Cleaver-Brooks ClearFire CFLC-12000, ClearFire CFLC-4000, ClearFire CFLC-6000, ClearFire CFLC-8000, ClearFire CFLC Operation And Maintenance Manual

Model CFLC

ClearFire

Condensing Boiler

4,000 - 12,000 MBTU

Operation and Maintenance Manual

750-363

08/2017

!

WARNING

DANGER

If the information in this manual is not fol­lowed exactly, a fire or explosion may re­sult causing property damage, personal
injury or loss of life.

— Do not store or use gasoline or other
flammable vapors and liquids in the vicin­ity of this or any other appliance.

!

WARNING

DANGER

Improper installation, adjustment, ser­vice, or maintenance can cause equip­ment damage, personal injury, or death.
Refer to the Operation and Maintenance
manual provided with the boiler. Installa­tion and service must be performed by a
qualified Cleaver-Brooks service provid-

— WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use
any phone in your building.

• Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.

• If you cannot reach your gas supplier, call the
fire department.

— Installation and service must be performed by
a qualified Cleaver-Brooks, service agency or the
gas supplier.

!

WARNING

DANGER

To minimize the possibility of serious personal in­jury, fire or damage to the equipment, never vio­late the following safety rules.
— Always keep the area around the boiler free of
combustible materials, gasoline, and other flam­mable liquids and vapors
— Never cover the boiler, lean anything against it,
stand on it, or in any way block the flow of fresh
air to the boiler.

!

WARNING

DANGER

Be sure the fuel supply which the boiler
was designed to operate on is the same
type as specified on the boiler name
plate.

!

WARNING

DANGER

Should overheating occur or the gas sup­ply valve fail to shut off, do not turn off or
disconnect the electrical supply to the
boiler. Instead turn off the gas supply at a
location external to the boiler.

!

WARNING

DANGER

Do not use this boiler if any part has been under
water. Immediately call your Cleaver-Brooks ser­vice representative to inspect the boiler and to re­place any part of the control system and any gas
control which has been under water.

Notice

Where required by the authority having jurisdic­tion, the installation must conform to the Standard
for Controls and Safety Devices for Automatically
Fired Boilers, ANSI/ASME CSD-1.

!

WARNING

DANGER

The boiler and its individual shutoff valve must be
disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of 1/2 psi (3.5 kPa).

Notice

This manual must be maintained in legible condi­tion and kept adjacent to the boiler or in a safe
place for future reference. Contact your local
Cleaver-Brooks representative if additional manu­als are required.

!

WARNING

DANGER

The installation must conform to the requirements
of the authority having jurisdiction or, in the ab­sence of such requirements, to UL 795 Commer­cial-Industrial Gas Heating Equipment and/or the
National Fuel Gas Code, ANSI Z223.1

ii

CLEAVER-BROOKS

Model CFLC

ClearFire Packaged Boiler

Condensing Boiler

Operation and Maintenance Manual

 Cleaver-Brooks 2017

Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative.

Manual Part No. 750-363

08/2017

iii

Printed in U.S.A.

!

WARNING

DANGER

DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL
APPLICABLE SECTIONS OF THIS MANUAL.

DO NOT ALLOW OTHERS TO OPERA TE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULL Y
UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.

FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVERE
PERSONAL INJURY OR DEATH.

TO: Owners, Operators and/or Maintenance Personnel

This operating manual presents information that will help to properly operate and care for the equipment. Study its con­tents carefully. The unit will provide good service and continued operation if proper operating and maintenance instruc­tions are followed. No attempt should be made to operate the unit until the principles of operation and all of the
components are thoroughly understood. Failure to follow all applicable instructions and warnings may result in severe
personal injury or death.

It is the responsibility of the owner to train and advise not only his or her personnel, but the contractors' personnel who
are servicing, repairing or operating the equipment, in all safety aspects.

Cleaver-Brooks equipment is designed and engineered to give long life and excellent service on the job. The electrical
and mechanical devices supplied as part of the unit were chosen because of their known ability to perform; however,
proper operating techniques and maintenance procedures must be followed at all times. Although these components af­ford a high degree of protection and safety, operation of equipment is not to be considered free from all dangers and
hazards inherent in handling and firing of fuel.

Any “automatic” features included in the design do not relieve the attendant of any responsibility. Such features merely
free him of certain repetitive chores and give him more time to devote to the proper upkeep of equipment.

It is solely the operator’s responsibility to properly operate and maintain the equipment. No amount of written instructions
can replace intelligent thinking and reasoning and this manual is not intended to relieve the operating personnel of the
responsibility for proper operation. On the other hand, a thorough understanding of this manual is required before at­tempting to operate, maintain, service, or repair this equipment.

Because of state, local, or other applicable codes, there are a variety of electric controls and safety devices which vary
considerably from one boiler to another. This manual contains information designed to show how a basic burner operates.

Operating controls will normally function for long periods of time and we have found that some operators become lax in
their daily or monthly testing, assuming that normal operation will continue indefinitely. Malfunctions of controls lead to
uneconomical operation and damage and, in most cases, these conditions can be traced directly to carelessness and
deficiencies in testing and maintenance.

It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly main­tenance activities and recording of any unusual operation will serve as a valuable guide to any necessary investigation.
Most instances of major boiler damage are the result of operation with low water. We cannot emphasize too strongly the
need for the operator to periodically check his low water controls and to follow good maintenance and testing practices.
Cross-connecting piping to low water devices must be internally inspected periodically to guard against any stoppages
which could obstruct the free flow of water to the low water devices. Float bowls of these controls must be inspected
frequently to check for the presence of foreign substances that would impede float ball movement.

The waterside condition of the pressure vessel is of extreme importance. Waterside surfaces should be inspected fre­quently to check for the presence of any mud, sludge, scale or corrosion.

It is essential to obtain the services of a qualified water treating company or a water consultant to recommend the proper
boiler water treating practices.

The operation of this equipment by the owner and his or her operating personnel must comply with all requirements or
regulations of his insurance company and/or other authority having jurisdiction. In the event of any conflict or inconsis­tency between such requirements and the warnings or instructions contained herein, please contact Cleaver-Brooks be­fore proceeding.

iv

TABLE OF CONTENTS

Section 1 Introduction

CFLC Features and Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Standard Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Optional Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Section 2 Installation

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Boiler Room . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Flue gas/combustion air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Water Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Boiler flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Using glycol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Gas connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Boiler water piping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Minimum boiler overpressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Condensate removal and treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Section 3 Stack and Intake Vent Sizing and Installation

Venting Connections - General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Vertical Venting / Inside Combustion Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Vertical Venting / Direct Vent or Sealed Combustion Air . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Venting for Multiple Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

Combustion Air / Boiler Room Ventilation Requirements. . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Section 4 Commissioning

Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Filling Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Control Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Model CFLC Boiler / Burner Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Falcon Display/Operator Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Controller Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Variable Speed Drive Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Burner Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Fan Speed Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Initial Start-up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Post Start-up Checkout Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Falcon Control Functions and Customer Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

Section 5 Service and Maintenance

Disassembly for Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Ignition and Flame Detection Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

Extended Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Emergency Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Section 6 Parts

Recommended Spare Parts List Model CFLC ................................................................... 6-2

Boiler Mechanical Assembly........................................................................................... 6-3

Burner Assembly .........................................................................................................6-7

UV Scanner ................................................................................................................. 6-9

Gas Train .................................................................................................................. 6-10

Dual Fuel Gas Trains .................................................................................................. 6-18

Pilot Gas Train ..........................................................................................................6-21

Control Panel ............................................................................................................6-22

Cables and Cable Harness ..........................................................................................6-23

Optional Parts ........................................................................................................... 6-24

Casing & Insulation ..................................................................................................... 6-25

Appendix A - Falcon Parameters
Appendix B - VSD Parameters
Appendix C - Gas Valve
Appendix D - Falcon Alert, Hold, and Lockout Codes
Appendix E - Falcon Lead Lag
Appendix F - Falcon Program Module

v

vi

Section 1

Introduction

CFLC Features and Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Standard Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Optional Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

www.cleaverbrooks.com

Section 1 — Introduction

1.1 CFLC FEATURES AND BENEFITS

Compact Firetube Design

The CFLC boiler is a two pass horizontally fired durable Firetube boiler. The extended heating surface tubes
provide for very high levels of performance in a compact space. The boiler is designed to fire natural gas.

High Efficiency

With the extended heating surface tubes the boiler can produce fuel to water efficiency of up to 99%
depending upon operating conditions.

Advanced Construction

Constructed to ASME standards, the CFLC Boiler will provide many years of trouble free service.

First pass tubes are made from SA178A Carbon Steel and are of rifle design for maximum heat transfer.
Second pass tubes are made from UNS S32101 Duplex Stainless Steel with AluFer extended heating
surface inserts for maximum heat transfer.

Dual Temperature Return

Two return pipes - high and low temperature - allow condensing performance with as little as 10% return
water at condensing temperature.

Ease of Maintenance

The steel enclosures are readily removable for access to all key components. A hinged burner provides
access for burner maintenance and fireside inspection.

Quality Construction

ASME construction ensures high quality design, safety, and reliability.

ISO 9001 certified manufacturing process ensures the highest degree of manufacturing standards is always
followed.

Full Modulation

The burner and combustion fan modulate to provide only the amount of heat required, providing quiet and
efficient operation under all conditions.

Premix Technology

The CFLC boiler utilizes "Premix" technology to mix both fuel and combustion air prior to entering the firing
chamber. This technology provides clean, efficient combustion with very low emission levels.

Designed For Heating Applications

The pressure vessel is constructed of durable ASTM Grade Steel and Stainless Steel materials to provide
many years of operating life.

Thermal shock resistant design with large water volume and low pressure drop is ideal for primary variable
flow applications.

1.2 STANDARD EQUIPMENT

1.2.1. The Boiler

The boiler is designed for a Maximum Allowable Working Pressure (MAWP) of 160 psig (11 Bar) in
accordance with the ASME Code for Low Pressure Section IV Hot Water Boilers and is stamped accordingly.
Operating pressure shall be less than 144 psig (9.9 Bar).

The vessel is mounted on a steel base with insulation & casing provided including trim and controls. Trim
and controls include safety relief valve, pressure and temperature gauges, probe type low water control, and
Falcon hydronic boiler control with associated sensors.

1-2 Part No. 750-363

1.2.2. The Burner

The burner utilizes a premix venturi, self-regulating
fuel train, variable speed blower modulation, and
Fecralloy metal fiber burner head.

Modulating combustion air fan provides 5:1
turndown.

Combustion canister of the burner is constructed of a
Fecralloy-metal fiber for solid body radiation of the
burner flame, which provides low emissions.

At maximum firing rate, the sound level of the burner
is less than 85 dBA, measured in front of the boiler at
a distance of 3 feet.

Room air for combustion is standard (combustion air
filter provided).

A direct vent combustion air adapter kit is available.
Refer to Installation and Parts sections in this manual
for options and details.

VENTURI

BLOWER
ASSEMBLY

Section 1 — Introduction

BURNER CANISTER

HAPS

CAPS

Figure 1-1 Burner Assembly

1.2.3. Burner Gas Train

The gas train assembly is provided in accordance with UL
certification and complies with ASME CSD-1. The gas train
assembly is factory assembled and wired, consisting of the
following components:

A. Low Gas Pressure Switch - manual reset
B. High Gas Pressure Switch - manual reset
C. Single body, dual safety motorized shut-off valves

with POC and regulating actuator
D. Manual Shutoff Butterball Valve
E. Regulator (optional, based on gas supply pressure)
F. Test cocks

1.2.4. Controls

The Falcon hydronic control is an integrated burner
management and modulation control with a touch-screen
display/operator interface.

The controller is capable of the following functions:

• Two (2) heating loops with PID load control.

• Burner sequencing with safe start check, pre-purge, pilot
ignition, and post purge.

• Electronic ignition.

• Flame Supervision.

• Safety shutdown with time-stamped display of lockout
condition.

• Variable speed control of the combustion fan.

• Supervision of low and high gas pressure, air proving, stack
back pressure, high limit, and low water.

• First-out annunciator.

• Real-time data trending.

• (3) pump/auxiliary relay outputs.

• Modbus communication capability.

• Outdoor temperature reset.

• Remote firing rate or setpoint control

• Setback/time-of-day setpoint

• Lead/Lag for up to 8 boilers

E

GAS INLET

F

TO VENTURI

C

D

E

A

B

Figure 1-2 Gas Train (8000 shown)

Part No. 750-363 1-3

Section 1 — Introduction

TRANSFORMER, 460/230/208V PRI, 115 V SECONDARY,
350VA, FUSED TOP

TRANSFORMER, 115v/25v

IGNITION TRANSFORMER
(FAR SIDE)

WATER LEVEL
CONTROL - LWCO

FALCON CONTROLLER, HYDRONIC

FUSE, 9 AMP

Figure 1-3 Control panel interior

1.2.5. Variable Speed Drive

Modulating combustion air fan speed is controlled by a Variable
Speed Drive mounted inside the front casing below the Falcon control
panel.

1.2.6. Component/Connection Locations

Figure 1-5 shows the CFLC component orientation and heat flow

path. The return water connections are at the lower vessel and the
hot water outlet is at the top of the boiler.

Figure 1-6 shows the locations of the safety valve and air vent
connections. Figure 1-7 shows the location of the return water
temperature sensor.

The stack is connected on the right side of the boiler when facing the
front. The flue gas duct sizes may be reduced at the vent connection.
See also Section 3,

Stack and Intake Vent Sizing and Installation.

TERMINAL TRACK

Figure 1-4 VSD (cutaway view)

1-4 Part No. 750-363

Section 1 — Introduction

Gas Train

Burner
Assembly

Control Panel

Flue/
condensate
collection
chamber

Condensate
drain

Air Vent (optional)

Water Outlet

TO STACK

Combustion
gas flow

LWCO probe holder

Furnace

Water circulation

Safety Valve(s)

EX Tubes

Alufer Tubes

Water
Return (2)

Boiler Drain

SAFETY VALVE(S)

Figure 1-5 CFLC Cutaway

AUTO AIR VENT
(OPTIONAL)

GATE VALVE

LWCO PROBE
HOLDER

Figure 1-6 Boiler safety valve(s) & air vent

Part No. 750-363 1-5

Section 1 — Introduction

Figure 1-7 Return temperature sensor (rear casing & insulation not shown)

WATER
OUTLET

OUTLET TEMP.
sensor well

COMBUSTION AIR FILTER

STACK OUTLET

Figure 1-8 Stack Outlet, Water Outlet, and Combustion Air Inlet

1-6 Part No. 750-363

Section 1 — Introduction

1.3 OPTIONAL EQUIPMENT

Certain project-specific options may have been supplied with the boiler if these options were specified at
the time of order entry. In addition, some options may have been provided (by others) that are not part of
Cleaver-Brooks’ scope of supply. In either case, the Cleaver-Brooks authorized representative should be
consulted for project specifics.

These are the options that are available for the CFLC boiler from Cleaver-Brooks:

A. Condensate neutralization tank assembly - consists of neutralizing media, filter, and PVC

condensate holding tank. This assembly is further described in Chapter 2.
B. Direct vent combustion air adapter kit
C. Outdoor temperature sensor for outdoor reset, frost protection, and warm weather shutdown
D. Header temperature sensor for multiple boiler Lead/Lag operation
E. Alarm Horn for safety shutdown
F. Relays for output signal for burner on, fuel valve open
G. Stack Thermometer
H. Stack temperature limit-sensor
I. Auto air vent
J. Boiler drain valve
K. Gas pressure relief valve
L. Gas pressure gauge
M. Water isolation valves
N. Hydronic circulating pumps
O. Seismic anchoring provisions

For options not listed, consult your authorized CB representative.

Part No. 750-363 1-7

Section 1 — Introduction

1-8 Part No. 750-363

Section 2

Installation

Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Boiler Room . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Flue gas / combustion air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Water treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Boiler flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Using glycol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Gas connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Boiler water piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

Minimum boiler overpressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Condensate removal and treatment . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

Wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Warning

!

Provisions for combustion and ventilation air must
be in accordance with the National Fuel Gas
Code, ANSI Z223.1, or the CAN/CSA B149
Installation Codes, or applicable provisions of the

local building codes. Failure to follow this warning

could result in personal injury or death.

Caution

The boiler must be installed such that the gas
ignition system components are protected from
water (dripping, spraying, rain, etc.) during
appliance operation and sevice. Failure to follow
this warning could result in equipment failure.

Warning

!

If an external electrical source is utilized, the boiler
when installed must be electrically bonded to
ground in accordance with the requirements of the
authority having jurisdiction, or in the absence of
such requirements with the National Electrical
Code ANSI/NFPA 70 and/or the Canadian
Electrical Code Part I CSA C22.1.

www.cleaverbrooks.com

Warning

!

The installation must conform to the require­ments of the authority having jurisdiction, or in
the absence of such requirements, to the
National Fuel Gas Code, ANSI Z223.1 and/or
CAN/CSA B149 Installation Codes.

Section 2 — Installation

2-2 Part No. 750-363

Section 2 — Installation

2.1 BOILER ASSEMBLY AND PLACEMENT

2.1.1 Packaging

The Cleaver-Brooks Model CFLC boiler is shipped fully assembled, ready for installation.

2.1.2 Lifting and moving the boiler

The Model CFLC boiler is lifted by means of the holes provided in the upper tube sheets. See rigging diagram
below.

Caution

!

In order to avoid damage to the unit, lifting or
moving the boiler should only be done by
experienced personnel suitably equipped for
moving heavy equipment.

Figure 2-1 CFLC Rigging

Note: The boiler
should not be moved
by pushing, prying, or
pulling on any part of
the casing.

Part No. 750-363 2-3

Section 2 — Installation

2.1.3 Boiler placement

The boiler or boilers should be mounted in accordance with Figure 2-2 below. Required front, rear, and side
clearances are shown. Under special circumstances, reduced side clearance between boilers may be
feasible. Contact your C-B authorized representative for assistance.

NOTE

The boiler assemblies are intended for installation in accordance with the appropriate
standards of the National Fire Protection Association and the building code recommended
by the American Insurance Association. Local codes may differ. Installation should provide
clearances to unprotected combustible material not less than those indicated in the
following:

Clearances to adjacent combustible construction not less than 36 inches from control
panel front, 24 inches from sides, and 36 inches above and rear. The floor beneath these
units may be combustible. In all cases, the flue pipe shall not pass through any floor or
ceiling or any combustible wall or partition unless suitably guarded.

Top Clearance = 36”

Figure 2-2 Clearance Required (inches)

2-4 Part No. 750-363

Section 2 — Installation

2.2 BOILER ROOM

The boiler room must comply with all building codes and regulations. An adequate supply of combustion
air is required for safe operation. If the optional sealed combustion/direct vent kit is used, ventilation must
be provided to meet applicable regulations for air supply.

Note: For further details on sealed combustion/direct vent kits, see Section 3, Stack and Intake Vent Sizing

and Installation and Section 6, Parts.

Clean combustion air is required for optimum efficiency and boiler operation. Dust and airborne
contaminants will adversely effect burner performance. An air filter is included to keep airborne
contamination from the burner.

If using sealed combustion/direct venting, the air intake should be positioned to keep rain or snow from
entering the intake piping.

The boiler must be installed so that the gas ignition system components are protected from water (dripping,
spraying, etc.) during appliance operation and service.

2.3 FLUE GAS / COMBUSTION AIR

The flue gases from the Model CFLC boiler should be removed via a gas-tight, temperature and corrosion
resistant flue gas pipeline. Only flue gas systems approved and tested by the relevant region or province are
to be connected to the boiler. Refer to flue piping manufacturer for proper installation and sealing
instructions. See also Chapter 3 of this manual for combustion air and flue gas venting requirements.

Table 2-1. Boiler room environmental limits

Maximum temperature 122 deg F
Minimum temperature 32 deg F
Humidity 90% RH non condensing

Warning

!

The boiler must not be installed on carpeting.

2.4 WATER TREATMENT

Cleaver-Brooks ClearFire condensing boilers are suitable for heating systems without significant oxygenation
capacity. Systems with continuous oxygenation capacity due to unknown or unseen leaks must be equipped
with a system separation or pretreatment device. Closed loop hydronic systems should incorporate air
separation, dirt elimination, and air venting.

Clean, soft water is generally the best heating medium for filling and make-up water in systems utilizing the
Model CFLC. If the water available from the main system is not suitable for use, then demineralization and/
or treatment with inhibitors is necessary. Treated filling and make-up water must be checked at least once
a year or more frequently if so specified in the application guidelines from the inhibitor manufacturer.

Those parts of the boiler in contact with water are manufactured with both ferrous materials and corrosion­resistant stainless steel. The chloride content of the heating water should not exceed 30 ppm and the pH
level should be between 8.3 to 10.5 after six weeks of operation.

To maintain the boiler's efficiency and prevent overheating of the heating surfaces, the values in Table 2-2
should not be exceeded. Water make-up during the lifetime of the boiler should not be greater than 3 times
the system volume. A water meter should be installed on the makeup line to monitor makeup water volume.

Should the system require flushing or cleaning after installation of the CFLC, take care that no particulate
matter reaches the boiler during the cleaning process.

Part No. 750-363 2-5

Section 2 — Installation

Note: Corrosion and sludge deposits in old systems must be removed

prior to installation of a new boiler.

Table 2-2 Model CFLC Water Chemistry Requirements

Parameter Limit Means of control

Glycol 25-50% Glycol fill/mixing station

pH 8.3 - 10.5 Buffering agent

Nitrates 50 ppm
Sulfates 50 ppm
Chloride < 250 ppm

Oxygen < 0.1 ppm Air separator/eliminator

Specific Conductivity

< 3500 mmho/cm

Total Hardness < 10 ppm Softener

Table 2-3 Model CFLC Water Temperature Data (Non-Glycol)

Minimum inlet temp. 33
Maximum operating supply set point temp. 230
Maximum design temp. 250
Minimum supply set point temperature 130
Max allowable Delta T 100

Chemical additives

o

F

o

F

o

F

o

F

o

F

2.5 BOILER FLUSH

Cleaver-Brooks recommends cleaning in accordance with the recommendations of the boiler owner’s water treatment
company for each individual site. The boiler may be flushed with or without heat applied, as deemed appropriate by the
chemical treatment company. A traditional steam “Boil Out” is not required on Cleaver-Brooks hot water boilers.

Following are some general recommendations to help ensure long boiler life and efficient operation.

NOTE: these are recommendations only. The chemical treatment supplier should recommend a procedure based on
the site conditions and quality of water being used to fill the system.

If the entire system is being flushed THROUGH the boiler, weld slag and deposits from the piping system may settle in
the boiler. The boiler is typically a low velocity zone where these deposits tend to accumulate. The boiler should be
drained periodically during the flushing process to keep any deposit build up to a minimum. When the system flush is
complete, drain the boiler completely and open water side inspection ports for visual inspection. Any deposits should be
manually flushed out.

If the boiler is isolated during the system flush, or if this is an equipment replacement only where minimal amounts of
system piping have been replaced, there should be minimal manufacturing deposits inside the boiler and no boiler flush
is required.

To provide the longest life of the equipment it is recommended but not mandatory to chemically treat the boiler prior to
start-up. The owner’s water treatment company should determine needed course of action for each installation.

2.6 USING GLYCOL

The Model CFLC boiler may be operated with a solution of glycol and water. Where glycols are added, the
system must first be cleaned and flushed. Correct glycol selection and regular monitoring of the in-use
concentration and its stability is essential to ensure adequate, long-term freeze protection, including
protection from the effects of glycol-derived corrosion resulting from glycol degradation.

2-6 Part No. 750-363

Section 2 — Installation

Typically, ethylene glycol is used for freeze protection, but other alternatives exist, such as propylene glycol.
Glycol reduces the water-side heat capacity (lower specific heat than 100% water) and can reduce the
effective heat transfer to the system. Because of this, design flow rates and pump selections should be sized
with this in mind.

Generally, corrosion inhibitors are added to glycol systems. However, all glycols tend to oxidize over time in
the presence of oxygen, and when heated, form aldehydes, acids, and other oxidation products. Whenever
inadequate levels of water treatment buffers and corrosion inhibitors are used, the resulting water glycol
mixture pH may be reduced to below 7.0 (frequently reaching 5) and acid corrosion results. Thus, when
pH levels drop below 7.0 due to glycol degradation the only alternative is to drain, flush, repassivate, and
refill with a new inhibited glycol solution.

The following recommendations should be adhered to in applying ClearFire model CFLC boilers to hydronic
systems using glycol:

1) Maximum allowable antifreeze proportion (% volume):
50% antifreeze (glycol)
50% water

2) Glycol minimum temperature rating 300 deg F (149 deg C).

3) Maximum allowable boiler outlet/supply temperature: 200 deg F (93 deg C).

4) Minimum water circulation through the boiler:

a) The minimum water circulation must be defined in such a way that the temperature difference between the boiler

outlet/supply and inlet/return is a maximum of 40 deg F (22 deg C), defined as DT (Delta T). A DT Limit algorithm

should be enabled in the boiler controller.

b) Independent from the hydraulics of the heating system, regular water circulation through each boiler is required

while the boiler is operating (requires a dedicated boiler pump if in a primary/secondary loop arrangement). Refer
to table below for minimum boiler circulation rates.

5) Minimum over-pressure at the boiler:

For outlet temperatures up to the maximum of 200 deg F (93 deg C), a minimum operating pressure of 30 psig (2.1 bar) is
required.

6) pH level should be maintained between 8.3 and 10.5

Table 2-4 Glycol Application Guidelines — ClearFire Model CFLC

Minimum required boiler circulation rate (gpm) at maximum firing rate

ClearFire
Model-Size

CFLC-4000

CFLC-5000

CFLC-6000

CFLC-8000

CFLC-10000

CFLC-12000

Notes/Limitations:

1. Glycol concentration limit of 25%-50%. Minimum required system operating pressure is 30 psig.

2. Maximum system operating temperature of 200 ˚F. Maximum ΔT of 40˚.

3. Circulation rates correlate with boiler output based on 92% nominal efficiency.

4. Standard altitude (<2000' ASL). Contact C-B for high altitude applications.

5. Pumps should be sized based on system design ΔT and minimum required flow rates.

6. At minimum firing rate, the minimum circulation rate should correspond to the boiler's turndown.

ΔT = 10˚ ΔT = 20˚ ΔT = 30˚ ΔT = 40˚

813 407 271 203

1016 508 339 254

1220 610 374 281

1626 813 499 368

2033 1016 624 468

2439 1220 749 562

System ΔT (˚F)

Part No. 750-363 2-7

Section 2 — Installation

2.7 GAS CONNECTIONS

2.7.1 General

The ClearFire Model CFLC gas fired condensing boilers use full modulating burners that require appropriate
gas supply pressure and volume for proper operation. The gas requirements specified in this section must
be satisfied to ensure efficient and stable combustion. Installation must follow these guidelines and those
of any local authorities having installation jurisdiction.

2.7.2 Gas Train Components

CFLC boilers are equipped with a gas train that meets the requirements of ASME CSD-1, FM and XL-GAP
(formerly IRI). The gas train and its components have been designed and tested to operate for the highest
combustion efficiency for the CFLC units.

Leak test cocks

Manual
shutoff valve
(MSOV)

High pressure
regulator (optional)

Gas valve, top view

Low gas press. switch

Figure 2-3 CFLC Gas Train (typical)

MSOV

High gas press. switch

Double-body gas valve

2-8 Part No. 750-363

Section 2 — Installation

2.7.3 Gas Pressure Requirements

For proper and safe operation, each CFLC Series boiler requires a stable gas supply pressure. See table
below for pressure requirements. Refer also to

Table 2-5 CFLC gas pressure requirements

Gas Supply Pressure (at gas regulator outlet)

Natural Gas 20ppm Natural Gas 9ppm Propane

Boiler

size
4000 9 14 10 14 9 14 3-5
5000 9 14 10 14 9 14 3-5
6000 35 56 35 56 31 56 3-5
8000 35 56 42 56 31 56 3-5

10000 38 56 38 56 35 56 3-5
12000 38 56 40 56 35 56 3-5

Min

(“WC)

Max*

(“WC)

Min

(“WC)

*Listed max. pressures are without the use of a step-down regulator. The CFLC can accommodate higher
supply pressures with the addition of an upstream regulator:

CFLC 4000 - 5000 >1/2 psig requires step-down regulator

>5 psig requires overpressure protection

CFLC 6000 - 12000 >2 psig requires step-down regulator

>7 psig requires overpressure protection

When an upstream regulator is installed, required minimum pressures will be higher due to the pressure
drop across the regulator.

Actual gas pressure should be measured when the burner is firing using a manometer at the upstream test
port connection on the main gas valve. For a multiple unit installation, gas pressure should be set for a
single unit first, then the remaining units should be staged on to ensure that gas supply pressure drop is
not more than 7" w.c. and never below the required pressure. Fluctuating gas pressure readings could be
indicative of a faulty supply regulator or improper gas train piping to the boiler. Refer to Tables 2-6 and 2­7 for gas piping recommendations.

APPENDIX C - GAS VALVE.

Max*

(“WC)

Min

(“WC)

Max

(“WC)

Gas pilot pressure

(“WC)

To measure pilot gas pressure, use the test port on the pilot solenoid valve.

VALVESOLENOID PILOT

COCKGAS SERVICE

Test Port

Figure 2-4 Pilot train

Part No. 750-363 2-9

Section 2 — Installation

2.7.4 Gas Piping

A dedicated pressure regulator is recommended for each CFLC boiler when the gas supply exceeds the
maximum values in Table 2-5. If below the referenced max. gas supply pressure and no step-down regulator
is installed, the CFLC gas train does not require gas venting (the pilot gas regulator may require a vent
limiter at its vent connection depending on the local code requirements).

The regulator for each boiler must be installed outside the boiler enclosure with at least 2 feet of pipe
between the regulator and the boiler gas valve connection. The discharge range of the regulator must be able
to maintain steady gas pressures as noted in Table 2-5.

For buildings or boiler rooms with gas supply pressure exceeding 14” WC (CFLC 4000/5000) or 2 psi (CFLC
6000-12000) a “full lock-up” type regulator is required.

In addition to the regulator, a full port plug type or “butterball” type gas shutoff valve must be installed
upstream of the regulator for use as a service valve. This is also required to provide positive shutoff and
isolate the unit during gas piping tests.

It is recommended that a strainer be installed upstream of the regulator or boiler gas connection to remove
debris from the gas supply.

Drip legs are required on any vertical piping at the gas supply to each boiler so that any dirt, weld slag, or
debris can deposit in the drip leg rather than into the boiler gas train. The bottom of the drip leg should
removable without disassembling any gas piping. The connected piping to the boiler should be supported
from pipe supports and not supported by the boiler gas train or the bottom of the drip leg.

All gas piping and components to the boiler gas train connection must comply with NFPA 54, local codes,
and utility requirements as a minimum. Only gas approved fittings, valves, or pipe should be used. Standard
industry practice for gas piping is normally Schedule 40 black iron pipe and fittings.

Before starting the unit(s) all piping must be cleaned of all debris to prevent its entrance into the boiler gas
train. Piping should be tested as noted in NFPA 54 and the boiler must be isolated during any tests.

After initial startup, the inlet screen to the gas valve should be checked and cleaned of any debris buildup
that may have resulted from installation.

See Figure 2-5 for a typical piping configuration.

Caution

!

The boiler and its individual shutoff valve must be disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in excess of 1/2 psi (3.5 kPa).
The boiler must be isolated from the gas supply piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/
2 psi (3.5 kPa).

2-10 Part No. 750-363

Figure 2-5 Gas Piping

Section 2 — Installation

TO GAS TRAIN

As required

Same or large r tha n boiler ga s connect ion
size

As required

As required

Ga s header - size for boiler room

capacity and to minimize press ure loss

Dr ip le g r e quir e d f or a ny ver t ic a l ru n of
pipi ng

2.7.5 Gas Supply Pipe Sizing

For proper operation of a single unit or a multiple unit installation, CB recommends that the gas piping be
sized to allow no more than 0.3" w.c. pressure drop from the source (gas header or utility meter) to the final
unit location. Higher supply pressure systems may allow for a greater pressure drop. In ALL cases, minimum
supply pressures must be met for proper operation of the boiler(s). The gas supplier (utility) should be
consulted to confirm that sufficient volume and normal pressure are provided to the building at the
discharge side of the gas meter or supply pipe.

For installations of new boilers into an existing building, gas pressure should be measured with a
manometer to ensure sufficient pressure is available. A survey of all connected gas-using devices should be
made. If appliances other than the boiler or boilers are connected to the gas supply line, then a
determination must be made of how much flow volume (cfh) will be demanded at one time and the pressure
drop requirement when all appliances are firing.

The total length of gas piping and all fittings must be considered when sizing the gas piping. Total equivalent
length should be calculated from the utility meter or source to the final unit connection. As a minimum
guideline, see gas piping Tables 2-6 and 2-7. The data in these tables is from the NFPA 54 source book,
2006 edition.

To verify the input of each device that is connected to the gas piping, obtain the btu/hr input and divide this
input by the calorific value of the gas that will be utilized. For instance, a unit with 4,000,000 btu/hr input
divided by a gas calorific value of 1060 will result in a flow of 3774 cfh. The single boiler is approximately
20 feet from the gas supply header source. And with a measured gas supply pressure of 10" w.c. we find
from Table 2-6 that a supply pipe size of 3" should be used as a minimum.

Part No. 750-363 2-11

Section 2 — Installation

Table 2-6: Gas Line Capacity - Schedule 40 Metallic Pipe

Pipe Size
Nominal 2-1/2" 3" 4"
Actual I.D. 2.469" 3.068" 4.026"
Length in feet **Maximum Capacity in Cubic Feet of Gas per Hour (cfh)
10 4,860 8,580 17,500
20 5,900 12,000
30 9,660
40 8,290
50 7,330
60 6,640
70 6,110
80 5,680
90 5,330
100 5,040
125 4,460
150 4,050
175
200
**Fuel: Natural Gas
**Inlet Pressure: Less than 2.0 psi

**Pressure Drop: 0.30" w.c.

**Specific Gravity: 0.60

Table 2-7: Gas Line Capacity - Schedule 40 Metallic Pipe

Pipe Size
Nominal 2" 2-1/2" 3" 4"
Actual I.D. 2.067" 2.469" 3.068" 4.026"
Length in feet **Maximum Capacity in Cubic Feet of Gas per Hour (cfh)
10 4,020 6,400 11,300 23,100
20 4,400 7,780 15,900
30 6,250 12,700
40 5,350 10,900
50 4,740 9,600
60 4,290 8,760
70 8,050
80 7,490
90 7,030
100 6,640
125 5,890
150 5,330
175 4,910
200 4,560
**Fuel: Natural Gas
**Inlet Pressure: Less than 2.0 psi

**Pressure Drop: 0.50" w.c.

**Specific Gravity: 0.60

2-12 Part No. 750-363

Section 2 — Installation

4

2.7.6 Gas Header

Design of a single common gas header with individual takeoffs for a multiple unit installation is
recommended. Boiler gas manifold piping should be sized based on the volume requirements and lengths
between boilers and the fuel main header.

For installations with a mixed sized use, determine the flow of each unit and total the input. With the total
input, determine length of run from the source and determine what size header will be needed for the flow
of all units firing.

Figure 2-6 Gas header piping

From
Meter

Manua l Shut Off

Gas Strainer

Re g ula to r
See Note 1

Gas Hea der Piping, Typical

Header Pipe

Re lie f Valve
See Note 5

NOTES:

1. Dedicated gas pressure regula tor required for each boiler if gas supply greater than max. pressure in Table 1

2. Refer to local fuel gas codes when applicable.

3. Header to be sized for room capacit y.

4. Provision required for measuring gas supply pressure at boiler.

5. Ove rpre ss ur e prote ct ion re quired if gas supply press ure > 5 ps ig.

Part No. 750-363 2-13

Section 2 — Installation

2.8 BOILER WATER PIPING

2.8.1 General

All boiler hot water outlet and return piping is connected at the rear of the boiler. Piping is to be installed
per local codes and regulations.The pipelines for the hot water outlet and return may be connected in the
usual manner without removing the cladding elements. Unused connectors must be safely blanked off.

2.8.2 Safety valve

The pressure relief valve (safety valve) should be piped from the coupling on top of the boiler (see Figure
2-7). Use pipe sealing compound and a flat sided wrench when securing the Safety relief valve. Do not use

a pipe wrench and do not over tighten the relief valve. The safety valve must be mounted in a vertical
position so that discharge piping and code-required drains can be properly piped to prevent buildup of back
pressure and accumulation of foreign material around the valve seat area. Apply only a moderate amount
of pipe compound to male threads and avoid overtightening, which can distort the seats. Use only flat­jawed wrenches on the flats provided.

Figure 2-7 Safety relief valve piped to safe point of discharge

Warning

!

Only properly certified personnel such as the safety valve
manufacturer’s certified representative should adjust or repair the
boiler safety valve. Failure to follow this warning could result in

serious personal injury or death.

2.8.3 Dual return design

The Model CFLC features separate high and low temperature return water connections, allowing for
condensing performance within high temperature hydronic systems. With as little as 10% return water at
or below 120 deg F, the Model CFLC will achieve condensing performance, with associated gains in
efficiency.

2-14 Part No. 750-363

Section 2 — Installation

If using only a single (common) return, the low temperature connection should be used. The low
temperature connection is on the left when facing the rear of the boiler.

Low Temp.
Return

High Temp.
Return

Figure 2-8 Dual returns

2.8.4 Pressure drop curves

The information in Figure 2-9 and in Tables 2-8 and 2-9 can help in determining pump requirements for
Model CFLC installations.

Part No. 750-363 2-15

Section 2 — Installation

CFLC 4000 CFLC 5000

Pressure PSI

Pressure PSI

Flow rate GPM

CFLC 6000

Flow rate GPM

Pressure PSI

Flow rate GPM

CFLC 8000

Pressure PSI

Flow rate GPM

Pressure PSI

CFLC 10000

Pressure PSI

Flow rate GPM

CFLC 12000

Flow rate GPM

Figure 2-9 Pressure Drop Curves, CFLC

2-16 Part No. 750-363