RBI Futera II Modulation User manual

12/15 Copyright 2015 Mestek, Inc.
FTIII-I0M-HN-7
82-0300
Boiler Manual
Installation and Operation
Instructions
Also read and follow:
HeatNet® Control 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-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 (MB) &
Water Heaters (MW)

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If the information in this manual is not followed
exactly, a re or explosion may result causing property,
personal injury or loss of life.
Do not store or use gasoline or other ammable vapors
and liquids in the vicinity of this or any other applianc
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neighbor’s
phone.Followthegassupplier’sinstructions.
• If you cannot reach your gas supplier, call the re
department.
Installationandservicemustbeperformedbyaqualied
installer,serviceagencyorthegassupplier.
Assurez-vous de bien suivre les instructions données
dans cee 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 inammables 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 qualié 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.
BEFORE YOU START . . . . . . . . . . . . . . . . . . . . 2
RATINGS & CAPACITIES . . . . . . . . . . . . . . . . . . 3
BOILER/WATER HEATER LOCATION . . . . . . . . . . . . 3
COMBUSTION AIR & VENTILATION . . . . . . . . . . . . . 3
GENERAL VENTING GUIDELINES. . . . . . . . . . . . . . 5
OUTDOOR VENTING . . . . . . . . . . . . . . . . . . . . . 10
COMMON VENT SYSTEMS . . . . . . . . . . . . . . . . .11
GENERAL PIPING REQUIREMENTS . . . . . . . . . . . . 12
HEATING SYSTEM PIPING . . . . . . . . . . . . . . . . . 13
DOMESTIC WATER SUPPLY PIPING . . . . . . . . . . . .17
GAS SUPPLY PIPING . . . . . . . . . . . . . . . . . . . . 20
ELECTRICAL WIRING . . . . . . . . . . . . . . . . . . . .21
GENERAL OPERATION . . . . . . . . . . . . . . . . . . . 21
OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . .22
SEQUENCE OF OPERATION . . . . . . . . . . . . . . . . 24
CHECKING & ADJUSTMENTS. . . . . . . . . . . . . . . . 25
HEATNET FIELD WIRING . . . . . . . . . . . . . . . . . . 26
CONTROL DESCRIPTION . . . . . . . . . . . . . . . . . . 28
DIAGNOSTIC . . . . . . . . . . . . . . . . . . . . . . . . . 28
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . 31
TROUBLE-SHOOTING . . . . . . . . . . . . . . . . . . . .33
REPAIR PARTS . . . . . . . . . . . . . . . . . . . . . . . . 34
START-UP SHEET . . . . . . . . . . . . . . . . . . . . . . 40
MASS CODE . . . . . . . . . . . . . . . . . . . . . . . . .42
WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . 43
BEFORE YOU START
is manual covers the application, installation, operation and
maintenance of a Futera III Series nned copper heating boiler/
water heater/pool heater (Canada only). To obtain the safe,
dependable, ecient operation and long life for which this heating
boiler/water heater was designed, these instructions must be read,
understood and followed.
e Futera III Series nned copper heating boiler/water heaters
have been design certied by CSA for use with natural and propane
gas under the latest revision of ANSI-Z21.10.3/CSA 4.3, Gas Water
Heaters, ANSI-Z21.13/CSA 4.9, Gas-Fired Low Pressure Steam
and Hot Water Boilers ANSI-Z21.56/CSA 4.7 Gas-Fired Pool
Heaters (Canada only) and CAN1-3.1, Industrial and Commercial
Gas Fired Packaged Boilers. Each unit has been constructed and
hydrostatically tested for a maximum working pressure of 160 psi,
1103 kPa in accordance with Section IV of the A.S.M.E. Boiler
and Pressure Vessel Code.

Finned copper tube gas boilers & water heaters – Boiler Manual
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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.
In Canada, the installation must be in accordance with the require-
ments of CSA B149.1 or .2, Installation Code for Gas Burning
Appliances and Equipment.
If installed in the Commonwealth of Massachuses, you MUST
FOLLOW the additional instructions contained in RBI’s instruction
sheet MACODE-3. Which is located in the back of this manual.
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 Customer Service Department at: 260 North Elm Street,
Westeld, MA 01085 for US or 7555 Tranmere Drive, Mississauga
ONT L5S 1L4 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 Futera III Series boiler/
water heater check the rating plate to ensure that the unit has been
sized properly for the job. e “Net I=B=R Ratings” specify the
equivalentamountofdirectcopperradiationthattheunit cansupply
under normal conditions. Also ensure that the unit has been set
upforthetypeofgasavailableattheinstallationsite.Otherimportant
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 oudooor
installations. Locate the boiler/water heater in an area
that provides good access to the unit. Servicing may
require the removal of jacket panels. Allow the minimum
clearances between 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 30 762
Back 6153 24 610
Left Side 6153 12 306
Right Side 6153 12 306
Front 6153 30 762
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.
eFuteraIIImaybeinstalleddirectlyoncombustible
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 introduction of combustion air into the unit or
subject it to a negative pressure, see “GENEL VENTING
GUIDELINES”.
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 13.
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!
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 CAN/ CGA B149.1
or .2 Installation Code for Gas Burning Appliances
and Equipment, or applicable provisions of the local
buildingcodes.Failuretoprovideadequatecombustion
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!

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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!
If the boiler/water heater is operated while the building
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.
Any building utilizing other gas burning appliances, 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.
Never operate the Futera III in an environment
subjected to a negative pressure unless it is Direct
Vented. 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
If the Futera III is to be located in a conned space, the minimum
clearances listed in Table 1 must be maintained between it and any
combustible construction. When installed in a conned space
withouttheintakeairoption, Figures 5, 6 and 7, two permanent
openings communicating with an additional room(s) are required.
e combined volume of these spaces must have sucient volume
to meet the criteria for an unconned space. e total air
requirements of all gas utilization equipment, replaces, wood stoves
or any type of exhaust fan must be considered when making this
determination. Each opening must have a minimum free area of
1 in2/1000 Btu/hr, 2200 mm2/kW based on the total input rating
of ALL gas utilization equipment in the conned area. Each opening
must be no less than 100 in2, 64,516 mm2in size. 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.
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 the outdoors must be present. 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.
Where directly communicating with the outdoors or communi-
cating 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 ducts 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, 6.4 mm. If the free area through a
louver or grill is not known, ducts should be sized per Table 2.
Canadian installations must comply with CSA B149.1 when air
supply is provided by natural air ow from the outdoors for natural
draft, 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.
Table 2 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
500 125 806 167 1077 500 3226
750 187 1206 250 1613 750 4839
1000 250 1613 333 2148 1000 6452
1250 313 2019 416 2684 1250 8065
1500 375 2419 500 3226 1500 9677
1750 437 2819 583 3761 1750 11,290
1999 500 3226 667 4303 2000 12,900
Intake Air Option – General Guidelines
is conguration provides combustion air directly to the boiler/
water heater’s air intake adapter using a dedicated pipe when using
the direct vent option. Combustion air can be drawn in horizontally
through the same outside wall which terminates the exhaust gases
or vertically through the roof, see Figures 1, 2, 3 & 4.
Commonintake air systems maybeused provided the
commonduct is sizedproperly.Anintakecombustion
air damper should be installed if the common vent
option is used 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,
exible aluminum pipe, PVC or CPVC pipe can be used for the
intake air pipe. It must be sized per Table 3.

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Table 3 Intake Air Pipe Sizing
Model For Vertical For Horizontal
Size (Up to 60’) (Up to 60’)
in mm in mm
500 8203 6152
750 8203 6152
1000 8203 6152
1250 10 254 8203
1500 10 254 10 254
1750 12 305 12 305
2000 12 305 12 305
All joints in metal intake air systems must be secured using corro-
sion resistant fasteners and sealed using a suitable Silicone caulk.
If PVC or CPVC is used, the joints must be cleaned with a suitable
solvent and connected using a solvent based PVC cement. e
combustion air system MUST be supported by the building
structurenottheboiler/waterheater.
A combustion air damper interlocked with the unit
should be installed in the intake air pipe when the
inltration of subfreezing air could occur, otherwise
the unit could freeze up voiding the warranty!
Intake Air Option – Vertical Guidelines
e maximum equivalent length for the vertical intake air pipe is
60 , 18.3 m. Each 90° elbow and the intake air terminal are equal
to 10 linear , 3.0 m of pipe, see Table 3.
An approved, nonrestrictive intake air terminal must be used. e
intake air terminal must terminate as shown in Figure 3. e
penetration point in the roof must be properly ashed and sealed.
Intake Air Option – Horizontal Guidelines
e maximum equivalent length for the horizontal intake air pipe
is 60 , 18.3 m. Each 90° elbow and the intake air terminal
are equal to 10 linear , 3.0 m of 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 intake air terminal from RBI must
be used, see Figures 1, 2 and 4.
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 appli-
cable provisions of the local building codes. Canadian
installations must comply with CAN/CGA B149.1
or .2 Installation Code. Improper venting can result
in excessive levels of carbon monoxide which can
result 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 .03 in, 0.8 mm
to .1 in, 2.5 mm W.C. 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!
VENT SYSTEM OPTIONS – (CATEGORY I, II, IV)
Correctly identify the type of vent system the appliance
requires before proceeding. Category identication is
noted on the unit rating plate.
e ue products in a Category II and IV vent system may be
cooled below their dew point and form condensate in the ue. e
materials used for a Category II and IV vent must be resistant
to any corrosive damage from ue gas condensate. e ue from
a Category II and IV vent system must have a condensate drain
with provisions to properly collect and dispose of any condensate
that may occur in the venting system.
e Futera III may be vented the following ways:
1) DirectVent,PositivePressure,CategoryIV uses a vent
system certied to UL 1738 for installations in the United
States, ULC S636 for installations in Canada. Combustion air
is piped from the outdoors to the blower inlet.
2) SideWallVent,PositivePressure,CategoryIV uses a
vent system certied to UL 1738 for installations in the
United States, ULC S636 for installations in Canada. Combus-
tion air is obtained from the space in which the unit is installed.
3) Vertical/ChimneyVent,NegativePressure,CategoryII
uses a metal chimney system approved for Category II.
4) VerticalVent,PositivePressure,CategoryIV uses a vent
system certied to UL 1738 for installations in the United States,
ULC S636 for installations in Canada. Combustion air is
obtained from the outdoors or the space in which the unit is
installed.
5) VerticalVent/ChimneyVent(750-2000),NegativePres-
sureNon-Condensing,CategoryI uses an approved metal
chimney system or masonry chimney. Combustion air is ob-
tained from the space in which the unit is installed.
All venting and combustion air material supplied by
installer.Allventingmaterialsmustbeapprovedforthe
application. Consult the vent manufacturer’s product
literature.
e maximum equivalent length for the ue outlet vent
system for Category IV conditions is 60 , 18.3 m.
Use Table 4 for the equivalent lengths per ing.
Table 4 “Category Equivalent Length Per Fiing”
chart is meant as a guideline for preliminary sizing.
If vent length approaches 75% of maximum length
listed an engineered vent system calculation must be
performed, consult factory.

Finned copper tube gas boilers & water heaters – Boiler Manual
6
DIRECT VENT, POSITIVE PRESSURE,
CATEGORY IV
In this conguration the boiler/water heater blower is used
topushtheue productstotheoutdoorswhiledrawingcombustion
air from the outdoors. e Intake Air Option instructions under
the “COMBUSTION AIR & VENTILATION” section must be
followed! e vent system must be sized per Table 4.
Table 4 Category IV
Horizontal Direct Vent Systems
Figures 1 & 2
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.
If any part of a single wall metal vent system passes through an
unheated space, it must be insulated with insulation rated for 400°F,
204°C. Structrual penetrations must be made using approved re-
stops. For best results, horizontal vent systems should be as short
and 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.
When horizontal vent runs exceed 5 , 1.5 m they must be supported
at 3 , 0.9 m intervals with overhead hangers. e vent system
must be pitcheddown, toward the ventterminal,1/4 in/, 20 mm/m.
If any part of a single wall metal vent system passes through an
unheated space it must be insulated with insulation rated for 400°F,
204°C.
Horizontal vent systems shall terminate at least 4 , 1.2 m below,
4 , 1.2 m horizontally from or 1 , 0.30 m above any door, window
or gravity air inlet into any building. It must not terminate less than
4 , 1.2 m horizontally from, and in no case above or below, unless
a 4 , 1.2 m horizontal distance is maintained, from electric meters,
gas meters, regulators and relief equipment and not less than 7 ,
2.1 m above adjacent public walkway. e boom of the vent
terminal(s) shall be located at least 5 , 1.5 m above the air intake
terminal(s) unless there is a minimum 5 , 1.5 m horizontal
separation between them. Avoid terminal 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.
Vertical Direct Vent Systems – Figure 3
If any part of a single wall metal vent system passes through an
unheated space, it must be insulated with insulation rated for 400°F,
204°C. Structural penetrations must be made using approved re-
stops.
An approved, nonrestrictive vent terminal must be used e top
of a vertical vent system must extend at least 51/2,1.7 m above
the roof surface and maximum snow line that it passes through,
4 , 1.2 m above the intake air terminal, see Figure 3.
In addition the vent system must conform to the dimensions shown
in Figure 3. e penetration point in the roof must be properly
ashed and sealed.
e vent system must be gas tight. All seams and joints in metal
pipes must be joined and sealed in accordance with the vent system
manufacturer’s instructions.
Combination Direct Vent Systems – Figure 4
e boiler/water heater can be vented vertically with the intake
air piped horizontally through an outside wall. Follow the instruct-
ions in the Intake Air Option – Horizontal Guidelines on page
5. Also follow the general instructions in the “COMBUSTION
AIR & VENTILATION” and “GENEL VENTING GUIDE
LINES” sections.
Model/
Outlet Diameter
Equivalent Feet of Straight Pipe (ft)
K 500 750 1000
5" 5" 6"
Standard Tee 1.25 15 ft 20 ft 25 ft
Boot Tee 0.65 10 ft 10 ft 15 ft
Cap - Low Res. (UL) 0.50 10 ft 10 ft 10 ft
45° w/Bird Screen 0.40 7 ft 7 ft 10 ft
Elbow – 90° 0.38 10 ft 10 ft 10 ft
Elbow – 45° 0.15 5 ft 5 ft 5 ft
Model/
Outlet Diameter
Equivalent Feet of Straight Pipe (ft)
K 1250 1500 1750 2000
6" 8" 10" 10"
Standard Tee 1.25 25 ft 35 ft 40 ft 40 ft
Boot Tee 0.65 15 ft 15 ft 20 ft 20 ft
Cap - Low Res. (UL) 0.50 10 ft 10 ft 15 ft 15 ft
45° w/Bird Screen 0.40 10 ft 10 ft 10 ft 10 ft
Elbow – 90° 0.38 10 ft 10 ft 15 ft 15 ft
Elbow – 45° 0.15 5 ft 5 ft 5 ft 5 ft

Finned copper tube gas boilers & water heaters – Boiler Manual
7
Figure 1 Hoizontal Air Intake an Venting for a Single Direct Vent System (Category IV)
Figure 2 Horizontal Air Intake and Venting for Multiple Direct Vent Systems (Category IV)
When running horizontal combustion air and venting for
single or multiple units, exhaust and combustion air ter-
minals 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.
5 FT 1.5 m
1.5 FT 0.5 m
2 IN.5.0 cm
4001 & LARGER
2001 TO 4000
1001 TO 2000
500 TO 1000
MBHFT m
15 4.6
20 6.1
51.5
10 3.1
kW
146 TO 293
293 TO 586
586 TO 1172
1172 & LARGER
16 FT 4.9 m
1/4 IN. PER FOOT
20 mm/m
1.5 FT 0.5 m
1000 BTU'S
16 FT 4.9 m
1/4 IN. PER FOOT
20 mm/m
1.5 FT 0.5 m
1000 BTU'S

Finned copper tube gas boilers & water heaters – Boiler Manual
8
Figure 3 Vertical Air Intake and Venting for a Direct Vent System (Category IV)
Figure 4 Combination Direct Vent Systems (Category IV)
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..5 m
10 FT.3.1 m
3 FT.1 m

Finned copper tube gas boilers & water heaters – Boiler Manual
9
SIDE WALL VENT, POSITIVE PRESSURE,
CATEGORY IV – Figure 5
In this conguration the boiler/water heater blower is used to push
the ue products horizontally to the outdoors, see Figure 5. e
air for combustion is taken from the space in which the unit is
installed. e applicable instructions under the “COMBUSTION
AIR & VENTILATION” section must be followed! e vent
guidelines under the Horizontal Direct Vent Systems section must
also be followed.
VERTICAL VENT, POSITIVE PRESSURE,
CATEGORY IV – Figures 7 & 9
(Vent pipe equivalent length up to 60 , 18.3 m maximum)
Masonry chimneys, when used, must be lined with a
metal liner certied for Category IV venting.
A thorough inspection of the masonry chimney must be performed
to ensure that the chimney is clean, properly constructed lined, and
sized. Exterior masonry chimneys should not be used unless
properly lined to prevent condensation and dra problems.
Figure 5 Side Wall Venting (Category IV)
VERTICAL VENT, NEGATIVE PRESSURE –
CATEGORY I & II
e Futera III when listed as a Category II appliance and vent-
ed vertically into a listed metal chimney system, Figures 7 & 9.
echimneymustprovidea negativepressurenotgreaterthan0.10
in, 2.5 mm W.C. at the boiler/water heater ue collar with the unit
running. e Futera III when listed as a Category I appliance and
vented vertically into a listed metal chimney system, Figures 6 & 8.
e chimney must provide a negative pressure not greater than
0.01to0.10in, 0.25 to 2.5 mm W.C. at the boiler/water heater
ue collar with the unit running. A barometric damper must be
installed between the ue collar and the vent connector when nega-
tive pressures exceed 0.10in, 2.5 mm W.C.
Whenusingalistedmetalchimneysystemthechimney
system manufacturer’s instructions must be followed.
Masonry chimneys, when used with Category II
appliances, must be lined with a metal liner certied
to UL 1738 for installations in the United States and
ULC S636 for installations in Canada.
When more than one appliance is connected to the same chimney
ue, the ue must be large enough to safely vent the combined
output of all of the appliances.
If an appliance using any type of a mechanical dra
system operatingunder positivepressureisconnected
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!

Finned copper tube gas boilers & water heaters – Boiler Manual
10
Chimney Inspection & Sizing – Category I and II
A thorough inspection of the masonry chimney must be performed to
ensure that the chimney is clean, properly constructed, lined and sized.
Exterior masonry chimneys should not be used unless properly lined
to prevent condensation and dra problems. Tables 5 & 6 list the
equivalent breeching and ue sizes required for the boiler/water heater.
Correctly identify the type of vent system the appliance
requires before proceeding. Category identication is
noted on the unit rating label.
Table 5 Equivalent Breeching & Chimney Size, Negative Pressure
(Category I)
Model Size Pipe Diameter
in mm
500 – –
750 8 203
1000 10 254
1250 10 254
1500 10 254
1750 12 305
2000 12 305
Note: These sizes are based on a 20 ft, 6.1m chimney height.
Figure 6 Vertical Venting with a Metal Chimney System
(Category I)
Figure 7 Vertical Venting with a Metal Chimney System
(Category II)
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
single wall stainless steel vent pipe the same diameter as the ue
collar to connect the boiler/water heater to a masonry chimney.
When using a listed 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/, 21 mm/m. On masonry chimneys
the connector must terminate ush with the inside of the chimney
ue, Figures 8 & 9. Fasten each single wall vent connection with at
least 3 corrosion resistant sheet metal screws.
Always provide a minimum clearance of 6 in, 152 mm between
single wall vent pipe and any combustible materials.
Failure to maintain minimum clearances between vent
connectors and any combustible material can result
in a re causing extensive property damage, severe
personal injury or death!
Exit cones are favorable when used to increase
the velocity of the ue gas exiting the stack and,
may alsohelp,incoldclimates,toreduceicebuild-
up. Exit cone terminations must be supplied by
others, installed per manufacturer’s instructions,
and meet local and federal code.
generic exit cone
Model Size Pipe Diameter
in mm
500 6 152
750 6 152
1000 7 178
1250 8 203
1500 8 203
1750 10 254
2000 10 254
Note: These sizes are based on a 20 ft, 6.1m chimney height.
Table 6 Equivalent Breeching & Chimney Size, Negative Pressure
(Category II)

Finned copper tube gas boilers & water heaters – Boiler Manual
11
Figure 9 Vertical Venting Using a Lined Masonry Chimney
(Category II)
Figure 11 Multiple Outdoor Units
Figure 8 Vertical Venting Using a Lined Masonry Chimney
(Category I)
Figure 10 Outdoor Venting (Category IV)
DISCHARGE VENT
AIR INLET LOUVERS
2 FT
(0.62M)
3 FT
(1M)
RIOM-60 REV.B

Finned copper tube gas boilers & water heaters – Boiler Manual
12
OUTDOOR VENTING
WheninstalledoutdoorstheFuteraIII mustbe edwiththefactory
supplied outdoor hood, air intake adapter with lter and exhaust
terminal, see Figure 10. Multiple units must be spaced per Figure 11.
eboiler/heater mustbe atleast2 ,.62 m fromanydoor, window
or gravity air inlet into any building and at least 3 , 1 m from any
overhang unless local codes dictate dierently.
Avoid locations where wind deection o of adjacent walls, buildings
or shrubbery might cause a downdra. e unit(s) should be located
at least 3 , 1 m from structures. Outdoor installations are not
recommended in areas where the danger of snow blockage exists.
Do not place the boiler/water heater in a location that
would subject it to runo from adjacent buildings or
damage may occur voiding the warranty!
COMMON VENT SYSTEMS
On multiple boiler common vent applications, the master boiler
may be required to be rst on and installed closest to the verticle
chimney (consult factory).
If an existing boiler/water heater is removed from a common venting
system, the common venting system may then be too large for the
proper venting of the remaining appliances connected to it. At the time
of removal of an existing boiler/water heater, the following steps shall
be followed with each appliance remaining connected to the common
venting system placed in operation, while the other appliances remaining
connected to the common venting system are not in operation.
Aumomentduretraitd’unechaudièreexistante,lesmesuressuivantes
doiventêtreprisespourchaqueappareiltoujoursraccordéausystème
d’évacuation commun et qui fonctionne alors que d’autres appareils
toujours raccordés au système d’évacuation ne fonction-nent pas:
système d’évacuation
a) Seal any unused openings in the common venting system.
Scellertouteslesouverturesnonutiliséesdusystèmed’évacuation.
b) Visually inspect the venting system for proper size and horizontal
pitch and determine there is no blockage or restriction, leakage,
corrosionandotherdeciencieswhichcouldcauseanunsafecondition.
Inspecter de façon visuelle le système d’évacuation pour déterminer
la grosser et l’inclinaison horizontale qui conviennentet s’assurer que
le système est exempt d’obstruction, d’étranglement de fruite, de
corrosion et autres défaillances qui pourraient présenter des risques.
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 appliance
notconnectedtothe common venting system.Turn on any exhaust
fans, such as range hoods and bathroom exhaust, so they will
operate at maximum speed. Do not operate a summer exhaust
fan for a boiler installation. Close replace dampers.
Dans la mesure du possible, fermer toutes les portes et les fenêtres
du bâtiment et toutes les portes entre l’espace où les appareils
toujours raccordés du système d’évacuation sont installés et les
autres espaces du bâtiment. Mere en marche les sécheuses, tous
les appareils non raccordés au système d’évacuation commun et
tous les ventilateurs d’extraction comme les hoes de cuisinère
et les ventilateurs des salles de bain.
S’assurer que ces ventilateurs fonctionnent à la vitesse maximale.
Ne pas faire fonctionner les ventilateurs d’été. Fermer les registres
des cheminées.
d) Place in operation the appliance being inspected. Follow the lighting
instructions. Adjustthermostatso appliancewill operate continuously.
Mere l’appareil inspecté en marche. Suivre les instructions
d’allumage. Régler le thermostat de façon que l’appareil fonc-
tionne de façon continue.
e) Test for spillage at the dra hood relief opening aer 5
minutes of main burner operation. Use the ame of a match
or candle, or smoke from a cigaree, cigar or pipe.
Faire fonctionner le brûleur principal pendant 5 min ensuite,
déterminer si le coupe-tirage déborde à l’ouverture de décharge.
Utiliser la amme d’une allunee ou d’une chandelle ou la fumée
d’une cigaree, d’un cigare ou d’une pipe.
f) Aer it has been determined that each appliance remaining
connected to the common venting system properly vents when
tested as outlined above, return doors, windows, exhaust fans,
replace dampers and any other gas-burning appliance to their
previous condition of use.
Une fois qu’il a été d éterminé, selon la métode indiquée ci-dessus,
que chaque appareil raccordé au système d’évacuation est mis à l’air
libredefaçoradéquate.Remerelesporteset lesfenêtres,les ventilateurs,
lesregistresde cheminéesetlesappareils au gazà leurpositionoriginale.
g) Any improper operation of the common venting system should be
corrected so the installation conforms with the National Fuel Gas
Code, ANSI Z223.1/NFPA 54. 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 Appendix F in the National Fuel Gas Code,
ANSIZ223.1/NFPA54 and or CAN/CGAB149InstallationCodes.
Tout mauvais fonctionnement du systéme d’évacu-tion commun
devrait étré corrigé de façor que l’installation soit conforme au
National Fue Gas Code, ANSI Z223.1/NFPA 54 et (ou) aux codes
d’installation CAN/CGA-B149. Si la grosseur d’une section du
système d’ évacuation doit étré modiée, le système devrait étré
modié pour respecter les valeurs minimales des tableaux pertinents
de l’appendice F du National Fuel Gas Code, ANSI Z223.1/ NFPA
54 et (ou) des codes d’installation CAN/CGA-B149.
GENERAL PIPING REQUIREMENTS
Improper piping of this boiler/water heater will void the
manufacturer’s warranty and can cause boiler failure
resulting in ooding and extensive property damage!
Excessivewaterhardness causingscalingin thecopper heat
exchangertubes isNOTcovered underthemanufacturer’s
warranty, see Table 9. Excessive piing and erosion of the
internalsurface ofthecopper heat exchanger tubesis NOT
covered under the manufacturer’s warranty if the result of
highwaterowrates, seeTable8.Returnwatertemperatures
below 125°F, 52°C will result in heat exchanger damage
from excessive condensation voiding the manufacturer’s
warranty, see Primary/Secondary Piping, Figure 13.

Finned copper tube gas boilers & water heaters – Boiler Manual
13
Figure 12 Futera III Piping
Shut o valves and unions should be installed at the
inlet and outlet connections of the boiler/hot water
heater to provide for isolation of the unit should
servicing be necessary.
Freeze Protection
Installations in areas where the danger of freezing exists are not
recommended unless proper freeze protection is provided. e
following precautions MUST be observed:
1. A continuous ow of water through the unit MUST be main-
tained!e pump responsible for owthroughthe boiler/water
heater must run continuously!
2. An ethylene glycol/water mixture suitable for the minimum
temperature that the unit will be exposed to must be used. e
pump must be capable of producing a minimum of 15% more
ow and overcoming a 20% increase in head loss. Domestic
water systems must be isolated from the water heater by the
use of a heat exchanger or other approved method.
3. If the unit must be shut o for any reason the electric, gas and
water supplies MUST be shut o and the unit and its pump
completely drained.
Improper outdoor installation of this unit can cause
boiler failure voiding the manufacturer’s warranty!
Valve
Pipe the discharge of the pressure relief valve as shown in Figure 12.
Never install any type of valve between the boiler/
water heater and the relief valve or an explosion causing
extensive property damage, severe personal injury or
death may occur!
Flow Switch
e ow switch supplied with the boiler/water heater must be wired to
the terminal strip in the control panel to prevent the boiler from ring
unless there’s adequate water ow through the unit. e ow switch must
be installed in the supply piping adjacent to the boiler outlet connection.
Failure to properly install the ow switch may result
in damage to the boiler/water heater heat exchanger
voiding the warranty!
HEATING SYSTEM PIPING
General Piping Requirements
All heating system piping must be installed by a qualied technician in
accordance with the latest revision of the ANSI/ASME Boiler and
Pressure Vessel Code, Section IV, and ANSI/ASME CSD-1, Standard
for Controls and Safety Devices for Automatically Fired Boilers. All
applicablelocalcodes andordinancesmustalso befollowed. Aminimum
clearance of 1 in, 25 mm must be maintained between heating system
pipes and all combustible construction. All heating system piping must
be supported by suitable hangers not the boiler. e thermal expansion
of the system must be considered when supporting the system. A
minimum system pressure of 12 psig, 82.7 kPa must be maintained.
Heating Boiler Piping Connections
e supply and return connections should be sized to suit the system,
see Table 7.
Table 7 Supply & Return Pipe Sizing (Flanged)
Model Size Supply Size Return Size
500 thru 1000 2” 2”
1250 thru 2000 2 1/2” 2 1/2”

Finned copper tube gas boilers & water heaters – Boiler Manual
14
Pump Requirements
is low mass boiler requires a continuous minimum water ow
for proper operation. e system pump must be sized to overcome
the head loss of the boiler and the heating system in order to achieve
the required temperature rise. Table 8 provides the heat exchanger
pressure drop and temperature rise gures. e temperature rise
across the boiler must never exceed 35°F, 19.4°C. e adjustable
pump delay turns the pump on each time the burner res and runs
the pump for 20 to 600 seconds aer the call for heat is satised.
A temperature rise outside of the range listed in Table
8 indicatesthatthe owrate throughthe heat exchanger
is incorrect which will damage the heat exchanger
voiding the warranty! e maximum allowable
temperature rise is 35°F, 19.4°C.
e maximum allowable ow rate through a Futera III
boileris 97 GPM,6.1L/son500through1000models
and 136 GPM, 8.6 L/s for 1250 through 2000 models.
eCupro-Nickelheatexchangerallowsfor108GPM,
6.8 L/s on 500 through 1000 models and 151 GPM,
9.5 L/s on 1250 through 2000 models.
Table 8 Temperature Rise Table
∆T = 20°F ∆T = 11.1°C
Model Flow Rate Pres. Drop Flow Rate Pres. Drop
Number GPM Ft L/s kPa
500 43.5 0.55 2.7 1.6
750 65.3 1.63 4.1 4.8
1000 87.0 3.59 5.5 10.6
1250 108.8 2.21 6.9 6.5
1500 130.5 3.73 8.2 11.0
∆T = 25°F ∆T = 13.9°C
Model Flow Rate Pres. Drop Flow Rate Pres. Drop
Number GPM Ft L/s kPa
500 34.8 0.36 2.2 1.1
750 52.2 1.08 3.3 3.2
1000 69.6 2.37 4.4 7.0
1250 87.0 1.46 5.5 4.3
1500 104.4 2.46 6.6 7.3
1750 121.8 3.84 7.7 11.3
2000 139.2 5.63 8.8 16.6
∆T = 30°F ∆T = 16.7°C
Model Flow Rate Pres. Drop Flow Rate Pres. Drop
Number GPM Ft L/s kPa
750 43.5 0.77 2.7 2.3
1000 58.0 1.69 3.7 5.0
1250 72.5 1.04 4.6 3.1
1500 87.0 1.76 5.5 5.2
1750 101.5 2.74 6.4 8.1
2000 116.0 4.01 7.3 11.8
∆T = 35°F ∆T = 19.4°C
Model Flow Rate Pres. Drop Flow Rate Pres. Drop
Number GPM Ft L/s kPa
750 37.3 0.58 2.4 1.7
1000 49.7 1.27 3.1 3.8
1250 62.1 0.78 3.9 2.3
1500 74.6 1.32 4.7 3.9
1750 87.0 2.06 5.5 6.1
2000 99.4 3.02 6.3 8.9
Low Water Cutoff
If a boiler is installed above any radiation elements it must be ed
with a low water cuto device.
Refer to the wiring diagram supplied with the boiler/water heater
for proper wiring connections.
Expansion Tank & Air Separator
An expansion tank or other means to control thermal expansion
must be installed in the heating system. An expansion tank must
be installed close to the boiler on the suction side of the pump. An
air scoop and automatic air vent must also be installed to eliminate
air trapped in the system.
Primary/Secondary Piping
Boilers connected to heating systems using zone valves, zone pumps, or
systems that have excessive flowrates or returnwatertemperatureslessthan
125°F, 52°C must be isolated from these systems to protect the boiler.
Variable Water Flows
Figure 13 shows a typical primary/secondary piping system. A
dedicated pump is used to maintain a constant water ow through
the boiler. is secondary pump is sized to overcome the head loss
of the boiler and secondary piping system while supplying the ow
rate required to maintain the desired temperature rise across the
boiler. e primary pump is sized to provide the required ow to
theheating system.e secondary pipingconnectionstotheprimary
system piping must not be more than 12 in, 305 mm apart to
ensure zero pressure drop in the primary system, see Figure 13.
Low Return Water Temperatures
To prevent the problems associated with condensation of the products
ofcombustiondue to low returnwatertemperaturesaprimary/secondary
piping system with a bypass conguration must be installed, see Figure
14. e bypass system must be sized the same as the secondary piping.
e primary and secondary pumps should be sized to provide the
required ow through each system. e secondary piping connections
to the primary system piping must not be more than 12 in, 305 mm
apart to ensure zero pressure drop in the primary system, see Figure 14.
Multiple Boiler Systems
Systems using multiple boilers can also be installed using a primary/
secondary manifold system, Figure 15.
Piping For Use With Cooling Units
The boiler, when used in connection with a refrigeration system, must be
installedsothechilledmediumispipedinparallelwiththeboiler.Appropriate
valves must be used to prevent the chilled water from entering the boiler.
When a boiler is connected to a heating coil that may be exposed to
refrigerated air from an air handling device, the piping system must be
equipped with ow-control valves or some other automatic means of
preventing gravity circulation of the boiler water during the cooling cycle.

Finned copper tube gas boilers & water heaters – Boiler Manual
15
Figure 13 Typical Primary/Secondary Piping System (See Notes)
Figure 14 Low Temperature Piping with Thermostatic Valve (See Notes and Adjustment Procedures)
NOTES:
1. For pump selection consult factory.
2. Boiler pump sized to boiler and thermostatic
3-way valve design flow requirements.
3. Boiler circuit piping must be sized large enough
to handle maximum flow through unit.
4. All boilers furnished with factory mounted
outlet water temperature gauge.
5. Boiler pump purging required. Use terminals
supplied.
6. Valve is pre-calibrated for 140oFreturn temperature.
7. For HeatNet operation a sensor is required and
installed at a minimum of 12” from primary loop tee.
supplied.
Notice: These drawings show suggested piping
configuration and valving.
Check with the local codes and ordinances for specific
requirements.
NOTES:
1. Boiler circuit piping must be sized
large enough to handle maximum
flow through unit.
2. Boiler pump sized to boiler design
flow requirements.
3. All boilers furnished with factory
mounted outlet water temperature
gauge.
4. Boiler pump purging required.
Use terminals supplied.
5. For HeatNet operation, a sensor is
required and installed at a minimum
of 12” from primary loop tee.
Notice: These drawings show suggested
piping configuration and valving.
Check with the local codes and ordinances
for specific requirements.
H-1 Rev 5
H-18 Rev 4

Finned copper tube gas boilers & water heaters – Boiler Manual
16
Figure 15 Multiple Boiler Piping (See Notes)
NOTES:
1. Boiler circuit piping must be sized large enough to handle maximum flow through unit.
2. Boiler pump sized to boiler design flow requirements.
3. All boilers furnished with factory mounted outlet water temperature gauge.
4. Boiler pump purging required. Use terminals supplied.
5. Secondary loop pipe diameter must be sized large enough to handle maximum flow through all units.
6. For HeatNet operation, a sensor is required and installed at a minimum of 12”from primary loop tee.
Notice: Theses drawings show suggested piping configuration and valving.
Check with local codes and ordinances for specific requirements.
H-15 Rev 6

Finned copper tube gas boilers & water heaters – Boiler Manual
17
DOMESTIC WATER SUPPLY PIPING
Proper controls must be used to prevent water sup-
plied for domestic use from exceeding 130°F, 54°C
or a scald injury will occur! When higher water tem-
peratures are required for appliances such as a dish-
washer, a mixing valve or some other tempering means
must be installed. Households with small children may
require water temperatures less than 120°F, 49°C.
Local codes must be complied with!
General Piping Requirements
Ensure that the water heater is equipped with bronze
headers. Piping and components connected to the water heater
must be suitable for use with potable water. e water heater must
not be connected to any heating system piping or components
previously used with a non-potable water heating appliance. No
toxic chemicals, such as those used for boiler treatment, are to be
introduced into the potable water used for space heating. If a hot
water storage tank is used in the system it must be equipped with
a temperature and pressure relief valve that complies with ANSI
Z21.22 or CAN-4.4 and CAN-4.6.
e storage tank must be located as close to the water
heater as possible to prevent excessive head loss which
will reduce ow.
Water Chemistry
e required temperature rise across the water heater is based on
water having a hardness between 8 and 18 grains per gallon with
a level of dissolved solids not exceeding 350 ppm. Water having a
hardness less than 8 grains can cause excessive corrosion of the
heat exchanger. Water that has a hardness greater than 18 grains
per gallon and/or a level of dissolved solids exceeding 350 ppm
will require a recalculation of the pump size and temperature rise.
A cupro-nickel heat exchanger may also be required. e manufac-
turer should be consulted when these water conditions are
encountered. See Table 9.
e maximum allowable ow rate through a Futera III
water heater is 97 GPM, 6.1 L/s on 500 through 1000
models and 136 GPM, 8.9 L/s for 1250 through 2000
models. e cupro-nickel heat exchanger allows for
108 GPM, 6.8 L/s on 500 through 1000 models and
151 GPM, 9.5 L/s on 1250 through 2000 models, see
Table 8B.
RBI water heaters are designed to run scale free. Due to the extreme
variables of water conditions world wide it is necessary to
consider pH values and water hardness in relationship to scaling.
It is crucial to consider these two variables when making heat
exchanger and pump selections. If local water conditions are extreme,
follow the guidelines in the Heat Exchanger Selection (Table 9)
and the Pumping Performance (Table 10). Scale free operation
can be achieved by using water with a hardness between 8 and 18
and by maintaining the pH between 5 and 9. Follow the conditions
listed under NORMAL in the table. In some areas of the country
additional precautions must be observed due to unusual charac-
teristics of the local water supply. Call the nearest RBI representa-
tive for details.
To properly size the pump a grain hardness and pH test
must be taken at the installation site before the order is placed.
Proper pump sizing will improve heater performance and help
ensure heater longevity.
Expansion Tank
An expansion tank or other means to control thermal expansion
must be installed in the water heating system if back ow preven-
tion devices are installed.
Pump Requirements
is low-mass water heater requires a continuous mini-mum water
ow for proper operation. e low water ow switch provided for
this unit will shut down the water heater if ow falls below the
required minimum level. Table 10 provides the heat exchanger pres-
sure drop chart and temperature rise table. e temperature rise
acrossthewaterheatermustneverexceed35°F,19.4°C.
Cold Water Supply
e cold water supply must be piped to the water heater’s outlet
piping between the water heater and the hot water storage tank.
is will prevent untempered water from entering the water heater,
see the Temperature Rise Control section below. Two typical water
heating systems are shown in Figures 16 & 17.
Temperature Rise Control
Water returned to the water heater inlet must not be less than 125°F,
52°C or excessive condensation of the products of combustion will
damage the water heater voiding the warranty. e method outlined
below can be employed to prevent this condition from occurring.
A balancing valve should be installed on the outlet side of
the water heater for purposes of adjusting the ow rate through
the heat exchanger. ermometers are installed on both the inlet
and outlet of the water heater for determining the temperature rise
through the unit.
e proper velocity through the water heater must be maintained
in accordance with Table 10 for ecient operation and long life.
If the temperature rise through the water heater is lower than
recommended the water velocity is too high. Premature erosion of
the heat exchanger will occur. Conversely, if the temperature rise
is higher than recommended in Table 10 the ow rate is too low.
Scaling and soening of the heat exchanger will occur.
ermostatic Mixing Valve – Water Above 140°F,60°C Water
can be stored at temperatures above 140°F, 60°C provided that a
thermostatically controlled mixing valve is used to temper the hot
water to an acceptable temperature before it’s supplied for domestic
use.
e mixing valve MUST be set to prevent a scald injury from
occurring, see the caution against scalding.
Storage of water for domestic use above 140°F, 60°C will provide
anincreased quantityoftemperedwaterandhelppreventthe growth
of water born bacteria.

Finned copper tube gas boilers & water heaters – Boiler Manual
18
Table 9 Futera III Heat Exchanger Selection Graph
Table 10 Futera III Pumping Performance Requirement

Finned copper tube gas boilers & water heaters – Boiler Manual
19
Figure 16 Typical Water Heating Piping (MW Models Only)
Figure 17 Multiple Water Heating Piping (MW Models Only)
(See Notes)
NOTES:
1. Optional cold water make up and recirculation line location.
2. When using intermittent pump and pump delay, locate remote HeatNet sensor with well in lower 1/3 of tank. Install sensor with heat sensing compound.
For multiple tanks, self balancing reverse-return systems, a single HeatNet sensor is applied.
3. ermal expansion tank may be required, check local codes.
4. When using optional factory mounted pump, max pipe length 30  total, 6-90° elbows, full pipe size.
5. CAUTION: MEASURE WATER HARDNESS AND pH AT JOB SITE.
6. e pH and water hardness must be measured before selecting heat exchanger and pump. Consult the Heat Exchanger Graph and Pumping Performance
Table before making selection.
7. Common piping must be sized for maximum combined heater flow.
8. Hot water tanks should be equipped with a combination temperature & pressure relief valve.
9. MA Code requires an 1/8 in hole in check valve to compensate for thermal expansion.
Notice: ese drawings show suggested piping configuration and valving. Check with local codes and ordinances for specific requirements.
These drawings show sug-
gested piping configuration
and valving. Check with
local codes and ordinances
for specific requirements.

Finned copper tube gas boilers & water heaters – Boiler Manual
20
GAS SUPPLY PIPING
Check the boiler/water heater rating plate to make
sure that the boiler/water heater is for the type of gas
that will be used. If it isn’t, do not connect the boiler/
water heater to the gas supply. Gas supply piping must
be in accordance with the National Fuel Code, ANSI
Z223.1-latest revision or applicable provisions of the
local building codes. Canadian installations must
comply with CAN/CGA B149.1 or .2 Installation
Code. Failure to comply with this warning can result
in extensive property damage, severe personal injury
or death!
e Futera III comes from the factory ready to be piped to the gas
supply. If for any reason the boiler/water heater is not for the type
of gas available at the installation site, call your RBI representative
to resolve the problem.
A minimum gas supply pressure of 2 in, 51mm, W.C.
natural or propane and maximum 14 in, 356 mm W.C.
natural or propane, must be available at the safety
shuto valve inlet with the unit(s) operating.
Table 11 should be used to ensure that the gas supply piping is
sized properly. If more than one appliance is supplied by the same
supplypipe,thepipingmustbesizedbasedon the maximumpossible
demand.Do notneglect thepressuredropdue topipe ings. Table
11 should be used in conjunction with Table 12 to ensure that the
gas supply piping has the capacity to meet the demand.
Figure 18 depicts the proper way to connect the boiler/water heater
to the gas supply piping. e manual shut-o valve MUST be
installed in the supply piping. It should be installed 5 , 1.5 m
above the oor where required by local codes. Provide a sediment
trap at the boom of the vertical section of the gas supply pipe
upstream of the gas controls.
A ground joint union should be installed between the boiler gas
controls and the supply piping. Each of these items are needed to
ensure long life and ease of servicing. Always use a pipe sealant
that is suitable for use with LP gas.
Table 11 Gas Pipe Capacity
Maximum pipe capacity in ft3/hr based on 0.60 specific gravity gas
at a pressure of 0.5 psig or less and a 0.3" WC pressure drop.
Nominal
Iron Pipe
Size
Pipe length, (ft)
10 20 30 40 50 60 80 100 150
Maximum gas volume of pipe, (ft3/hr)
1" 520 350 285 245 215 195 170 150 120
1 1/4" 1050 730 590 500 440 400 350 305 250
1 1/2" 1600 1100 890 760 670 610 530 460 380
2" 3050 2100 1650 1270 1270 1150 990 870 710
Note: Multiply the gas volume by 0.62 for propane flow capacity in ft3/hr.
Multiply the propane flow capacity by 2500 Btu/ft3to determine
the propane Btu/hr capacity for a given pipe size and length.
Table 12 Equivalent Pipe Length Chart
Nominal
Iron Pipe
Size
Type of pipe fitting
90° Elbow Te e 1Gate Valve2Gas Cock2
Equivalent pipe length, (ft)
1" 2.6 5.2 0.6 1.5
1 1/4" 3.5 6.9 0.8 1.9
1 1/2" 4.0 8.0 0.9 2.3
2" 5.2 10.3 1.2 3.0
Notes: 1. For flow through branch.
2. For flow at full open.
Always use a wrench on the gas valve body when
making gas connections to it. Never over-tighten the
piping entering the gas valve body or gas valve failure
may result!
When applicable, provisions for vent, bleed and gas relief lines must
be made in accordance with the latest revision of ANSI Z223.1/
NFPA 54. e main Dungs gas valve supplied with boiler/water
heater does not require external venting.
Safe lighting and other performance criteria were met with the gas
manifold and control assembly provided on the boiler. All gas
connections MUST be leak tested before puing the boiler into
operation.
Figure 18 Gas Supply Piping