An industrial burner that has been tested before shipment still needs to be checked and commissioned after it is installed on the actual boiler or thermal equipment. The burner may arrive with suitable initial ignition settings, but the conditions it encounters on site can be very different from those used during factory testing.
Fuel pressure, combustion chamber resistance, chimney draft, electrical supply, fuel characteristics, installation geometry and control signals can all influence the first startup. Successful factory testing provides a useful starting point, but it does not replace final commissioning under actual operating conditions.
For boiler manufacturers, burner distributors, commissioning engineers and industrial plant operators, understanding this distinction can prevent unnecessary adjustment and make startup problems easier to diagnose.
Why Industrial Burner Commissioning Matters
Factory testing and site commissioning serve different purposes.
Factory testing verifies that the burner can complete the required ignition sequence and operate correctly under controlled test conditions. Site commissioning confirms whether the burner, boiler or furnace, fuel system, combustion air system, flue system and controls can operate correctly together under the conditions of the actual project.
The difference matters because the burner is only one part of the complete combustion system. Available fuel pressure, furnace resistance, electrical conditions, process load, combustion air supply, chimney draft and installation details can all affect startup and combustion after installation.
The purpose of commissioning is therefore not to keep changing settings until the flame simply “looks right.” It is to verify the installation, establish reliable ignition, confirm combustion performance throughout the required firing range and record the final operating settings.
BAITE Burners Are Ignition-Tested Before Shipment
Before shipment, BAITE industrial burners undergo ignition testing as part of the factory preparation process. The burner is fired to confirm that the ignition sequence, flame establishment and relevant burner components operate normally under the available test conditions.
The initial ignition-related settings are also adjusted to a practical starting position before shipment. This gives the installer a known starting point for the first site startup and can reduce unnecessary adjustment during commissioning.
However, this initial factory setting should not be treated as the final combustion setting for every boiler or furnace.
A burner that ignites normally during factory testing may still require adjustment after it is installed on the customer's equipment because the operating environment has changed.
Typical differences include:
- Actual gas inlet pressure being different from the factory test condition
- Gas pressure dropping as fuel demand increases
- Different oil quality, viscosity or fuel supply conditions
- Boiler or furnace back pressure
- Combustion chamber dimensions and burner-head insertion position
- Chimney draft or flue-system resistance
- Altitude and ambient air conditions
- Electrical voltage, frequency or phase conditions
- Control wiring and external interlock configuration
- Different minimum and maximum operating loads
Factory ignition testing therefore improves startup readiness, but it cannot guarantee that every burner will ignite and operate correctly at every installation without further adjustment.
If a factory-tested burner does not ignite correctly after installation, the first response should not be to change several burner settings at once. Fuel supply, combustion air, electrical conditions, furnace pressure, burner installation and the ignition sequence should first be checked systematically.
Information Required Before Burner Startup
Before welcoming the burner, the commissioning engineer should have access to the burner manual, wiring diagram, boiler or furnace information, fuel specifications and the required control sequence.
| Information | What Should Be Confirmed |
|---|---|
| Burner | Model, capacity range, fuel, firing mode and combustion-head configuration |
| Heated equipment | Boiler or furnace output, combustion chamber dimensions and expected furnace pressure |
| Fuel supply | Fuel type, available inlet pressure, regulator or pump settings and required flow capacity |
| Electrical supply | Voltage, phase, frequency, grounding and motor rotation |
| Controls | Start signal, operating limits, controller and modulation signal where applicable |
| Safety devices | Air-pressure proving, fuel-pressure switches, flame supervision and equipment interlocks |
| Site conditions | Altitude, ambient conditions, ventilation and flue or chimney condition |
If important project information is missing, commissioning should not become a trial-and-error process for discovering the correct burner configuration.
1. Complete the Mechanical Inspection Before First Fire
The first part of an industrial burner startup checklist takes place before fuel is admitted.
Check that the burner is mounted squarely and securely to the boiler or furnace front plate. The burner head should have the specified insertion position, and the refractory opening should not obstruct combustion air or expose unsuitable surfaces to direct flame.
The technician should also inspect the air intake, fan housing, damper movement and any flexible connections. On three-phase burner motors, rotation direction must be verified before normal firing. Incorrect fan rotation can produce airflow far below the expected value even though the motor appears to be operating normally.
For oil-fired equipment, inspect the oil supply and return piping where applicable, filters, pump connections, flexible hoses and nozzle assembly before starting the industrial oil burner.
For gas-fired equipment, inspect the gas train orientation, pipe supports, filter, regulator, safety shutoff valves, pressure switches and pressure test points before starting the industrial gas burner.
2. Verify Fuel Pressure Under Operating Conditions
One of the more common commissioning mistakes is checking only static fuel pressure before the burner starts.
A gas supply can show an acceptable pressure while no gas is flowing and then fall significantly when the burner starts or moves toward high fire. The commissioning engineer therefore needs to distinguish between upstream supply pressure, regulated pressure and the pressure available while the burner is actually operating.
This is also one reason a burner that passed its factory ignition test may behave differently after installation. If the site fuel pressure or supply conditions differ from the factory test conditions, the same initial setting may produce a different result.
Fuel pressure should therefore be checked under the operating conditions that matter to the application, particularly when the burner moves toward a higher firing rate.
For an oil burner, fuel pump pressure and stable oil delivery must be confirmed according to the burner and nozzle configuration. Air entering a suction line, a restricted filter, an incorrect pump setup or unsuitable fuel viscosity can cause poor atomization even when the burner itself is otherwise operating normally.
Pressure settings should remain within the permitted range for the burner and fuel system. Changing fuel pressure solely to force one combustion reading toward a preferred number can create other problems, including incorrect firing rate or unstable combustion.
3. Prove Combustion Air and Furnace Conditions
A burner needs sufficient air not only for combustion but also to establish the pressure conditions required by the combustion head.
During startup, confirm that the fan, damper, air-pressure switch and associated linkage or servo operate through the intended range. Air inlets should be clear, and the boiler room must have an adequate source of combustion and ventilation air.
The furnace and flue system also matter. Unexpected positive furnace pressure, restricted heat-transfer passages, a closed or incorrectly positioned damper, or abnormal chimney draft can change the amount of combustion air the burner actually delivers.
This is another reason factory and site conditions should not be considered identical. After the burner is installed, its fan must work against the resistance created by the actual burner head, combustion chamber, boiler gas passages and flue system.
The difference usually becomes more noticeable as firing rate increases. A burner may ignite normally at low fire but lose combustion stability as furnace resistance increases toward full load.
4. Establish First Ignition at the Correct Firing Position
Because the burner has been prepared with an initial ignition setting before shipment, installers should avoid making large adjustments before the basic site conditions have been checked.
For burners designed to ignite at a defined ignition or low-fire position, the first site light-off should follow the manufacturer's commissioning procedure and use the supplied initial setting as the starting point.
If ignition is unsuccessful, check the fuel supply, ignition system, combustion air, flame detector, electrical conditions and relevant interlocks before assuming that the initial burner setting itself is incorrect.
During ignition, observe whether flame establishment is prompt and repeatable. Delayed ignition, a hard light-off, pulsation, repeated flame failure or an unstable flame signal should be investigated before progressing to higher firing rates.
Do not repeatedly reset a burner that continues to lock out without identifying the reason for the failed sequence. A recurring lockout can indicate a fuel, ignition, airflow, flame-detection or interlock problem that requires diagnosis rather than another reset.
5. Use Combustion Analysis Instead of Flame Color Alone
Successful ignition does not mean commissioning is complete.
A visually stable flame is useful information, but it is not enough to determine whether the final air-fuel relationship is suitable for the actual boiler or furnace.
Combustion should be measured at an appropriate flue-gas sampling point using suitable calibrated instruments. Depending on the application and fuel, commissioning data may include oxygen, carbon dioxide, carbon monoxide, stack temperature, excess air, draft or furnace pressure, smoke condition for oil firing, and NOx where emissions verification is required.
There is no single oxygen or carbon monoxide value that should be applied to every industrial burner. Acceptable values depend on burner design, fuel, equipment, firing rate, local requirements and the manufacturer's specified operating range.
The measurements should also be interpreted together. Increasing combustion air may solve one problem while increasing excess-air heat loss. Reducing air solely to improve efficiency can increase the risk of incomplete combustion or unstable operation.
6. Test More Than One Firing Point
A burner should not be declared commissioned after obtaining an acceptable result at only one operating point.
For a two-stage burner, both firing stages should be checked. For a progressive or modulating burner, representative points across the operating range should be evaluated according to the manufacturer's procedure.
This is particularly important with electronic or mechanical ratio control because air and fuel relationships can change as the burner moves through its firing curve.
An industrial burner can be correctly adjusted at high fire and still operate poorly at low fire. The reverse is also possible.
Low-fire settings influence ignition and minimum-load stability, while high-fire settings determine whether fuel delivery, airflow and furnace pressure remain acceptable at maximum demand.
The same principle applies to dual fuel burners. Each approved fuel mode should be commissioned according to its own fuel-supply and combustion requirements rather than assuming that one set of operating conditions applies to both fuels.
Why Is a Burner Stable at Low Fire but Unstable at High Fire?
This is a useful diagnostic question because some system problems only become visible when the burner is required to deliver more heat.
Possible causes include:
- Gas supply pressure falling as flow increases
- Fuel regulator or gas train capacity that is insufficient for maximum demand
- Restricted oil supply or poor atomization at the required firing rate
- Combustion air that does not increase in the correct relationship with fuel
- Fan performance that cannot overcome furnace resistance at high load
- Incorrect combustion-head or air-damper adjustment
- Excessive or unstable furnace pressure
- Incorrect servo or linkage calibration
- Flame geometry that does not suit the combustion chamber
Instead of changing several adjustments at once, record what changes when the problem appears. Fuel pressure, combustion air position, furnace pressure, flame signal, combustion readings and firing command can usually narrow the investigation much faster than visual inspection alone.
7. Verify the Burner Control Signal and Modulation Direction
For modulating burners, commissioning includes more than combustion adjustment. The burner must respond correctly to the boiler or process controller.
Check that the control signal corresponds to the expected burner position and that increasing demand actually increases firing rate.
Where 0–10 V, 4–20 mA, three-point control or another approved control method is used, the complete signal range should be verified according to the burner and controller configuration.
The system should also be observed near its normal setpoint. A burner that reaches full output correctly but hunts continuously around the process setpoint may require review of the control parameters, burner minimum output, process response or system sizing.
8. Test Required Shutdowns and Interlocks
Once stable combustion has been established, the required burner and equipment safety functions should be tested according to the equipment documentation and applicable requirements.
Depending on the installation, these may include flame failure response, air-pressure proving, fuel-pressure limits, boiler operating and high limits, low-water or low-flow protection, emergency stop and other process-specific interlocks.
Testing should confirm not only that the burner stops, but also that it follows the intended restart or lockout behavior afterward.
9. Record Final Commissioning Data
Commissioning records establish a useful operating baseline. Without baseline data, a maintenance technician returning months later may know that the burner is behaving differently but have no reliable reference for comparison.
A useful commissioning report can include:
- Burner and boiler or furnace identification
- Fuel type and relevant fuel data
- Static and operating fuel pressures
- Low-, intermediate- and high-fire combustion results where applicable
- Furnace or draft measurements
- Final air, fuel, servo or linkage settings
- Flame detector signal where the controller provides it
- Safety and interlock test results
- Control signal and firing-rate verification
- Technician, date and measuring instrument information
These records can later help distinguish normal equipment aging from a change in fuel pressure, air supply, burner adjustment or boiler condition.
Commissioning Information for Overseas Projects
For overseas projects, technical preparation before the burner arrives on site can reduce commissioning problems significantly.
Boiler manufacturers and distributors should provide the burner supplier with accurate information about boiler output, combustion chamber dimensions, expected furnace resistance, fuel specification, available pressure, voltage, control method and installation environment.
The closer the information supplied before production is to the final operating conditions, the more useful the factory preparation and initial burner settings can be during site startup.
A Practical Commissioning Principle
A factory ignition test provides a verified starting point. Site commissioning establishes the final operating condition.
The two should not be confused.
BAITE burners are tested and prepared before shipment to support initial startup, but final combustion settings must still reflect the actual boiler or furnace, fuel supply, combustion air and operating conditions at the installation site.
The goal is not simply to achieve one successful ignition or one visually clean flame. The goal is repeatable ignition, stable combustion, correct heat input and reliable operation throughout the required firing range.
For projects that are still determining the appropriate burner configuration, the complete industrial burner range can be reviewed according to fuel type, required capacity and application conditions.
For project-specific selection or commissioning information, contact BAITE for burner application support.