CleaverBrooks FLX Series

Questions and Answers

M
munozalyssaAug 23, 2025
What to do if there is a pilot flame but no main flame in my CleaverBrooks FLX Boiler?
- A
  Antonio HawkinsAug 23, 2025
  If your CleaverBrooks Boiler shows a pilot flame but no main flame, first consider if the unit is gas-fired or oil-fired. For gas-fired units, check if the manual gas cock is closed, if the main gas valve is inoperative, or if the gas pressure regulator is malfunctioning. For oil-fired units, ensure the oil supply isn't cut off by an obstruction, closed valve, or loss of suction. Also, verify the supply pump is operational, there is sufficient fuel, the main oil valve is working, and the oil nozzle, gun, and lines are clear. Additionally, check the flame detector for defects, obstructions in the sight tube, or a dirty lens. Furthermore, verify sufficient voltage at the main fuel valve circuit terminal and ensure that the pilot flame is sufficient.
A
Alexander DanielAug 26, 2025
How to fix CleaverBrooks Boiler burner that does not start?
- M
  Mark NashAug 26, 2025
  If the CleaverBrooks Boiler burner does not start, here are a few things to check: * Ensure there is voltage at the program relay power input terminals by verifying the main disconnect switch is not open, the control circuit fuse is intact, and all electrical connections are secure. * Reset the program relay safety switch, if necessary. * Confirm the limit circuit is completed by checking pressure, temperature, and water levels. * Verify fuel pressure is within the settings of the low and high-pressure switches, and inspect the burner air proving switch and high-fire limit switch. * Investigate and repair any high or low gas pressure issues.
C
Cassandra HolmesSep 2, 2025
Why is the modulating motor not operating in my CleaverBrooks Boiler?
- A
  Anna JohnsonSep 2, 2025
  If the modulating motor in your CleaverBrooks Boiler is not operating, here are some things to investigate: * Ensure the manual-automatic switch is in the correct position. * Check for any looseness or jamming in the linkage. * If the motor does not drive to open or close during pre-purge or close on burner shutdown: * Inspect the motor for defects. * Check for loose electrical connections. * Test the damper motor transformer for defects. * If the motor does not operate on demand: * Ensure the manual-automatic switch is in the correct position. * Verify the modulating control is properly set and operative. * Inspect the motor for defects. * Check for loose electrical connections. * Test the damper motor transformer for defects.
J
Jennifer HodgesSep 4, 2025
Why does my CleaverBrooks Boiler burner stay in low-fire?
- M
  mark69Sep 5, 2025
  If the CleaverBrooks Boiler burner remains in low-fire, here’s what you should check: * Verify if the pressure or temperature is above the modulating control setting. * Confirm that the manual-automatic switch is in the correct position. * Inspect the modulating motor for proper operation. * Check the modulating control for any defects. * Look for any binding or loose linkages, cams, setscrews, etc.
J
jacksontiffanySep 9, 2025
Why does my CleaverBrooks Boiler shut down during firing?
- M
  Michael SheltonSep 9, 2025
  A CleaverBrooks Boiler shutting down during firing can stem from several issues. It could be due to a loss or stoppage of the fuel supply or a defective fuel valve with a loose electrical connection. The flame detector might be weak or defective, or the lens could be dirty, or the sight tube obstructed. Check the limit circuit for an opened safety control if the programmer lockout switch hasn't tripped. If the programmer lockout switch has tripped, investigate the cause. Inspect the fuel lines and valves. Check the flame detector. Look for an open circuit in the running interlock circuit. The flame failure light indicates ignition failure, main flame failure, inadequate flame signal, or an open control in the running interlock circuit.
J
Jill ThompsonSep 14, 2025
Why is there excessive rust on the tubes of my CleaverBrooks FLX Boiler?
- C
  Christopher HughesSep 14, 2025
  Excessive rust on the tubes of your CleaverBrooks Boiler is often due to condensation of flue gases on cool tubes. Modify the system to ensure return temperatures are above 120°F, or install a blend pump to guarantee water entering the boiler exceeds 120°F. An open stack or condensate running down the stack or breeching can also contribute; consider offsetting, insulating, and draining the stack. Frequent cold starts can exacerbate the issue; try resetting the controls for less cycling.
J
Jerry BrewerNov 17, 2025
Why is there no ignition in my CleaverBrooks FLX?
- K
  kellyadamsNov 17, 2025
  If there's no ignition in your CleaverBrooks Boiler, here's what to check: * Lack of spark: Check the electrode for grounding or cracks, ensure the electrode setting is correct, verify the ignition cable is securely connected and not shorted, test the ignition transformer, and confirm sufficient voltage at the pilot ignition circuit terminal. * Spark but no flame: Ensure there's fuel supply with adequate gas pressure, open fuel valve, and full tank, check for excessive airflow, verify voltage to the pilot solenoid, inspect for a defective pilot solenoid, and properly position the electrode (for direct spark models). * Low-fire switch open: Confirm the damper motor is closed, check for slipped cam or defective switch, and ensure the damper isn't jammed or the linkage binding. * Run...
J
Jonathan RiversNov 19, 2025
What to do if my CleaverBrooks FLX has no ignition?
- E
  Ernest ClarkNov 19, 2025
  If your CleaverBrooks Boiler isn't igniting, begin by checking for spark. A grounded electrode, cracked porcelain, loose terminal on the ignition cable, shorted cable, or an inoperative ignition transformer can all cause a lack of spark. Also, check for sufficient voltage at the pilot ignition circuit terminal. If there's a spark but no flame, ensure there's an adequate fuel supply, the pilot solenoid is working, and there's sufficient voltage at the pilot ignition circuit terminal. Too much air can also prevent ignition. Check the damper motor, ensuring it's closed and the switch isn't defective, opening the low fire switch in the low fire proving circuit. Make sure the damper isn't jammed and the linkage isn't binding. Ensure the running interlock circuit is completed, and the combustion...
D
Dennis HarveyNov 27, 2025
What to do if CleaverBrooks FLX Boiler shutdown occurs during firing?
- K
  Katherine HuertaNov 27, 2025
  If the CleaverBrooks Boiler experiences a shutdown during firing, consider the following: * Check for any loss or stoppage of fuel supply. * Inspect the fuel valve for defects and ensure all electrical connections are secure. * Examine the flame detector for any signs of weakness or defects. * Clean the scanner lens and ensure the sight tube is not obstructed. * If the programmer lockout switch hasn't tripped, examine the limit circuit for any opened safety control. * If the programmer lockout switch has tripped, check fuel lines and valves, the flame detector, and the running interlock circuit for any open circuits. * Check for improper air/fuel ratio due to slipping linkage, a stuck damper, or fluctuating fuel supply. * Ensure the interlock device is operative and not de...
J
Jennifer BennettDec 1, 2025
What to do if CleaverBrooks Boiler has pilot flame, but no main flame?
- P
  peckandreaDec 1, 2025
  If the CleaverBrooks Boiler has a pilot flame but no main flame, consider the following troubleshooting steps: * Ensure the pilot flame is sufficient. * For gas-fired units: * Verify the manual gas cock is open. * Check if the main gas valve is inoperative. * Inspect the gas pressure regulator for proper function. * For oil-fired units: * Confirm the oil supply is not cut off by any obstruction, closed valve, or loss of suction. * Check if the supply pump is inoperative. * Ensure there is fuel and inspect the oil pump coupling for breaks, looseness, or if it's missing. * Verify the main oil valve is operative. * Check the oil nozzle, gun, and lines. * Check the flame detector for defects, obstructions in the sight tube, or a dirty le...

CleaverBrooks FLX Series Specifications

General

Boiler Type	Firetube
Heat Exchanger Material	Carbon Steel
Fuel Type	Natural Gas
Operating Pressure	Up to 300 psi
Applications	Commercial, Industrial, Institutional

Summary

CHAPTER 1 General Description

General Boiler Overview

Covers manual scope, boiler input range, fuel types, and design pressures.

Boiler Construction and Components

Details the five-pass steel boiler construction, ASME code compliance, and system components.

Steam Boiler Applications

Explains steam boiler design for low and high pressure applications based on psig.

Hot Water Boiler Applications

Describes hot water boiler use in heating, operating pressure, and temperature ranges.

Steam and Hot Water Controls

Explains steam and hot water controls including pressure/temperature limits and low water cutoffs.

CHAPTER 2 Profire V Burner

Burner Introduction and Specifications

Introduces V series burners, listing certifications and model sizes for FLX boilers.

Burner Control Panel and Operation

Details panel components like switches, lamps, and flame safeguard controls for burner operation.

Combustion Air Handling System

Explains combustion air system components, including blower, diffuser, and air supply requirements.

Firing Head and Oil System

Describes the radial spud firing head and key components of the oil system, including nozzle and valves.

Gas System Components and Operation

Details gas train components like valves, regulators, and pressure switches for gas operation.

Pilot Gas Train and Installation

Covers pilot gas train components and installation considerations, including draft conditions.

Burner Startup and Operation

Outlines startup procedures, burner operation, and initial checks before firing.

Burner Firing Modes and Sequences

Explains Low-High-Low and Full Modulation firing modes and their operating sequences.

Burner Adjustments Overview

Introduces adjustments for efficiency, covering combustion, stack temperature, and smoke measurements.

Gas System Adjustments

Guides on adjusting gas pilot flame, pressure, flow, combustion, and pressure switches.

Oil System Adjustments

Provides instructions for adjusting oil pressure, temperature, and combustion for various oil burners.

Combination Gas-Oil System Adjustments

Guides on adjusting combination gas-oil systems, starting with oil then adjusting gas.

Modulation and Air;Fuel Control

Covers linkage adjustments, modulating motor, air shutters, and fuel/air ratio control.

Burner Maintenance Procedures

Outlines maintenance for controls, air handling, firing head, pilot, electrodes, and flame scanner.

Burner Troubleshooting

Lists common burner problems and their solutions, covering start, ignition, shutdown, and motor issues.

Burner Specifications

Lists model characteristics, maximum input, burner models, and fan motor specifications.

CHAPTER 3 Pressure Vessel Care

General Waterside Care

Emphasizes proper water treatment for boiler life, covering hot water system circulation and air removal.

Steam Boiler Water Requirements

Details deaeration, feed water supply, and minimum feed water flow rates for steam boilers.

Water Treatment Objectives

Outlines water treatment goals to prevent scale and corrosion, and recommends consulting experts.

Blowdown Procedures

Explains periodic blowdown to lower solids concentration, its effectiveness, and the blowdown procedure.

Boiler Cleaning and Boilout

Describes cleaning the boiler, necessary chemical solutions for boilout, and the boilout procedure.

Waterside Inspection and Layup

Covers periodic inspections, waterside checks, and preparation for extended boiler layup.

CHAPTER 4 Sequence of Operation

General Operation Sequence

Outlines the overall sequence of controls for pre-purge, ignition, run, and shutdown cycles.

Circuit and Interlock Controls

Explains the burner control circuit, types of controls, and their functions in the system.

Oil or Gas Firing Sequence

Details the operational sequence for oil or gas firing, including pre-purge, ignition, and run cycles.

Flame Loss Sequence

Describes actions taken during flame loss, safety shutdowns, and lockout conditions.

CHAPTER 5 Adjustment Procedures

General Adjustment Principles

Explains the need for adjustments due to variable conditions and the role of combustion analysis.

Linkage, Motor, and Switch Adjustments

Covers adjustments for linkage, modulating motor travel, and low/high fire switches.

Boiler Operating Controls Adjustment

Details setting adjustments for operating limit, modulating controls, and pressure/temperature controls.

Steam Pressure Control Adjustments

Covers adjustments for modulating, operating limit, and high limit pressure controls for steam.

Hot Water Temperature Control Adjustments

Details adjustments for modulating, operating limit, and high limit temperature controls for hot water.

Gas System Adjustments

Guides on adjusting gas pilot flame, pressure, flow, combustion, and pressure switches.

Fuel Oil System Adjustments

Provides instructions for adjusting oil pressure, temperature, and combustion for various oil burners.

CHAPTER 6 Troubleshooting

General Troubleshooting Approach

Emphasizes safety, understanding the system, and systematic checks for pinpointing issues.

Burner Start and Ignition Issues

Addresses problems like burner not starting, lack of spark, or spark but no flame.

Flame and Shutdown Issues

Covers troubleshooting pilot flame, main flame, low fire operation, and shutdowns during firing.

Motor and Rust Issues

Details problems with the modulating motor not operating and excessive rust on tubes.

Water on Base Issues

Explains causes for water on the base, including condensation and gasket leaks.

CHAPTER 7 Inspection and Maintenance

General Maintenance Program

Stresses the importance of a planned maintenance program for safety, efficiency, and longevity.

Periodic Inspection Procedures

Outlines requirements for periodic inspections, including pressure vessel and component checks.

Fireside and Upper Pass Cleaning

Describes cleaning soot from heat exchanger surfaces and the upper pass areas of the boiler.

Controls and Safety Devices Maintenance

Details maintenance for relief valves, low water cutoff devices, and flame safeguard controls.

Burner System Maintenance

Covers maintenance for oil burners (strainers) and gas burners (valves), including refractory and casing seals.

CHAPTER 8 PARTS

Flextube Casing Parts

Lists parts for Flextube casings for Hot Water, Low Pressure Steam, and High Pressure Steam.

Controls Parts

Details parts for steam pressure controls, water level controls, and water columns.

Safety Valves Parts

Provides information on safety valves required for different pressure ranges and boiler sizes.

Related product manuals

CleaverBrooks FLX

110 pages

CleaverBrooks FLX 700

136 pages

CleaverBrooks FLX 150

CleaverBrooks CBEX-DE

124 pages

CleaverBrooks CFC-E 2000

61 pages

CleaverBrooks CBEX Elite

134 pages

CleaverBrooks CFC-E Series

61 pages

CleaverBrooks CFC ClearFire

70 pages

CleaverBrooks ClearFire CFC-E

54 pages

CleaverBrooks FLX Series - User Manual

Table of Contents

Questions and Answers

CleaverBrooks FLX Series Specifications

Summary

CHAPTER 1 General Description

General Boiler Overview

Boiler Construction and Components

Steam Boiler Applications

Hot Water Boiler Applications

Steam and Hot Water Controls

CHAPTER 2 Profire V Burner

Burner Introduction and Specifications

Burner Control Panel and Operation

Combustion Air Handling System

Firing Head and Oil System

Gas System Components and Operation

Pilot Gas Train and Installation

Burner Startup and Operation

Burner Firing Modes and Sequences

Burner Adjustments Overview

Gas System Adjustments

Oil System Adjustments

Combination Gas-Oil System Adjustments

Modulation and Air;Fuel Control

Burner Maintenance Procedures

Burner Troubleshooting

Burner Specifications

CHAPTER 3 Pressure Vessel Care

General Waterside Care

Steam Boiler Water Requirements

Water Treatment Objectives

Blowdown Procedures

Boiler Cleaning and Boilout

Waterside Inspection and Layup

CHAPTER 4 Sequence of Operation

General Operation Sequence

Circuit and Interlock Controls

Oil or Gas Firing Sequence

Flame Loss Sequence

CHAPTER 5 Adjustment Procedures

General Adjustment Principles

Linkage, Motor, and Switch Adjustments

Boiler Operating Controls Adjustment

Steam Pressure Control Adjustments

Hot Water Temperature Control Adjustments

Gas System Adjustments

Fuel Oil System Adjustments

CHAPTER 6 Troubleshooting

General Troubleshooting Approach

Burner Start and Ignition Issues

Flame and Shutdown Issues

Motor and Rust Issues

Water on Base Issues

CHAPTER 7 Inspection and Maintenance

General Maintenance Program

Periodic Inspection Procedures

Fireside and Upper Pass Cleaning

Controls and Safety Devices Maintenance

Burner System Maintenance

CHAPTER 8 PARTS

Flextube Casing Parts

Controls Parts

Safety Valves Parts

Related product manuals