Crown Boiler KSZ065 KSZ075 KSZ100 KSZ090 User manual

KSZ Series
Oil-Fired Steam Boilers
INSTALLATION INSTRUCTIONS
These instructions must be afxed on or adjacent to the boiler
Models:
• KSZ065
• KSZ075
• KSZ100
• KSZ090
• KSZ125
• KSZ150
• KSZ120
• KSZ175
• KSZ200
DESIGNED TO LEAD
Manufacturer of Hydronic Heating Products
P.O. Box 14818 3633 I. Street
Philadelphia, PA 19134
www.crownboiler.com
WARNING: Improper instal-
lation, adjustment, alteration,
service or maintenance can
cause property damage, injury,
or loss of life. For assistance or
additional information, consult a
qualied installer, service agency
or the oil supplier. Read these
instructions carefully before
installing.

2

1
FOLLOW ALL INSTRUCTIONS and warnings
printed in this manual and posted on the boiler.
INSPECT THE BOILER, BURNER AND
CONTROLS ANNUALLY. To keep your boiler safe
and efficient, have a service technician follow the
Service checklist near the end of this manual.
IF YOU ARE NOT QUALIFIED to install or service
boilers, do not install or service this one.
THE BOILER MAY LEAK WATER at the end of
its useful life. Be sure to protect walls, carpets,
and valuables from water that could leak from the
boiler.
PROTECT YOUR HOME IN FREEZING
WEATHER. A power outage, safety lockout, or
component failure will prevent your boiler from
lighting. In winter, your pipes may freeze and
cause extensive property damage. Do not leave
the heating system unattended during cold weather
unless alarms or other safeguards are in place to
prevent such damage
DO NOT BLOCK AIR FLOW into or around the
boiler. Insufficient air may cause the boiler to
produce carbon monoxide or start a fire.
KEEP FLAMMABLE LIQUIDS AWAY from the
boiler, including paint, solvents, and gasoline.
The boiler may ignite the vapors from the liquids
causing explosion or fire.
KEEP CHILDREN AND PETS away from hot
surfaces of the boiler, boiler piping, and vent pipe.
CARBON MONOXIDE (CO) is an odorless, deadly
gas that may be introduced into your home by
any malfunctioning fuel-burning product or vent
system failure. Consider installing CO alarms near
bedrooms in all levels of the building to warn you
and your family of potential CO exposure.
READ THIS ENTIRE MANUAL before attempting
installation, start-up, or service. Improper
installation, adjustment, alteration, service, or
maintenance may cause serious property damage,
personal injury, or death.
DO NOT DISCONNECT PIPE FITTINGS on the
boiler or in the heating system without first verifying
that the system is cool and free of pressure and
that your clothing will protect you from a release
of hot water or steam. Do not rely solely on the
boiler’s temperature and pressure gage when
making this judgment.
USE PROPER PERSONAL PROTECTION
EQUIPMENT when servicing or working near the
boiler. Materials of construction, flue products, and
fuel contain alumina, silica, heavy metals, carbon
monoxide, nitrogen oxides, and/or other toxic or
harmful substances that can are hazardous to
health and life and that are known to the State of
California to cause cancer, birth defects, and other
reproductive harm.
INSTALL ALL GUARDS, cover plates, and
enclosures before operating the boiler.
SIZE THE BOILER PROPERLY relative to the
design heat load or, if using domestic hot water
priority, the peak hot water load, whichever
is larger. A grossly oversized boiler will cycle
excessively and this will lead to premature failure
of the boiler and its components. Our warranty
does not apply to damage from excessive cycling.
ADHERE TO ALL LOCAL CODE
REQUIREMENTS. Contact your local code
inspector prior to installation. In the absence of
a local code, adhere to the latest editions of the
Installation of Oil Burning Equipment ANSI/NFPA
31 in the USA or CAN/CSA B139, Installation Code
for Oil Burning Equipment in Canada.
ALL WIRING must comply with the National
Electrical Code ANSI/NFPA 70 (in the USA) or the
Canadian Electrical Code CSA C22.1 (in Canada)
and any local regulations.
WARNINGS FOR THE HOMEOWNER
WARNINGS FOR THE INSTALLER

2
Table of Contents
I. Product Description .............................................................. 2
II. Specications ........................................................................ 2
III. Before Installing.................................................................... 3
IV. Locating the Boiler ............................................................... 4
V. Air for Combustion & Ventilation......................................... 6
VI. Venting ................................................................................ 10
VII. System Piping Connections ................................................ 12
I Product Description
The KSZ series boiler is a cast iron oil-red low pressure steam boiler designed for use in closed heating systems. This
boiler must be vented by natural draft into a lined masonry or metal chimney, or Type L vent. An adequate supply of air for
combustion, ventilation and dilution of ue gases must be available in the boiler room. This boiler has connections for use
with an indirect domestic water heater.
The KSZ series boilers are not designed for use in process or other “open” steam systems.
II Specications
FIGURE 1: GENERAL CONFIGURATION
VIII. Indirect Water Heater & Tankless Coil
Piping ........................................................... 14
IX. Fuel Line Piping ........................................... 17
X. Wiring ........................................................... 20
XI. Start-up and Checkout .................................. 24
XII. Service & Maintenance ................................ 27
XIII. Parts .............................................................. 32

3
TABLE 1a: GENERAL SPECIFICATIONS
Notes:
1. Net Ratings are based on piping and pick-up allowances of 1.333.
2. Burner Capacity Rating, GPH is based on #2 oil with a Gross Heating
Value equal to 140000 BTU/Gal.
3. Maximum Working Pressure, Steam -15 PSI.
4. Tankless heater ratings based on 40F inlet water, 140F outlet water, and 190F
boiler water. Ratings are also based on 5 minute intermittent draws with 10 minutes
between draws.
III Before Installing
1) Safe, reliable operation of this boiler depends upon installation by a professional heating contractor in strict accordance
with this manual and the requirements of the authority having jurisdiction.
• In the absence of an authority having jurisdiction, installation must be in accordance with this manual and the latest
edition of Installation of Oil Burning Equipment (ANSI/NFPA31).
• Where required by the authority having jurisdiction, this installation must conform to the latest edition of Standard for
Controls and Safety Devices for Automatically Fired Boilers (ANSI/ASME CSD-1).
2) Make sure that a properly sized chimney is available which is in good condition. Consult the authority having
jurisdiction, Part VI of this manual, and ANSI/NFPA31 for additional information on venting requirements.
Power (“Side Wall”) Venting - Important Note
Two problems arise when any oil-red appliance is power vented:
1. There is sometimes an accelerated rate of soot buildup on the oil burner cad-cell, spinner etc.
2. There is a potential for severe damage to the side of the structure in the event that the boiler operates at a high smoke
level. This can happen for many reasons, some of which are out of the control of both the installer and appliance
manufacturer.
Crown Boiler Company recommends the use of a chimney to vent the KSZ series boilers. If a power venter must be used, it
is the responsibility of the installer and power vent manufacturer to “engineer” the power vent system. CROWN BOILER
COMPANY WILL ASSUME NO RESPONSIBILITY FOR DAMAGE TO SIDING, ETC. FROM A POWER
TABLE 1b: TANKLESS HEATER RATINGS
"A" "B" "C"
KSZ065 3 0.65 79000 85.1 59000 246 17-3/8 8-5/16 6
KSZ075 3 0.75 90000 84.5 68000 283 17-3/8 8-5/16 6
KSZ100 3 1.00 119000 83.5 89000 370 17-3/8 8-5/16 6
KSZ090 4 0.90 110000 85.0 83000 346 22-3/8 10-13/16 7
KSZ125 4 1.25 149000 84.2 112000 467 22-3/8 10-13/16 7
KSZ150 4 1.50 177000 83.1 133000 554 22-3/8 10-13/16 7
KSZ120 5 1.20 147000 85.4 110000 458 27-3/8 13-5/16 8
KSZ175 5 1.75 207000 83.1 155000 646 27-3/8 13-5/16 8
KSZ200 5 2.00 235000 82.9 176000 733 27-3/8 13-5/16 8
I=B=R Net
Rating (Sq. ft)AFUE (%)
I=B=R Net
Rating (Btu/hr)
Dimensions (inches)
Boiler Model
Number of
Sections
Burner
Input
(Gal/hr)
DOE Heating
Capacity
(Btu/hr)
MODEL RATING (gpm)
KSZ065 2.25
KSZ075 2.25
KSZ100 2.50
KSZ090 2.50
KSZ125 2.75
KSZ150 3.00
KSZ120 2.75
KSZ175 3.25
KSZ200 3.50

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3) Make sure that the boiler is correctly sized. Use an industry accepted sizing method such as the I=B=R Guide RHH
published by the Air-Conditioning, Heating and Refrigeration Institute (AHRI).
4) In some cases, boilers installed at altitudes above 2000ft may require a different burner conguration from that at sea level.
Consult the local Crown representative for more information.
IV Locating the Boiler
1) Clearances:
• Observe the minimum clearances shown below. Except as noted, these clearances apply to all combustible con-
struction, as well as noncombustible walls, ceilings and doors. Also see Figure 2.
Front – 24”
Left Side – 6” (24” for Boilers Equipped with Float Type Low Water Cut-offs)
Right Side – 6” (24” for Boilers Equipped with Tankless Heaters)
Rear – 6” (24” for boilers connected to indirect water heaters)
Top – 6”
Single Wall Chimney Connector (to combustible construction) - 18”
• A 24” service clearance from the jacket is recommended from the top of the boiler. This clearance may be
reduced to that shown above; however, servicing the boiler will become increasingly difcult as this clearance
is reduced.
• A 24” service clearance is required on the left side of KSZ series boilers equipped with oat type low water cut-
offs. This is to facilitate low water cut-off maintenance.
2) If listed Type L vent is used, follow vent pipe manufacturer recommendations for minimum clearances.
3) Do not install this boiler directly on a combustible surface. Where it is desired to install the KSZ over a non-carpeted com-
bustible surface, install the boiler on the base shown in Figure 3.
4) Do not install this boiler in a location where gasoline or other ammable vapors or liquids will be stored or used. Do not
install this boiler in an area where large amounts of airborne dust will be present, such as a workshop.
WARNING
FAILURE TO OBSERVE THE FOLLOWING LOCATION REQUIREMENTS COULD RESULT
IN PROPERTY DAMAGE, A FIRE, EXPLOSION OR CARBON MONOXIDE (CO) HAZARD.

5
FIGURE 2: CLEARANCES
FIGURE 3: INSTALLATION OVER A COMBUSTIBLE FLOOR

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V Air for Combustion and Ventilation
Sufcient fresh air must be supplied for combustion and ventilation. Provisions for combustion and ventilation air for oil
burning equipment must be made in accordance with Section 1.5, Air for Combustion and Ventilation, in the latest edition of
Installation of Oil Burning Equipment (ANSI/NFPA 31).
To ensure an adequate supply of air for combustion, ventilation and ue gas dilution, start by determining whether the
boiler is to be installed in a building of unusually tight construction. A building of unusually tight construction can be dened
as having one of the following features:
• Walls and ceilings exposed to outside atmosphere have a continuous water vapor retarder with a rating of 1 perm or
less with openings gasketed and sealed.
• Weather stripping has been added on openable windows and doors.
• Caulking and sealants are applied to areas such as joints around window and door frames, between sole plates and
oors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and
at other openings.
For Buildings of Other than Unusually Tight Construction
1) Determine whether the boiler is to be installed in a conned space - A conned space is dened as having a volume less
than 50 cubic feet per 1000 BTU/hr input of all appliances installed in that space. To determine whether the boiler room is a
conned space:
a. Total the input of all appliances in the boiler room in thousands of BTU/hr. Round the result to the next highest
1000 BTU/hr.
b. Find the volume of the room in cubic feet. The volume of the room in cubic feet is:
Length (ft) x width (ft) x ceiling height (ft)
In calculating the volume of the boiler room, consider the volume of adjoining spaces only if no doors are installed
between them. If doors are installed between the boiler room and an adjoining space, do not consider the volume of
the adjoining space, even if the door is normally left open.
c. Divide the volume of the boiler room by the input in thousands of BTU/hr. If the result is less than 50, the boiler
room is a conned space.
Example:
A KSZ090 and a water heater are to be installed in a room measuring 6 ft - 3 in x 7 ft with an 8 ft ceiling. The water
heater has an input of 30000 BTU/hr:
Input of KSZ090 = 0.90 Gal/hr x 140000 BTU/Gal = 126000 BTU/hr
Total input in thousands of BTU/hr = (126000 BTU/hr + 30000 BTU/hr)/1000 = 156
Volume of room = 6.25 ft x 7 ft x 8 ft = 350 ft3
350/156 = 2.24. Since 2.24 is less than 50, the boiler room is a conned space.
WARNING
• INSUFFICIENTCOMBUSTIONAIRSUPPLYMAYRESULTINTHEPRODUCTIONAND 
RELEASE OF SOOT OR DEADLY CARBON MONOXIDE (CO) INTO THE HOME WHICH CAN
CAUSE PROPERTY DAMAGE, SEVERE PERSONAL INJURY OR DEATH.
• THISBOILERISNOTDESIGNEDFORUSEINASPACETHATISDEPRESSURIZED 
RELATIVE TO THE OUTDOORS. OPERATING THIS BOILER IN A DEPRESSURIZED SPACE
MAY CAUSE PROPERTY DAMAGE, SEVERE PERSONAL INJURY OR DEATH.

7
FIGURE 4: BOILER INSTALLED IN CONFINED SPACE,
ALL AIR FROM INSIDE
2) Unconned Space - Natural inltration into the boiler room will normally provide adequate air for combustion and venti-
lation without additional louvers or openings into boiler room.
3) Conned Space - Provide two openings into the boiler room, one near the oor and one near the ceiling. The top edge of
the upper opening must be within 12” of the ceiling and the bottom edge of the lower opening must be within 12” of the oor
(Figure 4).
• Each opening must have a free area of 1 square inch per 1000 BTU/hr input of all fuel burning appliances in the boiler
room. The minimum opening dimension is 3 inches. Minimum opening free area is 100 square inches per opening.
• If the total volume of both the boiler room and the room to which the openings connect is less than 50 cubic feet per
1000 BTU/hr of total appliance input, install a pair of identical openings into a third room. Connect additional rooms
with openings until the total volume of all rooms is at least 50 cubic feet per 1000 BTU/hr of input.
• The “free area” of an opening takes into account the blocking effect of mesh, grills, and louvers. Where screens are
used, they must be no ner than ¼” (4 x 4) mesh.
For Buildings of Unusually Tight Construction:
1) Openings must be installed between the boiler room and the outdoors or a ventilated space, such as an attic or crawl
space, which communicates directly with the outdoors.
2) Two openings are required. The top edge of the upper opening must be within 12 inches of the ceiling. The bottom
edge of the lower opening must be within 12 inches of the oor.
3) Size openings and ducts as follows:
• Vertical ducts or openings directly outdoors (Figure 5, Figure 6, and Figure 7) - Each opening must have a free
cross sectional area of 1 square inch per 4000 BTU/hr of the total input of all fuel red appliances in the boiler
room but not less than 100 square inches. Minimum opening size is 3 inches.
• Openings to outdoors via horizontal ducts (Figure 8) - Each opening must have a free cross sectional area of 1
square inch per 2000 BTU/hr of the total input of all fuel red appliances in the boiler room but not less than 100
square inches. Minimum opening size is 3 inches.
• The “free area” of an opening takes into account the blocking effect of mesh, grills, and louvers. Where screens
are used, they must be no ner than ¼” (4 x 4) mesh.

8
FIGURE 6: ALL AIR FROM OUTDOORS,
VIA VENTILATED ATTIC
FIGURE 5: ALL AIR FROM OUTDOORS, VENTILATED
CRAWL SPACE AND ATTIC

9
FIGURE 8: ALL AIR FROM OUTDOORS, USING
HORIZONTAL DUCTS INTO BOILER ROOM
FIGURE 7: ALL AIR FROM OUTDOORS, USING
OPENINGS INTO BOILER ROOM

10
VI Venting
Vent installation must be in accordance with local building codes, or the local authority having jurisdiction.
Typical vent installation is illustrated by Figure 9. The components of vent installation are the vent connector (breeching),
barometric draft regulator, and chimney.
1) Acceptable Chimneys - The following chimneys may be used to vent a KSZ series boiler:
• Listed Type L vent - Install in accordance with the manufacturer’s instructions, the terms of its listing, and applicable
codes.
• Masonry Chimney - The masonry chimney must be constructed in accordance with the latest edition of Standard
for Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances (NFPA 211) and lined with a clay liner or other
listed lining system. Do not vent a KSZ series boiler into an unlined chimney.
FIGURE 9: TYPICAL VENT SYSTEM
INSTALLATION AND COMPONENTS
WARNING
• IMPROPERVENTINGMAYRESULTINPROPERTYDAMAGEAND/ORTHERELEASEOF
FLUE GASES, WHICH CONTAIN DEADLY CARBON MONOXIDE (CO), INTO THE HOME,
WHICH CAN CAUSE SEVERE PERSONAL INJURY OR DEATH.
• INSPECTEXISTINGCHIMNEYBEFOREINSTALLINGBOILER.FAILURETOCLEANOR
REPLACE DAMAGED PIPE OR TILE LINING WILL CAUSE PROPERTY DAMAGE, SEVERE
PERSONAL INJURY OR DEATH.

11
2) Acceptable Vent Connectors - The following may be used for vent connectors:
• Listed Type L vent.
• Single Wall Galvanized Pipe - Use 0.018” (26 gauge) or heavier.
3) Chimney and Vent Connector Sizing - See Table 2 for minimum vent connector and chimney sizing. The vent connector
size must not be smaller than the boiler ue collar diameter.
4) Do not vent this appliance into any portion of a mechanical vent system operating under positive pressure.
5) Do not connect the boiler into a chimney ue serving an open replace or other solid fuel appliance.
6) Prior to boiler installation, inspect chimney for obstructions or other defects and correct as required. Clean chimney as
necessary.
7) Vent pipe should slope upward from the boiler not less than one inch in four feet. No portion of vent pipe should run
downward or have sags. Vent pipe must be securely supported.
8) The vertical section of vent pipe coming off the boiler should be as tall as possible, while still maintaining the proper
clearance from the horizontal vent connector to combustibles and the proper pitch called for in (7) above.
9) Vent pipe should be installed above the bottom of the chimney to prevent blockage.
10) Vent pipe must be inserted ush with inside face of the chimney liner and the space between vent pipe and chimney
sealed tight. A thimble permanently cemented in place can be used to facilitate removal of chimney connector for cleaning.
11) Install the barometric draft regulator in accordance with the regulator manufacturer’s instructions.
12) Secure all joints in the vent connector system with sheet metal screws. This includes the joint between the vent
connector and the boiler collar, as well as the barometric draft regulator. Use at least three screws at each joint.
Power (“Side Wall”) Venting - Important Note
Two problems arise when any oil-red appliance is power vented:
1. There is sometimes an accelerated rate of soot buildup on the oil burner cad-cell, spinner etc.
2. There is a potential for severe damage to the side of the structure in the event that the boiler operates at a high smoke
level. This can happen for many reasons, some of which are out of the control of both the installer and appliance
manufacturer.
Crown Boiler Company recommends the use of a chimney to vent the KSZ series boilers. If a power venter must be used, it
is the responsibility of the installer and power vent manufacturer to “engineer” the power vent system. CROWN BOILER
COMPANY WILL ASSUME NO RESPONSIBILITY FOR DAMAGE TO SIDING, ETC. FROM A POWER
TABLE 2: MINIMUM RECOMMENDED BREECHING AND
CHIMNEY SIZE
Round I.D. (in) Rectangular I.D. (in) Height (ft)
KSZ065 6 6 8 x 8 15
KSZ075 6 6 8 x 8 15
KSZ100 6 6 8 x 8 15
KSZ090 7 7 8 x 8 15
KSZ125 7 7 8 x 8 15
KSZ150 7 7 8 x 8 15
KSZ120 8 8 8 x 8 15
KSZ175 8 8 8 x 8 15
KSZ200 8 8 8 x 8 15
Boiler
Model
Min Breeching
Dia. (inches)
Min. Recommended Chimney Size and Height

12
FIGURE 10: STEAM BOILER PIPING FOR GRAVITY RETURN
Figure 10 shows recommended near boiler Piping for most common types of gravity return steam systems. Additional
information on steam system design may be found in the I=B=R Guide RHH published by the Air-Conditioning, Heating and
Refrigeration Institute (AHRI).
One of the primary purposes of this near boiler piping is to separate tiny water droplets from the steam exiting the boiler
so that “dry” steam is sent to the system. If the near boiler piping is not correct, wet steam will enter the system and the
following problems may occur:
• Short cycling on low water
VII System Piping
WARNING
• INSTALLBOILERSOTHATTHEELECTRICALCOMPONENTSAREPROTECTED
FROM WATER (DRIPPING, SPRAYING, RAIN, ETC.) DURING APPLIANCE
OPERATION AND SERVICE (CIRCULATOR REPLACEMENT, ETC.).
• OPERATIONOFTHISBOILERINASYSTEMHAVINGSIGNIFICANTAMOUNTSOF
DISSOLVED OXYGEN CAN CAUSE SEVERE HEAT EXCHANGER CORROSION
DAMAGE.
• DONOTUSETOXICADDITIVESINTHISSYSTEM.
• PIPESAFETYVALVEDISCHARGETOASAFELOCATION.THESAFETYVALVE
MAY DISCHARGE STEAM OR SCALDING HOT WATER.
• DONOTINSTALLAVALVEINTHESAFETYVALVEDISCHARGELINE.
• DONOTMOVESAFETYVALVEFROMFACTORYLOCATION.
• DONOTPLUGSAFETYVALVEDISCHARGE.BLOCKINGTHESAFETYVALVE
MAY RESULT IN BOILER EXPLOSION.

13
• Boiler or system Flooding
• Hammering
• Failure to heat one or more radiators
Avoid the common piping mistakes shown in Figure 11. This applies even if the existing boiler has one of the piping mistakes
shown in Figure 11 and appears to be working. If two or more steam mains must be connected to the boiler, connect a
separate take-off for each main into the header between the riser(s) and equalizer. Also note the following points:
1) A size reduction must be made to connect the header to the equalizer. This reduction must be made in the vertical equalizer
line. Do not make this size reduction in the horizontal header.
2) One-pipe steam systems require air vents on each radiator, as well as at the end of each main. For the system to work
properly, these vents must be properly installed, sized, and be in good condition. Inspect and replace any defective vents. If
there are no vents at the ends of the mains, install them.
3) Do not attempt to manifold multiple KSZ boilers with gravity returns.
4) For installations with condensate or boiler feed pumps, follow the pump manufacturer’s piping instructions. Such systems
generally do not require Hartford loops.
5) Do not use a check valve in place of, or in addition to, a Hartford loop on a gravity return system.
6) Pipe the ll connection from a clean source of cold water. When the water supply is from a well, make sure that a strainer
is installed in the well system.
Piping Installation
1) Remove parts bag from boiler crate.
2) Install safety valve (spindle must be in vertical position) into the 3/4” tapping on top of the boiler.
3) Pipe the discharge of the safety relief valve to a location where water or steam will not create a hazard or cause property
damage if the valve opens. The end of the discharge pipe must terminate in an unthreaded pipe. If the safety valve discharge
is not piped to a drain, it must terminate at least 6 inches above the oor. The termination of the safety valve discharge piping
must be in an area where it is not likely to become plugged by debris or subjected to freezing.
4) Install drain valve provided into the return piping.
5) Connect system supply and return to boiler. See Figure 10. All KSZ boilers use one supply riser and one return tapping.
FIGURE 11: COMMON NEAR-BOILER PIPING MISTAKES

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VIII INDIRECT & TANKLESS WATER HEATER PIPING
INDIRECT WATER HEATER PIPING
All KSZ series boilers are equipped with tappings to permit the connection of a Crown Mega-Stor, or other indirect water
heater. In this type of system, hot boiler water is drawn from below the water line and passed through the heat exchanger in
the indirect water heater. This section describes boiler-side piping only. Refer to the indirect water heater instruction manual
for domestic water piping. The components in this system and their functions are as follows:
1) Circulator - Mount the circulator as shown in Figure 12A. The circulator should be located as low and as close to the
boiler as practical. Do not install valves, or other devices having a signicant pressure drop, between the boiler and the
circulator inlet. All piping between the boiler and the circulator inlet should be 1”, regardless of the size of the piping
required in the rest of the system. See Figure 17 in Part X for wiring information.
2) “Y” Strainer - Install a “Y” strainer to prevent sediment from accumulating inside the indirect water heater.
3) Check Valve - Prevents gravity circulation through the indirect water heater when the boiler is responding to a call for
heat.
4) Boiler Limit Control - Use a SPST break-on-rise temperature limit control such as the Honeywell L4006A. Do not set
the limit above 180F as doing so may cause the boiler to steam when there is no call for heat. See Figure 17 for wiring
information.
5) Valves and Unions - Install shut-off valves, drain valves, and unions in locations that will facilitate maintenance of the
system. Do not install any valves between the boiler and circulator inlet.
FIGURE 12a: INDIRECT WATER HEATER BOILER-SIDE PIPING

15
IMPORTANT
•Some indirect water heaters may not be suitable for use with a steam boiler. Consult the water heater
manufacturer’s guidelines before installing it in this type of system.
• Boiler water temperatures and ow rates in this type of system may be considerably lower than those upon which the
water heater manufacturer’s ratings are based. This may result in substantially longer water heater recovery times.
2) Flow Restrictor (Recommended) - If water is drawn from the tankless coil at a rate in excess of the rating in Table 1b,
the temperature of the hot water may be too low to be of use. The use of a ow restrictor will prevent this problem by
limiting the rate at which water can pass through the tankless heater. If a restrictor is used, select one having a rating
in GPM approximately equal to the rating shown in Table 1b. If possible, locate this restrictor at least 3 feet from the
tankless heater inlet so that it is not subjected to excessive temperatures when no water is owing through the coil.
3) Pressure Relief Valve (Required) - Limits the pressure in the tankless heater and piping. Use an ASME constructed valve
designed for domestic water service, such as the Watts #3L. Note that this is a pressure relief valve, not a T&P valve.
Select a valve with a pressure setting less than or equal to the working pressure marked on the tankless coil. Pipe the
discharge to a safe location using piping the same size as the discharge connection on the valve.
4) Hose Bib Valves (Recommended) - These valves permit the coil to be periodically “backushed” to remove sediment.
TANKLESS HEATER PIPING
KSZ Series boilers equipped with tankless heaters are supplied with a Honeywell L4006A limit control and a 3/4 NPT
well. For shipping purposes, these components are shipped unmounted. This control is mounted in the 3/4 tapping in the
center of the tankless coil.
Make the piping connections to the coil before installing the L4006A. When making the “OUT” connection, make sure
that the piping is routed so that it will not interfere with the L4006A.
Pipe the heater as shown in Figure 12b. The components in this system and their functions are as follows:
1) Mixing Valve (Required) - During the heating season, the water exiting the tankless heater may be 180 degrees or more.
The mixing valve blends hot water leaving the tankless heater with cold water so as to maintain the hot water supplied
to the xtures at a xed temperature. This saves energy, increases the amount of usable hot water available to the
homeowner, and reduces the risk of scalding.
Install a mixing valve with a setting range of approximately 110 to 130F. Follow the manufacturer’s instructions for
installing this valve. Usually a “heat trap” will be required between the coil and the “hot” connection on the mixing
valve.
WARNING
A MIXING VALVE DOES NOT ELIMINATE THE RISK OF SCALDING.
 • SETTHEMIXINGVALVEANDBOILERLOwLIMITADjUSTMENTSASLOwAS
POSSIBLE.
 • FEELwATERBEFORESHOwERINGORBATHING.
 • IFANTI-SCALDORANTI-CHILLPROTECTIONISREqUIRED,USEDEVICES
SPECIFICALLY DESIGNED FOR SUCH SERVICE. INSTALL AND MAINTAIN
THESE DEVICES IN ACCORDANCE WITH THE MANUFACTURER’S
INSTRUCTIONS. DO NOT USE THE MIXING VALVE AS A SUBSTITUTE FOR
PRESSURE BALANCING VALVES OR OTHER DEVICES REQUIRED BY
PLUMBING CODES TO PROTECT AGAINST SCALDING.

16
5) Globe or Ball Valve (Recommended) - Used to adjust the ow through the entire tankless heater system if needed.
6) Unions (Required) - Tankless heaters may require periodic gasket replacement or other maintenance which requires
removal of the heater from the boiler. Install unions anywhere in the tankless heater piping that will facilitate removal of
the heater.
FIGURE 12b: TANKLESS HEATER PIPING

17
IX Fuel Line Piping
Fuel line piping design, materials and constructions must be in accordance with local building codes, requirements of the
local authority having jurisdiction, and the latest edition of Installation of Oil-Burning Equipment (ANSI/NFPA 31). Refer
also to the instruction manuals provided with the burner and oil pump.
Depending on the location of the fuel oil storage tank in relation to the oil burner, there are four types of oil piping systems
generally being used:
a) ONE-PIPE GRAVITY SYSTEM - used when a fuel oil storage tank is positioned above an oil burner fuel pump. See
Figure 13. A vertical distance from top of the tank to center line of the pump (Dimension ‘H’) over 8 feet will result in
a pump inlet pressure in excess of the 3-psi limit in NFPA-31.
b) ONE-PIPE LIFT SYSTEM (not recommended) - Used when a fuel oil storage tank is located below an oil burner fuel
pump. See Figure 14. The vertical distance from bottom of the tank to center line of the pump (Dimension ‘H’) must
not exceed that shown in the pump manufacturer’s instructions. Although all oil piping systems must be airtight, one-
pipe lift systems are particularly susceptible to nuisance lockout problems if the suction line is not completely airtight.
A two-pipe lift system is therefore recommended over a one-pipe lift system.
c) TWO-PIPE GRAVITY SYSTEM (not recommended) - Used when a fuel oil storage tank is located above an oil
burner fuel pump. See Figure 15. A vertical distance from top of the tank to center line of the pump (Dimension ‘H’)
over 8 feet will result in a pump inlet pressure in excess of the 3-psi limit in NFPA-31. This type of system should be
converted to a one-pipe gravity system, as doing so will result in lower inlet line ow and longer lter life.
FIGURE 13: ONE-PIPE GRAVITY SYSTEM
WARNING
• UNDERNOCIRCUMSTANCESCANCOPPERwITHSwEATSTYLECONNECTORS
BE USED.
• DONOTUSECOMPRESSIONFITTINGS.
• OILPIPINGMUSTBEABSOLUTELYAIRTIGHTORLEAKSORLOSSOFPRIME
MAY RESULT.
• SOMEjURISDICTIONSREqUIRETHEUSEOFAFUSIBLESHUTOFFVALVEAT
THE TANK AND/OR THE BURNER. IN ADDITION, SOME JURISDICTIONS REQUIRE
THE USE OF A FUSIBLE ELECTRICAL INTERLOCK WITH THE BURNER CIRCUIT.
CHECK YOUR LOCAL CODES FOR SPECIAL REQUIREMENTS.

18
d) TWO-PIPE LIFT SYSTEM - used when a fuel oil storage tank is located below an oil burner fuel pump suction port.
See Figure 16. The vertical distance from bottom of the tank to center line of the pump (Dimension ‘H’) must not
exceed that shown in the pump manufacturer’s instructions. Distance ‘H’ allowed is reduced by number of ttings,
lters and valves installed in the line.
Once the type of system has been selected, observe the following:
1) Fuel line piping must be airtight. Do not use compression type ttings for tubing connections in fuel line piping. Use
only listed are type ttings. Cast iron threaded ttings shall not be used for wrought iron or steel piping connections.
2) Piping shall be substantially supported and protected against physical damage and corrosion where required.
3) Refer to supplied oil pump instruction manual for proper connections. On one-pipe systems, ensure that the fuel pump
return port plug is tightened securely.
4) Some fuel pumps, such as the Suntec A and B series, are supplied with a loose bypass plug which must be installed on
two-pipe systems. If such a plug is supplied, install it as shown in the pump manufacturers’s instructions. Do not install
this bypass plug on one-pipe systems as pump seal damage will result.
5) Do not use check valves, especially on gravity feed systems.
6) Do not use Teon tape for threaded connections. Use a listed non-hardening thread sealant instead.
7) Attach required piping between burner fuel pump and fuel oil storage tank. Install one fuel shut-off valve near the storage
tank and second fuel shut-off valve near the oil burner fuel pump. Use heavy wall copper tubing in a continuous run. On
two-pipe systems, the return line should terminate 3” - 4” above suction line depth within the storage tank. Refer to the
pump manufacturer’s instructions for tube sizing information.
8) All systems require an oil lter. On KSZ065 and KSZ075 boilers, the use of a Garber cartridge type lter is recommended.
9) Use only #2 Fuel Oil with physical and chemical characteristics meeting the requirements of ASTM D-396.
FIGURE 14: ONE-PIPE LIFT SYSTEM