjustable length does not jut into elbows or terminations. is could block
ue gas and condensate ow.
❑Maximum vent piping length — See the table in Figure 8 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
❑Insulate the vent piping where it passes through unheated areas to prevent
condensate freeze-up. Do not insulate the within 18 inches of the termination
when it passes through a combustible wall.
❑If the pipe passes through an occupied space, install a chase around the pipe,
following the vent pipe instructions and applicable codes.
❑Clearance from combustible materials — Provide minimum clearance to all
combustible materials of at least 2 inches (51 mm).
3 & 4 — Support the vent piping completely
❑DO NOT use the boiler vent connection to support the vent piping. Provide
support straps from the ceiling and pedestal supports from the oor; utilize
noncombustible saddle. is is required on ALL installations, regardless of the
length of the horizontal piping connected to the boiler.
❑Install at least one support on every horizontal run. For horizontal runs
longer than 5 feet (1.5 m), install a support every 3 feet (0.9 m).
❑Ventpipingcannotbesupportedfromabove(suchasrelyingonroofjacksections).
You must install supports on the horizontal piping before the vent turns upward.
Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
❑Follow the vent pipe manufacturer’s instructions for placement and installation of
supports.
❑Followapplicablecodesand the ventpipe instructionstoinstallrestops,thimbles
or other devices at all oor and wall penetrations.
❑Provide minimum 2 inches (51 mm) clearance to all combustible construction. continued on next page

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 17KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent piped through a side wall (combustion air from the boiler room) (cont.)4
Figure 11 Termination minimum clearances
5 — Sidewall termination (see Figure 11)
❑See Table 4 for part numbers of the sidewall termination components required for
EZ-Seal vent pipe installations. e vent termination must be constructed using
the stainless steel vent materials listed in Table 4 to ensure the conguration is
correct. DO NOT terminate the air piping with any other method.
A. Wall thimble — Use only the thimble listed in Table 4. e hole in the
thimble will prevent the pipe length (B) from being pushed inward. e
raised portion of the pipe female end is too large to pass through the hole in
the thimble. Follow the vent pipe manufacturer’s instructions supplied with
the thimble. If the wall thimble isn’t long enough for the application, follow the
vent manufacturer’s instructions to add an extension.
Noncombustible walls — For noncombustible walls ONLY, you can omit
the thimble. For this option, attach a storm collar on both the inside and
outside walls at the penetration. Before aaching the collars, seal around
the vent pipe thoroughly with silicone RTV to prevent air leakage or insect
access. e storm collar tightens around the vent pipe with a gear clamp. is
prevents movement of the nished assembly. You will still need to use the
length of vent pipe and the termination elbow described below.
B. Length of vent pipe — Use a 1-foot length of vent pipe as listed in Table 4
unless the wall penetration quires a longer length. If a longer length is required,
use a length of EZ-Seal long enough for the application.
Insert the pipe from OUTSIDE, male end rst. e pipe will stop at the raised
section of the female end.
C. Gear clamp — Use a hose clamp or a gear clamp manufactured by the vent
manufacturer (see Table 4).
Slide the clamp over the male end of the pipe aer the pipe has been inserted
from outside.
From the inside, pull the pipe so it is rmly against the outside plate.
Push the gear clamp against the inside plate and tighten securely. is will
prevent the termination assembly from being pushed outward.
D. Termination elbow — Use only the termination elbow listed in Table 4. e
elbow must be pointed downward.
Before inserting the male end of the elbow into the pipe, apply a bead of
silicone RTV and spread around the end.
Insert the termination elbow and secure using the vent pipe manufacturer’s
joint assembly procedure.
Termination location — Install the vent pipe termination where it meets the
minimum clearances shown in Figure 12.
Exiting below grade or snow line — See Figure 13. When the vent pipe
must exit the building grade or below the minimum height for the termination
elbow, install vertical piping as necessary for the termination elbow to be high
enough to meet the minimum clearances of Figure 12. Make sure to support
the piping using wall brackets available from the vent pipe manufacturer.
If the pipe extends more than 3 feet, insulate the external portion of the pipe
and ings with at least 1/2-inch closed-cell foam polyolen pipe insulation.
Combustion air openings
❑Combustion air must be supplied from the boiler room as
shown in Figure 1. Make sure the installation provides air
openings as required by applicable codes and the Boiler
manual.
Multiple boiler installations
❑Install multiple vents through the side wall following all
guidelines for single-vent installations.
❑Install the vents so they are no closer than 12 inches
(305 mm) on centers.

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 18 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Figure 12 Termination minimum clearances
Vent piped through a side wall (combustion air from the boiler room) (cont.)4
Figure 13 Using external piping to raise the termination
To convert to metric dimensions:
meters = feet x 0.3
millimeters = inches x 25.4

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 19KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent and air piped through a side wall (separate terminations)5
Figure 14 Vertical venting/sidewall air
Table 5 Vent and air system components
Read before proceeding
The vent piping operates with positive pressure. e vent
piping must be completely sealed and securely supported.
Use only the vent components listed in this manual. Use
of any other materials could result in vent system failure.
Exposed vent pipe poses a potential burn hazard to people and
pets. Insulate or shield the pipe where necessary to prevent
risk.
Never drill through, or install screws into, the vent pipe or
vent components.
Seal test hole with high temperature silicone aer each
combustion test and annual inspection to prevent gases and
condensation from leaking during appliance operation.
Failure to properly install the vent piping could result in ue
gas leakage, causing possible severe personal injury, death or
substantial property damage.
Code compliance — Follow all applicable local codes when
installing the vent system. Where codes dier from this
manual, follow code requirements. Contact Hydrotherm if you
have any questions regarding the installation.
Terminate the vent and air piping following the guidelines
in this manual. Avoid vent termination locations likely to be
aected by winds, snowdris, people and pets. Protect building
materials and vegetation from degradation caused by the ue
gases and condensation.
Vent piping (see Figure 14)
1 — Boiler vent connection
❑e vent connection at the boiler is for Heat-Fab EZ-Seal vent piping only.
EZ-Seal vent aachment
EZ-Seal connection: Insert EZ-Seal pipe male end into the boiler connection
(Do not cover combustion test port). Make sure the locking tabs slide under
the EZ-Seal locking ring. Bend back locking tabs to complete the joint. Follow EZ-
Seal instructions to complete the vent piping installation.
KN-2 KN-4
Vent components Heat-Fab Heat-Fab
Vent piping/components
(incl. supports, thimbles, etc.)
EZ-Seal
3-inch
EZ-Seal
4-inch
Termination elbow
Termination pipe section (1 ft)
Termination thimble
Gear clamp (nose clamp)
9314TERM
9302
9393S
3-inch clamp
9414TERM
9402
9493S
4-inch clamp
Joint sealant, required GE RTV106 or equivalent
Air components Heat-Fab Heat-Fab
Termination elbow Same as vent termination Same as vent termination
Air piping/components
(also supports, thimbles, etc.)
3-inch PVC, CPVC, ABS,
galvanized or aluminum
4-inch PVC, CPVC, ABS,
galvanized or aluminum

P/N 42-9540 11/12 Copyright 2012 Hydrotherm
Page 20 KN INSTALLATION INSTRUCTIONS FOR VENT AND AIR PIPING
Vent and air piped through a side wall (separate terminations) (cont.)5
❑Slope horizontal runs toward the boiler. All horizontal runs of vent pipe
must slope continuously at least 1/4 inch per foot (21 mm per meter) to ensure
condensate drains completely back to the boiler. DO NOT install the vent piping
with any sections that could trap condensate.
2 — Vent piping components
❑See Table 5 for acceptable vent components. NO OTHER vent materials are
acceptable.
❑Carefully follow the instructions supplied by the vent piping manufacturer.
❑Install the sidewall vent termination before installing the vent piping.
❑e vent joints seal with elastomer rings in the pipe and ings. Avoid damaging
these seals.
❑Adjustable lengths of EZ-Seal pipe —Lengthadjustmentswith EZ-Seal piping
are done with slip-t adjustable length sections, not by cuing the pipe. Make sure
the adjustable length does not jut into elbows or terminations. is could block
ue gas and condensate ow.
❑Maximum vent piping length — See the table in Figure 14 for the maximum
allowable length. Each elbow causes the same pressure drop as 10 feet of vent pipe,
so the allowable length reduces 10 feet for each elbow used in the piping. When
45° elbows are used, two 45° elbows are equivalent to one 90° elbow.
❑Insulate the vent piping where it passes through unheated areas to prevent
condensate freeze-up. If the vent terminates through a combustible wall, leave the
last 18 inches of vent pipe uninsulated.
❑If the pipe passes through an occupied space, install a chase around the pipe,
following the vent pipe instructions and applicable codes.
❑Clearance from combustible materials — Provide minimum clearance to all
combustible materials of at least 2 inches (51 mm).
3 & 4 — Support the vent piping completely
❑DO NOT use the boiler vent connection to support the vent piping. Provide
support straps from the ceiling and pedestal supports from the oor; utilize
noncombustible saddle. is is required on ALL installations, regardless of the
length of the horizontal piping connected to the boiler.
❑Install at least one support on every horizontal run. For horizontal runs
longer than 5 feet (1.5 m), install a support every 3 feet (0.9 m).
❑Ventpipingcannotbesupportedfromabove(suchasrelyingonroofjacksections).
You must install supports on the horizontal piping before the vent turns upward.
Provide a support on the horizontal piping within 6 inches of every upturned
elbow to support the vertical run.
❑Follow the vent pipe manufacturer’s instructions for placement and installation of
supports.
❑Followapplicablecodesand the ventpipe instructionstoinstallrestops,thimbles
or other devices at all oor and wall penetrations.
❑Provide minimum 2 inches (51 mm) clearance to all combustible construction. continued on next page
5 — Air pipe connection
❑Before installing the air piping, install the air pipe sidewall
termination assembly (item 7, Figure 14). See instructions
on next page.
❑Construct the air piping from PVC, CPVC or ABS plastic,
or galvanized or aluminum metallic pipe (including exible
aluminum duct if desired).
When using metallic piping — seal all of the
longitudinal seam joints in addition to the
component joints.
❑Aach the air piping to the boiler air connection, requiring
useofsiliconeRTVtosealtheconnection.Iftheboilerroom
air is free of contaminants you can use metallic duct tape to
seal the joints. With age, however, duct tape adhesives can
loosen, so duct tape is not as reliable as silicone RTV.
❑If the installation is required to meet direct vent (sealed
combustion) requirements, seal all joints with silicone RTV.
e air pipe installation must be air-tight and water-tight.
❑Maximum air piping length — See the table in Figure 14
for the maximum allowable length. Each elbow causes the
same pressure drop as 10 feet of vent pipe, so the allowable
length reduces 10 feet for each elbow used in the piping.
When 45° elbows are used, two 45° elbows are equivalent
to one 90° elbow.
6 — Supporting air piping
❑DO NOT use the boiler air connection to support the
air piping. Provide support straps from the ceiling or install
wall brackets.
❑Provide at least one support on all air pipe installations.
❑Provide a support every 3 feet for air pipe lengths greater
than 5 feet horizontally.
❑Provide a support on the horizontal piping within 6 inches
of every upturned elbow to support the vertical run.
7 — Sidewall termination assemblies
❑See next page.