HVAC Procedure and Performance Guide

Determine furnace efficiency through combustion analysis

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Furnace efficiency must be determined by conducting complete analysis according to manufacturer’s specifications.  Applicable safety procedures must be followed.


  1. Review manufacturer’s specifications.
  2. Determine manufacturer’s requirements for products of combustion and furnace operating temperatures.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Start furnace and ensure that burner is operating at rated fuel capacity.
  6. Shut off furnace.
  7. Calibrate combustion equipment and connect to furnace according to manufacturer’s instructions.
  8. Restart furnace and take measurements according to manufacturer’s specifications including, but not limited to, draft measurements, temperature measurements, products of combustion and smoke tests.
  9. Record data and determine furnace efficiency from manufacturer’s tables.
  10. Make required adjustments and repeat analysis until satisfactory efficiency is achieved.
  11. Shut off furnace and disconnect test apparatus.
  12. Leave equipment in required operating status.
  13. Remove safety and protective equipment and apparel.
  14. Gather tools, equipment and leftover materials, and leave work site clean.