RBI LCD-I0M-8R User manual

06/15 Copyright 2014 Mestek, Inc.
LCD-I0M-8R
82-0278
Boiler Manual
Installation and Operation
Instructions
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-free air supply. Follow the instruction manual procedures to duct air to the boiler air intake. If the boiler has been contaminated
by operation 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. 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.
Finned Copper Tube
Gas Boilers (LB) &
Water Heaters (LW)

Finned copper tube gas boilers & water heaters – Boiler Manual
2
BEFORE YOUR START. . . . . . . . . . . . . . . . . PAGE 2
RATINGS & CAPACITIES . . . . . . . . . . . . . . . . PAGE 3
BOILER/WATER HEATER LOCATION . . . . . . . . .PAGE 3
COMBUSTION AIR & VENTILATION . . . . . . . . . . PAGE 3
GENERAL VENTING GUIDELINES. . . . . . . . . . . PAGE 9
VENTING OPTIONS . . . . . . . . . . . . . . . . . . PAGE 9
VERTICAL/CHIMNEY VENTING . . . . . . . . . . . PAGE 10
HORIZONTAL VENTING . . . . . . . . . . . . . . . PAGE 11
OUTDOOR VENTING . . . . . . . . . . . . . . . . PAGE 11
COMMON VENT SYSTEMS . . . . . . . . . . . . . PAGE 12
GENERAL PIPING REQUIREMENTS . . . . . . . . PAGE 13
HEATING SYSTEM PIPING . . . . . . . . . . . . . PAGE 14
DOMESTIC WATER SUPPLY PIPING . . . . . . . . PAGE 18
GAS SUPPLY PIPING . . . . . . . . . . . . . . . . PAGE 21
ELECTRICAL WIRING . . . . . . . . . . . . . . . . PAGE 22
GENERAL OPERATION . . . . . . . . . . . . . . . PAGE 22
OPERATING INSTRUCTIONS . . . . . . . . . . . . PAGE 26
CHECKING & ADJUSTMENTS. . . . . . . . . . . . PAGE 28
CONTROL DESCRIPTION . . . . . . . . . . . . . . PAGE 30
MAINTENANCE . . . . . . . . . . . . . . . . . . . PAGE 31
TROUBLESHOOTING . . . . . . . . . . . . . . . . PAGE 34
REPAIR PARTS . . . . . . . . . . . . . . . . . . . . PAGE 36
START UP SHEET . . . . . . . . . . . . . . . . . . PAGE 44
MASS. CODE . . . . . . . . . . . . . . . . . . . . . PAGE 46
WARRANTY . . . . . . . . . . . . . . . . . . . . . PAGE 47
BEFORE YOU START
is manual covers the application, installation, operation and
maintenance of a LCD Series nned copper heating boiler/water
heater/pool heater (Canada only).
To obtain the safe, dependable, ecient operation and long life for
whichthisheatingboiler/waterheaterwasdesigned,theseinstructions
must be read, understood and followed.
eLCDSeriesnnedcopperheatingboiler/waterheatershavebeen
designcertied by CSA forusewith naturalandpropanegasunder
thelatestrevisionofANSI-Z21.10.3/CSA4.3,GasWaterHeaters,and
ANSI-Z21.13/CSA 4.9, Gas-Fired Low Pressure Steam and Hot
Water BoilersandCAN1-3.1 IndustrialandCommercialGasFired
Boilers. Eachunithasbeenconstructedandhydrostaticallytestedfor
amaximum working pressureof160 psi,1103 kPain accordance
with Section IV of the A.S.M.E.BoilerandPressureVesselCode.
All aspects of the boiler/water heater installation must conform
to the requirements of the authority having jurisdiction, or, in the
absence of such requirements, to the National Fuel Gas Code, ANSI
Z223.1/NFPA 54-latest revision. Where required by the authority
having jurisdiction, the installation must conform to the Standard
for Controls and Safety Devices for Automatically Fired Boilers,
ANSI/ASME CSD-1.
If the information in this manual is not followed
exactly, a fire or explosion may result causing property,
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
WHAT TO DO IF YOU SMELL GAS:
• Donottrytolightanyappliance.
• Do not touch any electrical switch. Do not use any
phoneinyourbuilding.
• Immediatelycallyourgassupplierfromaphoneoutside
thebuilding.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.
Assurez-vous de bien suivre les instructions données
dans cette notice pour réduire au minimum le risque
d’incendieoud’explosionoupourévitertoutdommoge
matériel, toute blessure ou la mort
Ne pas entreposer ni utiliser d’essence ou ni d’autres
vapeurs ou liquides inflammables à proximité de cet
appareiloudetoutautreappareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
• Nepastenterd’allumerd’appareil.
• Netouchezàaucuninterrupteur;nepasvousservir
destéléphonessetrouvantdanslebâtiment.
• Appelezimmédiatementvotrefournisseurdegasdepuis
unvoisin.Suivezlesintructionsdufournisseur.
• Sivousnepurvezrejoindrelefournisseur,appelezle
servicedesincendies.
L’installation et l’entretien doivent être assurés par un
installateur ou un service d’entretien qualifié ou par le
fournisseurdegaz.
Failure to properly vent this unit can cause excessive
amounts of carbon monoxide resulting in severe
personal injury or death!
DESIGNEDANDTESTEDACCORDINGTOA.S.M.E.
BOILER AND PRESSURE VESSEL CODE, SECTION
IV FOR A MAXIMUM ALLOWABLE WORKING PRES-
SUREOF160PSI,1103 kPaWATER.
INSTALLER, THESE INSTRUCTIONS TO BE AFFIXED
ADJACENT TO THE HEATER.
CONSUMER, RETAIN THESE INSTRUCTIONS FOR
FUTURE REFERENCE PURPOSES.

Finned copper tube gas boilers & water heaters – Boiler Manual
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In Canada, the installation must be in accordance with the
requirementsofCSAB149.1or.2,InstallationCodeforGasBurning
Appliances and Equipment.
If installed in the Commonwealth of Massachuses, you MUST
FOLLOW the additional instructions located in the back of this
manual (MACODE-3).
e owner should maintain a record of all service work performed
with the date and a description of the work done. Include the name
of the service organization for future reference.
Direct all questions to your RBI distributor or contact the RBI Cus-
tomer Service Department, 260 North Elm Street, Westeld, MA
01085forU.S.or7555TranmereDrive,Mississauga, ONTL5S1L4
for Canada. Always include the model and serial numbers from the
rating plate of the boiler/water heater in question.
RATINGS & CAPACITIES
Before undertaking the installation of the LCD Series boiler/water
heater check the rating plate to ensure that the unit has been sized
properly for the job. e “Net AHRI Ratings” specify the equivalent
amount of direct cast iron radiation that the unit can supply under
normal conditions. Also ensure that the unit has been set up for the
type of gas available at the installation site. Other important
considerations are the availability of an adequate electrical supply,
fresh air for combustion and a suitable chimney or vent system.
BOILER/WATER HEATER LOCATION
1. is boiler/water heater is suitable for indoor and outdoor
installations. Locate the boiler/water heater in an area that
provides good access to the unit. Servicing may require the
removalofjacketpanels.Allowtheminimumclearancesbetween
adjacent construction and the boiler/water heater as listed in
Table 1.
Service clearances are not mandatory, but are
recommended to ensure ease of service should it be
required.
Table 1
Clearance to
Combustibles
Service
Clearance
in mm in mm
Top 6153 20 508
Back 6153 24 610
Left Side 6153 24 610
Right Side 6153 24 610
Front 6153 30 762
Flue 6153
2. An optimum site will be level, central to the piping system, close
to a chimney or outside wall and have adequate fresh air for
combustion. Ensure that the boiler/water heater is level from
front to back and from side to side. Use metal shims to level the
boiler/water heater. Electrical and electronic components must
also be protected from exposure to water during operation and
maintenance. DO NOT install this boiler/water heater in a
location that would subject any of the gas ignition components
to direct contact with water or excessive moisture during
operation or servicing.
3. Ensure that the oor is structurally sound and will support the
weight of the boiler/water heater.
e LCD may be installed directly on combustible
ooring, but never on carpeting.
4. Locate the boiler/water heater in an area that will prevent water
damage to adjacent construction should a leak occur or during
routine maintenance. If such a location doesn’t exist, a suitable
drain pan that’s adequately drained must be installed under the
unit.
5.
DO NOT place this boiler/water heater in a location that would
restrict the introductionofcombustionairintotheunitorsubject
the air inlet to a negative pressure, see “GENEL VENTING
GUIDELINES”.
Never store combustible materials, gasoline or any
product containing ammable vapors or liquids in the
vicinity of the boiler/water heater. Failure to comply
with this warning can result in an explosion or re
causing extensive property damage, severe personal
injury or death!
6. NEVER place this boiler/water heater in a location that would
subject it to temperatures at or near freezing. See the “Freeze
Protection Section” on page 14.
Units installed outdoors MUST be protected from ice
and snow accumulation or the unit will be damaged
voiding the warranty!
COMBUSTION AIR & VENTILATION
is boiler/water heater must be supplied with
combustion air in accordance with Section 5.3, Air
for Combustion & Ventilation, of the latest revision
of the National Fuel Gas Code, ANSI Z223.1/NFPA
54 and all applicable local building codes. Canadian
installations must comply with CSA B149.1 or .2
Installation Code for Gas Burning Appliances and
Equipment, or applicable provisions of the local
building codes. Failure to provide adequate
combustion air for this boiler/water heater can result
in excessive levels of carbon monoxide which can
result in severe personal injury or death!
To operate properly and safely this boiler/water heater requires a
continuous supply of air for combustion. NEVER store objects on
or around the boiler/water heater!

Finned copper tube gas boilers & water heaters – Boiler Manual
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Combustion air contaminated with uorocarbons or
other halogenated compounds such as cleaning
solvents and refrigerants will result in the formation
of acids in the combustion chamber. ese acids will
cause premature failure of the boiler/water heater
voiding the warranty!
Ifthe boiler/waterheateris operatedwhilethebuilding
is under construction it MUST be protected from
wood, concrete, sheet rock and other types of dust.
Failure to properly protect the unit from construction
dust will damage the unit voiding the warranty!
Buildings will require the installation of a fresh air duct or other
means of providing make-up air if the intake air option isn’t used.
Anybuildingutilizingothergasburningappliances,areplace,wood
stove or any type of exhaust fan must be checked for adequate
combustion air when all of these devices are in operation at one
time. Sizing of an outside air duct must be done to meet the
requirements of all such devices.
NeveroperatetheLCDinanenvironmentsubjectedto
anegativepressureunlessthe air intakeis connectedto
the outdoors. Failure to comply with this warning can
result in excessive levels of carbon monoxide causing
severe personal injury or death!
All Air From Inside The Building
IftheLCDistobelocatedinaconnedspacetheminimumclearances
listedin Table1mustbemaintainedbetweenitandanycombustible
construction. When installed in a conned space without the
intake air option, Figures 1, 2 & 3, two permanent openings
communicating with an additional room(s) are required. e
combined volume of these spaces must have sucient volume to
meetthecombustionairrequirementsofallgasutilizationequipment.
Fireplaces,wood stovesoranytypeofexhaustfanmustbeconsidered
whenmakingthisdetermination.Eachopeningmusthaveaminimum
free area of 1 in2/1000 Btu/hr, 2200 mm2kW based on the total
input rating of ALL gas utilization equipment in the conned area.
Eachopeningmustbeno lessthan100in2,64,516 mm2insize.e
upper opening must be within 12 in, 305 mm of, but not less than
3 in, 76 mm from, the top of the enclosure. e boom opening
must be within 12 in, 305 mm of, but not less than 3 in, 76 mm
from, the boom of the enclosure.
Figure 1 Vertical venting with a metal chimney system and inside air
10 FT

Finned copper tube gas boilers & water heaters – Boiler Manual
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Figure 2 Vertical venting using a masonry chimney system and inside air
Figure 3 Horizontal venting using inside air
305 TO 457
127 TO 254
VENT PIPE DIAMETER
5" TO 10"
12" TO 18"
MINIMUM VERTICAL RISE
OFF THE TOP OF UNIT "A"
IN. mm FT mm
12"
24"
305
610
1.5 FT 0.5 m
1/4 IN. PER F00T 20 mm/m
Table 2

Finned copper tube gas boilers & water heaters – Boiler Manual
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All Air From Outside The Building
When installed in a conned space withoututilizingtheintake
air option two permanent openings communicating directly with,
or by ducts to, the outdoors or spaces that freely communicate with
theoutdoorsmustbepresent.eupperopeningmustbewithin12
in, 305 mm of, but not less than 3 in, 76 mm from, the top of the
enclosure. e boom opening must be within 12 in, 305 mm of,
but not less than 3 in, 76 mm from, the boom of the enclosure.
Wheredirectlycommunicatingwiththeoutdoorsorcommunicating
with the outdoors through vertical ducts, each opening shall have a
minimum free area of 1 in2/4000 Btu/hr, 550 mm2/kW of the
total input rating of all of the equipment in the enclosure.
Where communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1 in2/2000
Btu/hr, 1100 mm2/kW of the total input rating of all of the
equipment in the enclosure. When louvers and screens are used, they
must have the same cross-sectional area as the free area of the
opening to which they connect.
When calculating the free area necessary to meet the make-up air
requirements of the enclosure,consideration must be given to the
blockage eects of louvers, grills and screens. Screens must have a
minimum mesh size of 1/4 in, 6.4mm. If the free area through a
louver or grill is not known, ducts should be sized per Table 3.
Table 3 Make-up air louver sizing
Required Cross Sectional Area
Input
(MBH)
1/4 in 6.4 mm
Wire Screen
75% Free Area
Metal Louvers
25% Free Area
Wooden Louvers
in2cm2in2cm2in2cm2
399 100 645 133 858 399 2573
600 150 968 200 1290 600 3870
750 190 1210 250 1613 750 4840
1050 263 1696 350 2258 1050 6773
1200 300 1936 400 2580 1200 7740
1480 370 2388 494 3182 1480 9546
1650 413 2662 550 3548 1650 10,643
1970 493 3179 657 4236 1970 12,707
2300 575 3711 767 4945 2300 14,835
Canadian installations must comply with CSA B149.1 when air
supply is provided by naturalairowfromtheoutdoorsfor natural
dra, partial fan-assisted, fan-assisted, or power dra-assisted
burners, there shall be a permanent air supply opening(s) having
a cross-sectional area of not less than 1 in2per 7,000 Btuh
(310 mm2per kW) up to and including 1millionBtuh,plus
1 in2 per 14,000 Btuh (155 mm2per kW) in excess of 1
million Btuh.
Intake Air Option - General Guidelines
is conguration provides combustion air directly to the boiler/
waterheater’sair intakeusingadedicatedpipe toobtaincombustion
air from the outdoors. Combustion air can be drawn in horizontally
through an outside wall or vertically through the roof, see Figures
4, 5, 6 & 7.
Common intake air systems may be used to provide
the common duct is sized properly and an intake
combustion air damper is installed in the intake air
pipe of each heater. Improper installation can result in
excessive levels of carbon monoxide which can cause
severe personal injury or death!
Single wall galvanized smoke pipe, single wall aluminum pipe or
exible aluminum pipe can be used for the in-take air pipe. It must
be sized per Table 4. All joints in metal combustion air systems
must be secured using corrosion resistant fasteners and sealed using
a suitable Silicon caulk or tape. e combustion air system
MUST be supported by the building structure not the
boiler/waterheater.
Table 4 Combustion air pipe sizing
Model Size Pipe Diameter
in mm
400 6152
600 - 750 8 203
1050 10 254
1200 - 2300 12 305
A combustion air damper interlocked with the unit
should be installed in the intake air pipe when the
inltration of sub-freezing air could occur, otherwise
the unit could freeze up voiding the warranty!
Intake Air Option - Horizontal Guidelines
e maximum equivalent length for the horizontal combustion
air pipe on installations that used the Direct Vent option is 35 ,
10.8 m. e maximum equivalent length for the horizontal
combustion air pipe on installations that use the Horizontal Vent
option is 100 , 30.5 m. Each 90° elbow and the combustion air
terminal are equal to 10 linear , 3.0 mof pipe. If horizontal runs
exceed 5,1.5 m they must be supported at 3 , 0.9 m intervals
with overhead hangers. e certied combustion air terminal from
RBI must be used and installed as shown in Figures 4 and 5.
Intake Air Option - Vertical Guidelines
e maximum length for the vertical combustion air pipe is 30 ,
9.1 m plus two 90° elbows. A listed, nonrestrictive combustion air
cap must be used. e combustion air cap must terminate as shown
in Figure 6. e penetration point in the roof must be properly
ashed and sealed.

Finned copper tube gas boilers & water heaters – Boiler Manual
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Figure 4 Horizontal combustion air and venting for a single unit
Figure 5 Horizontal combustion air and venting for a multiple units
When running horizontal combustion air and venting for single or multiple units, exhaust and combustion air terminals must be
installed on the same plane (outside wall) in order to prevent pressure dierences due to prevailing winds. In cold climates, double-
wall or insulated inlet pipe recommended to prevent condensation.
1.5 FT 0.5 m
2 IN.5.0 cm
0
1
2
3
4
5
6
7
8
9
0510 15 20
Horizontal Distance, X
Y,ecnatsiDlacitreV
2000 & Larger
1201 To 2000
901 To 1200
200 To 900
1000 BTU'S
0
1
2
3
4
5
6
7
8
9
05101520
Horizontal Distance, X
Y,ecnatsiDlacitreV
2000 & Larger
1201 To 2000
901 To 1200
200 To 900
1000 BTU'S
400

Finned copper tube gas boilers & water heaters – Boiler Manual
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Figure 6 Vertical combustion air and venting, metal chimney system shown
Locate exhaust terminal downwind from air intake to reduce potential for flue gas recirculation.
Figure 7 Combination air intake and venting, masonry chimney shown
10 FT 3.1 m
4 FT
1.2 m
5 FT
1.5 m
1.5 FT
0.5 m
5 1/2 FT
1.7 m
1.5 FT .5m
10 FT 3.1 m
3 FT 1 m

Finned copper tube gas boilers & water heaters – Boiler Manual
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GENERAL VENTING GUIDELINES
e vent installation must be in accordance with Part
7, Venting of Equipment, of the National Fuel Gas
Code, ANSI Z223.1/NFPA 54-latest revision or
applicable provisions of the local building codes.
Canadian installations must comply with CSA B149.1
or .2 Installation Code. Improper venting can result
inexcessivelevelsofcarbonmonoxidewhichcanresult
in severe personal injury or death!
All vent systems must be fully supported by the building structure
and not by the boiler/water heater. Appropriate thimbles and re-
stops must be used where required.
Common vent systems must be properly engineered
and sized to provide a negative dra of 0.01to0.08
in, .25 to 2.0 mm WC at the ue outlet! Common
positive pressure vent systems are not to be used.
Improper installation can result in excessive levels of
carbon monoxide which can cause severe personal
injury or death!
A single acting barometric damper must be
installed directly to the boiler/water heater ue
outlet to ensure proper operation. is does not apply
to outdoor units or direct vent positive pressure units.
Some venting applications may require the stop to be
removed for smooth operation. e barometric
damper should be located aer the ue collector, refer
to Figures 2, 7A and 8 for proper location. Be sure that
the damper is mounted horizontally (never vertically).
Carefully follow the instructions provided with the
barometric damper. Check with local codes for specic
requirements.
In Canada, B149 (7.25 Dra Regulators) states the
damper shall be of double-acting type.
To avoid spillage into the room of dangerous ue gas
containing carbon monoxide, the opening in damper
must never face against the ow of ue gas.
VENT SYSTEM OPTIONS
e LCD may be vented the following ways:
1) Vertical/Chimney Venting, Negative Pressure, Category
I - uses an approved metal chimney system or properly lined
masonry chimney. Combustion air is obtained from the space
in which the unit is installed or from outdoors. A barometric
damper must be installed near the ue outlet when venting
vertically.SeeFigures6 and 7. is alsoappliestoanyfan-assisted
chimneys or vents.
2) Direct Vent, Positive Pressure, Category III - for
horizontal vent runs equivalent to 35 , 10.8 m or less.
A stainless steel vent system certied to UL 1738 for
installations in the United States. ULC S636 for
installations in Canada must be used when combustion air is
ducted from outdoors, from the same wall.
3) Horizontal Vent, Negative Pressure, Category I -
for horizontal vent runs equivalent to more than 35 ,
10.8 m (90° elbow equals 10 equivalent ). A dedicated wall
mounted power venter must be used. e vent system can be
single wall galvanized steel or type B vent pipe. Combustion
air is obtained from the space in which the unit is installed or
from the outdoors.
A barometric damper must be installed when the horzontal run
is longer than 35 equivalent feet. (90° elbow = 10 equivalent
). If this is the case, a power venter must also be used.
If horizontal run is less than 35 equivalent , do not use a
barometric damper. Follow applicable instructions under the
“COMBUSTION AIR & VENTILATION” section.
4) Outdoor Installation -usestheoutdooroptionkit.Barometric
damper is not required.
All venting, combusiton air material supplied by
installer. All venting material must be approved for the
application. Consult the vent manufacturer’s product
literature.

Finned copper tube gas boilers & water heaters – Boiler Manual
10
VERTICAL/CHIMNEY VENTING
e LCD is listed as a Category I appliance when vented vertically
into a metal chimney system or properly sized masonry chimney,
Figures 1, 2, 6 & 7. e chimney must provide a negative pressure
of 0.01to 0.08in, .25 to 2.0 mm WC at the boiler/water heater
ue collar with the unit running at full load. A barometric damper
must be installed between the ue collar and the vent connector.
Approved thimbles and re-stops must be used when combustible
construction is penetrated.
If an appliance using any type of a mechanical dra
system operating under positive pressure is connected
to a chimney ue, never connect any other appliances
to this ue. Doing so can result in excessive levels of
carbon monoxide which can cause severe personal
injury or death!
Chimney Inspection & Sizing
A thorough inspection of the masonry chimney must be
performed toensurethatthechimneyisclean,properlyconstructed,
lined and sized. Exterior masonry chimneys should not be used
unless properly lined to prevent condensation and dra problems.
Table 5 lists the equivalent breeching and ue sizes required for
theboiler/waterheater. Whenmorethanoneapplianceisconnected
to the same chimney ue, the ue must be large enough to safely
vent the combined output of all of the appliances.
Table 5 Equivalent Breeching & Chimney Size (Category I)
Model Size Pipe Diameter
in mm
400 6152
600 7 178
750 8 203
1050 10 254
1200 - 1480 12 305
1650 - 2300 14 356
Note: These sizes are based on 20 ft, 6.1 m chimney height.
Vent Connections
Locate the boiler/water heater as close to the chimney as possible.
Use the shortest, straightest vent connector possible for the
installation. If horizontal runs exceed 5 , 1.5 m they must be
supported at 3 , 0.9 m intervals with overhead hangers. Use a
type B, single wall stainless or single wall galvanized steel vent pipe
the same diameter as the ue collar to connect the boiler/water
heater to a masonry chimney. When using an approved metal
chimney system use the appropriate vent connector. e vent
connector should be sloped up toward the chimney at a minimum
rate of 1/4 in/, 20 mm/m. On masonry chimneys the connector
must terminate ush with the inside of the chimney ue, Figure 2.
Fasten each single wall vent connection with at least 3 corrosion
resistant sheet metal screws.
Never install a vent pipe having a diameter dierent
than that of the boiler/water heater ue collar. Failure
to comply with this warning can result in excessive
levels of carbon monoxide which can cause severe
personal injury or death.
Always provide a minimum clearance of 6 in, 152 mm between
single wall vent pipe and any combustible materials. Type B1 vent
may be used, clearance between it and any combustible material
must be as listed.
Failuretomaintainminimumclearancesbetweenvent
connectors and any combustible material can result
in a re causing extensive property damage, severe
personal injury or death!
DIRECT VENT, POSITIVE PRESSURE,
CATEGORY III
In this conguration the boiler/water heater blower is used to push
the ue products to the outdoors while drawing combustion air
fromtheoutdoors.eequivalentlengthofthe ventandcombustion
air systems must not exceed 35 , 10.7 m for each. e Intake
Air Option instructions under the “COMBUSTION AIR &
VENTILATION” section must be followed! e vent system ue
pipe diameter must be sized per Table 5a.
Horizontal Direct Vent Systems - Figures 4 & 5
e vent materials used in horizontal vent systems must be certied
to UL 1738 for installations in the United States, ULC S636 for
installations in Canada. e certied vent terminal from RBI must
also be used.
e maximum equivalent length for the horizontal vent and
combustion air pipes is 35 , 10.8 m for each. Each 90° elbow
and the intake air and vent terminals are equal to 10 , 3.1 m of
straight pipe. To maximize the performance of single wall sheet
metalventsystemslocate90°elbowsasfarfromtheboileraspossible
and from one another. For best results, horizontal vent systems
should be as straight as possible.
e vent system must be both gas tight and watertight. All seams
and joints in metal pipes must be joined and sealed in accordance
with the vent system manufacturer’s instructions.
Whenhorizontalventrunsexceed5 ,1.5 mtheymustbesupported
at 3 , 0.9 m intervals with overhead hangers. e vent system
must be pitched down, toward the vent terminal, 1/4 in/,
20 mm/m. If any part of a single wall metal vent system passes
throughanunheated spaceitmustbeinsulatedwithinsulationrated
for 400°F, 204°C.