HVAC Combustion Analysis Report: What to Record

Example: A technician leaves a boiler room with an analyzer printout showing a low carbon-monoxide reading. The printout does not identify the firing rate, reference-oxygen setting, vent condition, or whether the appliance passed the required checks. The next technician cannot reconstruct the conclusion.

A combustion report connects readings to a particular appliance, procedure, and operating state. It should explain what was tested, what changed, what was repeated, and whether operation is permitted under the governing criteria.

If a CO alarm sounds or exposure is suspected, routine testing must give way to emergency action. CPSC's Carbon Monoxide Fact Sheet directs occupants outside to fresh air, to call emergency services, and not to re-enter until responders permit it. Do not run the appliance to finish a report during an unresolved emergency.

Identify the appliance and the acceptance source

Start the HVAC work order with the customer, site, asset ID, full model and serial number, fuel, burner, vent arrangement, and reason for testing. Name the required firing states and scope limits. A residential furnace visit, commercial boiler tune-up, and emissions-compliance test are different assignments.

Identify the exact appliance, burner, vent, and analyzer instructions, with revision and relevant section. Record applicable adopted requirements, program procedures, and project criteria. A model-code publication is not proof of local adoption: the 2024 IFGC preface explains code use and identifies Appendix C as informative. Do not copy a generic CO or draft limit onto unrelated equipment.

The commercial RTU reporting guide explains why sequence and operating state belong beside readings. Use the same discipline here, with the procedure appropriate to this equipment.

Preserve the setup behind the numbers

Record the analyzer model and serial number, relevant sensor/calibration status, selected fuel, zeroing method, sample location, units, and calculation settings. Keep the native export or printout identified in the job file.

The Fieldpiece CAT45 operator manual, version 06 addresses qualified use, fresh-air zeroing, and equipment-manufacturer sampling instructions; it warns that the analyzer is not a safety device. Follow the manual for the actual instrument. Do not improvise a test hole in a listed vent or treat an analyzer as an occupant CO alarm.

Document doors, exhaust equipment, other common-vent appliances, airflow conditions, firing rate, stabilization, and sample duration where the procedure requires them. State how the operating mode was established. “Worst case” needs the prescribed configuration, not an unexplained label.

A job hazard analysis should address the hazards and controls for the actual task. Operational measurement and isolated repair are different states; OSHA 1910.147 governs covered hazardous-energy servicing and has specific applicability and exceptions. Use the applicable employer procedure when switching from testing to repair.

Make each result interpretable

In the HVAC service report, connect every decision-driving result to its mode and criterion:

Air-free CO refers to correction to zero reference oxygen. A value corrected to another reference is different. The Fieldpiece CAT45/CAT85 bulletin, November 22, 2023, illustrates why the displayed label and reference setting must be checked. Compare readings and criteria on the same basis.

Keep calculated CO2, excess air, or efficiency distinguishable from direct readings. A passing result in one mode does not establish an untested mode. Do not use zero to mean “not tested.”

Explain physical findings and the final disposition

Record the vent, combustion-air, visible appliance, and operating observations in the HVAC inspection report. A low flue CO result does not establish every other inspection item. Name inaccessible areas and tests not completed rather than issuing an unrestricted safety claim.

Preserve as-found evidence. If work is needed beyond the authorization, issue an HVAC estimate or change order as appropriate, while following any immediate protective-action procedure. Do not adjust a setting merely to make one number pass.

EPA's Boiler Tune-up Guide supports recording operating conditions, qualified corrections, and repeatability, while expressly preserving safety procedures and manufacturer instructions. It is not a universal furnace safety protocol.

Repeat affected tests under the required final conditions. Use a safety closeout checklist to record restored ports, panels, guards, controls, and temporary test settings. State the actual disposition: met listed criteria, incomplete, failed, restricted under identified authority, shut down/tagged, or referred. A customer declining repair does not convert a failed result into permission to operate. The PPE assessment guide helps document controls and the conditions needed to resume work.