Most boiler operators use combustion efficiency data, when they use it at all, purely to manage their own plant. That is the smaller opportunity. The same signals, packaged and validated, are a service line most customers do not currently get from anyone.
What the underlying data already tells you
Combustion and excess air trends, condensing operation, flue and standby losses, sequencing across boilers, benchmarking across sites. Every well-tuned monitoring setup already produces this. The US Department of Energy's rule of thumb is that efficiency improves by about 1% for every 15% reduction in excess air: a physical relationship you can report against, not a vague sustainability claim.
From internal metric to customer-facing service
First for your own plant and reporting, then as a data-backed service to your customers. The step that makes this credible rather than a sales pitch: thresholds set with your engineers and validated against real plant, not asserted by a dashboard vendor who has never seen the equipment.
Where the ceiling actually is
Deeper, real-time efficiency reporting comes once sensor telemetry is in place across a customer's estate, and that is a later, separately scoped step, not a prerequisite to starting. The service can begin with what you already measure, and grow as the underlying instrumentation does.