RBI 8800 Installation and Operation Instruction

CIOM-8

82-0252

42-9134 R

SERIES 8800 & 8900 FINNED COPPER

GAS BOILERS (MODEL HB) &

WATER HEATERS (MODEL HW)

INSTALLATION & OPERATION MANUAL

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.

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 fl ammable 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 fi re department.

Installation and service must be performed by a qualifi ed 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!

INSTALLER, THESE INSTRUCTIONS TO BE AFFIXED ADJACENT TO THE HEATER.

CONSUMER, RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE PURPOSES.

260 North Elm Street 7555 Tranmere Drive
Westfi eld, MA 01085  Mississauga, Ontario L5S 1L4 Canada
Phone: [phone] Phone: [phone]
Fax: [phone] Fax: [phone]

05/10

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 2

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 infl 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 qualifi é ou par le fournisseur de gaz.

CONTENTS

Before You Start ................................................. page 2

Ratings & Capacities ......................................... page 3

Boiler/Water Heater Location ............................page 3

Combustion Air & Ventilation .............................page 4

Chimney & Vent Pipe Connections ....................page 8

Common Vent Systems .....................................page 9

General Piping Requirements .........................page 10

Heating System Piping .................................... page 10

Domestic Water Supply Piping ........................page 15

Gas Supply Piping ...........................................page 20

Electrical Wiring ...............................................page 21

General Operation ...........................................page 21

Operating Instructions .....................................page 22

Checking & Adjustments .................................page 23

Control Description ..........................................page 25

Maintenance ....................................................page 26

Trouble-Shooting .............................................page 28

Repair Parts, 8900 ...........................................page 30

Repair Parts, 8800 ...........................................page 39

BEFORE YOU START

This manual covers the application, installation,
operation and maintenance of a Series 8800
and 8900 fi nned copper heating boiler/water heater/pool
heater.

To obtain the safe, dependable, effi cient operation and
long life for which this heating boiler/water heater was
designed, these instructions must be read, understood
and followed.

The Series 8800 and 8900 fi nned copper heating boiler/
water heaters have been design certifi 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, ANSI­Z21.13/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
jurisdiction, or, in the absence of such requirements, to
the National Fuel Gas Code, ANSI Z223.1/NFPA 54­latest 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 CAN/CGA 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-3. If you do not have a
copy, call your RBI distributor or contact the RBI Customer
Service Department.

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.

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 3

Direct all questions to your RBI distributor or contact the
RBI Customer Service Department, 260 North Elm Street,
Westfi eld, MA 01085 for U.S. 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 Series 8800
and 8900 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 copper 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. Locate the boiler/water heater in an area that
provides good access to the unit. Servicing may
require the removal of jacket panels.
minimum clearances between adjacent construction
and the boiler/water heater as listed in Table 1 or 1A.

NOTE: Service clearances are not mandatory, but
are recommended to ensure ease of service should
it be required.

Table 1 (8800)
Clearance to Service
Combustibles Clearance
in mm in mm

Top 24 610 18 457
Back 24 610 18 457
Left Side 24 610 24 610
Right Side 24 610 24 610
Front 48 1220 48 1220
Flue 6 152 6 152

Table 1A (8900)
Clearance to Service
Combustibles Clearance
in mm in mm

Top 24 610 18 457
Back 18 457 18 457
Left Side 18 457 18 457
Right Side 18 457 18 457
Front 48 1220 36 914
Flue 6 152 6 152

Allow the

2. An optimum site will be level, central to the piping
system, close to a chimney 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 fl oor is structurally sound and will
support the weight of the boiler/water heater.

NOTE: Never install a Series 8800 or 8900 boiler/
water heater on a concrete fl oor that contains wires,
cables, water pipes or hoses. This boiler/water
heater is designed for noncombustible fl oors only!
Never install this boiler/water heater on combustible
materials or carpeting even if a non-combustible
foundation material is placed over them!

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. The
combustion air to 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.

WARNING: Never store combustible materials,
gasoline or any product containing fl ammable vapors
or liquids in the vicinity of the boiler/water heater.
Failure to comply with this warning can result in an
explosion or fi re causing extensive property damage,
severe personal injury or death!

pan must not restrict the flow of

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 4

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
fl uorocarbons 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!

All Air From Inside The Building

If the boiler/water heater is to be located in a confi ned
space minimum clearances listed in Table 1 or 1A must
be maintained between the boiler/water heater and any
combustible construction. When installed in a confi ned
space, Figures 1, 2, 3, 4 and 5, two permanent openings
communicating with an additional room(s) are required.
The combined volume of these spaces must have
suffi cient volume to meet the criteria for an unconfi ned
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
confi ned area. Each opening must be no less than

100 in2, 64,516 mm2 in 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 confi ned space 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.

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 5

10 FT 3.4 m

2 FT .6 m

3 FT 1 m

3 FT 1 m

5 FT 1.52 m

Where communicating with the outdoors through
horizontal ducts, each opening shall have a minimum
free area of 1 in

2

/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 cross­sectional area as the free area of the opening to which
they connect.

Canadian installations must comply with CSA B149.1
when air supply is provided by natural air fl ow from the
outdoors for natural draft, partial fan-assisted, fan­assisted, or power draft-assisted burners, there shall
be a permanent air supply opening(s) having a cross­sectional area of not less than 1 in2 per 7,000 Btuh
(310 mm2 per kW) up to and including 1 million Btuh,
plus 1 in2 per 14,000 Btuh (155 mm2 per kW) in excess
of 1 million Btuh.

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
in2 cm

2

in

2

cm

2

in

2

cm

2

420 105 677 140 903 420 2710
530 133 858 177 1142 530 3419
630 158 1019 210 1355 630 4064
735 184 1187 245 1581 735 4742
840 210 1355 280 1806 840 5419
950 238 1535 317 2032 950 6129
1050 263 1697 350 2258 1050 6774
1160 290 1871 387 2497 1160 7484
1260 315 2032 420 2710 1260 8129
1370 343 2213 457 2948 1370 8839
1470 368 2374 490 3161 1470 9484
1580 395 2548 527 3400 1580 10,194
1685 421 2716 562 3626 1685 10,871
1790 448 2890 597 3852 1790 11,548
1900 475 3065 633 4084 1900 12,258
2000 500 3226 667 4303 2000 12,903
2400 600 3871 800 5161 2400 15,483
2800 700 4516 933 6019 2800 18,064
3200 800 5161 1067 6884 3200 20,645
3600 900 5806 1200 7742 3600 23,226
4000 1000 6452 1333 8600 4000 25,806

Figure 1 - Vertical Venting Using A Metal Chimney And Inside Air (8900/8800 Series)

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SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 6

10 FT 3.1 m

3 FT 1 m

5 FT 1.52 m

3 FT 1 m

10 FT 3.4 m

3 FT 1 m

2 FT .6 m

10 FT 3.4 m

5 FT 1.5 m

Figure 2 - Vertical Venting Using A Masonary Chimney And Inside Air (8900/8800 Series)

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Figure 3 - Dual Flue Outlets And Inside Air (8900/8800 Series)

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SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 7

3FT 1m

10FT 3.1m

3FT 1m

5FT 1.52m

PITCH PIPE DOWN TOWARDS TERMINAL
CAP 1/4 IN. PER FOOT 20MM/M OF RUN TO
ALLOW FOR CONDENSATE DRAINAGE

BUILDING OVERHANG

4FT 1.2 M MAX.

3FT .9 m

1.5 FT 0.5 m MINIMUM DISTANCE FROM

EXHAUST TO MAXIMUM SNOW LINE.

3FT 1 m

5FT 1.52 m

3 FT

1 m

10 FT

3.1 m

3 FT

1 m

5 FT

1.52 m

Figure 4 - Common Vents and Inside Air (8900/8800 Series)

Figure 4A - Common Vents and Inside Air (8800/8900 Series) Dual Flue

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Figure 5 - Horizontal Venting And Inside Air (8900/8800 Series)

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SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 8

CHIMNEY & VENT PIPE
CONNECTIONS

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!

Chimney Inspection & Sizing

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 draft problems. Table 3A and 3B lists
the equivalent breeching and fl ue sizes required for the
boiler/water heater.

Table 3A - Equivalent Breeching & Chimney Size

Model Size Model Size
Size in mm Size in mm
420 10 254 1580 18 457
530 10 254 1685 18 457
630 12 305 1790 20 508
735 14 356 1900 20 508
840 14 356 2000 22 559
950 14 356 2400 24 610
1050 16 406 2800 26 660
1160 16 406 3200 28 711
1260 16 406 3600 30 762
1370 18 457 4000 30 762
1470 18 457

Note: These sizes are based on a 20 ft, 6.1m chimney height.

Table 3B - Equivalent Breeching & Chimney Size Dual Flue

Model Size Model Size
Size in mm Size in mm
840 10 254 1790 16 406
950 10 254 1900 16 406
1050 12 305 2000 14 356
1160 12 305 2400 16 406
1260 12 305 2800 18 457
1370 14 355 3200 20 508
1470 14 355 3600 22 559
1580 14 355 4000 22 559
1685 14 355

Note: Minimum vertical rise off top dual fl ue units: 3 ft, 1 m (sizes
840-3200), 5 ft, 1.5 m (sizes 3600-4000).

When more than one appliance is connected to the
same chimney fl ue, the fl ue must be large enough to
safely vent the combined output of all the appliances.

WARNING: If an appliance using any type of a
mechanical draft system operating under
positive pressure is connected to a chimney
fl ue, never connect any other appliances to this
fl ue. Doing so can result in the accumulation of
carbon monoxide which can cause severe
personal injury or death!

Vent Connections

Always use a type B or single wall galvanized metal vent
pipe the same diameter as the draft diverter fl ue collar.
Use the shortest, straightest vent system possible for
the installation. If horizontal runs exceed 6 ft, 1.8 m they
must be supported at 6 ft, 1.8 m intervals with overhead
hangers. The vent system should be sloped up toward
the chimney at a minimum rate of 1/4 in/ft, 20 mm/m
and terminate fl ush with the inside of the chimney fl ue.
Fasten each connection with at least 3 corrosion
resistant sheet metal screws.

WARNING: Never modify or alter any part of the
boiler’s draft diverter. This includes the removal
or alteration of any baffl es. Never install a vent
pipe of a diameter different than that of the
boiler draft hood fl ue collar. Failure to comply
with this warning can result in severe personal
injury or death.

Always provide a minimum clearance of 6 in, 152 mm
between type C vent pipe and any combustible
materials. Type B1 vent may be used, clearance between
it and any combustible material must be as listed.

WARNING: Failure to maintain minimum
clearances between vent connectors and any
combustible material can result in a fi re causing
extensive property damage, severe personal
injury or death!

To determine the appropriate power venter for the boiler/
water heater, see Table 4, Power Venter Sizes. Follow
the power venter manufacturer’s installation instructions.

Table 4 - Power Venter Sizes
8900 Power Venter Max. Pipe Length
Model Size FT m

420-530 HS-2 100 31
630 HS-3 100 31
735-1160 HS-4 100 31
1260-1900 HS-5 100 31
Models 2000-4000 - Consult Tjernlund

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 9

COMMON VENT SYSTEMS

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.

Au moment du retrait d’une chaudière existante, les
mesures suivantes doivent être prises pour chaque
appareil toujours raccordé au système d’évacuation
commun et qui fonctionne alors que d’autres appareils
toujours raccordés au système d’évacuation ne fonction­nent pas: système d’évacuation

a) Seal any unused openings in the common venting

system.

Sceller toutes les ouvertures non utilisées du sys-

tème d’évacuation.

b) Visually inspect the venting system for proper size

and horizontal pitch and determine there is no
blockage or restriction, leakage, corrosion and other
defi ciencies which could cause an unsafe condition.

Inspecter de façon visuelle le système d’évacu-ation

pour déterminer la grosser et l’inclinaison horizontale
qui conviennent et 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
not connected to the 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 fi 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. Mettre en marche
les sécheuses, tous les appareils non raccordés au
système d’évacuation commun et tous les
ventilateurs d’extraction comme les hottes 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. Adjust thermostat so
appliance will operate continuously.

Mettre l’appareil inspecté en marche. Suivre les

instructions d’allumage. Régler le thermostat de
façon que l’appareil fonctionne de façon continue.

e) Test for spillage at the draft hood relief opening after

5 minutes of main burner operation. Use the fl ame
of a match or candle, or smoke from a cigarette,
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 fl amme d'une
allunette ou d'une chandelle ou la fumée d'une
cigarette, d'un cigare ou d'une pipe.

f) After 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, fi 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 libre de façor
adéquate. Remettre les portes et les fenêtres, les
ventilateurs, les registres de cheminées et les
appareils au gaz à leur position originale.

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
Part 11 in the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and or CAN/CGA-B149 Installation
Codes.

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 CSA-B149. Si la grosseur d'une section
du système d'évacuation doit étré modifiée, le
système devrait étré modifi 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
CSA-B149.

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 10

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OUTLET

INLET

DISCHARGE PIPE SIZE TO
EQUAL VALVE OUTLET.
DO NOT RESTRICT FLOW.

DISCHARGE SO AS TO AVOID
EXPOSURE OF PERSONS TO
HOT LIQUID OR VAPOR AND
ALLOW COMPLETE DRAINAGE
0F RELIEF VALVE AND PIPING

.

1" (25mm) CLEARANCE MUST
BE MAINTAINED BETWEEN HOT
WATER PIPING AND COMBUSTIBLE
CONSTRUCTION.

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
lime build-up in the copper heat exchanger tubes is
NOT covered under the manufacturer’s warranty.
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 fl ow rates, see Table 6A and 6B. Return
water temperatures below 110°F, 43°C will result
in heat exchanger damage from excessive
condensation voiding the manufacturer’s warranty,
see Primary/Secondary Piping Figure 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.

Relief Valve

Pipe the discharge of the pressure relief valve to prevent
scalding in the event of a discharge, see Figure 6. The
discharge piping must be sized the same as the
pressure relief valve outlet and installed to allow
complete drainage of both the relief valve and the
discharge piping.

Figure 6

CAUTION: Failure to properly install the fl 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 qualifi 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
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 5.

Table 5 - Supply & Return Pipe Sizing

Model Supply Return
8900 21/2" NPT 21/2" NPT
8800 3" Victaulic 3" Victaulic
*Models 420-950 may have 21/2" x 2" reducing fi tting
installed.

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 fl ow switch supplied with the boiler/water heater
must be wired to the terminal strip in the junction box
to prevent the boiler from fi ring unless there’s adequate
water fl ow through the unit. The fl ow switch must be
installed in the supply piping adjacent to the boiler outlet
connection.

Pump Requirements

This low mass boiler requires a continuous minimum
water fl ow 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 6A and 6B provides the heat
exchanger pressure drop and temperature rise fi gures.
The temperature rise across the boiler must never
exceed 35°F, 19.4°C. The pump delay turns the pump
on each time the burners fi re and runs the pump for up
to 10 minutes after the call for heat is satisfi ed.

CAUTION: A temperature rise outside of the range
listed in Table 6A and 6B indicates that the fl ow rate
through the heat exchanger is incorrect which will
damage the heat exchanger voiding the warranty!

The maximum allowable fl ow rate through an 8900
boiler with copper heat exchanger is 92 GPM,

5.8 L/s and 185 GPM, 11.7 L/s on single pass.

The maximum allowable fl ow rate through an 8800
boiler with copper heat exchanger is 185 GPM,

11.7 L/s and 370 GPM, 23.3 L/s on single pass.

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 11

Table 6A - Temperature Rise Table — 2 Pass Headers

20°F

Press

Flow

Model

420
530
630
735
840
950
1050
1160
1260
1370
1470
1580
1685
1790
1900
2000
2400
2800
3200
3600
4000

*Flow exceeds recommended maximum use a greater temperature rise or consult manufacturer. Cupro-nickel heat exchanger should be considered.

GPM Ft

34.0

42.9

51.0

59.5

68.0

77.0

85.1

94.0*

164.0

196.8*

Rate

—
—
—
—
—
—
—

—
—
—
—

Drop

0.4

0.7

1.1

1.6

2.4

3.3

4.4

5.8
—
—
—
—
—
—
—

4.1

6.8
—
—
—
—

11.1°C

Press

Flow

Drop

Rate

L/s kPa

1.1

2.1

2.0

2.7

3.2

3.2

4.8

3.8

7.0

4.3

9.8

4.9

12.9

5.4

17.0

5.9

—

—

—

—

—

—

—

12.0

10.3

20.0

12.4

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

25°F

Flow
Rate

GPM Ft

—

34.3

40.8

47.6

54.4

61.6

68.0

75.2

81.6

88.8

95.3*
—
—
—
—

131.2

157.4

183.7
—
—
—

Press

Drop

—

0.4

0.7

1.1

1.6

2.2

2.9

3.8

4.8

6.1

7.4
—
—
—
—

2.7

4.5

6.9
—
—
—

13.9°C

Press

Flow
Rate

Drop

L/s kPa

—

1.3

2.2

2.1

2.6

3.2

3.0

4.6

3.4

6.5

3.9

8.6

4.3

11.2

4.7

14.2

5.2

17.9

5.6

21.8

6.0

—

—

—

—

8.0

8.3

13.2

9.9

20.3

11.6

—

—

—

—

—

—

—

—

—

—

—

30°F

Flow
Rate

GPM Ft

—
—

34.0

39.7

45.4

51.3

56.7

62.6

68.0

74.0

79.4

85.3

91.0

96.7*
—

109.3

131.2

153.1

174.9

196.8*
—

Press

Drop

—
—

0.5

0.8

1.1

1.6

2.1

2.7

3.4

4.3

5.3

6.5

7.7

9.2
—

1.9

3.2

4.9

7.2

10.0
—

16.7°C

Press

Flow

Drop

Rate

L/s kPa

—

—

—

—

2.1

1.5

2.5

2.3

2.9

3.3

3.2

4.6

3.6

6.1

4.0

8.0

4.3

10.1

4.7

12.8

5.0

15.6

5.4

19.0

5.7

22.8

6.1

27.0

—

—

6.9

5.7

8.3

9.4

9.7

14.5

11.0

21.1

12.4

29.3

—

—

35°F

Flow
Rate

GPM Ft

—
—
—

34.0

38.9

44.0

48.6

53.7

58.3

63.4

68.0

73.1

78.0

82.9

87.9

93.7

112.5

131.2

149.9

168.7

187.4*

Press

Drop

—
—
—

0.6

0.8

1.2

1.6

2.0

2.6

3.3

4.0

4.8

5.8

6.9

8.1

1.4

2.4

3.7

5.4

7.5

10.1

19.4°C

Press

Flow

Drop

Rate

L/s kPa

—

—

—

2.1

1.7

2.5

2.5

2.8

3.5

3.1

4.6

3.4

6.0

3.7

7.6

4.0

9.6

4.3

11.7

4.6

14.3

4.9

17.1

5.2

20.3

5.5

23.9

5.9

4.3

7.1

7.1

8.3

10.9

9.5

15.8

10.6

22.0

11.8

29.6

—

—

—

Table 6B - Temperature Rise Table — Single Pass Headers

25°F

Press

Flow

Drop

Rate
GPM Ft

—
—
—
—
—

61.6

68.0

75.2

81.6

88.8

95.3

102.4

109.2

116.0

123.1

131.2

157.4

183.7

209.9

236.2

262.4

—
—
—
—
—

0.3

0.4

0.5

0.7

0.8

1.0

1.3

1.5

1.8

2.1

0.4

0.6

1.0

1.4

1.9

2.6

Model

420
530
630
735
840
950
1050
1160
1260
1370
1470
1580
1685
1790
1900
2000
2400
2800
3200
3600
4000

20°F

Press

Flow

GPM Ft

68.0

77.0

85.1

94.0

102.1

111.0

119.1

128.0

136.5

145.0

153.9

164.0

196.8

229.6

262.4

295.2

328.0

Rate

—
—
—
—

Drop

—
—
—
—

0.3

0.5

0.6

0.8

1.0

1.3

1.6

1.9

2.3

2.7

3.2

0.6

0.9

1.4

2.1

2.9

3.9

11.1°C

Press

Flow

Drop

Rate

L/s kPa

—

—

—

—

1.0

4.3

1.4

4.9

1.8

5.4

2.4

5.9

3.0

6.4

3.7

7.0

4.6

7.5

5.6

8.1

6.7

8.6

7.9

9.1

9.3

9.7

1.7

10.3

2.8

12.4

4.3

14.5

6.2

16.6

8.6

18.6

11.6

20.7

—

—

—

—

13.9°C

Press

Flow
Rate

Drop

L/s kPa

—

—

—

—

—

3.9

4.3

4.7

5.2

5.6

6.0

6.5

6.9

7.3

7.8

8.3

9.9

11.6

13.2

14.9

16.6

—

—

—

—

—

0.9

1.2

1.6

2.0

2.5

3.0

3.7

4.4

5.2

6.2

1.1

1.8

2.8

4.1

5.7

7.7

30°F

Press

Flow
Rate

GPM Ft

—
—
—
—
—
—
—

62.6

68.0

74.0

79.4

85.3

91.0

96.7

102.6
—

131.2

153.1

174.9

196.8

218.7

Drop

—
—
—
—
—
—
—

0.4

0.5

0.6

0.7

0.9

1.1

1.3

1.5
—

0.4

0.7

1.0

1.4

1.9

16.7°C

Press

Flow

Drop

Rate

L/s kPa

—

—

—

—

—

—

—

—

—

—

—

—

—

—

4.0

4.3

4.7

5.0

5.4

5.7

6.1

6.5

8.3

9.7

11.0

12.4

13.8

1.1

1.4

1.8

2.2

2.6

3.2

3.7

4.4

—

—

1.3

2.0

2.9

4.1

5.5

35°F

Press

Flow
Rate

GPM Ft

—
—
—
—
—
—
—
—
—

63.4

68.0

73.1

78.0

82.9

87.9
—
—

131.2

149.9

168.7

187.4

Drop

—
—
—
—
—
—
—
—
—

0.5

0.6

0.7

0.8

1.0

1.1
—
—

0.5

0.7

1.0

1.4

19.4°C

Press

Flow

Drop

Rate

L/s kPa

—

—

—

—

—

—

—

—

—

4.0

4.3

4.6

4.9

5.2

5.5

—

—

8.3

9.5

10.6

11.8

—

—

—

—

—

—

—

—

—

1.3

1.6

2.0

2.4

2.8

3.3

—

—

1.5

2.2

3.1

4.1

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 12

Low Water Cutoff

If a boiler is installed above any radiation elements it
must be fi tted with a low water cutoff device.

Refer to the wiring diagram supplied with the boiler/
water heater for proper wiring connections.

Expansion Tank

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.

Primary/Secondary Piping

Boilers connected to heating systems using zone
valves, zone pumps, or systems that have excessive
fl ow rates or return water temperatures less than 110°F,
43°C must be isolated from these systems to protect the
boiler.

Variable Water Flows

Figure 7 shows a typical primary/secondary piping
system. A dedicated pump is used to maintain a
constant water fl ow through the boiler. This secondary
pump is sized to overcome the head loss of the boiler
and secondary piping system while supplying the fl ow
rate required to maintain the desired temperature rise
across the boiler. The primary pump is sized to provide
the required fl ow to the heating system. The 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 7.

Low Return Water Temperatures

To prevent the problems associated with condensation
of the products of combustion due to low return water
temperatures a primary/secondary piping system with
a bypass and bypass valve must be installed, see
Figure 8. The bypass and bypass valve must be sized
the same as the secondary piping. A balancing valve
must also be installed in the supply side of the
secondary piping downstream of the bypass. The
balancing valve should be adjusted to divert some of
the heated discharge water into the return water until
the required inlet water temperature is achieved. The
primary and secondary pumps should be sized to
provide the required fl ow through each system. The
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 8.

Multiple Boiler Systems

Systems using multiple boilers can also be installed
using a primary/secondary manifold system, Figure 9.

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 fl ow­control valves or some other automatic means of
preventing gravity circulation of the boiler water during
the cooling cycle.

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 13

Figure 7 - Typical Primary/Secondary Piping System

(See Notes)

NOTES:

1. Boiler circuit piping must be sized
large enough to handle maximum fl ow
through unit.

2. Boiler pump sized to boiler design fl ow
requirements.

3. All boilers furnished with factory
mounted outlet water temperature
gauge.

4. Boiler pump purging required. Use ter­minals supplied.

Notice: These drawings show suggested
piping confi guration and valving.
Check with local codes and ordinances
for specifi c requirements.

H-1 Rev 3

Pump

Gate Valve

Globe Valve

Angle Valve

Bufferfly Valve

Balance Valve

Ball Valve

Motorized Valve

Solenoid

Operated Valve

Self-Operated

Val ve

Figure 8 - Low Temperature Piping

See Notes and Adjustment Procedures

H-3 Rev 5

Pressure

Reducing Valve

Check Valve

Pressure

Relief Valve

Flow Switch

Thermometer

Aquastat Union

Pressure Switch

Gas Pressure

Regulator

Automatic

Air Vent

Backflow­Prevention

Device

3-Way Valve

NOTES:

1. Boiler circuit piping must be large enough to
handle maximum fl ow through unit.

2. Boiler pump sized to boiler design fl ow requirements.

3. All boilers furnished with factory mounted outlet water
temperature gauge.

4. Boiler pump purging required. Use terminals supplied.

Notice: These drawings show suggested piping
confi guration and valving.
Check with local codes and ordinances for specifi c
requirements.

Adjustment Procedure

To Maintain Inlet Temperature

Above Dew Point

T1-Temp-Min+110° For Atmospheric

T1-Temp-Min=125° Sealed Combusion

1. Turn heater on and open valves A & B.

2. After steady-state operation, if T1 is less than Temp-Min slowly
close valve B until T1 climbs to desired operating temperature
above Temp-Min.

3. If T1 is greater than desired operating temperature, slowly close
valve A to adjust to lower desired temperature above Temp-Min.

4. Check after system operating temperature has stabiized. Make
fi nal adjustments.

5. Follow same adjustment procedure for sealed combustion.

Expansion

Tan k

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONSPage 14

Figure 8A - Low Temperature Piping with Thermostatic Valve

(See notes and adjustment procedures)

Pump

Gate Valve

Globe Valve

H-18 Rev 2

Figure 9 - Multiple Boiler Piping

(See Notes)

NOTES:

1. For pump selection consult factory.

2. Boiler pump sized to boiler and
thermostatic 3-way valve design
fl ow requirements.

3. Boiler circuit piping must be sized
large enough to handle maximum
fl ow through unit.

4. All boilers furnished with factory
mounted outlet water temperature
gauge.

5. Boiler pump purging required. Use
terminals supplied.

6. Valve is precalibrated for 140°F
return temperature.

Notice: These drawings show
suggested piping confi guration and
valving.Check with local codes and
ordinances for specifi c requirements.

Angle Valve

Bufferfly Valve

Balance Valve

Ball Valve

Motorized Valve

Solenoid

Operated Valve

Self-Operated

Val ve

Pressure

Reducing Valve

Check Valve

Pressure

Relief Valve

Flow Switch

Thermometer

NOTES:

1. Boiler circuit piping must be large enough to handle
maximum fl ow through unit.

2. Boiler pump sized to boiler design fl ow 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 fl ow through all units.

Notice: These drawings show suggested piping confi guration and valving.
Check with local codes and ordinances for specifi c requirements.

H-15 Rev 4

Aquastat Union

Pressure Switch

Gas Pressure

Regulator

Automatic

Air Vent

Backflow­Prevention

Device

3-Way Valve

Expansion

Tan k

SERIES 8800 & 8900 INSTALLATION AND OPERATING INSTRUCTIONS Page 15

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. Toxic chemicals,
such as those used for boiler treatment, are not to be
introduced into any 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 fl ow.

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.

CAUTION:
through a water heater with copper heat exchanger
on an 8900 is 92 GPM, 5.8 L/s and is 185 GPM, 11.7 L/s
on single pass. The cupro-nickel heat exchanger
allows for 100 GPM, 6.3 L/s and 200 GPM, 12.6 L/s on
single pass.

The maximum allowable flow rate through a water
heater with copper heat exchanger on an 8800 is 185
GPM, 11.7 L/s and 370 GPM, 23.3 L/s on single pass.
The cupro-nickel heat exchanger allows for 200 GPM,

12.6 L/s and 400 GPM, 25.2 L/s on single pass. See
Tables 6A and 6B.

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 7A) and the Pumping Performance
Table (Table 7B). 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.

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 fl ow prevention devices are installed.

The maximum allowable flow rate

A cupro-nickel heat exchanger may also be required. The
manufacturer should be consulted when these water
conditions are encountered. See Table 7A.