Combustion Control Technology

With strict legislation that sets stringent limits on the amount of harmful Nitrogen Oxide (NOx) emissions produced by heating systems, some innovative ‘add-on’ technologies are available to combat NOx production.

O2 Trim
O2 trim adds or reduces either fuel or air (depending on the system used) to compensate for changes in combustion variables. For each point on the combustion profile, there is an O2 setpoint. If the O2
reading for any point increases, then air is reduced, or fuel added, to bring the process variable back to the setpoint. If the O2 decreases the opposite happens.

CO Contol

CO Control takes a more empirical approach than O2 Trim, enabling combustion systems to get closer to stoichiometric conditions whilst remaining safe. A self-adapting algorithm optimises the fuel/air ratio over the entire firing range. It ‘learns’ each point on the programmed combustion curve by reducing air to the point where CO is detected and then ‘backing-off’’ to a safe setpoint. Each ’learned’ point has a lifetime of eight hours after which it is ‘learned’ again. This ensures that if external conditions have improved then the CO Control will readapt to compensate for this and increase efficiency.


Key benefits:

  • Improved boiler efficiency
  • Easier maintenance
  • Extended boiler lifespan
  • Reduced NOx emissions
  • Higher levels of safety


EOGB has the engineering experience and industry knowledge to tailor bespoke energy-saving packages for all types of boiler plants.

Initial site surveys and expert advice are available at no cost from our technical team.

For any information please reach out to us at / 01480 477066