Lennox OWB86-4D User manual

RETAIN THESE INSTRUCTIONS FOR
FUTURE REFERENCE
These instructions must be axed on or
adjacent to the boiler.
PN 240013016, Rev. B [12/31/2020]
INSTALLATION
INSTRUCTIONS
PRODUCT LITERATURE
Lennox Industries Inc.
Dallas, Texas
Tested For 50 psi.
ASME
Working Pressure
WARNING
Improper installation, adjustment, alteration,
service, or maintenance could result in death
or serious injury. Refer to this manual for
assistance. For additional information consult
a qualied installer, service agency, or the oil
supplier.
!
OWB86-3
OWB86-4D
OWB86-4
OWB86-5
OIL FIRED BOILER

2PN 240013016, Rev. B [12/31/2020]
Introduction
OWB boiler is a natural draft oil red hot water boiler
comprised of cast iron sections. Boiler is available with 3, 4,
or 5 cast iron sections. These sections are held together by
cast iron push nipples.
Boiler is capable of ring #2 fuel oil from 0.80 to 1.55 gph.
All packaged boilers include a swing door, Honeywell limit,
temperature and pressure gauge, safety relief valve, drain
valve, ue brush, and extra boiler tap for expansion tank or
air elimination.
These low pressure oil red hot water boilers are
constructed and hydrostatically tested for maximum
working pressure of 50 psig (pounds per square inch)
in accordance with the latest revision of the A.S.M.E.
(American Society of Mechanical Engineers) Boiler Pressure
Vessel Code Section IV Standards for heating boilers.
Heating capacity indicates amount of heat available after
subtracting losses up the stack. Most of this remaining
heat is available to heat water. A small portion is heat from
the jacket and boiler surface and it is assumed that this
heat stays in the structure. Net AHRI Rating represents
portion of remaining heat that can be applied to heat
radiation or terminal unites (i.e. nned tube baseboard,
cast iron radiators, radiant oor, etc.). Dierence between
Heating Capacity and Net AHRI Rating, called piping and
pickup allowance, establishes reserve for heating volume
of water in the system and o-setting heat losses from
system piping. Net AHRI Rating of the boiler selected
should be greater than or equal to calculated peak heating
load (heat loss) for building or area(s) served by the
boiler and associated hot water heating systems. Consult
manufacturer before selecting boiler for installations having
unusual piping and pickup requirements.
TABLE OF CONTENTS
Boiler installation shall be completed by qualied agency.
NOTICE
Used to address practices not related to personal
injury.
CAUTION
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
!!
WARNING
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
!
DANGER
Indicates a hazardous situation which, if not avoided,
WILL result in death or serious injury
!
This is the safety alert symbol. Symbol alerts youThis is the safety alert symbol. Symbol alerts you
to potential personal injury hazards. Obey all safetyto potential personal injury hazards. Obey all safety
messages following this symbol to avoid possible injury or messages following this symbol to avoid possible injury or
death.death.
Become familiar with symbols identifyingBecome familiar with symbols identifying
potential hazards.potential hazards.
Boiler Ratings And Capacities ............................. 3
Safety Notices .....................................................4
Safe Installation And Operation........................... 5
Locating The Boiler.............................................. 6
Fresh Air For Combustion....................................8
System Piping....................................................10
Antifreeze In The System .................................. 16
Chimney And Chimney Connections................. 16
Electrical Connections.......................................18
Filling The Boiler ..............................................19
Operating The Boiler .......................................20
Preliminary Burner Settings............................... 21
Checking And Adjusting Controls ...................... 22
Maintenance......................................................23
Oil Boiler / Burner Cleaning Instructions ........... 24
Oil Burner Cleaning ........................................... 25
Service Hints .....................................................26
Pump Curve.......................................................27

3PN 240013016, Rev. B [12/31/2020]
36”
20 1/2”
BOILER RATINGS AND CAPACITIES
BOILER MODEL
NO.
INPUT **HEATING
CAPACITY
*Mbh
‡NET
AHRI
RATING
WATER
*Mbh
A.F.U.E.
++
NO.
SEC.
MINIMUM
CHIMNEY
SIZE/
HEIGHT
DIMENSIONS
(inches)
+gph *Mbh A B C
OWB86-3 0.80 112 98 85 86.0 3 8” X 8” X 15” 14½ 6 8
OWB86-4D*** 1.00 140 122 106 86.2 4 8” X 8” X 15” 17¾ 6 9⅝
OWB86-4 1.25 175 152 132 86.0 4 8” X 8” X 15” 17¾ 6 9⅝
OWB86-5 1.55 217 189 164 86.0 58” X 8” X 15” 21 6 11½
* Mbh = 1,000 BTU per hour [BTU = British Thermal Unit]
**Heating Capacity based on 13.1% CO
2
with a -0.02” w.c. draft over re, 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 oil at 140,000 BTU per gallon
++A.F.U.E. = Annual Fuel Utilization Eciency based upon D.O.E. test procedure.
‡ Net AHRI Water Ratings based on piping and pickup allowance of 1.15. Consult manufacturer before selecting boiler for
installations having unusual piping and pickup requirements, such as intermittent system operation, extensive piping
systems, etc.
BOILER RATINGS AND CAPACITIES
Figure 1 - Dimensions
*** OWB86-4D is a eld derate of OWB86-4 with oil nozzle change accomplished by using 0.85-60°A nozzle
furnished with OWB86-4 boiler.

4PN 240013016, Rev. B [12/31/2020]
SAFETY NOTICES
Boiler installation shall be completed by qualied agency.
WARNING
Do not tamper with or use this boiler for any
purpose other than its intended use. Failure to follow
these instructions could result in death or serious
injury. Use only manufacturer recommended parts
and accessories.
!
CAUTION
Laceration, burn hazard. Metal edges and parts
may have sharp edges and/or may be hot. Use
appropriate personal protection equipment to
include safety glasses and gloves when installing
or servicing this boiler. Failure to follow these
instructions could result in minor or moderate injury.
!!
WARNING
Fire, explosion, asphyxiation and electrical shock
hazard. Improper installation could result in death
or serious injury. Read this manual and understand
all requirements before beginning installation.
!
FOR YOUR SAFETY READ BEFORE OPERATING
Hot Water Can Scald!
Water heated to temperature for clothes washing,
dish washing and other sanitizing needs can scald and
cause permanent injury.
Children, elderly, and inrm or physically handicapped
persons are more likely to be permanently injured by
hot water. Never leave them unattended in bathtub or
shower. Never allow small children to use a hot water
tap or draw their own bath.
If anyone using hot water in the building ts the above
description, or if state laws or local codes require
certain water temperatures at hot water taps, you
must take special precautions:
• Use lowest possible temperature setting.
• Install some type of tempering device, such as
an automatic mixing valve, at hot water tap or
water heater. Automatic mixing valve must be
selected and installed according to manufacturer's
recommendations and instructions.
• Water passing out of drain valves may be
extremely hot. To avoid injury:
• Make sure all connections are tight.
• Direct water ow away from any person.
DANGER
!
Water
Temperature
Seng
1st Degree Burn
Exposure Time For
An Adult
2nd and 3rd Degree Burn
Exposure Time For An
Adult
120° F 1 minute 5 minutes
130° F 5 seconds 30 seconds
140° F 2 seconds 5 seconds
150° F 1 second 1.5 seconds
160° F Instantaneous 0.5 seconds
Note: Warning for Infants, Children, and Elderly:
Great care must be taken when exposing the
aforementioned groups to warm or hot water as they
can be badly burned in exposure times less than half
of the time for an adult.
WARNING
Fire, Explosion, Asphyxiation, Electrical shock
hazard! Flooding will result in damages such as
electrical problems, corrosion, inoperative parts,
mold and other unforeseen issues which can
occur over time. Any equipment determined by
a professional as damaged by a ood, dened as
excess of water or other liquid, shall be replaced.
Failure to follow these directions will result in a
Hazardous Situation.
!

5PN 240013016, Rev. B [12/31/2020]
1. Read the Owner’s Manual for Safe Operation. Failure
to follow rules for safe operation and instructions can
cause malfunction of boiler and result in death, serious
bodily injury, and/or property damage.
2. Install boiler in accordance with requirements of
authority having jurisdiction, or in the absence of such
requirements : United States, NFPA 31: Standard
for the Installation of Oil Burning Equipment (latest
edition).
3. Before servicing, allow boiler to cool. Always shut o
any electricity and oil to boiler when working on it.
4. Inspect oil line and connections for leaks.
5. Be certain oil burner nozzle is the size required. Over-
ring will result in early failure of the boiler sections.
This will cause dangerous operation.
6. Never vent this boiler into enclosed space. Always vent
to outside. Never vent to another room or inside a
building.
7. Be sure there is adequate air supply for complete
combustion.
8. Follow regular service and maintenance schedule for
ecient and safe operation.
9. Keep boiler area clean and free of combustible material,
gasoline and other ammable vapors and liquids.
10. Oil burners are not do-it-yourself items. This boiler
must be installed and serviced by qualied professionals
using combustion test instruments.
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!
11. Be aware when piping the safety relief valve if system
pressure exceeds safe limit of 30 pounds per square
inch, the safety relief valve will automatically lift
open. Lifting of the safety relief valve can discharge
large quantities of steam and hot water, which may
damage the surroundings. Before installing the safety
relief valve read the manufacturer’s instructions and
maintenance section of the manual on safety relief
valves.
12. Installation and sizing of the expansion tank must
consider heating systems total water volume,
temperature, boiler initial ll pressure, and system
arrangement. Improperly installed and sized expansion
tank may result in frequent lifting of the safety
relief valve or other heating system problems. For
proper installation, sizing, and maintenance of the
expansion tank follow guidelines established by tank
manufacturer.
13. Expansion tank performance and life expectancy can
be hindered by overlling the boiler. Recommend initial
ll pressure of 10-12 psig. For higher ll pressures
expansion tank’s air charge will need to be increased to
match ll pressure. Consult manufacturer’s guidelines
for sizing and selection.
14. Purging the heating system of air and gases when
rst putting boiler into service is critical for proper
circulation and quiet performance. Once air and gases
are purged, for boiler installations using oat type
vents, air vents should be closed for normal operation.
If air is heard or noticed by loss of heat, purge system
and open vents for short period of time.
SAFE INSTALLATION AND OPERATION
NOTICE
This boiler has been designed for residential
installations. If used for commercial applications,
all jurisdictional requirements shall be met. This
may require wiring and/or piping modications.
Manufacturer is not responsible for any changes to
the original design.
WARNING
Combustion chamber insulation in this product
contains ceramic ber material. Ceramic bers can
be converted to cristobalite in very high temperature
applications. The International Agency for Research
on Cancer (IARC) has concluded, Crystalline silica
inhaled in the form of quartz or cristobalite from
occupational sources is carcinogenic to humans
(Group1). Avoid breathing dust and contact
with skin and eyes. Use NIOSH certied dust
respirator (N95). This type of respirator is based
on the OSHA requirements for cristobalite at the
time this document was written. Other types of
respirators may be needed depending on the job
site conditions. Current NIOSH recommendations
can be found on the NIOSH website https://
www.cdc.gov/niosh/topics/silica/. approved
respirators, manufacturers, and phone numbers are
also listed on this website. Wear long-sleeved, loose
tting clothing, gloves, and eye protection. Apply
enough water to the combustion chamber lining to
prevent dust. Wash potentially contaminated clothes
separately from other clothing. Rinse clothes washer
thoroughly.
NIOSH stated First Aid. Eye: Irrigate immediately.
Breathing: Fresh air.
!
WARNING
Fire, Explosion, burn, scald hazard. Use only number
2 fuel oil. Do not use gasoline, kerosene, crankcase
oil or any oil containing gasoline. Failure to follow
these instructions could result in death or serious
injury.
!

6PN 240013016, Rev. B [12/31/2020]
Complete Prior To Installing Boiler.
A. Verify you have selected the right size boiler with
proper capacity. AHRI rating of boiler selected
should be greater than or equal to calculated peak
heating load (heat loss) for building or area(s)
served by boiler and associated hot water heating
systems. See boiler rating and capacity table
previously listed in this manual. Any heat loss
calculations used should be based on approved
methods.
B. Boiler must be supplied with proper oil supply
and oil piping, sucient fresh combustion air, and
suitable electrical supply.
C. Boiler must be connected to suitable venting system
and piping system adequate to distribute heating
load.
D. Properly locate and install thermostat for heating
system control.
Any doubts as to requirements, check with local authorities
and obtain professional help where needed. OPERATING
INSTRUCTIONS, FINAL CHECKS AND ADJUSTMENTS, and
MAINTENANCE sections in this manual are vital to the
proper and safe operation of the heating system.
1. Place boiler in location centralized with the piping system
and as close to chimney as possible.
2. Boiler must be level. If necessary use metal shims
beneath boiler’s feet.
3. Use raised base if oor can become wet or damp.
4. Maintain clearances for re safety as well as servicing.
18” clearance must be maintained at side where
passage is required for access to another side for
cleaning, servicing, inspection or replacement of any
parts that may normally require attention. Install
boilers at least 6” from combustible material on left
side, rear, and above, and at least 24” on right side
and front. Allow at least 24” accessibility clearance
above for servicing.
5. Fresh air for combustion must be available at front of
the boiler. Fresh air for ventilation must be available to
front and rear of boiler. Air passages must be free of
obstructions at all times. Ventilating and combustion air
must enter boiler room without restrictions.
WARNING
Fire hazard. Do not install boiler directly on
combustible ooring or carpeting. Failure to follow
these instructions could result in death or serious
injury.
!
6. FOR INSTALLATION ON NON-COMBUSTIBLE
FLOORS ONLY. Floor supporting boiler shall be
noncombustible and stable. Boiler is permitted to
be placed over combustible oor provided the oor
is protected in accordance with the requirements of
accepted building code practice and approved by the
Authority Having Jurisdiction . In absence of local
codes, follow NFPA-31 Standard for the Installation of
Oil-Burning Equipment.
7. Install boiler in accordance with requirements of
authority having jurisdiction, or in the absence of such
requirements: United States. NFPA31: Installation of
Oil Burning Equipment.
BOILER CLEARANCES
Unit Combustible
Clearance
Accessibility,
Cleaning, and
Servicing
Flue to
Combustible
Clearance
Top 6” 24”
9”
Left Side 6” 6”
Right Side 24” 24”
Base non-combustible non-combustible
Front 24” 24”
Back 6” 6”
All distances measured from the cabinet of the boiler.
24” Min.
6”
Min.
6”
Min.
24” Min.
Front
(Burner
Side)
LOCATING THE BOILER
Figure 2 - Clearances
MINIMUM CLEARANCE DIMENSIONS

7PN 240013016, Rev. B [12/31/2020]
OIL TANK
C H I M N E Y
ELECTRIC LINE
VENT
PIPE
DRAFT
REGULATOR
DIAPHRAGM EXPANSION TANK
AUTOMATIC
FILL VALVE
AND SHUTOFF
RELIEF VALVE
TO RADIATION
FROM RADIATION
CIRCULATING
PUMP IN RETURN LINE
OR AFTER THE
EXPANSION
TANK
SHUT OFF
VALVE
OIL FILTER
OIL LINES
FOUNDATIONS
TO OUTSIDE
LINES TO OTHER APPLIANCES
SERVICE LINE
OVERCURRENT
PROTECTED
SAFETY SWITCH
2" FILL
PIPE
MIN. 2" I.D.
VENT PIPE
ENTRANCE SWITCH
OIL BURNER
GENERAL PRINCIPAL REQUIREMENTS FOR A TYPICAL INSTALLATION
LOCATING THE BOILER
Figure 3 - Boiler With Piping System
ALWAYS KEEP MANUAL FUEL SUPPLY VALVE SHUT OFF IF
BURNER IS SHUT DOWN FOR EXTENDED PERIOD OF TIME.

8PN 240013016, Rev. B [12/31/2020]
Provide adequate supply of combustion air in accordance
with requirements of authority having jurisdiction. In
absence of such requirements: United States. NFPA 31:
Standard for Installation of Oil Burning Equipment (latest
edition).
EXAMPLE 1: Boiler Located in Unconned Space
If your boiler is in an open area (un-partitioned basement)
in conventional house, air that leaks through cracks around
doors and windows will usually be adequate to provide air
for combustion. Doors should not t tightly. Do not caulk
cracks around windows.
An unconned space is dened as space whose volume is
not less than 50 cubic feet per 1,000 Btu per hour of total
input rating of all appliances installed in that space.
EXAMPLE 2: Boiler Located in Conned Space
A. All Air from Inside the Building: Conned space shall
be provided with two permanent openings communicating
directly with additional room(s) of sucient volume so
the combined volume of all spaces meets the criteria for
unconned space. Total input of all combustion equipment
installed in combined space shall be considered in making
this determination. Each opening shall have minimum free
area of one square inch per 1,000 Btu per hour of total
input rating of all combustion equipment in the conned
space, but not less than 100 square inches. One opening
shall be within 12 inches of top and one within 12 inches of
bottom of the enclosure.
Example: Your boiler is rated at 100,000 Btu per hour.
Water heater is rated at 30,000 Btu per hour. Total is
130,000 Btu per hour. You need two grilles, each with 130
square inches of FREE opening. Metal grilles have about
60% FREE opening. To nd louvered area needed, multiply
free opening required by 1.7 (130 x 1.7 = 221.0 sq. in.
louvered area). In this example, two grilles each having 8”
x 30” (240 sq. in.) louvered area would be used.
FRESH AIR FOR COMBUSTION
WARNING
Asphyxiation, re hazard. Do not obstruct air
openings to combustion area. Follow instructions
below, to maintain adequate combustion air.
!
NOTICE
Install outside air intake if you use replace or
kitchen or bathroom exhaust fan. These devices rob
boiler and water heater of combustion air.
Figure 4 - Air Openings For Boiler Located In
Conned Space (Utility Room)

9PN 240013016, Rev. B [12/31/2020]
B. All Air from Outdoors: Conned space shall be
provided with two permanent openings, one commencing
within 12 inches of top and commencing within 12 inches of
bottom of enclosure. Openings shall communicate directly,
or by ducts, with outdoors or spaces (crawl or attic) that
freely communicate with outdoors.
1. When directly communicating with outdoors, each
opening shall have minimum free area of one square
inch per 4,000 Btu per hour of total input rating of
all equipment in the enclosure.
2. When communicating with outdoors through vertical
ducts, each opening shall have minimum free area
of one square inch per 4,000 Btu per hour of total
input rating of all equipment in the enclosure.
3. When communicating with outdoors through
horizontal ducts, each opening shall have minimum
free area of one square inch per 2,000 Btu per
hour of total input rating of all equipment in the
enclosure.
4. When ducts are used, they shall be of same cross
sectional area as free area of openings to which they
connect. Minimum dimension of rectangular air ducts
shall be not less than three inches.
FRESH AIR DUCT CAPACITIES
THROUGH LOUVERS
Fresh Air
Duct Size
¼” Mesh
Screen
Wood
Louvers
Metal
Louvers
(Btuh)* (Btuh)* (Btuh)*
3 ½” x 12” 144,000 36,000 108,000
8” x 8” 256,000 64,000 192,000
8” x 12” 384,000 96,000 288,000
8” x 16” 512,000 128,000 384,000
*Btuh = British Thermal Units per hour based on
opening covered by ¼” mesh screen , wood louvers,
or metal louvers.
FRESH AIR FOR COMBUSTION
Figure 5 - Fresh Air Duct Capacities For Ducts Supplying Fresh Air To Boiler In
Tightly Constructed Houses

10 PN 240013016, Rev. B [12/31/2020]
1. Installation of boiler for new heating system,
Install all of radiation units (panels, radiators,
baseboard, or tubing) and supply and return mains
rst. After all heating system piping and components
have been installed, make nal connection of system
piping to boiler. It is recommended to mount circulating
pump on supply side piping, such that it pumps away
from expansion tank. Refer to gures on next pages.
2. Equip hot water boiler installed above radiation
level with low water cut o device. Periodic inspection
is necessary, as is ushing of oat type devices, per
low water cut o manufacturer’s specic instructions.
3. Packaged boiler is set up with 1¼” NPT supply
and return piping from front of boiler. Boiler supply
and return piping can be moved to rear of boiler. Boiler
should not be piped return line to front, supply line
to rear, or vice versa, will cause boiler water to short
circuit heat exchanger. Piping connections may require
additional ttings and parts.
4. Install drain valve provided with boiler in return tee.
5. Install Safety Relief valve in rear section using
¾” nipple and street elbow provided with boiler.
See Figures 6a and 6b.
A. Install safety relief valve with spindle in vertical
position.
B. Do not install shuto valve between boiler and
safety relief valve.
C. Install discharge piping from safety relief valve.
• Use ¾” or larger pipe.
• Use pipe suitable for temperatures of 375°F
(191°C) or greater.
• Individual boiler discharge piping shall be
independent of other discharge piping.
• Size and arrange discharge piping to avoid
reducing safety relief valve relieving capacity
below minimum relief valve capacity stated on
rating plate.
• Run pipe as short and straight as possible to
location protecting user from scalding and properly
drain piping.
• Install union, if used, close to safety relief valve
outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
• Terminate pipe with plain end (not threaded).
6. Verify clean cold water supply is available when
connecting to pressure reducing valve. When water
supply is from well or pump, a sand strainer should be
installed at the pump.
SYSTEM PIPING
Figure 6a - Safety Relief Valve Installation
Follow Instructions to
install discharge piping
from safety relief valve
to drain.
Check local
codes for
maximum
distance
from oor
or allowable
safe point of
discharge.
SAFETY RELIEF VALVE
DISCHARGE
LINE
Figure 6b - Discharge Piping From Safety Relief
Valve

11 PN 240013016, Rev. B [12/31/2020]
> LOW DESIGN WATER TEMPERATURE
SYSTEMS
> LARGE WATER CONTENT SYSTEMS
> PIPING ARRANGED FOR “POWER
PURGING” AIR OUT OF THE SYSTEM
PIPING, REFER TO THIS MANUAL’S
SECTION ON “FILLING THE SYSTEM
WITH WATER” OPTION #1
SYSTEM PIPING
Figure 7 - Bypass Piping Arrangement
Diagram
Low Design Water Temperature Systems
(Below 140° F) And Large Water Content Systems
• Signicant condensation may form in this boiler and/
or venting system if boiler is operated with return
temperatures of less than 120°F.
• Condensation is corrosive and can eventually cause
damage to boiler and venting system. Minimum design
return water temperature to prevent this condensation in
boiler and venting is 120°F.
• Boiler used in heating system where design water
temperatures below 140°F are desired (e.g. radiant oor
heating), a 3-way or 4-way mixing valve or suitable
alternative (e.g. Bypass Piping Arrangement shown in
Figure 7) is required to prevent low temperature (below
return 120°F) return water from entering boiler. When
using mixing valve, follow manufacturer’s installation
instructions.
• Boiler connected to system having large water content
(such as former gravity system), use of Bypass Piping
Arrangement shown in diagram on following page is
suggested.

12 PN 240013016, Rev. B [12/31/2020]
SYSTEM PIPING
> CIRCULATOR ON SUPPLY PIPING PUMPS
AWAY FROM EXPANSION TANK
NOTE: CIRCULATOR MAY ALSO BE
INSTALLED ON RETURN PIPING.
>PIPING ARRANGED FOR “POWER PURGING”
AIR OUT OF SYSTEM PIPING, REFER TO
THIS MANUAL’S SECTION ON “FILLING THE
SYSTEM WITH WATER” OPTION #1
Figure 8 - System Piping Arrangement Zoning With Zone Valves

13 PN 240013016, Rev. B [12/31/2020]
> CIRCULATOR ON SUPPLY PIPING PUMPS AWAY
FROM EXPANSION TANK
> PIPING ARRANGED FOR “POWER PURGING”
AIR OUT OF SYSTEM PIPING, REFER TO THIS
MANUAL’S SECTION ON “FILLING THE SYSTEM
WITH WATER” OPTION #1
SYSTEM PIPING
Figure 9 - System Piping Arrangement Zoning With Circulators

14 PN 240013016, Rev. B [12/31/2020]
> DIAPHRAGM EXPANSION TANK MOUNTED
OFF THE BOILER
> CIRCULATOR ON SUPPLY PIPING PUMPS
AWAY FROM EXPANSION TANK
> PER THIS MANUAL, USE OPTION #2 IN
“FILLING THE SYSTEM WITH WATER”
> THIS PIPING ARRANGEMENT CAN BE USED
WITH ZONE VALVES OR ZONE CIRCULATORS
SYSTEM PIPING
Figure 10 - System Piping Arrangement Alternate Near Boiler Piping

15 PN 240013016, Rev. B [12/31/2020]
Boiler
Model
Burner
Input
Rate (gph)
Input
(MBH)
Tankless
Rating
(gpm)‡
OWB86-3 0.80 12 3.05
OWB86-4D 1.00 140 3.25
OWB86-4 1.25 175 3.50
OWB86-5 1.55 217 3.80
‡ Gallons of water per minute heated from 40°F to 140°F with
200°F boiler water temperature, intermittent draw
SYSTEM PIPING
Boilers may be factory packaged with tankless heater
coil see gure below. Coil provides instantaneous heating
of 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 continuous
ow.
NOTICE
Do not use tankless coil if your water is excessively
hard with lime or other deposits which will
accumulate inside the coil.
When using tankless coil, boiler is congured so Honeywell
L7248 operates with Honeywell L4006 low limit mounted on
well installed in tankless heater.
Tempering valve (mixing valve) is required as shown below.
Flow restrictor may be required on tankless coil inlet piping
so that ow rates are matched to boiler heat input (see
table).
Tankless Coil Piping Arrangement
Figure 11 -Tankless Coil Piping Arrangement
DANGER
Scald, Burn Hazard! Temperatures exceeding 120°F
will cause severe burns or death. Use of water
tempering device or mixing valve may be required
by the Authority having jurisdiction, follow all codes
as required before leaving installation.
!

16 PN 240013016, Rev. B [12/31/2020]
Antifreeze added to boilers must be nontoxic, and
must be of type specically 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% 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.
BOILER WATER VOLUMES
Number of
Boiler Section
Total Volume
(Gallons)
3 9.6
4 11.6
5 13.7
PIPING WATER VOLUMES
PIPE SIZE COPPER PIPE
FACTOR
STEEL PIPE
FACTOR
½” 82.5 63.5
¾” 40.0 36.0
1” 23.3 22.2
1 ¼” 15.3 12.8
1 ½” 10.8 9.5
2” 6.2 5.8
Divide total length of piping in feet by appropriate factor
in table to determine volume in gallons.
ANTIFREEZE IN THE SYSTEM
RECOMMENDED MINIMUM CHIMNEY SIZES
FIRING RATE
(gph)
CHIMNEY
HEIGHT (ft)
NOMINAL
CHIMNEY
ROUND
LINER INSIDE
SQUARE
LINER INSIDE
0.60 1.30 15 8” x 8” 6” 6 ¾” x 6 ¾”
1.31 1.80 15 8” x 8” 7” 6 ¾” x 6 ¾”
For elevations above 2,000 feet above sea level, add 3 feet to the chimney heights.
CHIMNEY AND CHIMNEY CONNECTIONS
For oil red boilers for connections to vents or chimneys,
vent installations shall be in accordance with requirements
of authority having jurisdiction, or in the absence of such
requirements: United States. NFPA 31: Standard for the
Installation of Oil Burning Equipment (latest edition).
NOTICE
Fresh air (ventilation) is important to proper
venting. Ventilation and venting are two parts of the
same system. Inadequate ventilation will result in
inadequate venting. Always be sure to have enough
ventilation to support proper venting.
Inspect chimney. Verify construction in accordance with
requirements of authority having jurisdiction, or in the
absence of such requirements: United State ANSI/NFPA
211: National Standard for Chimneys, Fireplaces, Vents and
Solid Fuel Burning Appliances.
Sidewall Venting With Listed Power Venter
— This boiler is not approved for direct sidewall horizontal venting.
—In the U.S. : Per section E.11 of NFPA 31-2020 Standard for the Installation of Oil Burning Equipment, a listed
power venter providing mechanical draft may be used when approved by the Authority having jurisdiction. Select
the listed power venter to match the BTU per hour input of the boiler being vented. Follow all manufacturer’s
installation and operating instructions for venting and termination included with the power venter.

17 PN 240013016, Rev. B [12/31/2020]
Chimney Connector And Draft Regulator
• Venting the boiler requires 6” diameter chimney
connector pipe and use of manufacturer provided draft
regulator.
• Regulator, when properly installed, automatically
controls the draft.
• Install in horizontal section of pipe, may also be
installed in angled or vertical section of pipe.
• Verify “top” of regulator is at the top and short pipe
section which holds the vane is horizontal.
WARNING
Fire Hazard. Maintain minimum vent pipe clearance
of 9” from surface of vent to wood and other
combustible materials. Failure to comply may result
in death or serious injury.
!
CHIMNEY AND CHIMNEY CONNECTIONS
• Even though locating draft regulator close to chimney
reduces noise, install draft regulator as close as
practicable to the boiler.
• Install chimney connector, start at boiler with vertical
pipe, elbow, then install draft regulator horizontally.
• When regulator is in place, start at chimney and work
back to the regulator.
• Join the two sections with draw-band.
• Horizontal pipe must slope up toward the chimney at
least 1/4 inch per linear foot of venting.
• Chimney connector must not leak and must be rmly
supported.
• Join each section with at least two sheet metal screws.
Support every second section with a stovepipe wire.
Figure 12 -
Typical Chimney Connection
ALTERNATE POSITIONS
TOP
TOP
DRAFT REGULATOR
VANE
CRIMPED END
BALANCED WEIGHT
DRAWBAND
LAST PIECE
INSTALLED
MUST SLOPE UP
AT LEAST 1/4 INCH
PER FOOT OF
HORIZONTAL RUN
MUST BE AT LEAST 4
INCHES THICK -
AND BE TIGHT.
TIGHT
CLEAN-OUT
DOOR
SEALED IN
THIMBLE
TIGHT, SMOOTH,
CORRECTLY SIZED.
Minimum Height:
Must be 3 FT higher than
highest part of passage through roof.
Must be at least 2 FT higher than
any neighboring object within 10 FT.
Must have unobstructed top opening
.
TYPICAL CHIMNEY CONNECTION

18 PN 240013016, Rev. B [12/31/2020]
ELECTRICAL CONNECTIONS
THERMOSTAT
Install 24 Volt thermostat (not provided) in proper location.
Location of thermostat has eect on boiler system operation.
Follow instructions included with thermostat.
GROUNDING
Permanently ground boiler according to local codes and
latest revision of the National Electrical Code. Run 14
gauge or heavier copper wire from boiler to grounded
connection in service panel or properly driven and
electrically grounded ground rod.
ELECTRIC POWER SUPPLY
Connect boiler to electrical supply in accordance with
requirements of authority having jurisdiction, or in the
absence of such requirements: United States. NFPA70:
National Electrical Code.
Connect 120 volt electrical supply to L1 and L2 terminals
on limit and two thermostat wires to T and T terminals on
same limit. Run separate circuit from separate over current
protection device in your electrical service entrance panel.
Minimum 15 ampere circuit. Locate shuto switch at boiler.
Turn o during any maintenance.
OIL BURNER WIRING
For boilers packaged with oil burners, burners are factory
wired.
WARNING
Electrical shock hazard. Turn OFF electrical power supply
at service panel before making electrical connections.
Failure to do so could result in death or serious injury.
!
Figure 13 - Honeywell L7248L Control with Beckett AFG Burner
*
*When Low Limit Is Used, Set ELL Parameter On L7248
Control To On. Boilers Factory Equipped With Tankless
Coil Are Factory Set To On.

19 PN 240013016, Rev. B [12/31/2020]
How A Hot Water System Operates
Entire heating system (boiler, piping, and radiation units)
is lled with water. As water in the boiler is heated, it
is circulated from top of boiler through supply main to
radiation units. Cooler water in radiation units ows back
through return piping through return main into the boiler.
This arrangement provides positive and rapid response to
the thermostat.
Filling The System With Water
OPTION #1 This method utilizes boiler piping as shown in
gures on page 7, 8 and 9.
A. Close main shuto valve, isolation valves, and zone
valves (if applicable). If bypass piping is installed,
also close two throttling valves. Leave boiler service
shuto valve (if installed) and balancing valves to
each heating zone fully open.
B. Open following valves in order: drain valve for power
purging, isolating valves before and after boiler
circulator (if applicable), both throttling valves (if
applicable), and then open ll line shuto valve. Water
will ll bypass piping and push air through piping and
out power purging drain valve. When power purging
drain valve runs air free, close bypass piping throttling
valve (leaving throttling valve to supply piping fully
open).
C. Next, open isolation valve (or zone valve) to rst
zone. Water will ll piping and push any air out power
purging drain valve. When power purging drain valve
runs air free, close isolation valve or zone valve).
Repeat this procedure for remaining heating zones.
D. Once all zones are lled with water and purged of air,
close power purging drain valve and ll line shut o
valve, open main shuto valve, and adjust throttling
valves and balancing valves as required.
OPTION #2
• Close air vents on all radiation units.
• Open valves to radiation units. Verify boiler drain
valve, expansion tank drain cock, and air bleed screw
on expansion tank drain tting are closed.
• Open ll valve on piping to expansion tank.
• Open water inlet to boiler and leave it open.
• Open air vent on lowest radiation unit.
• When all air has escaped and water starts to ow from
vent, close it.
• Go to next radiation unit, and repeat this process until
nishing with highest radiation unit.
• If heating system has automatic vents, this manual
venting is unnecessary but it will speed up proper lling
of the system.
If system is a closed expansion tank system, automatic ll
valve is needed. Leave automatic ll valve open to rell
system automatically as needed.
Note initial ll pressure on boiler’s temperature / pressure
gauge, which should be 10-15 psig. Any lowering of
pressure from its initial ll pressure indicates loss of
water due to leakage. Automatic ll valve should then
compensate for this water pressure loss. If it does not,
manually open this valve to rell system until needle is
again pointing to same pressure reading. Instructions are
packaged with valve.
FILLING THE BOILER

20 PN 240013016, Rev. B [12/31/2020]
Draft Regulators: Barometric draft regulator is required
for controlling draft through boiler. Mount barometric draft
regulator in chimney connector. Refer back to section on
“Chimney And Chimney Connections”. Once draft regulator
is installed, use draft gauge to adjust to proper opening:
A. Combustion chamber over re draft shall be -0.01”
WC to -0.02” WC.
B. Stack draft will be approximately -0.02” WC. to
-0.04” WC.
C. Larger installation, greater draft will be required in
stack to obtain desired over re draft.
Start: Fill entire system with water. Vent all air from
system following section for Filling The Boiler.
Fuel Units And Oil Lines:
• Install oil line(s) to oil burner.
• Recommend using heavy wall copper tubing and
ared ttings, not compression ttings.
• All connections and joints must be absolutely airtight.
Use an appropriate non-hardening thread sealing
compound on the threaded connections, not Teon
tape.
• See fuel unit data sheet furnished with the burner for
sizing, lift, and length of tubing recommendations.
Oil burner is equipped with single stage fuel unit
with bypass plug removed for single pipe installation.
Satisfactory where fuel supply is on same level as or
above burner permitting gravity ow of oil. Per NFPA 31
requirements, never exceed 3 psig pressure to inlet side of
fuel unit.
When necessary to lift oil to burner, two pipe installation
is required. Run return line between fuel unit and oil
supply. When two pipe installation is used, bypass plug
(furnished with burner) must be installed in fuel unit. Refer
to fuel unit instructions furnished with burner for specic
instructions on installing bypass plug. Do not exceed fuel
unit manufacturer’s recommendations for running vacuum.
NOTICE
If lift exceeds 14 feet for Beckett burners, two stage
fuel unit is required with return line.
Install oil lter of adequate size inside building between
tank shuto valve and oil burner. For ease of servicing,
locate shuto valve and lter near oil burner.
Air Supply For Combustion:
• Do not install boiler in rooms with insucient air, unless
corrective steps are taken.
• It may be necessary to install windows or cut holes in
a door to rooms used for supply air to obtain sucient
combustion air and prevent less than atmospheric air
pressure in that room.
• If there is a lack of combustion air, burner ame will be
dark orange and formation of soot will occur in heating
unit.
• In buildings of conventional frame, brick, or stone
construction that do not have utility rooms, basement
windows, or stair doors, air inltration is normally
adequate to provide enough air for combustion and for
operation of barometric draft control.
• Room used for supplying combustion air should be
isolated from any area served by exhaust fans.
• Refer back to the section on Fresh Air For Combustion
for additional sizing guidelines.
OPERATING THE BOILER
Nozzles And Electrodes:Use proper size, spray angle,
and spray pattern nozzle.
To install nozzle, remove nozzle line electrode assembly,
if necessary remove retention ring assembly, and install
and tighten nozzle. Take care not to damage electrode
insulators or bend electrode tips.
After installing nozzle, reassemble nozzle line electrode
assembly and set electrode tip spacing.
Depending on burner type, electrode tip spacing may
need to be set prior to reassembling nozzle line electrode
assembly.
Refer to following pages for setting electrode tip spacing.
Final Burner Adjustments: Final burner adjustments
must be made using combustion test instruments. Refer
to preliminary burner settings chart for initial startup. Set
burner accordingly.
• Check draft over re to verify it is between -0.01” WC
and -0.02” WC, adjust draft as necessary.
• After operating 10 minutes to warm up boiler, use
combustion test equipment to take smoke reading in
ue pipe between boiler and draft regulator.
• Smoke reading should be zero to trace (Shell Bacharach
Scale).
• A new boiler requires more than 10 minutes to burn
clean due to oil lm on new heat exchanger.
• If smoke reading is zero, gradually close burner’s air
adjustment to obtain smoke reading showing trace
smoke reading. Once smoke reading is trace, measure
CO2 and as insurance margin increase air to suciently
reduce CO2 by ½% to 1%.
If clean re cannot be obtained, it is necessary to verify
burner head and electrode alignment. Proper electrode
alignment gures are presented on following pages. If
re continues to be smoky, replace nozzle with correct
replacement.
Once burner is completely adjusted, burner should
be started and stopped several times to assure good
operation with no uttering or rumbling. Verify there
are no oil leaks and record nozzle size, oil pressure,
combustion readings, and air settings on tag or label
attached to burner or boiler.