RBI FUTERA FUSION Series User manual

FUTERA FUSION SERIES FINNED COPPER
GAS BOILERS (MODEL CB)
& WATER HEATERS (MODEL CW)
INSTALLATION & OPERATION MANUAL
INSTALLER, THESE INSTRUCTIONS TO BE AFFIXED ADJACENT TO THE BOILER / WATER HEATER.
CONSUMER, RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE PURPOSES.
DESIGNED AND TESTED ACCORDING TO A.S.M.E. BOILER AND PRESSURE
VESSEL CODE, SECTION IV FOR A MAXIMUM ALLOWABLE WORKING PRESSURE
OF 160 PSI, 1103 kPa WATER.
FTF-IOM-1
www.rbiwaterheaters.com
WARNING: 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.
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 fire department.
Installation and service must be performed by a qualified installer, service agency or
the gas supplier.
WARNING: Failure to properly vent this unit can cause excessive amounts of carbon
monoxide resulting in severe personal injury or death!
260 North Elm Street 7555 Tranmere Drive
Westfield, MA 01085 Mississauga, Ontario L5S 1L4 Canada
Phone: [phone] Phone: [phone]
Fax: [phone] Fax: [phone]

2
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
CONTENTS
Before You Start page 2
Ratings & Capacities page 3
Boiler/Water Heater Location page 3
Combustion Air & Ventilation page 3
General Venting Guidelines page 5
General Piping Requirements page 11
Heating System Piping page 11
Domestic Water Supply Piping page 16
Gas Supply Piping page 20
Electrical Wiring page 21
General Operation page 21
Operating Instructions page 22
Checking & Adjustments page 24
Control Description page 25
MPA Staging Control page 25
Diagnostics page 27
Maintenance page 27
Trouble-Shooting page 29
Repair Parts page 31
Startup Sheet page 38
BEFORE YOU START
This manual covers the application, installation, operation
and maintenance of a Futera Fusion Series finned copper
heating boiler/water heater.
To obtain the safe, dependable, efficient operation and long
life for which this heating boiler/water heater was designed,
these instructions must be read, understood and followed.
AVERTISSMENT. Assurez-vous de bien suivre les instructions données dans cette notice pour
réduire au minimum le risque d’incendie ou d’explosion ou pour éviter tout dommoge 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.
The Futera Fusion Series finned copper heating boiler/
water heaters have been design certified 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 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.
All aspects of the boiler/water heater installation must
conform to the requirements of the authority having juris-
diction, 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
requirements of CSA B149.1 or .2, Installation Code for
Gas Burning Appliances and Equipment.
If installed in the Commonwealth of Massachusetts, you
MUST FOLLOW the additional instructions contained in
RBI’s instruction sheet “MACODE”. If you don’t have a copy
call your RBI representative.
The 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, Westfield, 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.

3
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
RATINGS & CAPACITIES
Before undertaking the installation of the Futera
Fusion Series boiler/water heater check the rating
plate to ensure that the unit has been sized properly
for the job. The “Net I=B=R 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. This boiler/water heater is suitable for indoor
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.
NOTE: Service clearances are not mandatory, but are
recommended to ensure ease of service should it be
required.
Table 1
Clearance to Service
Combustibles Clearance
in mm in mm
Top 6153 30 762
Back 6153 24 610
Left Side 6153 24 610
Right Side 6153 24 610
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 floor is structurally sound and will
support the weight of the boiler/water heater.
NOTE: The Futera Fusion may be installed directly on
combustible flooring, 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
“GENERAL 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 11.
WARNING: Never store combustible materials,
gasoline or any product containing flammable
vapors or liquids in the vicinity of the boiler/water
heater. Failure to comply with this warning can
result in an explosion or fire causing extensive
property damage, severe personal injury or death!
COMBUSTION AIR & VENTILATION
WARNING: This 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 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!
CAUTION: Combustion air contaminated with
fluorocarbons or other halogenated compounds such
as cleaning solvents and refrigerants will result in the
formation of acids in the combustion chamber. These
acids will cause premature failure of the boiler/water
heater voiding the warranty!
CAUTION: 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 fireplace, 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.
WARNING: Never operate the Futera Fusion 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!

4
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
All Air From Inside The Building
If the Futera Fusion is to be located in a confined
space, the minimum clearances listed in Table 1 must be
maintained between it and any combustible construction.
When installed in a confined space without the intake
air option, Figures 5, and 6, two permanent openings
communicating with an additional room(s) are required.
The combined volume of these spaces must have
sufficient volume to meet the criteria for an unconfined
space. The total air requirements of all gas utilization
equipment, fireplaces, 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
confined area. Each opening must be no less than
100 in2, 64,516 mm2in size. The upper opening must
be within 12 in,305 mm of, but not less than 3 in,
76 mm from, the top of the enclosure. The bottom
opening must be within 12 in, 305 mm of, but not less
than 3 in, 76 mm from, the bottom of the enclosure.
All Air From Outside The Building
When installed in a confined 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.The
upper opening must be within 12 in, 305 mm of, but not
less than 3 in, 76 mm from, the top of the enclosure. The
bottom opening must be within 12 in, 305 mm of, but not
less than 3 in, 76 mm from, the bottom of the enclosure.
Where directly communicating with the outdoors
or communicating 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 effects 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.
Table 2 – Make-up Air Louver Sizing
Required Cross Sectional Area
Input 1/4 in 6.4 mm
75% Free Area 25% Free Area
(MBH) Wire Screen Metal Louvers Wooden Louvers
in2cm2 in2cm2 in2cm2
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
Canadian installations must comply with CSA B149.1 when
air supply is provided by natural air flow from the outdoors
for natural draft, partial fan-assisted, fan-assisted, or
power draft-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 in2per 14,000 Btuh
(155 mm2per kW) in excess of 1 million Btuh.
Intake Air Option – General Guidelines
This configuration provides combustion air directly to the
boiler/water heater’s air intake using a dedicated pipe when
using the direct vent option. The RBI air intake adapter
must be fitted to the blower inlet. 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.
WARNING: Common intake air systems may be
used provided 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, flexible aluminum pipe, PVC or CPVC pipe can be
used for the intake air pipe. It must be sized per Table 3.
Table 3 - Intake Air Pipe Sizing
Model For Vertical For Horizontal
Size (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
corrosion 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. The combustion air system
MUST be supported by the building structure not the
boiler/water heater.

5
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
VENT SYSTEM OPTIONS
The Futera Fusion may be vented the following ways:
1) Direct Vent, Positive Pressure, Category IV uses a
vent system certified 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 certified to UL 1738 for installations
in the United States, ULC S636 for installations in
Canada. Combustion air is obtained from the space in
which the unit is installed.
3) Must consult factory when venting single or multiple
unit(s) over 60 equivalent feet. Mechanical system may
be required.
NOTE: All venting, combustion air material supplied by
installer.
CAUTION: A combustion air damper interlocked with
the unit should be installed in the intake air pipe when
the infiltration of subfreezing air could occur, otherwise
the unit could freeze up voiding the warranty!
Intake Air Option – Vertical Guidelines
The maximum equivalent length for the vertical intake
air pipe is 60 ft, 18.3 m. Each 90˚ elbow and the intake
air terminal are equal to 10 linear ft, 3.0 m of pipe, see
Table 3.
An approved, nonrestrictive intake air terminal must be
used. The intake air terminal must terminate as shown in
Figure 3. The penetration point in the roof must be properly
flashed and sealed.
Intake Air Option – Horizontal Guidelines
The maximum equivalent length for the horizontal intake
air pipe is 60 ft, 18.3 m. Each 90˚ elbow and the intake air
terminal are equal to 10 linear ft, 3.0 m of pipe. If horizontal
runs exceed 5 ft 1.5 m they must be supported at 3 ft,
0.9 m intervals with overhead hangers. The certified intake
air terminal from RBI must be used, see Figures 1, 2
and 4.
GENERAL VENTING GUIDELINES
WARNING: The 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 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 fire-stops must be used where required.
WARNING: Common vent systems must be
properly engineered and sized, please contact the
factory.

6
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
DIRECT VENT,
POSITIVE PRESSURE, CATEGORY IV
In this configuration the boiler/water heater blower is used
to push the flue products to the outdoors while drawing
combustion air from the outdoors. The Intake Air
Option instructions under the “COMBUSTION AIR &
VENTILATION” section must be followed! The vent system
must be sized per Table 4.
Table 4 – Category IV
Model Pipe Diameter (Min.)
Size (Up to 60')
in mm
500 7178
750 7178
1000 7178
1250 8203
1500 8203
1750 10 254
2000 10 254
Horizontal Direct Vent Systems – Figures 1 & 2
The vent materials used in horizontal vent systems must
be certified to UL 1738 for installations in the United States,
ULC S636 for installations in Canada. The certified vent
terminal from RBI must also be used.
The maximum equivalent length for the horizontal vent pipe
is 60 ft,18.3 m.Each 90˚ elbow and the vent terminal are
equal to 10 linear ft, 3.0 m of pipe. 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 fire-
stops. For best results, horizontal vent systems should be
as short and straight as possible.
The 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 ft, 1.5 m they must be
supported at 3 ft, 0.9 m intervals with overhead hangers.
The vent system must be pitched back, towards the secondary
heat exchanger,1/4 in/ft, 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 ft,
1.2 m below, 4 ft, 1.2 m horizontally from or 1 ft,
0.30 m above any door, window or gravity air inlet into
any building. It must not terminate less than 4 ft, 1.2 m
horizontally from, and in no case above or below, unless
a 4 ft, 1.2 m horizontal distance is maintained, from electric
meters, gas meters, regulators and relief equipment and
not less than 7 ft, 2.1 m from any adjacent public walkway.
The bottom of the vent terminal(s) shall be located at
least 5 ft, 1.5 m above the air intake terminal(s) unless
there is a minimum 5 ft, 1.5 m horizontal separation
between them. Avoid terminal locations likely to be affected
by winds, snowdrifts, people and pets. Protect building
materials and vegetation from degradation caused by the
flue 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 fire-stops.
An approved, nonrestrictive vent terminal must be used.
The top of a vertical vent system must extend at least
51/2ft,1.7 m above the roof surface and maximum snow
line that it passes through, 4 ft, 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. The penetration point in the roof must
be properly flashed and sealed.
The 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
The boiler/water heater can be vented vertically with the
intake air piped horizontally through an outside wall. Follow
the instructions in the Intake Air Option – Horizontal
Guidelines. Also follow the general instructions in the
“COMBUSTION AIR & VENTILATION” and “GENERAL
VENTING GUIDELINES” sections.

7
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 1– Horizontal Combustion Air and Venting for a Single Unit
Figure 2 – Horizontal Combustion Air and Venting for 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 differences 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
16 FT 4.9 m
1/4 IN. PER FOOT
20 mm/m
1.5 FT 0.5 m
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20
Horizontal Distance, X
Y
,
e
c
n
at
si
D
la
ci
t
re
V
2000 & Larger
1201 To 2000
901 To 1200
200 To 900
1000 BTU'S

8
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 3 - Vertical Air Intake and Venting for Direct Vent System
Figure 4 – Combination Direct Vent Systems
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

9
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 5 – Side Wall Venting
SIDE WALL VENT,
POSITIVE PRESSURE, CATEGORY IV
In this configuration the boiler/water heater blower is used
to push the flue products horizontally to the outdoors, see
Figure 5. The air for combustion is taken from the space
in which the unit is installed. The applicable instructions
under the “COMBUSTION AIR & VENTILATION” section
must be followed! The vent guidelines under the Horizontal
Direct Vent Systems section must also be followed.
1.5 FT 0.5 m
1/4 IN. PER F00T
20 mm/m

10
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 6 – Vertical Venting with a Metal Chimney System
10 FT. 3.1 m

11
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
GENERAL PIPING REQUIREMENTS
CAUTION: Improper piping of this boiler/water heater
will void the manufacturer’s warranty and can cause
boiler failure resulting in flooding and extensive
property damage! Excessive water hardness causing
scaling in the copper heat exchanger tubes is NOT
covered under the manufacturer’s warranty, see Table
7. Excessive pitting and erosion of the internal surface
of the copper heat exchanger tubes is NOT covered
under the manufacturer’s warranty if the result of high
water flow rates, see Table 7.
NOTE: Shut off 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. The following precautions MUST be observed:
1. A continuous flow of water through the unit MUST be
maintained! The pump responsible for flow through the
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. The pump must be capable of producing
a minimum of 15% more flow 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 off for any reason the electric,
gas and water supplies MUST be shut off and the unit
and its pump completely drained.
Condensate Piping
The condensate trap provided with the boiler must be
attached to the bottom pan and piped to a suitable floor
drain or condensate pump. If a condensate neutralization
device is installed, it must be positioned prior to boiler room
drain. Condensate fill trap must be maintained with fluid.
Relief Valve
Pipe the discharge of the pressure relief valve as shown
in Figure 8.
WARNING: 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
The flow switch supplied with the boiler/water heater must
be wired to the terminal strip in the control panel to prevent
the boiler from firing unless there’s adequate water flow
through the unit. The flow switch must be installed in the
supply piping adjacent to the boiler outlet connection.
CAUTION: Failure to properly install the flow 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 qualified
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 applicable local
codes and ordinances must also be followed. A minimum
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. The 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
The supply and return connections should be sized to suit
the system, see Table 6.
Table 6 – Supply & Return Pipe Sizing
Model Size Supply Size Return Size
500 thru 1000 2" NPT 2" NPT
1250 thru 2000 2 1/2" NPT 2 1/2" NPT
Pump Requirements
This low mass boiler requires a continuous minimum water
flow for proper operation. The 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 7 provides the heat exchanger pressure drop and
temperature rise figures. The temperature rise across the
boiler must never exceed 35˚F, 19.4˚C. The adjustable
pump delay turns the pump on each time the burner fires
and runs the pump for 20 to 600 seconds after the call for
heat is satisfied.

12
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 8 – Futera Fusion Piping
Air Vent
Aquastat Union
Automatic
Thermometer
Flow Switch
Pressure
Relief Valve
Reducing Valve
Check Valve
Pressure
Pump
Valve
Balance Valve
Vacuum
Relief Valve
Temperature &
Pressure
Relief Valve
Drain Valve
(Typ.)
3-Way
Mixing Valve

13
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
CAUTION: A temperature rise outside of the range
listed in Table 7 indicates that the flow rate through the
heat exchanger is incorrect which will damage the heat
exchanger voiding the warranty! The maximum
allowable temperature rise is 35°F, 19.4°C.
The maximum allowable flow rate through a Futera
Fusion boiler is 97 GPM, 6.1 L/s on 500 through 1000
models and 136 GPM, 8.6 L/s for 1250 through 2000
models.The 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.
Table 7 - Temperature Rise Table
ΔT = 15°F ΔT = 8.3°C
Model Flow Rate Total Loss* Flow Rate Total Loss*
Number GPM Ft L/s kPa
500 58.0 8.8 3.7 26.3
ΔT = 20°F ΔT = 11.1°C
Model Flow Rate Total Loss* Flow Rate Total Loss*
Number GPM Ft L/s kPa
750 65.3 10.5 4.1 31.4
1250 108.8 11.6 6.9 34.7
ΔT = 25°F ΔT = 13.9°C
Model Flow Rate Total Loss* Flow Rate Total Loss*
Number GPM Ft L/s kPa
750 52.2 7.7 3.3 23.0
1250 87.0 8.2 5.5 24.4
1500 104.4 11.6 6.6 34.7
1750 121.8 14.7 7.7 43.9
ΔT = 30°F ΔT = 16.7°C
Model Flow Rate Total Loss* Flow Rate Total Loss*
Number GPM Ft L/s kPa
1000 58.0 9.5 3.7 28.4
1500 87.0 8.5 5.5 25.4
1750 101.5 10.6 6.4 31.7
2000 116.0 13.8 7.3 41.2
*Includes primary, secondary, mixing valve and piping.
Low Water Cutoff
If a boiler is installed above any radiation elements it must
be fitted with a low water cutoff 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
Figure 9 shows a typical primary/secondary piping system.
Boilers connected to heating systems using zone valves,
zone pumps, or systems that have excessive flow rates
must be isolated from these systems to protect the boiler.
Multiple Boiler Systems
Systems using multiple boilers can also be installed using
a primary/secondary manifold system, Figure 11.
Piping For Use With Cooling Units
The boiler, when used in connection with a refrigeration
system, must be installed so the chilled medium is piped
in parallel with the boiler. 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 flow-control valves
or some other automatic means of preventing gravity
circulation of the boiler water during the cooling cycle.

14
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 9 - Typical Primary/Secondary, Low Temperature Piping System
(See Notes)
NOTES:
1. Boiler circuit piping must be sized large enough to handle maximum flow through unit.
2. Boiler and pump purging required. Air must be purged from 3-way valve after the boiler is filled. Use
purge valves provided. Purge valve may be located on pump flange. On multiple boiler installations
the flow switch may fail due to trapped air. See manual for procedure.
3. All boilers furnished with factory mounted outlet water temperature gauge.
Notice: These drawings show suggested piping configuration and valving. Check with local codes and
ordinances for specific requirements.
Air Vent
Aquastat Union
Automatic
Thermometer
Flow Switch
Pressure
Relief Valve
Reducing Valve
Check Valve
Pressure
Pump
Valve
Balance Valve
Vacuum
Relief Valve
Temperature &
Pressure
Relief Valve
Drain Valve
(Typ.)
3-Way
Mixing Valve
1
2
H-16

15
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 11 - Multiple Boiler Piping (See notes)
NOTES:
1. Boiler circuit piping must be sized large enough to handle maximum flow through each unit.
2. System loop pipe diameter must be sized large enough to handle maximum flow through all units.
3. Boiler and pump purging required. Air must be purged from 3-way valve after the boiler is filled. Use
purge valves provided. Purge valve may be located on pump flange. On multiple boiler installations
the flow switch may fail due to trapped air. See manual for procedure.
4. All boilers furnished with factory mounted outlet water temperature gauge.
5. Condensate lines on each unit should be connected for a floor drain.
Air Vent
Aquastat Union
Automatic
Thermometer
Flow Switch
Pressure
Relief Valve
Reducing Valve
Check Valve
Pressure
Pump
Valve
Balance Valve
Vacuum
Relief Valve
Temperature &
Pressure
Relief Valve
Drain Valve
(Typ.)
3-Way
Mixing Valve
1
2
NOTES:
H-17
Factory Piped
3
3

16
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
DOMESTIC WATER SUPPLY PIPING
CAUTION: Proper controls must be used to prevent
water supplied for domestic use from exceeding 130˚F,
54˚C or a scald injury will occur! When higher water
temperatures are required for appliances such as a
dishwasher, 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. The
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.
NOTE: The storage tank must be located as close to
the water heater as possible to prevent excessive head
loss which will reduce flow.
Bleed Air From Boiler
Open the water heater piping bleed valves one at a time,
to purge the air trapped in the primary and secondary heat
exchangers. Refer to piping drawings (Figures 12 & 13) for
bleed locations.
Water Chemistry
The 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. The
manufacturer should be consulted when these water
conditions are encountered. See Table 8A.
CAUTION:
The maximum allowable flow rate through
a Futera Fusion 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.The 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.
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 (Table
8A). 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
characteristics of the local water supply. Call the nearest
RBI representative for details.
Expansion Tank
An expansion tank or other means to control thermal
expansion must be installed in the water heating system if
back flow prevention devices are installed.
Pump Requirements
This low-mass water heater requires a continuous mini-
mum water flow for proper operation. The proper velocity
through the water heater must be maintained in accordance
with Table 7 for efficient 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 7
the flow rate is too low. Scaling and softening of the heat
exchanger will occur. The temperature rise across the
water heater must never exceed 35°F, 19.4°C.
Storage Tank Thermostatic 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.
The 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 an increased quantity of tempered water and help
prevent the growth of water born bacteria.

17
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Table 8A - Futera Fusion Heat Exchanger Selection Graph
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.
For hard/soft water pump selection, must consult factory.

18
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 12 - Typical Water Heating Piping (CW Models Only)
(See Notes)
NOTES:
1. When using intermittent pump and pump delay, locate remote aquastat well in lower 1/3 of tank. Install
aquastat with heat sensing compound.
2. Thermal expansion tank may be required, check local codes.
3. CAUTION: MEASURE WATER HARDNESS AND pH AT JOB SITE.
Be sure to specify when ordering the pH and water hardness. This must be measured before selecting heat
exchanger and pump. Consult the Heat Exchanger Graph and Pumping Performance Table before making
selection.
4. Common piping must be sized for maximum combined heater flow.
5. Hot water tanks should be equipped with a combination temperature & pressure relief valve.
6. MA Code requires an 1/8" hole in check valve to compensate for thermal expansion.
7. Use balance valve to set the temperature rise through the boiler. (Delta T)
8. Boiler and pump purging required. Air must be purged from 3-way valve after the boiler is filled. Use
purge valves provided. Purge valve may be located on pump flange. On multiple boiler installations
the flow switch may fail due to trapped air. See manual procedure.
Notice: These drawings show suggested piping configuration and valving. Check with local codes and
ordinances for specific requirements.
Air Vent
Aquastat Union
Automatic
Thermometer
Flow Switch
Pressure
Relief Valve
Reducing Valve
Check Valve
Pressure
Pump
Val ve
Balance Valve
Va cuum
Relief Valve
Temperature &
Pressure
Relief Valve
Drain Valve
(Typ.)
3-Way
Mixing Valve
NOTES:
1
2
5
6
7
D-17
8
8

19
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Figure 13 - Multiple Water Heating Piping (CW Models Only)
(See Notes)
NOTES:
1. When using intermittent pump and pump delay, locate remote aquastat well in lower 1/3 of tank. Install
aquastat with heat sensing compound.
2. Thermal expansion tank may be required, check local codes.
3. CAUTION: MEASURE WATER HARDNESS AND pH AT JOB SITE.
Be sure to specify when ordering the pH and water hardness. This must be measured before selecting heat
exchanger and pump. Consult the Heat Exchanger Graph and Pumping Performance Table before making
selection.
4. Common piping must be sized for maximum combined heater flow.
5. Hot water tanks should be equipped with a combination temperature & pressure relief valve.
6. MA Code requires an 1/8" hole in check valve to compensate for thermal expansion.
7. Use balance valve to set the temperature rise through the boiler. (Delta T)
8. Boiler and pump purging required. Air must be purged from 3-way valve after boiler is filled. Use
purge valves provided. Purge valve may be located on pump flange. On multiple boiler installations
the flow switch may fail due to trapped air. See manual procedure.
Notice: These drawings show suggested piping configuration and valving. Check with local codes and
ordinances for specific requirements.
Air Vent
Aquastat Union
Automatic
Thermometer
Flow Switch
Pressure
Relief Valve
Reducing Valve
Check Valve
Pressure
Pump
Valve
Balance Valve
Vacuum
Relief Valve
Temperature &
Pressure
Relief Valve
Drain Valve
(Typ.)
3-Way
Mixing Valve
1
D-18
2
2
1
5
5
4
4
6
7
8
8
7
8
8

20
FUTERA FUSION INSTALLATION AND OPERATION INSTRUCTIONS
Gate Valve2
0.6
0.8
0.9
1.2
Table 9 – Gas Pipe Capacity
Table 10 – Equivalent Pipe Length Chart
Figure 14 – Gas Supply Piping
CAUTION: 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. The main Dungs gas valve supplied
with the 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
putting the boiler into operation.
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.
1"
1 1/4"
1 1/2"
2"
Type of pipe fitting
Equivalent pipe length, (ft)
90˚ Elbow
2.6
3.5
4.0
5.2
Tee 1
5.2
6.9
8.0
10.3
Gas Cock2
1.5
1.9
2.3
3.0
Nominal
Iron Pipe
Size, (in)
Notes: 1. For flow through branch.
2. For flow at full open.
Nominal
Iron Pipe
Size, (in)
10
520
1050
1600
3050
20
350
730
1100
2100
30
285
590
890
1650
40
245
500
760
1270
50
215
440
670
1270
60
195
400
610
1150
80
170
350
530
990
100
150
305
460
870
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.
150
120
250
380
710
Pipe length in feet
1"
1 1/4"
1 1/2"
2"
Maximum gas volume of pipe, (ft3/hr)
GAS SUPPLY PIPING
WARNING: 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!
The Futera Fusion 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.
NOTE: A minimum gas supply pressure of 2 in, 51 mm,
W.C. natural or propane and maximum 14 in, 356 mm
W.C. natural or propane, must be available at the safety
shutoff valve inlet with the unit(s) operating.
Table 9 should be used to ensure that the gas supply piping
is sized properly. If more than one appliance is supplied
by the same supply pipe, the piping must be sized based
on the maximum possible demand. Do not neglect the
pressure drop due to pipe fittings. Table 9 should be used
in conjunction with Table 10 to ensure that the gas supply
piping has the capacity to meet the demand.
Figure 14 depicts the proper way to connect the boiler/
water heater to the gas supply piping. The manual shut-
off valve MUST be installed in the supply piping. It should
be installed 5 ft, 1.5 m above the floor where required by
local codes. Provide a sediment trap at the bottom 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.