U.S. Boiler Company LE Series Service manual

103626-04 - 3/18 Price - $5.00
INSTALLATION, OPERATING AND
SERVICE INSTRUCTIONS FOR
LE®SERIES
OIL - FIRED BOILER
For service or repairs to boiler, call your heating contractor. When seeking information on boiler,
provide Boiler MOdel Number and Serial Number as shown on Rating Label.
Boiler Model Number
LE
Boiler Serial Number Installation Date
Heating Contractor Phone Number
Address

2103626-04 - 3/18
IMPORTANT INFORMATION - READ CAREFULLY
All boilers must be installed in accordance with National, State and Local Plumbing, Heating
and Electrical Codes and the regulations of the serving utilities. These Codes and Regulations
may differ from this instruction manual. Authorities having jurisdiction should be consulted
before installations are made.
In all cases, reference should be made to the following Standards:
USA BOILERS
A. Current Edition of American National Standard ANSI/NFPA 31, “Installation of Oil
Burning Equipment”, for recommended Installation Practices.
B. Current Edition of American National Standard ANSI/NFPA 211, “Chimneys, Fireplaces,
Vents, and Solid Fuel Burning Appliances”, For Venting requirements.
C. Current Edition of American Society of Mechanical Engineers ASME CSD-1, “Controls and
Safety Devices for Automatically Fired Boilers”, for assembly and operations of controls
and safety devices.
D. All wiring on boilers installed in the USA shall be made in accordance with the National
Electrical Code and/or Local Regulations.
DANGER
Indicates an imminently hazardous situation
which, if not avoided, will result in death, serious
injury or substantial property damage.
CAUTION
Indicates a potentially hazardous situation which,
if not avoided, may result in moderate or minor
injury or property damage.
WARNING
Indicates a potentially hazardous situation which,
if not avoided, could result in death, serious injury
or substantial property damage.
NOTICE
Indicates special instructions on installation,
operation, or maintenance which are important
but not related to personal injury hazards.
The following terms are used throughout this manual to bring attention to the presence of
hazards of various risk levels, or to important information concerning product life.
NOTICE
This boiler has a limited warranty, a copy of which is included with this boiler.
The warranty for this boiler is valid only if the boiler has been installed, maintained and operated in
accordance with these instructions.

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103626-04 - 3/18
DANGER
DO NOT store or use gasoline or other ammable vapors or liquids in the vicinity of this or any other appliance.
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage,
personal injury or loss of life. Failure to follow all instructions in the proper order can cause personal
injury or death. Read and understand all instructions, including all those contained in component
manufacturers manuals which are provided with the boiler before installing, starting-up, operating,
maintaining or servicing this boiler. Keep this manual and literature in legible condition and posted
near boiler for reference by owner and service technician.
This boiler requires regular maintenance and service to operate safely. Follow the instructions
contained in this manual.
Installation, maintenance, and service must be performed only by an experienced, skilled and
knowledgeable installer or service agency.
All heating systems should be designed by competent contractors and only persons knowledgeable in
the layout and installation of hydronic heating systems should attempt installation of any boiler.
Installation is NOT complete unless a pressure relief valve is installed into the 3/4" tapping located on
top of Shell Assembly, see Figures 1A and 1B. Also see Water Piping and Trim Section of this manual
for additional details.
It is the responsibility of the installing contractor to see that all controls are correctly installed and
are operating properly when installation is complete including verifying that the limit sensor is fully
installed (seated in bottom of Well).
Failure to properly install Limit Sensor may result in property damage, personal injury or loss of life
due to elevated operating temperatures and/or pressures.
This boiler is suitable for installation on combustible ooring. DO NOT install boiler on carpeting.
DO NOT tamper with or alter the boiler or controls.
Retain your contractor or a competent serviceman to assure that the unit is properly adjusted and
maintained.
Have Firetubes cleaned at least once a year - preferably at the start of the heating season to remove
soot and scale. The inside of combustion chamber should also be cleaned and inspected at the same
time.
When cleaning this boiler, DO NOT damage combustion chamber. If damaged, combustion chamber
must be replaced immediately.
Oil Burner and Controls must be checked at least once a year or as may be necessitated.
DO NOT operate boiler with jumpered or absent controls or safety devices.
DO NOT operate boiler if any control, switch, component, or device has been subject to water.
Boiler materials of construction, products of combustion and the fuel contain alumina, silica, heavy
metals, carbon monoxide, nitrogen oxides, aldehydes and/or other toxic or harmful substances which
can cause death or serious injury and which are known to the state of California to cause cancer, birth
defects and other reproductive harm. Always use proper safety clothing, respirators and equipment
when servicing or working nearby the boiler.

4103626-04 - 3/18
WARNING
This boiler contains very hot water under 12 - 15 PSI pressure. DO NOT unscrew any pipe ttings nor
attempt to disconnect any components of this boiler without positively assuring the water is cool and
has no pressure. Always wear protective clothing and equipment when installing, starting up or servicing
this boiler to prevent scald injuries. DO NOT rely on the pressure and temperature gauges to determine
the temperature and pressure of the boiler. This boiler contains components which become very hot
when the boiler is operating. DO NOT touch any components unless they are cool.
High water temperatures increase the risk of scalding injury. If this boiler is equipped with a tankless
heater for domestic water supply, a ow regulator and automatic mixing valve must be installed properly
in tankless heater piping. See Water Piping and Trim Section of this manual for details.
This boiler needs fresh air for safe operation and must be installed so there are provisions for adequate
combustion and ventilation air.
This boiler must be connected to an approved chimney or vent system in good condition. Serious property
damage could result if the boiler is connected to a dirty or inadequate chimney or vent system. The
interior of the chimney ue must be inspected and cleaned before the start of the heating season for any
obstructions. A clean and unobstructed chimney ue is necessary to allow noxious fumes that could
cause injury or loss of life to vent safely and will contribute toward maintaining the boiler's efciency.
DO NOT operate boiler with the absence of an approved vent system.
This boiler is supplied with controls which may cause the boiler to shut down and not re-start without
service. If damage due to frozen pipes is a possibility, the heating system should not be left unattended
in cold weather; or appropriate safeguards and alarms should be installed on the heating system to
prevent damage if the boiler is inoperative.
This boiler is designed to burn No. 2 fuel oil only. DO NOT use gasoline, crankcase drainings, or any oil
containing gasoline. Never burn garbage or paper in this boiler. DO NOT convert to any solid fuel (i.e.
wood, coal). DO NOT convert to any gaseous fuel (i.e. natural gas, LP). All ammable debris, rags, paper,
wood scraps, etc., should be kept clear of the boiler at all times. Keep the boiler area clean and free of
re hazards.
TABLE OF CONTENTS
I. General Information............................................................. 5
II. Pre-Installation ................................................................... 8
III. Packaged Boiler Assembly - Trim and Controls.................. 10
IV. Water Piping and Trim......................................................... 13
V. Venting................................................................................. 17
VI. Electrical............................................................................... 19
VII. Oil Piping............................................................................. 23
VIII. System Start-Up................................................................... 25
IX. Operating............................................................................. 33
X. Maintenance and Service Instructions................................. 37
XI. Boiler Cleaning..................................................................... 39
XII. Troubleshooting..................................................................... 42
XIII. Repair Parts ....................................................................... 45
Appendix A - Low Water Cut Off..................................................... 53
Appendix B - Figures...................................................................... 55
Appendix C - Tables........................................................................ 57

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103626-04 - 3/18
I. GENERAL INFORMATION
Figure 1A: LE®Packaged Water Boiler with Beckett AFG Burner

6103626-04 - 3/18
I. GENERAL INFORMATION (continued)
Figure 1B: LE®Packaged Water Boiler with Riello 40F Burner

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103626-04 - 3/18
I. GENERAL INFORMATION (continued)
Boiler Model
Burner Capacity DOE
Heating
Capacity -
MBH
(2)
AHRI NET
Ratings -
MBH
(3)
AFUE %
GPH MBH
(1)
LE1L 0.60 84 74 64 86.7
TABLE 1: RATING DATA
TABLE 2: GENERAL INFORMATION
Boiler Model Water Capacity
(Gallons)
Approximate Shipping
Weight (LBS)
Minimum Chimney Requirements
Round In. Dia. Rectangle In. x In Height
Ft.
LE1L 6.1 325 6 8 x 8 15
Notes:
1. MBH refers to thousands of BTU per hour.
2. Based on Standard Test prescribed by the United States Department of Energy at combustion condition of 13.5%
CO2.
3. Net AHRI ratings based on a piping and pickup allowance of 1.15.

8103626-04 - 3/18
Figure 2: Minimum Installation Clearances To Combustible Materials
II. PRE-INSTALLATION
2. Boiler is suitable for installation on combustible
oor. DO NOT install boiler on carpeting.
3. For basement installation, provide a solid elevated
base, such as concrete, if oor is not level, or if
water may be encountered on oor around boiler.
4. Provide service clearance of at least 24” clearance
from front jacket panel for servicing burner and
annual cleaning.
5. For minimum clearances to combustible materials.
See Figure 2.
NOTICE
Clearance to venting is for single wall vent
pipe. If Type L vent is used, clearance may be
reduced to the minimum required by the vent pipe
manufacturer.
C
A
Above
B
Front
Chimney
Connector
D
Rear
E
Sides
N/A 24 18 6 6
N/A: Not applicable, radial chimney connector clearance eliminates any
possibility of combustible material above boiler.
NOTE 1: Listed clearances comply with American National
Standard NFPA 31, Standard for the Installation of Oil Burning
Equipment.
NOTE 2: LE® Series boilers can be installed in rooms with
clearances from combustible material as listed above. Listed
clearances cannot be reduced for alcove or closet installations.
NOTE 3: For reduced clearances to combustible material,
protection must be provided as described in the ANSI/NFPA 31
standard.
A. INSPECT SHIPMENT carefully for any signs of
damage.
1. All equipment is carefully manufactured, inspected
and packed. Our responsibility ceases upon delivery
of crated boiler to the carrier in good condition.
2. Any claims for damage or shortage in shipment
must be led immediately against the carrier by the
consignee. No claims for variances from, or
shortage in orders, will be allowed by the manufac-
turer unless presented within sixty (60) days after
receipt of goods.
B. LOCATE BOILER near nal position before removing
crate, see Figures 1A and 1B. Using hand truck or pipe
rollers under skid, move boiler into position along side
installation site.
1. Locate so that vent pipe connection to chimney will
be short and direct.

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103626-04 - 3/18
II. PRE-INSTALLATION (continued)
C. REMOVE CRATE
1. Remove all fasteners at crate skid.
2. Lift outside container and remove all other inside
protective spacers and bracing. Remove parts bags
and Circulator Flange Kit from inside ue collar.
Parts bag contains Safety Relief Valve and Boiler
Drain Valve.
D. REMOVAL OF BOILER FROM SKID
1. Tilt boiler, "walk" boiler backward, and set rear legs
down on oor. Tilt boiler backward, pull skid
forward and set front legs down on edge of skid.
Install close nipple, tee, and plug in return coupling
located between the legs on bottom of boiler shell.
See Figures 1A and 1B and Figures 8A and 8B.
Point tee toward permanent return location.
Figure 3: Legs Secured to Skid
2. Tilt boiler backward and remove skid. Be careful not
to damage Burner and Jacket.
E. PROVIDE COMBUSTION AND VENTILATION
AIR. Local code provisions may apply and should be
referenced.
WARNING
Adequate combustion and ventilation air must
be provided to assure proper combustion and
to maintain safe ambient air temperatures.
DO NOT install boiler where gasoline or other
ammable vapors or liquids, or sources of
hydrocarbons (i.e. bleaches, fabric softeners,
etc.) are used or stored.
1. Determine volume of space (boiler room). Rooms
communicating directly with the space in which the
appliances are installed, through openings not
furnished with doors, are considered a part of the
space.
Volume(ft3) = Length(ft) x Width(ft) x Height(ft)
2. Determine total input of all appliances in the space.
Add inputs of all appliances in the space and round
the result to the nearest 1000 BTU per hour.
3. Determine type of space. Divide Volume by total input
of all appliances in space. If the result is greater than
or equal to 50 ft3/1000 BTU per hour, then it is
considered an unconned space. If the result is less
than 50 ft3/1000 BTU per hour then the space is
considered a conned space.
4. For boiler located in an unconned space of a conven-
tionally constructed building, the fresh air inltration
through cracks around windows and doors normally
provides adequate air for combustion and ventilation.
5. For boiler located in a conned space or an unconned
space in a building of unusually tight construction,
provide outdoor air with the use of two permanent
openings which communicate directly or by duct with
the outdoors or spaces (crawl or attic) freely
communicating with the outdoors. Locate one opening
within 12 inches of top of space. Locate remaining
opening within 12 inches of bottom of space. Minimum
dimension of air opening is 3 inches. Size each opening
per following:
a. Direct communication with outdoors. Minimum
free area of 1 square inch per 4,000 BTU per hour
input of all equipment in space.
b. Vertical ducts. Minimum free area of 1 square inch
per 4,000 BTU per hour input of all equipment in
space. Duct cross-sectional area shall be same as
opening free area.
c. Horizontal ducts. Minimum free area of 1 square
inch per 2,000 BTU per hour input of all equipment
in space. Duct cross-sectional area shall be same
as opening free area.
Alternate method for boiler located within conned
space. Use indoor air if two permanent openings
communicate directly with additional space(s) of
sufcient volume such that combined volume of
all spaces meet criteria for unconned space. Size
each opening for minimum free area of 1 square
inch per 1,000 BTU per hour input of all equipment
in spaces, but not less than 100 square inches.
6. Louvers and Grilles of Ventilation Ducts
a. All outside openings should be screened and
louvered. Screens used should not be smaller
than 1/4 inch mesh. Louvers will prevent the
entrance of rain and snow.
b. Free area requirements need to consider the
blocking effect of louvers, grilles, or screens
protecting the openings. If the free area of the
louver or grille is not known, assume wood
louvers have 20-25 percent free area and metal
louvers and grilles have 60-75 percent free area.
c. Louvers and grilles must be xed in the open
position, or interlocked with the equipment to
open automatically during equipment operation.

10 103626-04 - 3/18
III. PACKAGED BOILER ASSEMBLY - TRIM AND CONTROLS
Figure 4: Hinge Installation & Assembly, LE Boiler
A. CHANGE HINGE POSITION
1. Look at the area where boiler will be installed. If
left side of boiler will be less than 12 inches from a
wall, move hinges to right side of boiler to change
door rotation. Proceed to Steps 2 through 9 below.
If not necessary, proceed to Paragraph B.
2. Separate (2) halves of burner swing door interlock
harness at connector.
3. Remove 8 sheet metal screws from jacket. Remove
rear jacket box and bend both sides of Jacket
Wrapper up, see Figure 28.
4. Remove (2) 5/16" - 18 x 3" long hex head cap
screws and atwashers from right side of door.
Remove (2) hairpin cotter pins and (2) hinge pins
from hinges on left side of door and remove Door
Assembly from boiler. Inspect Front and Rear Door
Insulation Pieces and Combustion Chamber Liner,
see Paragraph C.
5. Remove (4) 5/16" - 18 x 1" long hex head cap
screws and hex nuts that attach hinges and hinge
spacers to left side of Tubesheet. Remove (4) 5/16"
- 18 x 1/2" hex head cap screws that attach hinges to
door.
6. Attach (2) hinge brackets & spacers to Tubesheet
and (2) hinge brackets to Door on right side of
boiler. (3) Holes in each Hinge Bracket must line up
with (3) matching holes in Spacer, Tubesheet or
Door. See Figure 4. Tighten all hex nuts and cap
screws by hand only.
7. Replace door assembly. Hinge brackets attached to
door must rest on top of hinge brackets attached to
Tubesheet. See Figure 4. Slide hinge pins through
hinges from top and install cotter pins. Close door
and install 5/16" - 18 x 3" long hex head cap screws
through atwashers and left side of door and into
tapped holes in tubesheet. Tighten all hex nuts and
cap screws. When door is installed properly, it is
parallel to Tubesheet when viewed from top and
sides.
8. Bend sides of Jacket Wrapper down and attach (2)
Jacket Straps to (4) slots at bottom of Jacket
Wrapper sides with sheet metal screws. Install Rear
Jacket Box with (4) sheet metal screws. See Figure
28.
9. Reconnect Swing Door Interlock.
B. INSPECT FRONT AND REAR DOOR INSULATION
PIECES, COMBUSTION CHAMBER LINER AND
ROPE GASKETS.
1. OPEN SWING DOOR on front of boiler. Use
ashlight to inspect insulation pieces secured to
front and rear doors. Inspect Ceramic Fiber Blanket
secured to bottom of combustion chamber with
water glass adhesive. Replace any damaged pieces
immediately.
2. Inspect berglass rope located on the swing door.
The rope must be evenly distributed around the
perimeter of the door groove and cannot bunch or
overhang. There must not be a gap where the two
ends of the rope meet. Repair or replace if the rope
is damaged or if there is a gap between the ends.

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103626-04 - 3/18
C. INSTALL BOILER CONTROL, refer to Figure 5A or
5B.
1. Beckett AFG Burner:
Step a. Cut the wire tie securing the L7248L Boiler
Control/Harness Assembly to ue collar. Loosen
mounting clamp screw on front of L7248L
Control. Mount Control on factory installed
immersion well located in center tapping on top
of boiler with burner harness on the right hand
side as shown in Figure 5A.
Step b. Locate (2) 5/8" cable clamps and (1) #8 x
1/2" sheet metal screw (SMS) in parts bag.
Secure burner wiring harness to jacket right side
panel with (2) cable clamps, (1) at mid point
with SMS provided and (1) at the lower front
corner with existing jacket screw as shown in
Figure 5A.
Step c. Locate the aquastat sensor inside L7248
Boiler Control. Carefully connect sensor into the
L7248 Boiler Control circuit board by pressing
connector on sensor unit into mating connector
on circuit board (refer to Figure 24). Insert
sensor through hole in circuit board above
terminals marked "ZR" and "L1", see Figure 24,
and into immersion well until it rests against the
bottom of the well as shown in Figure 6.
Figure 5A: Relief Valve and Boiler Control
Assembly Details - Beckett AFG Burner
III. PACKAGED BOILER ASSEMBLY - TRIM AND CONTROLS (continued)
2. Riello 40F Burner:
Step a. Locate the L7248L Boiler Control/
Transformer - Relay Control Center/Harness
Assembly in the carton secured to shipping skid.
Loosen mounting clamp screw on front of
L7248L Control. Mount Control on factory
installed immersion well located in center
tapping on top of boiler with L7248L Boiler
Control/Transformer - Relay Control Center/
Harness Assembly on the left hand side as shown
in Figure 5B.
Step b. Remove Transformer - Relay Cover from
Junction Box. Locate (2) #8 x 1/2" sheet metal
screws (SMS) and (1) 5/8" cable clamp in parts
bag. Use #8 x 1/2" SMS to secure Junction Box
to pre-punched holes in top panel. Replace
Transformer - Relay cover. See Figure 5B.
Step c. Locate burner swing door disconnect
harness wrapped around burner air tube. Un-
ravel harness and route to transformer/relay
terminals and show in Figures 1B and 5B.
Connect forked convectors to terminals "R" and
"G" on top of transformer as shown in Figure
15B.
Step d. Remove burner cover. Secure burner
harness to knockout located in lower right corner
on burner cover back plate.
Step e. Attach wires from burner harness to
terminals on Primary Control per Figure 12.
Step f. Secure burner harness to burner back plate
with 5/8" cable clamp and existing top screw in
back plate. DO NOT tighten top screw fully
until cover is replaced.
Step g. Replace burner cover and tighten (3)
retainer screws.
Step h. Locate the aquastat sensor inside L7248
Boiler Control. Carefully connect sensor into the
L7248 Boiler Control circuit board by pressing
connector on sensor unit into mating connector
on circuit board (refer to Figure 24). Insert
sensor through hole in circuit board above
terminals marked "ZR" and "L1", see Figure 24,
and into immersion well until it rests against the
bottom of the well as shown in Figure 6.

12 103626-04 - 3/18
Figure 5B: Relief Valve and Boiler Control Assembly Details - Riello 40F Burner
Figure 6: Limit Sensor Insertion
III. PACKAGED BOILER ASSEMBLY - TRIM AND CONTROLS (continued)

13
103626-04 - 3/18
IV. WATER PIPING AND TRIM
WARNING
Failure to properly pipe boiler may result in improper operation and damage to boiler or structure.
Oxygen contamination of boiler water will cause corrosion of iron and steel boiler components, and
can lead to boiler failure. U.S. Boiler Company’s Warranty does not cover problems caused by oxygen
contamination of boiler water or scale (lime) build-up caused by frequent addition of water.
A. DESIGN A PIPING SYSTEM and install boiler
which will prevent oxygen contamination of boiler
water and frequent water additions.
1. There are many possible causes of oxygen contami-
nation such as:
a. Addition of excessive make-up water as a result
of system leaks.
b. Absorption through open tanks and ttings.
c. Oxygen permeable materials in the distribution
system.
2. In order to insure long product life, oxygen sources
should be eliminated. This can be accomplished by
taking the following measures:
a. Repairing system leaks to eliminate the need for
addition of make-up water.
b. Eliminating open tanks from the system.
c. Eliminating and/or repairing ttings which allow
oxygen absorption.
d. Use of non-permeable materials in the distribu-
tion system.
e. Isolating the boiler from the system water by
installing a heat exchanger.
3. Connect System supply and return piping to boiler.
See Figures 8A and 8B. Also, consult I=B=R,
"Residential Hydronic Heating Installation and
Design Guide". Maintain minimum ½ inch clear-
ance from hot water piping to combustible materials.
WARNING
System supply and return piping must be
connected to correct boiler pipe.
U.S. Boiler Company recommends sizing
the system circulator to supply sufficient
flow (GPM) to allow a 20°F temperature
differential in the system. When sizing the
system circulator, the pressure drop of all
radiators, baseboard and radiant tubing and
all connecting piping must be considered.
a. Use a system bypass if the boiler is to be
operated in a system which has a large volume or
excessive radiation where low boiler water
temperatures may be encountered (i.e. converted
gravity circulation system, etc.) The bypass
should be the same size as the supply and return
lines with valves located in the bypass and return
line as illustrated in Figures 8A and 8B in order
to regulate water ow for maintenance of higher
boiler water temperature.
Set the bypass and return valves to a half throttle
position to start. Operate boiler until the system
water temperature reaches its normal operating
range.
Adjust the valves to maintain 180°F to 200°F
boiler water temperature and greater the 120°F
return temperature. Adjust both valves simulta-
neously. Closing the boiler return valve while
opening the bypass valve will raise the boiler
return temperature. Opening the boiler return
valve while closing the by-pass valve will lower
the boiler return temperature.
b. If this boiler is used in connection with refrigera-
tion systems, the boiler must be installed so that
the chilled medium is piped in parallel with the
heating boiler using appropriate valves to
prevent the chilled medium from entering the
boiler. See Figure 7. Also, consult I=B=R,
"Residential Hydronic Heating Installation and
Design Guide".
c. If this boiler is connected to heating coils located
in air handling units where they may be exposed
to refrigerated air, the boiler piping must be
equipped with ow control valves to prevent
Figure 7: Recommended Piping for Combination
Heating and Cooling (Refrigeration) System

14 103626-04 - 3/18
IV. WATER PIPING AND TRIM (continued)
Figure 8A: Recommended Water Piping for Circulator Zoned Heating Systems - Supply Side Circulator

15
103626-04 - 3/18
IV. WATER PIPING AND TRIM (continued)
Figure 8B: Recommended Water Piping for Zone Valve Zoned Heating Systems - Supply Side Circulator

16 103626-04 - 3/18
gravity circulation of boiler water during the
operation of the cooling system.
d. If boiler is used with an Indirect-Fired Domestic
Water Heater, install the Indirect-Fired Domestic
Water Heater as a separate heating zone. Refer
to the Indirect-Fired Domestic Water Heater
Installation, Operating, and Service Instructions
for additional information.
e. A water boiler installed above radiation level
must be provided with a low water cutoff device
as part of the installation.
B. INSTALL SAFETY RELIEF VALVE. See Figures
5A or 5B and 8A or 8B. Safety Relief Valve must be
installed with spindle in the vertical position.
Installation of the relief valve must be consistent with
ANSI/ASME Boiler and Pressure Vessel Code, Section
I V.
WARNING
Installation is NOT complete unless a safety relief
valve is installed as shown in Figure 8A or 8B.
Safety (relief) valve discharge piping must be
piped near oor to eliminate potential of severe
burns. DO NOT pipe in any area where freezing
could occur. DO NOT install any shut-off valves,
plugs or caps.
IV. WATER PIPING AND TRIM (continued)
C. INSTALL DRAIN VALVE in return piping. See
Figures 8A and 8B.
D. OIL, GREASE, AND OTHER FOREIGN
MATERIALS which accumulate in new hot water and a
new or reworked system should be boiled out, and then
thoroughly ushed. A qualied water treatment
chemical specialist should be consulted for
recommendations regarding appropriate chemical
compounds and concentrations which are compatible
with local environmental regulations.
E. AFTER THE BOILER AND SYSTEM HAVE BEEN
CLEANED and ushed, and before relling the entire
system add appropriate water treatment chemicals, if
necessary, to bring the pH between 7 and 11.

17
103626-04 - 3/18
V. VENTING
A. GENERAL GUIDELINES
1. Vent system installation must be in accordance with
these instructions and applicable provisions of local
building codes. Contact local building or re
ofcials about restrictions and installation inspection
in your area.
2. The LE Series is designed to be vented into a
reclay tile-lined masonry chimney or chimney
constructed from type-L vent or a factory built
chimney that complies with the type HT
requirements of UL103. The chimney or vent pipe
shall have a sufcient draft at all times, to assure
safe proper operation of the boiler. See Figure 9 for
recommended installation.
a. Install a draft regulator (supplied by installer)
following the instructions furnished with the
regulator. See Figure 10 for alternate regulator
locations.
b. With any new or replacement installation the
chimney has to be considered. Chimneys that
have a high heat loss become less suitable as the
heat loss of the home goes down and the
efciency of the boiler goes up. Most homes
have a chimney appropriate for the fuel and the
era in which the home was built. That may have
been a coal red or an inefcient oil red boiler
built into a home without insulation or storm
windows. With increasing fuel prices that home
probably has been insulated and tted with storm
windows so that the heat loss of the home has
been reduced. This requires less fuel to be
burned and sends less heat up the chimney.
A new boiler probably has a higher efciency
than the boiler being replaced. That probably
means that the stack temperature from the new
boiler will be lower than that from the old boiler
and with less room air being drawn up the
chimney to dilute the stack gases. The combina-
tion of a large uninsulated chimney, reduced
ring rate, reduced ring time, lower stack
temperature and less dilution air can, in some
cases, contribute to the condensing of small
amounts of water vapor in the chimney. Such
condensation, when it occurs, can cause chimney
deterioration. In extreme cases, the chimney
may have to be lined to insulate the chimney and
thus prevent the condensation. The addition of
dilution air into the chimney may assist in drying
the chimney interior surfaces.
A massive chimney on a cold, or exposed outside
wall may have produced adequate draft when it
was red with a higher input and greater vol-
umes of heated gases. With reduced input and
volume, the draft may be severely affected. In
one instance our research showed a new chimney
of adequate sizing produced only -.035” W.C.
after 30 minutes of continuous ring at 13.0%
CO2. Outside wall chimneys take longer to heat
up and can have .00” W.C. draft at burner
start-up. You may have to consider a special
alloy chimney ue liner with insulation around it
and stabilizing draft cap or even a draft inducing
fan in severe cases.
c. For the same reasons as in (2.) above, heat
extractors mounted into the breeching are not
recommended.
3. For minimum clearances to combustible materials
refer to Figure 2.

18 103626-04 - 3/18
V. VENTING (continued)
Figure 9: Recommended Smoke Pipe Arrangement and Chimney Requirements
Figure 10: Draft Regulator Locations

19
103626-04 - 3/18
VI. ELECTRICAL
DANGER
Positively assure all electrical connections are unpowered before attempting installation or service of
electrical components or connections of the boiler or building. Lock out all electrical boxes with padlock
once power is turned off.
WARNING
Failure to properly wire electrical connections to the boiler may result in serious physical harm.
Electrical power may be from more than one source. Make sure all power is off before attempting any
electrical work.
Each boiler must be protected with a properly sized fused disconnect.
Never jump out or make inoperative any safety or operating controls.
The wiring diagrams contained in this manual are for reference purposes only. Refer to the wiring diagram
of any controls used with the boiler. Read, understand and follow all wiring instructions supplied with
the controls.
A. GENERAL
1. Install wiring and electrically ground boiler in
accordance with requirements of the authority
having jurisdiction, or in absence of such require-
ments the National Electrical Code, ANSI/NFPA 70,
and/or the CSA C22.1 Electric Code.
2. A separate electrical circuit must be run from the
main electrical service with an over-current device/
disconnect in the circuit. A service switch is
recommended and may be required by some local
jurisdictions.
3. Wiring should conform to Figures 11A, 11B and 12.
B. SYSTEM CONTROLS AND WIRING
1. Refer to National Electric Code or Local Electric
Codes for proper size and type of wire required.
Follow Code.
2. Use anti-short bushings on all wiring passing
through boiler jacket, junction boxes and/or control
boxes.
3. Use armored cable (BX) over all exposed line
voltage wiring.
4. If an indirect water heater is used, use priority
zoning. DO NOT use priority zoning for Hydro-Air
Systems.
5. Single/Multiple Zone System – Refer to Figures 11A
or 11B for the electrical diagram for this type of
system. Connect the system circulator wire leads to
the proper terminal on the L7248 Aquastat control
as shown in Figure 11A or 11B.
C. INSTALL A ROOM THERMOSTAT on an inside
wall about four feet above oor. Never install
thermostat on an outside wall or where it will be
inuenced by drafts, hot or cold water pipes, lighting
xtures, television, rays of the sun or near a replace.
Keep large furniture away from thermostat so there will
be free movement of room air around this control.
Connect the thermostat to the ‘T-T’ terminals on the
L7248 control.
Heat Anticipator in Thermostat should be set to .1 amps.
If system tends to overheat above the thermostat’s
temperature setting, reduce heat anticipator setting by .1
or .2 amps. If system tends to short cycle without
reaching desired room temperature, increase heat
anticipator setting by .1 or .2 amps.
WARNING
The maximum allowable current for each circulator
is 5 amps at 120V AC. For circulators with higher
amp ratings, you must install a circulator relay or
starter coil to provide line voltage to the circulator
and connect only the relay or starter coil to boiler
terminals. The combined boiler and circulator
amperage must not exceed 15 amps.
Install over-current protection in accordance with
authority having jurisdiction or, in the absence of
such requirements, follow the National Electric
Code, NFPA 70, and/or CSA C22.1 Electrical Code.
DO NOT provide over-current protection greater
than 15 amperes.

20 103626-04 - 3/18
VI. ELECTRICAL (continued)
Figure 11A: Schematic Wiring Diagram, Cold Start Control with Beckett AFG Burner
REFER TO FIGURE 12 FOR SCHEMATIC WIRING DIAGRAM OF APPROPRIATE BURNER AND OIL PRIMARY CONTROL OPTION