Bryant BW4, BW5 Installation Instructions Manual

BW4
BW5

Installation Instructions

NOTE: Read the entire instruction manual before starting the
installation.

TABLE OF CONTENTS

PAGE

SAFETY CONSIDERATIONS 1........................

INTRODUCTION 3..................................

Explanation of Model Numbers and Rating Plate 3.........

General Information 4................................

Locating the Boiler 4................................

INSTALLATION 4...................................

Installation Requirements 4............................

Fresh Air for combustion 4............................

Boilers with Tankless Heater Coil 7.....................

Installation System Piping 8...........................

Chimney and Chimney Connection 10...................

Electrical Wiring 10.................................

Equipment and Optional Accessories 10..................

Filling Boiler 12....................................

OPERATING BOILER 13.............................

To S tart 13........................................

Fuel Units and Oil Lines 13...........................

Air Supply for Combustion 13.........................

Draft Regulators 13..................................

Nozzles 13........................................

Final Burner Adjustments 13..........................

Oil Burner Maintenance 15............................

Checking and Adjusting Controls 16....................

MAINTENANCE 16..................................

Relief Valve 16.....................................

Conventional Expansion Tank 16.......................

Diaphragm Expansion Tank 16.........................

Water System 16....................................

Tankless Coil (or Cover Plate Gasket) 16.................

Oil Boiler/Burner Cleaning Instructions 17................

Sequence of Operation 17.............................

Service Hints 22....................................

Parts List 22.......................................

Oil---Fired Cast Iron

Hot W ater Boilers

Sizes 140,000 through 280,000

ama

ASME

®

SAFETY CONSIDERATIONS

Installing and servicing heating equipment can be hazardous due
to oil and electrical components. Only trained and qualified
personnel should install, repair, or service heating equipment.
Untrained personnel can perform basic maintenance functions
such as maintaining water level. All other operations must be
performed by trained service personnel. When working on
heating equipment, observe precautions in literature, on tags, and
on labels attached to or shipped with unit and other safety
precautions that may apply. Recognize safety information. This is
the safety--alert symbol . When you see this symbol on unit or in
instructions and manuals, be alert to potential for personal injury.
Understand the signal words DANGER, WARNING,
CAUTION, and NOTE. These words are used with the
safety--alert symbol. DANGER identifies the most serious
hazards which will result in severe personal injury or death.
WARNING signifies hazards which could result in personal
injury or death. CAUTION is used to identify unsafe practices
which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions which
will result in enhanced installation, reliability, or operation. Read
and obey the following rules to ensure safe installation and
operation:

1. Read the Owner’s Manual carefully for safe operation.
Failure to follow the rules of safe operation and the
instructions can cause a
malfunction of the boiler and result in death, serious
bodily injury, and/or property damage.

2. Check local codes and utility requirements before
installation. The installation must be in accordance with
their directives, or follow NFPA 31–Installation of Oil
Burning Equipment, latest revision.

3. Before servicing, allow boiler to cool. Always shut off any
electricity and oil to boiler when working on it. This
prevents any electrical shocks or burns.

4. Inspect oil line and connections for leaks.

5. Be certain oil burner nozzle is size required. Overfiring
will result in early failure of boiler sections. This causes
dangerous operation.

6. Never vent this boiler into an enclosed space. Always vent
to the outside. Never vent to another room or inside a
building.

BW4 / BW5

A02217

Fig. 1 -- Model BW4/BW5

7. Be sure there is adequate air supply for complete
combustion.

8. Follow a regular service and maintenance schedule for
efficient and safe operation.

9. Keep boiler area clean and free from combustible
materials, gasoline, and other flammable vapors and
liquids.

10. Oil Burners are not do--it yourself items. This boiler must
be installed and serviced by qualified professionals using
combustion test instruments.

11. Be aware when piping the relief valve that if the system
pressure exceeds the safe limit of 30 pounds per square
inch, the relief valve will automatically lift open. Lifting of
the relief valve can discharge large quantities of steam and
hot water, which may damage the surroundings. Before
installing the relief valve read the manufacturer’s
instructions and maintenance section of the manual on
relief valves.

12. Installation and sizing of the expansion tank must consider
the heating systems total water volume, temperature, boiler
initial fill pressure, and system arrangement. An
improperly installed and sized expansion tank may result
in frequent lifting of the relief valve or other heating
system problems. For proper installation, sizing, and
maintenance of the expansion tank follow the guidelines
established by the boiler manufacturer and the expansion
tank manufacturer.

13. Expansion tank performance and life expectancy can be
hindered by overfilling the boiler. An initial fill pressure of

10.12 psig is recommended. For higher fill pressures the
expansion tank’s air charge will need to be increased to
match the fill pressure. Consult the manufacturer’s
guidelines for sizing and selection.

14. Purging the heating system of air and gases when first
putting the boiler into service is critical for proper

circulation and quiet performance. Once the air and gases
are purged, for boiler installations using float type vents,
the air vents should be closed for normal operation. If air
is heard or noticed by loss of heat, purge the system and
open the vents for a short period of time.

!

WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal
injury, death and or property damage.

Use only number 1 or number 2 fuel oil having commercial
standard grade CS 12-- 48. Do not use gasoline, kerosene,
crankcase oil, or any oil containing gasoline.

!

WARNING

OPERATION AND WARRANTY HAZARD

Failure to follow this warning could result in personal
injury, death and or property damage.

This boiler has been designed for residential installations. If
used for commercial applications, all jurisdictional
requirements must be met. This may require wiring and/or
piping modifications. The manufacturer is not responsible
for any changes to original design.

2

1

1

GAUGE

36″

1

20

/2″

FRONT SIDE REAR

/4 IN. SUPPLY

AQUASTAT
CONTROL
(WITHOUT COIL)

AQUASTAT
CONTROL
(WITH COIL)

1

/4 IN.

1
RETURN

9″

C B

TANKLESS
HEATER

1

/2 IN. N.P.T.

A

3

/4 IN.
ASME
RELIEF
VALVE

Fig. 2 -- Dimensional Drawing (See Table 1 for additional information)

A06591

BW4 / BW5

!

WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal
injury, death and or property damage

DO NOT USE GASOLINE CRANKCASE DRAININGS
OR ANY OIL CONTAINING GASOLINE.

INTRODUCTION

Check to be sure boiler size is correct before starting installation.
See rating and capacity table shown in Fig. 2 and Table 1a and
1b. Check rating plate on right side of boiler.

The boiler must be supplied with the proper oil, fresh air for
combustion, and a suitable electrical supply. Boiler must also be
connected to a suitable venting system and an adequate piping
system. Finally, a properly located thermostat is needed for
control of heating system. If there are any doubts as to the various
requirements, check with local authorities and obtain professional
help where needed. The Operating Boiler Instructions and Final
Checks and Adjustments sections later in this document are vital
to the proper and safe operation of the heating system. Take time
to be sure they are all done.

The following steps are all necessary for proper installation and
safe operation of boiler:

1. LOCATING THE BOILER

2. OIL SUPPLY AND PIPING

3. FRESH AIR FOR COMBUSTION

4. PIPING CONNECTIONS

5. CHIMNEY AND VENT PIPE CONNECTIONS

6. ELECTRICAL WIRING

7. THERMOSTAT LOCATION

8. CHECKING AND ADJUSTING

9. MAINTENANCE

!

WARNING

FIRE, EXPLOSION, ELECTRICAL, CARBON
MONOXIDE POISONING HAZARD

Failure to follow this warning could result in property
damage, personal injury, or death.

Improper installation, adjustment, alteration, service
maintenance, or use can cause carbon monoxide poisoning,
explosion, fire, electrical shock, or other conditions which
may cause personal injury or property damage. Consult a
qualified installer, service agency, fuel oil supplier, or your
distributor or branch for information or assistance. The
qualified installer or agency must use only
factory--authorized and listed kits or accessories when
modifying this product.

Explanation of Model Numbers and Rating Plate

Each model number except for the BW4(5)RAH280ABAA h as 3
possible firing rates depending on which nozzle or burner is
installed. The model number represents the burner installed in the
boiler and the largest possible input for the boiler. The
BW4(5)RAH280ABAA can only be fired at an input of 280,000
Btuh or 245,000 Btuh.

For example, a BW4BAH000140ABAA has a Beckett burner
and a maximum input of 140,000 Btuh. A BW4RAH000140 has
a Riello burner and a maximum input of 140,000 Btuh. The
rating plate for each model shows the possible firing rates. Boilers
come shipped with the largest nozzle installed. By changing
nozzles, the BW4BAH000140ABAA firing rate can be changed
to 91,000 or 105,000 Btuh input.

For BW4BAH models equipped with Beckett burners:

The BW4BAH000280ABAA is shipped with 2 additional
nozzles to fire the Beckett burner at the alternate inputs listed on
the rating plate. The BW4BAH000210ABAA and
BW4BAH000140ABAA are shipped with one additional nozzle
each, to fire the Beckett burner at the next lowest inputs listed on
the rating plate. To fire the BW4BAH000210ABAA and
BW4BAH000140ABAA at the lowest inputs listed on the rating
plate, an accessory low--fire kit for each boiler, not included with
the boiler, is required. The low--fire kits include the alternate size

3

nozzle and the alternate burner end cone to fire the burners on
these models at the lowest inputs for those models.

For BW4RAH models equipped with Riello burners:

There are two different Riello burners used on the BW4RAH
boilers, the F5 and F10 burner. The BW4RAH000280AAAA is
shipped with one additional nozzles to fire the F10 burner at the
next alternate lower input listed on the rating plate. The
BW4RAH000210AAAA and BW4RAH000140AAAA are
equipped with F5 burners and shipped with two additional
nozzles to fire the boilers at the next lowest inputs listed on the
rating plate.

The BW5B and BW5R models are the same as the BW4B and
BW5B models, except the tankless water heater is factory
installed.

Refer to Tables 1 and 7 (Beckett) or Table 8 (Riello) for
additional oil burner information. Refer to the boiler product data
sheet for the correct accessory low--fire kit.

General Information

Boilers with the same number of sections are identical to each
other except for their firing rate and/or type of burner. The firing
rate is determined by the nozzle size used in the oil burner and the

BW4 / BW5

oil pressure at the nozzle. For example, models BW4RAH091,
BW4RAH105, and BW4RAH140 are the same boiler, without a
tankless coil. They all have a Riello oil burner fired at a different
input rate. Models BW5RAH245 and BW4RAH280 are the same
boiler, with a tankless coil. They both have a Riello oil burner
fired at a different input rate.

1. Check to be sure you have selected the right size boiler
with the proper capacity. The I=B=R rating of the boiler
selected should be greater than or equal to the calculated
peak heating load (heat loss) for the building or area(s)
served by the boiler and associated hot water heating
systems. (See Table 1.) Any heat loss calculations used
should be based on approved methods.

2. Boiler must be supplied with the proper oil supply and oil
piping, sufficient fresh combustion air, and a suitable
electrical supply.

3. Boiler must be connected to a suitable venting system and
a piping system adequate to distribute the heating load.

4. A thermostat must be properly located and installed for
control of the heating system.

If there are any doubts as to the various requirements, check with
local authorities and obtain professional help where needed. The
Operation Instructions, Final Checks and Adjustments and
Maintenance sections in this manual are vital to the proper and
safe operation of the heating system. Take the time to be sure they
are all done.

Locating the Boiler

If boiler is part of a planned heating system, locate it as close as
possible to where it is shown on plan. If boiler is to be part of an
existing system, it is usually best to put it where the old one was.

If location is to be changed, additional materials as well as an
adequate base will be required. The following rules apply:

1. The boiler must be level.

2. Use a raised base if floor can become wet or damp.

3. These boilers must have a non -- combustible base if
installed on a combustible floor. Two inch concrete patio
blocks or a 2--in. Cladlite--pad may be used.

4. The vent pipe connection should be as short as possible.

5. Maintain clearances for fire safety as well as servicing.
Refer to Fig. 3 for minimum clearances. An 18--in.
clearance must be maintained at a side where passage is
required to access another side for cleaning, servicing,
inspection, or replacement of any parts that normally may
require such attention. Boilers must be installed at least
6--in. from combustible materials on all sides and above.
Allow at least 24--in. front clearance for servicing. Allow
at least 18 --in. right--side clearance for servicing boilers
equipped with a tankless coil.

6. Fresh air for combustion must be available at front of
boiler. Fresh air for ventilation must be available to front
AND rear of boiler. Air passages must be free of
obstructions at all times. V entilating and combustion air
must enter boiler room without restrictions.

7. Be sure installation is in accordance with the requirements
of local authorities having jurisdiction. Compliance with
these regulations is required. In the absence of local codes,
follow NFPA 31--Installation of Oil Burning Equipment.

INSTALLATION

Installation Requirements

Refer to Fig. 4 for the basic requirements of a typical installation.
NOTE: Always keep manual fuel supply valve shut off if burner

is shut down for an extended period of time.

Fresh Air for Combustion

6″ MIN

24″ MIN

BOILER

FRONT

6″ MIN

18″ WITH COIL

Fig. 3 -- Minimum Clearance Dimensions

6″

A95592

4

CIRCULATING PUMP
IN SUPPLY LINES

2 IN. FILL PIPE

VENT PIPE

MINIMUM 2 IN. ID

SHUTOFF

VALVE

OIL

FILTER

ENTRANCE

OIL

TANK

SERVICE LINE

SWITCH

ELECTRIC LINE

AUTOMATIC
FILL VALVE
AND SHUTOFF

DIAPHRAGM
EXPANSION TANK

OVERCURRENT
PROTECTED
SAFETY SWITCH

LINES TO OTHER
APPLIANCES

TO OUTSIDE

VENT PIPE

DRAFT

REGULATOR

RELIEF VALVE

TO RADIATION

FROM RADIATION

OIL BURNER

FOUNDATIONS

OIL LINES

Fig. 4 -- General Principal Requirements for a Typical Installation

Table 1 – Boiler Ratings and Capacities

C
H

I
M
N
E
Y

BW4 / BW5

A02230

WITHOUT

TANKL ESS

COIL

BW4BAH140

BW4RAH140

BW4BAH210

BW4RAH210

BW4BAH280

BW4RAH280

Shaded areas are as shipped. Alternate inputs require a field--- installed alternate oil nozzle supplied with base model.
* MBH = 1,000 BTU per hour/BTU=British Thermal Unit
** Heating Capacity is based on a 13 percent CO2 with a --- 0.02 in. wc draft over fire and a #1 smoke or less. Testing was done in accordance with the D.O.E.
(Department
of Energy) test procedure.
+ GPH = Gallons per hour of oil at 140,000 BTU per gallon
++ A.F.U.E. = Annual Fuel Utilization Efficiency based upon D.O.E. test procedure
# As an Energy Star Partner, the manufacturer has determined that this product meets Energy Star guidelines for Energy Efficiency
} The 168,000 Btuh input is only available with a Beckett burner.

NO.

INPUT

SEC

*MBH

3 91 80 70 0.65 #86.3 8” X8” X15’ 14 1/2 6 8 460 N/A
3 105 92 80 0.75 #85.2 8” X8” X15’ 14 1/2 6 8 460 N/A
3 140 119 103 1.00 83.4 8” X8” X15’ 14 1/2 6 8 460 N/A
4 126 111 97 0.90 #86.0 8” X8” X15’ 17 3/4 6 95/8 533 N/A
4 175 150 130 1.25 83.9 8” X8” X15’ 17 3/4 6 95/8 533 N/A
4 210 178 155 1.50 82.4 8” X8” X15’ 17 3/4 6 95/8 533 N/A
5 }168 147 128 1.20 #86.5 8” X8” X15’ 21 6 11 1/2 620 N/A
5 245 209 182 1.75 83.6 8” X8” X15’ 21 6 11 1/2 620 N/A
5 280 236 205 2.00 82.0 8” X8” X20’ 21 6 11 1/2 620 N/A

**HEATING

CAPACITY

*MBH

NET

I=B=R

RATING

*MBH

FIRING

RATE

GPH

A.F.U.E.

MIN.

CHIMNEY

SIZE/HEIGHT

DIMENSIONS --- IN

A B C

SHIPPING

WEIGHT

TANKL ESS

HEATER

G.P.M.

5

Table 1 -- Boiler Ratings and Capacities (Cont.)

NO.

WITH TANK-

LESS COIL

BW5BAH140

BW5RAH140

BW5BAH210

BW5RAH210

BW5BAH280

BW5RAH280

Shaded areas are as shipped. Alternate inputs require a field--- installed alternate oil nozzle supplied with base model.
* MBH = 1,000 BTU per hour/BTU=British Thermal Unit
** Heating Capacity is based on a 13 percent CO2 with a --- 0.02 in. wc draft over fire and a #1 smoke or less. Testing was done in accordance with the D.O.E.
(Department
of Energy) test procedure.
+ GPH = Gallons per hour of oil at 140,000 BTU per gallon
++ A.F.U.E. = Annual Fuel Utilization Efficiency based upon D.O.E. test procedure
# As an Energy Star Partner, the manufacturer has determined that this product meets Energy Star guidelines for Energy Efficiency
# # Gallons of water per minute, heated from 40˚F to 140˚F, with 200˚F boiler water temperature, intermittent draw.
} The 168,000 Btuh input is only available with a Beckett burner.

SEC

INPUT

*MBH

3 91 80 70 0.65 #86.3 8” X8” X15’ 14 1/2 6 8 470 2.90
3 105 92 80 0.75 #85.2 8” X8” X15’ 14 1/2 6 8 470 3.00
3 140 119 103 1.00 83.4 8” X8” X15’ 14 1/2 6 8 470 3.25
4 126 111 97 0.90 #86.0 8” X8” X15’ 17 3/4 6 95/8 545 3.15
4 175 150 130 1.25 83.9 8” X8” X15’ 17 3/4 6 95/8 545 3.50
4 210 178 155 1.50 82.4 8” X8” X15’ 17 3/4 6 95/8 545 3.75
5 }168 147 128 1.20 #86.5 8” X8” X 15’ 21 6 11 1/2 620 N/A
5 245 209 182 1.75 83.6 8” X8” X15’ 21 6 11 1/2 630 4.00
5 280 236 205 2.00 82.0 8” X8” X20’ 21 6 11 1/2 630 4.25

**HEATING

CAPACITY

*MBH

NET

I=B=R

RATING

*MBH

FIRING

RATE

GPH

A.F.U.E

MIN.

CHIMNEY

SIZE/HEIGHT

DIMENSIONS--- IN

SHIPPING

WEIGHT

TANK LES S

HEATER

##G.P.M.H W D

BW4 / BW5

FRESH AIR DUCT SIZE (IN.) 1/4–IN. MESH SCREEN (BTUH) WOOD LOUVERS (BTUH) METAL LOUVERS

3 ---1/2 X 12 144,000 36,000 108,000

8X8 256,000 64,000 192,000

8X12 384,000 96,000 288,000

8X16 512,000 128,000 384,000

!

WARNING

Table 2 – Fresh Air Duct for Tightly Sealed House

FIRE AND CARBON MONOXIDE POISONING
HAZARD

Failure to follow this warning can cause personal injury or
death.

Be sure to provide enough fresh air for combustion.
Enough air ensures proper combustion and ASSURES
THAT NO HAZARD WILL DEVELOP DUE TO LACK
OF OXYGEN.

!

WARNING

UNIT LIFE REDUCTION HAZARD

Failure to follow this warning could result in personal
injury, death and or property damage.

Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride,bromide, and
iodide. These elements are found in aerosol sprays,
detergents, bleaches, cleaning solvents, salts, air fresheners,
and other household products.

Enough fresh air must be provided to assure proper combustion.
The fire in the boiler uses oxygen. It must have a continuous
supply. The air in a house contains only enough oxygen to supply
the burner for a short time. Outside air must enter the house to
replace that used by the burner. The exact fresh air requirements
depend on whether the boiler is located in an unconfined or
confined space.

(BTUH)

!

WARNING

CARBON MONOXIDE POISONING AND UNIT
OPERATION HAZARD

Failure to follow this warning could result in personal
injury, death and or property damage.

If a fireplace or a kitchen or bathroom exhaust fan is used,
an outside air intake should be installed. These devices rob
the boiler and water heater of combustion air.

A. Boiler Located in Unconfined Space

An unconfined space is defined as a space with volume not less
than 50 cu ft.. per 1000 Btuh of total input rating of all appliances
installed in that space.

If boiler is in an open area (unpartitioned basement) in a
conventional house, air that leaks through cracks around doors
and windows will usually be adequate to provide air for
combustion. The doors should not fit tightly. Cracks around
windows should not be caulked.

B. Boiler Located in Confined Space

ALL AIR FROM INSIDE BUILDING

The confined space shall be provided with 2 permanent openings
communicating directly with an additional room(s) of sufficient
volume so that the combined volume of all spaces meets the
criteria for an unconfined space. The total input of all combustion
equipment installed in the combined space shall be considered in
making this determination. Each opening shall have a minimum
free area of 1 sq.. in. per 1000 Btuh of total input rating for all
combustion equipment in the confined space, but not less than
100 sq. in. One opening shall be within 12 in. of the top and 1
within 12 in. of the bottom of the enclosure. (See Fig. 5.)

6

VENTILATING

GRILLE

Fig. 5 -- Air Openings for Closet or Utility

COMBUSTION
AIR GRILLE

Room Installations

FRESH AIR
DUCT

A95594

3. When communicating with the outdoors through
horizontal ducts, each opening shall have a minimum free
area of 1 sq. in. per 2000 Btuh of total input rating of all
equipment in the enclosure.

4. When ducts are used, they shall be of the same
cross--sectional area as the free area of the openings to
which they connect. The minimum dimension of
rectangular air ducts shall not be less than 3--in.

Boilers With Tankless Heater Coil

Boilers may be factory packaged with a tankless heater coil. The
use of this coil eliminates the need for a hot water storage tank.
Instantaneous heating of water in the coil provides a flow of hot
water for domestic use if proper burner and water supply line
controls are used. Tankless coils are meant to provide domestic
hot water for intermittent draws, not

IMPORTANT: Do not use a tankless coil if water is
excessively hard with lime or other deposits which will
accumulate inside coil.

C. Mounting Aquastat Control

The control configuration on this boiler has been set up so that
the Honeywell L8124C Combination Hi/Low Limit Aquastat
Relay mounts on the tankless coil. This maximizes tankless coil
performance by making the burner respond more quickly to a call
for domestic hot water. The boiler is completely wired according
to schematic wiring diagram. (See Fig. 14.) The installer must
mount the L8124C Aquastat on control well in 3/4-- in. tapping
on tankless coil. (See Fig. 7.)

D. Tankless Coil Piping

continuous flows.

BW4 / BW5

BOILER

A95595

Fig. 6 -- Fresh Air Duct for Tightly Sealed House

Example: The boiler is rated at 100,000 Btuh. The water heater is
rated at 30,000 Btuh. The total is 130,000 Btuh. Two grilles are
needed, each with 130 sq. in. of FREE opening. Metal grilles
have about 60 percent FREE area. To find the louvered area
needed, multiply the FREE area required by 1.7 (130 X 1.7 =

221.0 sq. in. louvered area). In this example, 2 grilles each having
an 8 in. X 30 in. (240 sq. in.) louvered area would be used. Fig. 5
shows grille locations.
ALL AIR FROM OUTDOORS
The confined space shall be provided with 2 permanent openings,
1 commencing within 12--in. of the top and 1 commencing within
12--in. of the bottom of the enclosure. The openings shall
communicate directly, or by ducts, with the outdoors or spaces
(crawl or attic) that freely communicate with the outdoors. See
Table 2 and Fig. 5 or 6.

1. When directly communicating with the outdoors, each
opening shall have a minimum free area of 1 sq. in. per
4000 Btuh of total input rating of all equipment in the
enclosure.

2. When communicating with the outdoors through vertical
ducts, each opening shall have a minimum free area of 1
sq. in. per 4000 Btuh of total input rating of all equipment
in the enclosure.

IN

⁄2 IN. NPT

3



⁄4 IN. NPT



CONTROL WELL

A95596

1

Fig. 7 -- Tankless Heater Coil

Piping is as shown in Fig. 8. A tempering valve (mixing valve) is
recommended. A flow restrictor may be required on tankless coil
inlet piping so that flow rates are matched to boiler heat input.
See Table 3.

7

BW4BAH091
BW4RAH091

BW4BAH105
BW4RAH105

BW4BAH140
BW4RAH140

BW4BAH126
BW4RAH126

BW4BAH175
BW4RAH175

BW4RAH210
BW4BAH210

Table 3 – Boiler Rating Information

BOILER MODEL BURNER FIRING RATE INPUT (MBH) TANKLESS RATING (GPM)

BW5BAH091
BW5RAH091

BW5BAH105
BW5RAH105

BW5BAH140
BW5RAH140

BW5BAH126
BW5RAH126

BW5BAH175
BW5RAH175

BW5RAH210
BW5BAH210

0.65 91 2.90

0.75 105 3.00

1.00 140 3.25

0.90 126 3.15

1.25 175 3.50

1.50 210 3.75

BW4BAH168 BW5BAH168

BW4BAH245
BW4RAH245

BW4BAH280
BW4RAH280

* Gallon of water per minute h eated from 40_ F to 140_ F with 200_ F boiler water, intermittent draw. Tankless heater is factory installed on BW5 models, field

BW4 / BW5

install ed accessory on BW4 models.

(TO AUTOMATIC

DISHWASHER, ETC.)

BW5BAH245
BW5RAH245

BW5BAH280
BW5RAH280

UNTEMPERED

HOT WATER

TEMPERED

HOT WATER

1.20 168 3.45

1.75 245 4.00

2.00 280 4.25

responsible for any water damage. Connect a drain line of
the same pipe size (3/4--in.) to carry any water away to a
drain.

3. Connect the 1 1/4--in. NPT supply and return lines to
boiler. Both supply and return lines should be piped to the

TANKLESS COIL

OUT

CENTER LINE
OF COLD TAP

IN

front section or both to the rear section. The boiler should
NOT be piped return line to the front, supply line to the
rear, or vice versa, as this will cause boiler water to short
circuit heat exchanger. The connections may require
certain additional fittings and parts as shown on diagrams.
(See Fig. 9, 10, and 11.)

If installing an entire new heating system, first install all radiation
units (panels, radiators, or cabinets) and supply and return mains,
then make connections to boiler.

In connecting cold water supply to reducing valve, make sure that
a clean water supply is available. When water supply is from a
well or pump, a sand stainer should be installed at pump.

When boiler is used in connection with refrigeration systems, it

LIMIT

CONTROL

8 IN. TO

12 IN.

TEMPERING
VALVE

COLD WATER

INLET

shall be installed so that chilled medium is piped in parallel with

SHUTOFF

VALVE

the heating boiler with appropriate valves to prevent chilled
medium from entering the heating boiler.

The minimum boiler supply water temperature setting on the

A98269

Fig. 8 -- Recommended Piping with Tankless Heater Coil

Installation System Piping

1. Place boiler in selected location as close to flue as
possible. (See Fig. 4.) Boiler is shipped assembled. Only
the factory--supplied relief valve needs be installed.

2. Install relief valve in rear section on 3/4 --in. nipple and
street ell. Do not connect directly to a drain, but leave an
air gap. No shutoff of any description shall be placed
between safety relief valve and boiler, or on discharge
pipes between such safety valves and the atmosphere.
Installation of safety relief valve shall conform to
requirements of the ANSI/ASME Boiler and Pressure
Vessel Code, Section IV. The manufacturer is not

aquastat is 140_F. If the boiler is used in a heating system where
supply water temperatures below 140_F are desired, a suitable
method, such as, the use of bypass piping shown in the figure 10,
a 3 way or 4 way mixing valve, or some other means needs to be
used to ensure return water temperatures to the boiler are no less
than 120_F. When the boiler is operated with return water
temperatures less than 120_F, condensation may form in the
boiler and venting. This condensation is corrosive and can
eventually cause severe damage to the boiler and venting system.
Antifreeze added to boilers must be non--toxic and must be of a
type specifically intended for use in closed hydronic heating
systems. Under no circumstances should automotive antifreeze be
used. Antifreeze used in any boiler may reduce capacity by 10
percent or more and increase fuel consumption. Tankless coil
performance will fall as concentration of antifreeze is increased.
Refer to boiler and piping water volumes tables on next page.

8