What Happens at a Biomass Boiler Commissioning?

What Happens at a Biomass Boiler Commissioning?

Commissioning is one of the most important stages in getting a biomass boiler up and running. It’s the point where everything comes together, installation, controls, fuel handling, safety systems, and hydraulics. A good commissioning process ensures the system runs as designed, performs reliably, and is safe from day one.

Here’s a more detailed look at what happens.

Visual Inspection

Before anything is switched on, the engineer carries out a visual inspection of the entire installation. This includes:

• Boiler, seals, and refractory bricks/elements
• Fuel feed augers and agitators
• Pipework connections, valves, strainers, and pumps
• Flue system and termination
• Sensors, wiring, and control panels

Alongside this physical inspection, the commissioning engineer reviews the installation against the design drawings and schematics. They confirm that:

• Pipe sizes and routes match the approved design
• Valves, pumps, and sensors are positioned correctly
• The flue arrangement follows the specified layout
• Primary and secondary circuits are connected as intended
• Safety clearances and manufacturer requirements are met

They’re also checking for leaks, loose components, misplaced insulation, or anything that might cause issues during the first run. Identifying these small discrepancies early prevents far bigger issues once the boiler is fired and running at temperature.

Mechanical and Electrical Testing

Next, every moving and electrical part is tested. Motors, pumps, valves, and sensors are checked to ensure they’re wired correctly and reacting as expected. The engineer also confirms that any motors are rotating in the right direction.

• Motors and augers are powered up briefly to confirm they run as expected and in the right direction.
• Pumps are switched on and checked for correct rotation.
• Sensors (temperature, pressure, vacuum, lambda, etc.) are checked for correct readings.
• Safety switches and interlocks are confirmed to trigger as expected.
• Control wiring is checked against the schematics to ensure no crossed or missing connections.

This ensures that by the time the boiler is lit, every part that moves or takes a reading is set up to work correctly.

Dry Run Test

Before introducing fuel, the system is powered up to test:

• Start-up behaviour
• Control logic and sequencing
• Safety trips
• Alarm conditions
• Fan operation and airflow readings
• Actuators opening and closing

Running the boiler “cold” is essential for identifying unexpected behaviour safely. It also gives the engineer a baseline for how the system responds before combustion starts.

Fuel Firing and Combustion Tuning

Once the system passes its dry checks, fuel is introduced and the boiler is lit for the first time.

At this stage, the engineer adjusts:

• Fuel feed rate
• Combustion air settings
• Fan speeds
• Temperature targets
• Emissions levels

Specialist equipment often including flue gas analysers and lambda readings is used to fine-tune combustion. It’s about getting the boiler burning efficiently and cleanly.

Performance and Safety Verification

The final stage involves confirming the boiler performs exactly as expected:

• Verifying kW output against the design
• Checking flow and return temperatures
• Monitoring buffer tank behaviour
• Confirming smooth fuel handling
• Testing emergency stops, safety valves, and overheat protection
• Reviewing data logs and alarms

Only once the system consistently meets its performance and safety criteria is it signed off as commissioned.

Customer Training and Handover

Once the boiler has passed all performance and safety checks, the final step is to make sure the customer knows exactly how to run the system day to day. A proper handover is a key part of commissioning and helps prevent issues later on.

During this stage, the engineer will usually cover:

System overview

A walk-through of the boiler, buffer tank, controls, fuel store, and key safety features so the customer knows what everything does and how the system fits together.

Basic operation

Clear guidance on:

• How to start and stop the system
• What the normal operating screens look like
• What temperatures and readings to expect
• How the boiler behaves during heating cycles

This gives the customer confidence in what “normal” operation looks like.

Fuel management

Advice on:

• Loading or monitoring fuel levels
• Recognising issues with fuel quality
• What to look out for in the store (bridging, damp spots, etc.)

This helps avoid the most common causes of downtime.

Routine user checks

Simple tasks the customer should do regularly, such as:

• Checking ash levels
• Keeping access areas clear
• Monitoring warnings or alerts on the control panel

These are small jobs, but they make a big difference to overall reliability.

What to do if something goes wrong

The engineer will explain:

• What different alarms mean
• What can safely be reset
• What should be left for a service visit
• Who to call and what information to have ready

This prevents unnecessary system shutdowns and avoids customers trying to fix things that could make a fault worse.

Handover documentation

All commissioning documents are brought back to the office first, checked, and then forwarded on to the client. This means the client gets a clean, complete set of documents.
The pack normally includes:

• Commissioning sheets
• Manuals
• Service and maintenance guidance
• Warranty information (where relevant)
• Contact details
• Any site-specific notes or settings used during commissioning