Lochinvar CHF2 Manual

1
Upon receiving equipment, check for signs of shipping
damage. Pay particular attention to parts accompanying
the boiler which may show signs of being hit or
otherwise being mishandled. Verify total number of
pieces shown on packing slip with those actually
received. In case there is damage or a shortage,
immediately notify the carrier.
Installation and service must be performed by a
qualified service installer, service agency or the gas
supplier.
Factory warranty (shipped with unit) does not apply to
units improperly installed or improperly operated.
Experience has shown that improper installation or
system design, rather than faulty equipment, is the
cause of most operating problems.
1. Excessive water hardness causing a lime build up
in the copper tube is not the fault of the equipment
and is not covered under the manufacturer’s
warranty. (See Water Treatment and Water
Chemistry)
2. Excessive pitting and erosion on the inside of the
copper tube may be caused by too much water
velocity through the tubes and is not covered by
the manufacturer’s warranty (See Boiler Flow
Rates and Temperature Rise for flow
requirements).
This manual supplies information for the installation,
operation and servicing of the appliance. It is strongly
recommended that this manual be reviewed completely
before proceeding with an installation.
WARRANTY
CHECKING EQUIPMENT
Improper
Installation,Adjustment,
Alteration, Service or Maintenance
can cause injury or property damage.
Refer to this manual. For assistance or
additional information consult a qualified
installer, service agency or the gas supplier.
NOTE: Retain this manual for future reference.
SPECIAL INSTRUCTIONS TO OWNER
Hot Water Heating Boilers
Domestic Hot Water Supply Boilers
300,000 and 990,000 — 2,070,000 • BTU Models
CHF2-i&s-02
INSTALLATION AND SERVICE MANUAL
Use this appliance 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.
DO NOT
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.
Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.
-
• 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
neighbors 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:
— WHAT TO DO IF YOU SMELL GAS —
WARNING:
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2
The information contained in this manual is
intended for use by qualified professional installers,
service technicians or gas suppliers. Consult your
local expert for proper installation or service
procedures.
Your conventionally vented gas appliance must have a
supply of fresh air circulating around it during burner
operation for proper gas combustion and proper
venting.
1. Always keep the area around your appliance free
of combustible materials, gasoline, and other
flammable liquids and vapors.
2. Never cover your appliance, lean anything against
it, store trash or debris near it, stand on it or in
any way block the flow of fresh air to your unit.
The equipment shall be installed in accordance with
those installation regulations in force in the local area
where the installation is to be made. These shall be
carefully followed in all cases. Authorities having
jurisdiction shall be consulted before installations are
made. In the absence of such requirements, the
installation shall conform to the latest edition of the
National Fuel Gas Code, ANSI Z223.1and/or
CNA/CGA-B149 Installation Code. Where required by
the authority having jurisdiction, the installation must
conform toAmerican Society of Mechanical Engineers
CONTENTS
Warranty ............................................................................... 1
Safety Warnings ................................................................... 1
Codes ............................................................................... 2
Location ............................................................................... 3
Clearances ............................................................................ 4
Combustion/Ventilation Air ................................................. 4
Conventional Venting ........................................................... 6
Sidewall Venting................................................................... 10
Vertical DirectAire ............................................................... 12
Horizontal DirectAire .......................................................... 15
Outdoor Installations............................................................ 17
Gas Supply ........................................................................... 18
Gas Pressures & Piping ....................................................... 19
Manifold Pressure Adjustment ............................. 21
Supply Pressure Measurement.............................. 22
Water Connections ............................................................... 23
Relief Valve .......................................................................... 23
Gas Valves ............................................................................ 24
Electrical Requirements ....................................................... 24
Temperature Adjustment (Boiler) ........................................ 25
Temperature Adjustment (I/O Reset)................................... 28
Temperature Limit Control .................................................. 33
Lighting Instructions............................................................ 33
Ignition Module ................................................................... 36
Operation & Diagnostic Lights ........................................... 37
Ignition & Control Timings ................................................. 39
Freeze Protection.................................................................. 39
Maintenance ......................................................................... 40
Flame Patterns....................................................... 40
Burner Cleaning .................................................... 41
Heat Exchanger Inspection ................................... 41
Combustion Air Adjustment ................................. 42
Gas Train .............................................................................. 44
Heating Boiler ...................................................................... 44
Pump Requirements ............................................................. 44
Pressure Drop Chart .............................................. 45
Primary/Secondary Piping .................................... 46
Low Temperature Systems .................................... 46
Three Way Valves .................................................. 47
Temperature Rise Chart ........................................ 47
Boiler Flow Rates.................................................. 48
Bypass Requirements............................................ 48
Placing in Operation ............................................. 48
Boiler Temperature Control .................................. 50
Remote Temperature Control Connection (EMS) ............... 50
Domestic Hot Water Supply Boiler/Water Heater............... 51
Temperature Rise .................................................. 52
Water Chemistry ................................................... 52
Piping Requirements ............................................. 53
Pump Operation .................................................... 53
Temperature Adjustment ....................................... 54
Risk of Scald Warnings......................................... 54
Temperature Limit Control ................................... 56
OWNER WARNING
CODES
WARNING:
Should overheating occur or the gas supply fail
to shut off, do not turn off or disconnect the
electrical supply to the pump. Instead, shut off
the gas supply at a location external to the
appliance.
WARNING:
To minimize the possibility of serious personal
injury, fire or damage to your unit, never violate
the following safety rules.
CAUTION !!
Consult and follow local uilding and Fire
Regulations and other Safety Codes that apply
to this installation. Consult local gas utility
company to authorize and inspect all gas and flue
connections.

3
The pan must not restrict combustion air flow.
Under no circumstances is the manufacturer to be
held responsible for waterdamage in connection
with this unit, or any of its components.
2. The indoor units must be installed so that the
ignition system components are protected from
water (dripping, spraying, rain, etc.) during
appliance operation and service (circulator
replacement, control replacement, etc.)
3. Units located in a residential garage shall be
installed so that all burners and burner ignition
devices have a minimum clearance of 18" (46cm)
above the floor. The unit shall be located or
protected so that it is not subject to physical
damage by a moving vehicle.
4. The appliance must be installed on a level,
non-combustible floor. Concrete over wood is
not considered a non-combustible floor. Maintain
required clearances from combustible surfaces.
5. The appliance must not be installed on carpet or
other combustible material.
6. For installation on a combustible floor only when
installed on the specified special base:
300,000 Btu/hr input units installed over a
combustible floor MUST use the Special Combustible
Floor Base. The unit must be centered on the base as
show in FIG. 3. The correct part number for the
required base is noted on the rating plate of each unit
and listed below.
Safety Code for Controls and Safety Devices for
Automatically Fired Boilers,ASME CSD-1. All boilers
conform to the latest edition of the ASME Boiler and
Pressure Vessel Code, Section IV. Where required by
the authority having jurisdiction, in Canada, the
installation must comply with the CSA International
CNA/CGA-B149 Installation Code and/or local codes.
This appliance meets the safe lighting performance
criteria with the gas manifold and control assembly
provided, as specified in the ANSI standards for
gas-fired units, ANSI Z21.13.
1. 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 unit.
LOCATION OF UNIT
FIG. 1
Front & Re r View
300,000 Btu/hr Models
INSTALLATION PROCEDURE
FIG. 3
Speci l Combustible Floor B se
300,000 Btu/hr Model Only
FIG. 2
Front & Rear View
990,000 — 2,070,000 Btu/hr
Models
Front Re r
Front
Re r

4
Provisions for combustion and ventilation air must be
in accordance with section 5.3, Air for Combustion
andVentilation, of the latest edition of the National Fuel
Gas Code, ANSI Z223.1, in Canada, the latest edition of
CAN/CGA-B149 Installation Code for Gas Burning
Appliances and Equipment, or applicable provisions
of the local building codes.
The equipment room MUST be provided with properly
sized openings to assure adequate combustion air and
proper ventilation when the unit is installed with
conventional venting or sidewall venting.
1. If air is taken directly from outside the building
with no duct, provide two permanent openings:
a. Combustion air opening, with a minimum free
area of one square inch per 4000 Btu input
(5.5cm2per kW). This opening must be
located within 12" (30 cm) of the bottom of
the enclosure.
7. Outdoor models require the installation of an
optional vent cap. Instructions for mounting the
vent cap are included in the venting section.
Outdoor models must not be installed directly on
the ground. The outdoor unit must be installed on
a concrete, brick, block or other non-combustible
pad. Outdoor models have additional special
location and clearance equirements. These are
specifically addressed in the venting section under
outdoor installation. A windproof cabinet protects
the unit from weather.
Maintain minimum specified clearances for adequate
operation. Allow sufficient space for servicing pipe
connections, pump and other auxiliary equipment, as
well as the appliance. See rating plate for specific
service clearance requirements.
990,000 through 2,070,000 Btu/hr input units
installed over a combustible floor MUST be provided
with a base of hollow clay tile or concrete blocks from
8" to 12" thick and extending 24" beyond the sides.
The blocks must be placed in line so that the holes line
up horizontally to provide a clear passage through the
blocks.A 1/2" fire-proof millboard with a 20 gage sheet
metal cover shall be provided over the block base. The
unit must be countered on the base. This procedure
should also be followed if electrical conduit runs
through the floor, and beneath the appliance. A field
installed base must meet all local fire and safety code
requirements.
3 , CFK33
TA LE — A
COM USTI LE FLOOR KITS
Input tu/hr Kit Number
COMBUSTION nd VENTILATION
AIR REQUIREMENTS FOR
CONVENTIONALLY VENTED
APPLIANCES nd SIDEWALL
VENTED APPLIANCES
FIG. 4
Cle r nces from
Combustible Construction
Cle r nces from Combustible Construction:
Right Side - 3" (7.5cm)
Re r - 3" (7.5cm) (3" minimum from ny surf ce)
Left Side - 6" (15cm) (24" (0.61m) suggested for service)
Front - ALCOVE* (30" (0.76m) suggested for service)
Top - 3" (7.5cm)
Flue - 1" (25.4mm)
Hot W ter Pipes - 1" (25.4mm)
*An ALCOVE is closet without door.
Combustion Air Direct from Outside
FIG. 5
Front Left
Top
Right
3” From Top
nd Side
Minimum

5
b. Ventilation air opening, with a minimum free
area of one square inch per 4000 Btu input
(5.5cm2per kW). This opening must be
located within 12" (30cm) of the top of the
enclosure.
2. If combustion and ventilation air is taken from the
outdoors using a duct to deliver to the mechanical
room, each of the two openings should be sized
based on a minimum free area of one square inch
per 2000 Btu (11cm2per kW).
3. If air is taken from another interior space, each of
the two openings specified above should have a
net free area of one square inch for each 1000
Btu (22cm2per kW) of input, but not less than
100 square inches (645 cm2 ).
4. If a single combustion air opening is provided to
bring combustion air in directly from the
outdoors, the opening must be sized based on a
minimum free area of one square inch per 3000
Btu (7cm2per kW). This opening must be located
within 12" (30cm) of the top of the enclosure.
All dimensions are based on net free area in square
inches. Metal louvers or screens reduce the free area
of a combustion air opening a minimum of
approximately 25%. Check with louver manufacturers
for exact net free area of louvers. Where two openings
are provided, one must be within 12" (30 cm) of the
ceiling and one must be within 12" (30 cm) of the floor
of the mechanical room. Each opening must have a
minimum net free area as specified in Table B. Single
openings shall be installed within 12" (30 cm) of the
ceiling.
The combustion air supply must be completely free of
any chemical fumes which may be corrosive to the
boiler. Common chemical fumes which must be
avoided are fluorocarbons and other halogenated
compounds, most commonly present as refrigerants or
FIG. 8
Combustion Air from
Outside Single Opening
FIG. 6
Combustion Air Through Ducts
FIG. 7
Combustion Air from Interior Sp ce
CAUTION !!
Under no circumstances should the equipment
room ever be under a negative pressure.
Particular care should be taken where exhaust
fans, attic fans, clothes dryers, compressors,
air handling units, etc. may rob air from the
unit.

6
solvents, such as Freon, trichlorethylene,
perchloroethylene, chlorine, etc. These chemicals,
when burned, form acids which quickly attack the
boiler tubes, tube sheets, flue collectors, and the boiler
vent system. The result is improper combustion and a
non-warrantable, premature boiler failure.
EXHAUST FANS: Any fan or equipment which
exhausts air from the boiler room may deplete the
combustion air supply and/or cause a down draft in
the venting system. Spillage of flue products from the
venting system into an occupied living space can cause
a very hazardous condition that must be immediately
corrected. If a fan is used to supply combustion air to
the boiler room, the installer must make sure that it
does not cause drafts which could lead to nuisance
operational problems with the boiler.
DirectAire Vertical and DirectAire Horizontal
venting systems have specific requirements for
combustion air ducts from the outside which are
directly connected to the boiler. See the requirements
for this combustion air duct in the venting section for
each specialized vent system.
General
Vent installations for connection to gas vents or
chimneys must be in accordance with Part 7, “Venting
of Equipment,” of the latest edition of the National Fuel
Gas Code, ANSI Z223.1, in Canada, the latest edition
of CAN/CGA-B149 Installation Code for Gas Burning
Appliances and Equipment or applicable provisions of
the local building codes.
Conventional negative draft venting and sidewall
venting applications, where outside air is used, must
have adequate combustion and ventilation air supplied
to the mechanical room in accordance with the latest
edition of the National Fuel Gas Code, ANSI Z223.1,
in Canada, the latest edition of CAN/CGA-B149
Installation Code for Gas Burning Appliances and
Equipment, or applicable provisions of the local
building codes.
The distance of the vent terminal from adjacent
buildings, windows that open and building openings
MUST comply with the latest edition of the National
Fuel Gas Code, ANSI Z223.1, in Canada, the latest
edition of CAN/CGA-B149 Installation Code for Gas
Burning Appliances and Equipment.
Vent connection is made directly to the top of the unit.
No additional draft diverter or barometric damper is
required on single unit installations when a negative
draft is maintained within the specified range. The
connection from the appliance vent to the stack must
be made as direct as possible.
VENTING
Examine the venting
system at least once a year. Check all joints and
vent pipe connections for tightness. Also check
for corrosion or deterioration. Immediately
correct any problems observed in the venting
system.
IMPORTANT: 


TA LE —
MINIMUM RECOMMENDED COM USTION
AIR SUPPLY TO OILER ROOM
CombustionAir Source
Boiler Input OutsideAir*/2 Openings OutsideAir*/1 Opening InsideAir/2 Openings
300,000 75 in2(484cm2) 100 in2(645cm2) 300 in2(1936cm2)
990,000 248 in2(1600cm2)330 in2(2129cm2) 990 in2(63886cm2)
1,260,000 315 in2(2032cm2) 420 in2(2710cm2) 1260 in2(8130cm2)
1,440,000 360 in2(2323cm2) 480 in2(3097cm2) 1440 in2(9291cm2)
1,800,000 450 in2(2903cm2) 600 in2(3871cm2) 1800 in2(11,614cm2)
2,070,000 518 in2(3342cm2) 690 in2(4452cm2) 2070 in2(13,356cm2)
* Outside air openings shall directly communicate with the outdoors. When combustion air is drawn from the outside through a duct, the
net free area of each of the two openings must have twice (2 times) the free area required for Outside Air/2 Openings. The above
requirements are for the boiler only, additional gas fired appliances in the boiler room will require an increase in the net free area to supply
adequate combustion air for all appliances. Combustion air requirements are based on the latest edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada refer to CAN/CGA-B149 Installation Code. Check all local code requirements for combustion air.

7
Vent connection is made directly to the top of the unit.
No additional draft diverter or barometric damper is
required on single unit installations with a dedicated
stack and a negative draft within the specified range
of a negative 0.02 to 0.08 inches water. If the draft in
a dedicated stack for a single unit installation exceeds
the maximum specified draft, a barometric damper
must be installed to control draft. Multiple unit
installations with combined venting or common venting
with other Category I negative draft appliances require
that each boiler must have a barometric damper
installed to regulate draft within the proper range.
The flue pipe sizes are:
On a conventionally vented, negative draft unit, the
connection from the vent to the stack or vent
termination outside the building MUST be made with
listed Type “B” double wall (or equivalent) vent
connectors and must be direct as possible with no
reduction in diameter. Use the National Fuel Gas Code
venting tables for double wall vent to properly size all
vent connectors and stacks. The Type “B” vent
and accessories, such as firestop spacers, thimbles,
caps, etc., MUST be installed in accordance with the
manufacturers instructions. The vent connector and
firestop must provide correct spacing to combustible
surfaces and seal to the vent connector on the upper
and lower sides of each floor or ceiling through which
the vent connector passes.
Any vent materials specified must be listed by a
nationally recognized test agency for use as vent
material.
Locate units as close as possible to chimney or gas
vent.
Avoid long horizontal runs of the vent pipe, 90°elbows,
reductions and restrictions. Horizontal portions of the
venting system shall be supported to prevent sagging.
Horizontal runs must slope upwards not less than 1/4”
This boiler has five venting options. They are:
(1) Conventional Negative DraftVenting with vertical
rooftop flue termination and combustion air supplied
from the mechanical room, (2) SidewallVenting which
uses a powered vent assembly to exhaust the flue
products out a sidewall vent termination and
combustion air supplied from the mechanical room,
(3) Vertical DirectAire Venting with a vertical
conventional vent for flue products and a combustion
air pipe from either the sidewall or roof top,
(4) Horizontal DirectAireVenting with a powered vent
assembly to exhaust the flue products out a sidewall
and a combustion air pipe from the sidewall,
(5) Outdoor Installation with the installation of a
special air inlet/vent cap on top of the unit. All boilers
are shipped from the factory equipped for conventional
negative draft venting. All other optional vent systems
require the installation of specific vent kits and venting
materials. The following is a detailed explanation of
the installation requirements for each venting system,
components used and part numbers of vent kits for each
model.
Conventional Venting
The negative draft in a conventional vent installation
must be within the range of a negative 0.02 to 0.08
inches water to insure proper operation. All draft
readings are made while unit is in stable operation
(approximately 2 to 5 minutes).
VENT SYSTEM OPTIONS
A CONVENTIONAL NEGATIVE
DRAFT VENTING SYSTEM
Input tu/hr Flue Size
300,000 5”
990,000 10”
1,260,000 12”
1,440,000 12”
1,800,000 14”
2,070,000 14”
TA LE — C
Convention l Neg tive Dr ft Vertic l
Venting with Combustion Air Louvers
FIG. 9

8
(f) After it has been determined that each appliance
remaining connected to the common venting
system properly vents when tested as above,
return doors, windows, exhaust fans, fireplace
dampers and other gas burning appliances to their
previous conditions of use.
(g) Any improper operation of the common venting
system should be corrected so that the installation
conforms to the latest edition of the National Fuel
Gas Code, ANSI Z223.1, in Canada, the latest
edition of CAN/CGA-B149 Installation Code
for Gas Burning Appliances and Equipment.
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 II of the latest edition of the National
Fuel Gas Code,ANSI Z223.1, in Canada, the latest
edition of CAN/CGA-B149 Installation Code
for Gas Burning Appliances and Equipment.
The vent terminal should be vertical and exhaust
outside the building at least 2 feet (0.61m) above the
highest point of the roof within a 10 foot (3.05m) radius
of the termination.
The vertical termination must be a minimum of 3 feet
(0.91m) above the point of exit.
per foot (21 mm/m) from the appliance to the vent
terminal. Follow manufacturers instructions.
Do not use an existing chimney as a raceway if another
appliance or fireplace is vented thru the chimney.
The weight of the venting system must not rest on the
unit. Adequate support of the venting system must be
provided in compliance with local codes and other
applicable codes. All connections should be secured
with rustproof sheet metal screws.
Vent connectors serving appliances vented by natural
draft shall not be connected to any portion of a
mechanical draft system operating under positive
pressure. Connection to a positive pressure stack may
cause flue products to be discharged into the living
space causing serious health injury.
Common venting systems may be too large when an
existing unit is removed. At the time of removal of an
existing appliance, the following steps shall be followed
with each appliance remaining connected to the
common venting system placed in operation, while
other appliances remaining connected to the common
venting system are not in operation.
(a) Seal any unused opening in the common venting
system.
(b) Visually inspect the venting system for proper size
and horizontal pitch and determine there is not
blockage or restriction, leakage, corrosion and
other unsafe conditions.
(c) 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 other appliances 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.
VERTICAL VENTING TERMINATION
FIG. 10
Vent Termin tion from Pe ked Roof
10’ or Less from Ridge

9
A vertical termination less than 10 feet (3.05m) from
a parapet wall must be a minimum of 2 feet (0.61m)
higher than the parapet wall.
The vent cap should have a minimum clearance of 4
feet (1.22m) horizontally from and in no case above or
below, unless a 4 foot (1.22m) horizontal distance is
maintained from electric meters, gas meters, regulators
and relief equipment.
FIG. 12
Vent Termin tion from Fl t Roof
10’ or Less from P r pet W ll
The venting system shall terminate at least 3 feet (0.9m)
above any forced air inlet within 10 feet (3.05m).
The venting system shall terminate at least 4 feet (1.2m)
below, 4 feet (1.2m) horizontally from, or 1 foot (30cm)
above any door, window or gravity air inlet into any
building.
Do not terminate the vent in a window well, stairwell,
alcove, courtyard or other recessed area. The vent can
not terminate below grade. The bottom of the vent
terminal shall be located at least 12 inches (30cm)
above grade.
To avoid a blocked flue condition, keep the vent cap
clear of snow, ice, leaves, debris, etc.
Flue gases will form a white plume in winter. Plume
could obstruct window view.
Flue gas condensate can freeze on exterior surfaces or
on the vent cap. Frozen condensate on the vent cap
can result in a blocked flue condition. Flue gas
condensate can cause discoloration of exterior building
surfaces. Adjacent brick or masonry surfaces should
be protected with a rust resistant sheet metal plate.
FIG. 13
Vent Termin tion from Fl t Roof
More Th n 10’ from P r pet W ll
10’ OR LESS
3’
WALL OR
PARAPET CHIMNEY
NOTE: NO HEIGHT
ABOVE PARAPET
REQUIRED WHEN
DISTANCE FROM
WALLS OR
PARAPETS IS
MORE THAN 10’.
FIG. 11
Vent Termin tion from Pe ked Roof
More Th n 10’ from Ridge

1
FIG. 14
Sidew ll Venting Inst ll tion
with Powered Vent C p
SIDEWALL VENTING WITH A
POWERED VENT CAP
The SidewallVenting System
This venting system uses a powered vent assembly
which pulls the flue products out of the stack.This fan
generates a negative draft at the unit. Combustion air
is drawn from the mechanical room (see Combustion
and Ventilation Air Requirements).
300,000 Btu/hr Models
The sidewall fan is mounted in a vent cap which is
installed on an exterior wall. The sidewall fan and
accessories are included in a venting kit which must
be furnished by the manufacturer in accordance with
CSA International requirements. This venting kit
includes the sidewall fan/cap, proving switch and all
necessary relays to interlock with the heaters control
system. The internal damper on the sidewall fan must
be adjusted to supply a negative draft within the range
of 0.04 to 0.08 inches water negative while unit is
operating.
The maximum total equivalent length of the sidewall
vent pipe cannot exceed 50 equivalent feet (15.24m).
Subtract 5 feet (1.52m) for each elbow in the vent. Do
not exceed the limit for total equivalent vent pipe
length.
MASONRY CHIMNEY
INSTALLATION
A masonry chimney must be properly sized for the
installation of a high efficiency gas fired appliance.
Venting of a high efficiency appliance into a cold or
oversized masonry chimney can result in operational
and safety problems. Exterior masonry chimneys, with
one or more sides exposed to cold outdoor
temperatures, are more likely to have venting problems.
The temperature of the flue products from a high
efficiency appliance may not be able to sufficiently
heat the masonry structure of the chimney to generate
proper draft. This will result in condensing of flue
products, damage the masonry flue/tile, insufficient
draft and possible spillage of flue products into an
occupied living space. Carefully inspect all chimney
systems before installation. If there is any doubt about
the sizing or condition of a masonry chimney, it must
be relined with a properly sized and approved chimney
liner system.
Inspection of a Masonry Chimney
A masonry chimney must be carefully inspected to
determine its suitability for the venting of flue
products. A clay tile lined chimney must be structurally
sound, straight and free of misaligned tile, gaps
between liner sections, missing sections of liner or any
signs of condensate drainage at the breeching or clean
out. If there is any doubt about the condition of a
masonry chimney, it must be relined. An unlined
masonry chimney must not be used to vent flue
products from this high efficiency appliance. An
unlined chimney must be relined with an approved
chimney liner system when a new appliance is being
attached to it. Metallic liner systems (Type “B”
double-wall or flexible or rigid metallic liners) are
recommended. Consult with local code officials to
determine code requirements or the advisability of
using or relining a masonry chimney.
FIG. 14

11
The sidewall fan/powered vent cap MUST be
interlocked with the units control system to start
the fan on a call for heat and prove fan operation
before the boiler fires. Plug-in and terminal strip
connections are provided on the unit for easy
connection of the factory supplied vent kit and
control package for the sidewall vent fan. See the
installation instructions provided with the vent kit.
SidewallVent Pipe Requirements
The connection from the vent to the powered sidewall
fan/cap MUST be made with listed Type “B” double
wall (or equivalent) vent and accessories. There shall
be no reduction in vent size from the boiler’s flue outlet
to the inlet of the sidewall vent fan.Vent pipe material
must be supplied by the installer.
Follow all requirements in the General Venting and
Sidewall Vent Terminations sections for venting flue
products to the outdoors. See the Combustion and
Ventilation Air Requirements section to insure that
adequate combustion and ventilation air is supplied to
the mechanical room. All other general installation
requirements must be followed.
Sidewall Vent Termination
The sidewall vent cap shall terminate at least 3 feet
(0.91m) above any forced air inlet within 10 feet
(3.05m).
The sidewall vent shall terminate at least 4 feet (1.22m)
below, 4 feet (1.22m) horizontally from or 1 foot
(0.30m) above any door, window or gravity air inlet to
the building.
Do not terminate the sidewall vent in a window well,
stairwell, alcove courtyard or other recessed area, The
(0.30m) above grade.
The sidewall vent system shall terminate at least 1 foot
(0.30m) above normal snow levels and at least 7 feet
(2.13m) above grade when located adjacent to public
walkways. The sidewall vent shall not terminate
directly above a public walkway.
The sidewall vent terminal shall not be installed closer
than 3 feet (0.91m) from an inside corner of an
L-shaped structure.
990,000 through 2,070,000 Btu/hr Models
The sidewall fan is mounted on the inside with a
with a sidewall vent hood installed on the exterior
wall. The sidewall fan and accessories are included
in a venting kit which must furnished by the
manufacturer in accordance with CSA International
requirements. The venting kit includes the sidewall
fan, vent hood, tapered vent adaptor, barometric
damper, proving switch and all necessary relays to
interlock with the heaters control system. The
tapered vent adaptor reduces the vent size at the inlet
to the fan. There should be no reduction in vent
diameter from the unit’s flue outlet to the sidewall
fan. The barometric damper must be installed on the
flue and adjusted to supply a negative draft within
the range of 0.04 to 0.08 inches water negative while
unit is operating.
The maximum total equivalent length of the sidewall
vent pipe cannot exceed 100 equivalent feet
(30.48m). Subtract 5 feet (1.52m) for each elbow
in the vent. Do not exceed the limit for total
equivalent vent pipe length.
Sidewall Vent Cap
The sidewall vent cap must be installed on an
exterior sidewall.The sidewall fan/powered sidewall
vent cap and accessories are included in a venting
kit which must be furnished by the manufacturer in
accordance with CSA International requirements.
This venting kit includes the powered sidewall fan/
cap, proving switch and all necessary relays to
interlock with the heaters control system.
FIG. 15
Sidew ll Venting Inst ll tion
with nd Induced Dr ft F n
nd Sidew ll Vent

12
The sidewall vent cap should have a minimum clearance
of 4 feet (1.22m) horizontally from and in no case above
or below, unless a 4 foot (1.22m) horizontal distance is
maintained from electric meters, gas meters, regulators
and relief equipment.
Flue gas condensate can freeze on exterior walls or on
the vent cap. Frozen condensate on the vent cap can
result in a blocked flue condition. Some discoloration
to exterior building surfaces can be expected. Adjacent
brick or masonry surfaces should be protected with a
rust resistant sheet metal plate.
Sidewall Vent Kits
The SidewallVent Kit MUST be ordered from the boiler
manufacturer. The part number for each kit is listed by
unit size. Each kit includes a powered sidewall fan/
cap assembly, control relay, proving switch and
instructions for proper installation.
The Vertical DirectAire™Vent System:
Follow all requirements in the GeneralVenting section
and Conventional Negative Draft Venting for venting
flue products to the outdoors and general installation
instructions in the Installation and Service Manual.
The Vertical DirectAire vent system requires the
installation of two vent pipes directly to the unit, one
vertical pipe with a roof top termination for the flue
products and one pipe for combustion air. The
combustion air pipe may terminate horizontally with a
sidewall air inlet or vertically with a roof top air inlet.
Vent connection is made directly to the top of the unit.
No additional draft diverter or barometric damper is
required on single unit installations with a dedicated
stack and a negative draft maintained between 0.02 to
0.08 inches water. The flue may be combined with the
vent from any other negative draft, Category I
appliances. Multiple unit installations common vented
with other negative draft appliances require that each
boiler must have a barometric damper installed to
regulate draft within the proper range. The common
vent and connectors from multiple boilers must be sized
per the requirements of the venting tables forType “B”
double wall vents in the latest edition of the National
Fuel Gas Code, ANSI Z223.1 and/or CAN/CGA-B149
Installation Code.
The sidewall or vertical roof top DirectAire combustion
air supply system has specific vent material and
installation requirements. The air inlet pipe connects
directly to the boiler to supply combustion air. In most
installations, the combustion air inlet pipe will be a
dedicated system with one air inlet pipe per boiler.
Multiple air inlets may be combined if the guidelines
in “Combined Air Inlet Points” are followed. The air
inlet pipe will be connected to a combustion air inlet
cap as specified in this section.
Combustion air supplied from outdoors must be free
of contaminants ( See Combustion and Ventilation Air
of the Installation and Service Manual).
300,000 5" SVK3005
990,000 10" SVK3009
1,260,000 12" SVK3010
1,440,000 12" SVK3010
1,800,000 14” SVK3012
2,070,000 14” SVK3012
TA LE — D
Input Flue Sidewall
tu/hr Size Vent Cap Kit
oilers which are shut down or will not operate
may experience freezing due to convective air
flow in flue pipe or from negative pressure in
the mechanical room. In cold climates,
continuous pump operation is recommended to
help prevent freezing of boiler water. Proper
freeze protection must be provided. See Freeze
Protection.
CAUTION !!
A CONVENTIONAL VERTICAL
NEGATIVE DRAFT VENTING SYSTEM
WITH A COMBUSTION AIR PIPE
FROM A SIDEWALL
OR
ROOF TOP INLET CAP

13
Sidewall Air Inlet
The sidewall air inlet cap is supplied in the Vertical
DirectAire Sidewall Air Kit which must be ordered
from the manufacturer. This sidewall cap will supply
combustion air for a single boiler only.
Locate boiler as close as possible to sidewall where
the combustion air supply system will be installed.
To prevent recirculation of flue products from an
adjacent vent cap into the combustion air inlet, follow
all applicable clearance requirements in the latest
edition of the National Fuel Gas Code and/or CAN/
CGA-B149 Installation Code and instructions in this
manual.
The combustion air inlet cap must be installed at least
one foot (0.30m) above ground level and above normal
snow levels.
Vertical Roof Top Air Inlet
The air inlet cap for the vertical roof top air inlet is
supplied in the Vertical DirectAire Roof Top Air Kit
which must be ordered from the manufacturer. This
roof top cap will supply combustion air for a single
boiler only.
The point of termination for the combustion air inlet
cap MUST be at least 3 feet (0.91m) below the point
of flue gas termination (vent cap) if it is located within
10' (3.05m) of the flue outlet.
The combustion air inlet cap must not be installed
closer than 10 feet (3.05m) from an inside corner of a
L-shaped structure.
The air inlet point for the combustion air inlet cap must
be installed at least one foot (0.30m) above the roof
top and above normal snow levels.
Vertic l DirectAire™ Inst ll tion
with Roof Top Combustion Air
FIG. 18
Vertic l DirectAire™ Inst ll tion
with Sidew ll Combustion Air
FIG. 16
Air Inlet C p for
Sidew ll Termin tion
FIG. 17
Air Inlet C p for
Roof Top Termin tion
FIG. 19

14
Incorrect installation and/or location of the air inlet
cap can allow the discharge of flue products to be drawn
into the combustion process on the boiler. This can
result in incomplete combustion and potentially
hazardous levels of carbon monoxide in the flue
products. This will cause operational problems with
the boiler and possible spillage of flue products which
can cause personal injury, death or property damage.
Combined Air Inlet Points
The air inlet pipes from multiple boilers can be
combined to a single common connection if the
common air inlet pipe has a cross sectional area equal
to or larger than the total area of all air inlet pipes
connected to the common air inlet pipe. [Example:two
10" air inlet pipes (78.5 in2area each) have a total
area of 157 in2and will require a 15"(176.7 in2 area)
common air inlet pipe.] The air inlet point for multiple
boiler air inlets must be provided with an exterior
opening which has a free area equal to or greater than
the total area of all air inlet pipes connected to the
common air inlet.This exterior opening for combustion
air must connect directly to the outdoors. The total
length of the combined air inlet pipe must not exceed
a maximum of 50 (15.25m) equivalent feet. Subtract
5 feet (1.52m) for each elbow in the air inlet pipe.You
must deduct the restriction in area provided by any
screens, grills or louvers installed in the common air
inlet point.These are common on the sidewall air inlet
openings. Screens, grills or louvers installed in the
common air inlet can reduce the free area of the
opening from 25% to 75% based on the materials used.
Air Inlet Pipe Materials
The Vertical DirectAire system requires installation of
a single wall pipe to supply combustion air from
outdoors directly to the unit.
Length of Air Inlet Pipe
The total equivalent length of the sidewall or vertical
roof top DirectAire combustion air inlet pipe must not
exceed a maximum of 50 (15.24m) equivalent feet in
length. Subtract 5 feet (1.52m) for each elbow in the
air intake system. Do not exceed limits for the
combustion air inlet piping length.
Vent Kits
The Vertical DirectAire Vent Kit for sidewall or roof
top air inlet MUST be ordered from the boiler
manufacturer for single unit installations. The part
number for each kit is listed by unit size. Each kit
includes either a sidewall or roof top combustion air
inlet cap to supply air to a single boiler and instructions
for proper installation. The flue pipe and roof top vent
cap for the flue and air inlet pipe are purchased locally.
You must specify if the air inlet cap is for a vertical
roof top termination or a sidewall termination. The
air inlet cap for the combined air supply from multiple
boilers must be purchased locally.
The air inlet cap supplied in the Vertical DirectAire
Vent Kit is used to supply combustion air to a single
boiler. The roof top vent cap for flue products should
be a standard commercial cap purchased locally. The
use of a sidewall or roof top air inlet cap other than the
manufacturers recommended cap for single boiler
installations or use of a common air inlet cap for
multiple boilers with insufficient free area and/or
protection from wind and weather may result in
NOTE: 

 The use of double wall vent
material for the combustion air inlet pipe is
recommended in cold climates to prevent the
condensation of airborne moisture in the
incoming combustion air.
Input Conventional Vent Air Inlet Sidewall Air Rooftop Air
tu/hr Flue Size Pipe* Inlet Kit Inlet Kit
* Minimum diameter, installer may increase diameter one pipe size for ease of installation if needed. A 6" diameter air inlet cap
may be ordered for rooftop air inlet as Rooftop Air Inlet Kit VDK3 6.
TA LE — E
300,000 5"5"SVK3005 VDK3005
990,000 10"10"SVK3013 VDK3009
1,260,000 12"12"SVK3014 VDK3008
1,440,000 12"12"SVK3014 VDK3008
1,800,000 14"12"SVK3014 VDK3012
2,070,000 14"12"SVK3014 VDK3012

15
operational problems with the boiler or potentially
hazardous spillage of flue products which can cause
personal injury, death or property damage.
Venting of Flue Products
For venting flue products vertically to the outdoors,
follow all requirements in the installation instructions
for conventional venting in the Installation and Service
Manual.
Termination point for the flue products must follow
the clearance requirements in the Vertical Vent
Termination section of Conventional Venting in the
Installation and Service Manual.
A barometric damper is NOT required in the flue on
Vertical DirectAire installations if the draft is within
the 0.02 to 0.08 inches water negative required for
proper operation. If the draft exceeds this range, a
barometric damper must be installed.
HORIZONTAL DIRECTAIRE™
WITH A SIDEWALL FLUE AND
SIDEWALL AIR INLET
The Horizontal DirectAire Vent System
Follow all requirements in the GeneralVenting section
and Sidewall Venting for venting flue products to the
outdoors and general installation instructions.
The Horizontal DirectAire vent system requires the
installation of two vent pipes directly to the unit, one
pipe for flue products and one for combustion air. Both
vent pipes are installed horizontally with a sidewall
termination point. Vent connection is made directly to
the top of the unit. No additional draft diverter or
barometric damper is required on single unit
installations with a dedicated stack and a negative draft
maintained between 0.04 to 0.08 inches water.
The Horizontal DirectAire combustion air supply
system has specific vent material and installation
requirements. The air inlet pipe connects directly to
the boiler to supply combustion air. The combustion
air inlet pipe will be a dedicated system with one air
inlet pipe per boiler. The air inlet pipe must be
connected to a combustion air inlet cap as specified
in this section. Combustion air supply pipes for
multiple boiler installations can NOT be combined
into a single pipe and inlet termination point.
Combustion air supplied from outdoors must be free
of contaminants (See Combustion andVentilationAir).
Sidewall Air Inlet
The sidewall air inlet cap is supplied in the Horizontal
DirectAire Vent Kit which must be ordered from the
manufacturer. This sidewall cap will supply
combustion air for a single unit only.
Horizont l DirectAire Inst ll tion
FIG. 20
CAUTION !!
oilers which are shut down or will not operate
may experience freezing due to convective
air flow in the air inlet pipe connected to the unit.
In cold climates, continuous pump operation is
recommended to help prevent freezing of boiler
water on DirectAire systems.
Proper freeze protection must be provided.
See Freeze Protection in the Installation and
Service Manual. Air Inlet C p for Sidew ll Termin tion
FIG. 21

16
Locate units as close as possible to sidewall where the
combustion air supply system will be installed.
To prevent recirculation of flue products from an
adjacent vent cap into the combustion air inlet, follow
all applicable clearance requirements in the latest
edition of the National Fuel Gas Code and/or
CAN/CGA-B149 Installation Code and instructions in
this manual.
The combustion air inlet cap must be installed at least
one foot (0.30m) above ground level and above normal
snow levels.
The point of termination for the combustion air inlet
cap MUST be at least 3 feet (0.91m) below the point
of flue gas termination (powered vent cap) if it is
located within 10' (3.05m) of the flue outlet from the
powered vent cap. Use care to insure that the air inlet
cap assembly is properly installed on the air inlet pipe.
The combustion air inlet cap and the powered vent cap
MUST be installed on the same wall and in the same
pressure zone.
The combustion air inlet cap must not be installed
closer than 10 feet (3.05m) from an inside corner of a
L-shaped structure.
Incorrect installation and/or location of the air inlet
cap can allow the discharge of flue products to be drawn
into the combustion process on the boiler. This can
result in incomplete combustion and potentially
hazardous levels of carbon monoxide in the flue
products. This will cause operational problems with
the boiler and possible spillage of flue products which
can cause personal injury, death or property damage.
Air Inlet Pipe Materials
The Horizontal DirectAire system requires installation
of a single wall pipe to supply combustion air from
outdoors directly to the boiler.
Length of Air Inlet Pipe
The total equivalent length of the Horizontal
DirectAire combustion air inlet pipe must not exceed
a maximum of 50 (15.24m) equivalent feet in length.
Subtract 5 feet (1.52m) for each elbow in the air intake
system. Do not exceed limits for the combustion air
inlet piping lengths.
Vent Kits
The Horizontal DirectAire Vent Kit for sidewall
installation MUST be ordered from the boiler
manufacturer. The part number for each kit is listed
by unit size. Each kit includes a sidewall powered
vent cap, proving switch, controls, combustion air inlet
cap to supply air to a single boiler and instructions for
proper installation.The flue pipe and air inlet pipe are
purchased locally.
*Minimum diameter, installer may increase diameter
one pipe size for ease of installation if needed.
The sidewall air inlet cap supplied in the Horizontal
DirectAire Vent Kit is used to supply combustion air
to a single boiler. Combustion air supply pipes from
multiple units can NOT be combined into a single air
inlet pipe and inlet point. The use of a sidewall air
inlet cap other than the manufacturers recommended
cap may result in operational problems with the boiler
or potentially hazardous spillage of flue products
which can cause personal injury, death or property
damage.
The use of double wall vent
material for the combustion air inlet pipe is
recommended in cold climates to prevent the
condensation of airborne mositure in the
incoming combustion air.
NOTE:  
 

Outdoor Inst ll tion Illustr tion
Input Flue DiectAire Horizontal
tu/hr Size Inlet Pipe* DirectAire
Kit
300,000 5" 5" HDK3005
990,000 10" 10" HDK3009
1,260,000 12" 12" HDK3010
1,440,000 12" 12" HDK3010
1,800,000 14” 12” HDK3012
2,070,000 14” 12” HDK3012
TA LE — F

17
Venting of Flue Products
For venting flue products horizontally to the outdoors,
follow all requirements in the installation instructions
for sidewall venting.
Termination point for the flue products must follow
the clearance requirements in the Sidewall Vent
Termination section of Sidewall Venting.
A barometric damper is NOT required in the flue on
Horizontal DirectAire installations if the draft is within
the 0.02 to 0.08 inches water negative required for
proper operation. If the draft exceeds this range, a
barometric damper must be installed.
The Outdoor Vent System
Units are self venting and can be used outdoors when
installed with the optional Outdoor Cap. This cap
mounts directly to the top of the boiler and covers the
flue outlet and combustion air inlet openings on the
jacket. No additional vent piping is required.
CAUTION !!
oilers which are shut down or will not operate
may experience freezing due to convective
air flow in the outdoor vent cap installed on
the unit. In cold climates, continuous
pump operation is recommended to help
prevent freezing of boiler water on
Outdoor systems. Proper freeze protection
must be provided. See Freeze Protection.
Combustion air supply must be free of contaminants
(See Combustion and Ventilation Air). To prevent
recirculation of the flue products into the combustion
air inlet, follow all instructions in this section.
Outdoor Vent/Air Inlet Location
The venting areas must never be obstructed. Keep area
clean and free of combustible and flammable materials.
Maintain a minimum clearance of 3"(76 mm) to
combustible surfaces and a minimum of 3" (76 mm)
clearance to the air inlet. To avoid a blocked air inlet
or blocked flue condition, keep the outdoor cap air inlet,
flue outlet and drain slot clear of snow, ice, leaves
debris, etc.
A unit should not be located so that high winds can
deflect off of adjacent walls, buildings or shrubbery
causing recirculation. Recirculation of flue products
may cause operational problems, bad combustion or
damage to controls. The unit should be located at least
3 feet (0.19m) from any wall or vertical surface to
prevent adverse wind conditions from affecting
performance.
Multiple unit outdoor installations require 48" (1.22m)
clearance between each vent cap.
The outdoor cap must be located 4 feet (1.22m) below
and 4 feet (1.22m) horizontally from any window, door,
walkway or gravity air intake.
OUTDOOR INSTALLATION
FIG. 22
Outdoor Inst ll tion
CAUTION !!
oilers which are shut down or will not operate
may experience freezing due to convective air
flow in the air inlet pipe connected to the unit.
In cold climates, continuous pump operation is
recommended to help prevent freezing of boiler
water on Horizontal DirectAire systems. Proper
freeze protection must be provided.
See Freeze Protection.
WARNING:
Outdoor models MUST be
installed outdoors and MUST use the vent cap
supplied by the manufacturer. Personal injury
or product damage may result if any other cap is
used or if an outdoor model is used indoors. All
covers, doors and jacket panels must be properly
installed to insure proper operation and prevent
a hazardous condition.

18
Verify unit is supplied with type gas specified on rating
plate. This unit is orificed for operation up to 4000
feet altitude. Consult factory for installations above
4000 feet elevation. The unit will be marked to
indicate suitability for high altitude operation.
INLET PRESSURE: Measured at the inlet pressure
tap located upstream of the combination gas valve.
Maximum inlet gas pressure must not exceed the value
specified. Minimum value listed is for the purposes
of input adjustment.
The Outdoor Vent Cap Kit
The required outdoor cap part numbers are listed by
unit size. The venting kit must be furnished by the
manufacturer in accordance with CSA International
requirements. Each kit includes the flue products
outlet/combustion air inlet assembly and gasket.
CAUTION !!
oilers which are shut down or will not operate
may experience freezing due to convective air
flow down the vent cap installed on the unit.
Proper freeze protection must be provided.
See Freeze Protection.
Input Outdoor Cap
tu/hr Kit Number
3 , ODK3 3
99 , ODK3 9
1,26 , ODK3 1
1,44 , ODK3 1
1,8 , ODK3 11
2, 7 , ODK3 11
TA LE — G
TA LE — H
SUPPLY PRESSURE
Nat. Gas LPG
Max. (Inches-Water Column) 1 .5"w.c. 13"w.c.
Min. (Inches-Water column) 5. "w.c. 11"w.c.
The combustion air inlet of the outdoor cap must be
located at least one foot (0.30m) above grade and above
normal snow levels.
The unit must be at least 10 feet (3.05m) away from
any forced air inlet.
The unit must be at least 3 feet (0.91m) outside any
overhang.
Clearances around outdoor installations can change
with time. Do not allow the growth of trees, shrubs or
other plants to obstruct the proper operation of the
outdoor vent system.
Do not install in locations where rain from building
runoff drains will spill onto the boiler.
Flue gas condensate can freeze on exterior walls or on
the vent cap. Frozen condensate on the vent cap can
result in a blocked flue condition. Some discoloration
to exterior building or unit surfaces can be expected.
Adjacent brick or masonry surfaces should be protected
with a rust resistant sheet metal plate.
GAS SUPPLY
FIG. 24
Outdoor Vent C p Inst lled on Unit
FLUE OUTLET
AIR INLET
OUTDOOR
VENT CAP
FIG. 23
Outdoor Vent C p

19
MANIFOLD PRESSURE: Measured at the pressure
tap on the downstream side of the combination gas
valve. The gas regulator on the boiler’s combination
gas valve is adjustable to supply proper manifold
pressure for normal operation. If adjustment of
regulator pressure is required, see ManifoldAdjustment
Procedure. Do not increase regulator pressure
beyond specified pressure setting.
1. The appliance must be disconnected from the gas
supply piping system during any pressure testing
of that system at a test pressure in excess of 1/2
PSIG (3.5kPa).
2. The appliance must be isolated from the gas
supply piping system by closing a manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less
than 1/2 PSIG (3.5kPa).
3. The boiler and its gas connection must be
leak-tested before placing it in operation.
1. Safe operation of unit requires properly sized gas
supply piping. See data below.
2. Gas pipe size may be larger than heater
connection.
3. Installation of a union is suggested for ease of
service.
4. Install a manual main gas shutoff valve, outside
of the appliance gas connection and before the gas
valve, when local codes require.
5. A trap (drip leg) MUST be provided in the inlet
of the gas connection to the unit.
GAS PRESSURE TEST
SINGLE UNIT INSTALLATIONS
GAS CONNECTION
6. The combination gas valve has an integral vent
limiting device and does not require venting to
atmosphere, outside the building. The unit will
not operate properly if the reference hose is
removed or a vent to atmosphere is installed.
7. Optional gas controls may require routing of
bleeds and vents to the atmosphere, outside the
building when required by local codes.
300,000 4.0”10”
990,000 - 2,070,000 3.5”10”
tu/hr Regulator Settings
Input Natural Gas L.P.Gas
TA LE — I
For each elbow or tee, add equivalent straight pipe to
total length from table below.
300,000
990,000
1,260,000
1,440,000
1,800,000
2,070,000
0-50’
1 1/4”
2”
2”
2”
2 1/2”
2 1/2”
51’-100’
1 1/4”
2”
2 1/2”
2 1/2”
2 1/2”
3”
101’-200’
1 1/2”
2 1/2”
2 1/2”
3”
3”
3”
201’-300’
1 1/2”
2 1/2”
3”
3”
3 1/2”
3”
301’-500’
2”
3”
3”
3 1/2”
4”
3 1/2”
DISTANCE FROM METER
TA LE — J
SUGGESTED GAS PIPE SIZE
SINGLE UNIT INSTALLATIONS
BTU
INPUT
TA LE — K
FITTINGS TO
EQUIVALENT STRAIGHT PIPE
Diameter Pipe (inches)
3/4”1”11/4”11/2”2”3”4”5”
Equivalent length of Straight Pipe (feet)
2' 2' 3' 4' 5' 10' 14' 20'

2
Install Piping to Control
1. The gas line should be a separate line direct from
the meter unless the existing gas line is of
sufficient capacity. Verify pipe size with your gas
supplier.
2. Use new, properly threaded black iron pipe free
from chips. If tubing is used, make sure the ends
are square, deburred and clean. All tubing bends
must be smooth and without deformation. Avoid
flexible gas connections. Internal diameter of
flexible lines may not provide unit with proper
volume of gas.
3. Install a manual main gas shutoff valve at the
boiler gas inlet, outside of the boiler and before
the gas valve.
4. Run pipe or tubing to the boiler’s gas inlet. If
tubing is used, obtain a tube to pipe coupling to
connect the tubing to the boiler’s gas inlet.
5. Install a sediment trap in the supply line to the
boiler’s gas inlet. (See Figure 25)
All gas connections must be made with pipe joint
compound resistant to the action of liquefied petroleum
and natural gasses. All piping must comply with local
codes and ordinances. Tubing installations must
comply with approved standards and practices.
GAS PIPING
Maximum Capacity of Pipe in Thousands of BTU's per hour for gas pressures of 14 Inches Water Column (0.05 PSIG) or less and a
pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025•BTU's per Cubic Foot of Gas and 0.60 Specific Gravity).
TA LE — L
MULTIPLE UNIT INSTALLATIONS GAS PIPING SIZE CHART
G s Line Connection
FIG. 25
lanimoN
,eziSepiPnorI
sehcnI
teeFthgiartSniepiPfohtgneL
010203040506070809001521051571002
4/3 963652524715511418211213116159689747
1796774483823292762642652122971461941831
4/11 4,1479987776595345252741441496333383782
2/11 51,25,112,12,13293896777666636465315274144
21,428,262,259,127,165,144,133,152,181,11,147917828
2/12 64,664,416,31,327,264,213,21,2,29,17,145,14,13,1
32,119,74,64,578,414,4,48,345,33,3,327,25,243,2
45,321,611,311,11,1,93,896,783,778,651,646,531,527,4
CAP
NIPPLE
MANUAL
MAIN
SHUT-OFF
VALVE
GROUND
JOINT
UNION
USE
WRENCH
TO HOLD
PIPING