Patent ID: 7819334

Claim:
A computer implemented method of operating a boiler system having a plurality of boiler stages which may be active or inactive at a given time, the boiler stages having outputs, the method comprising: performing a boiler staging sequence, at a first timed interval, to determine how many of the plurality of boiler stages should be active or inactive, the boiler staging sequence including: implementing a boiler addition control loop to make a first number of the plurality of boiler stages active based at least partially on a calculated error rate, and implementing a boiler removal control loop to make a second number of the plurality of boiler stages inactive based at least partially on the calculated error rate; and performing a boiler modulation sequence, at a second timed interval shorter than the first timed interval, the boiler modulation sequence including: using the determinations made during the boiler staging sequence as to how many of the plurality of boiler stages should be active and inactive; modulating a first boiler stage to operate at less than 100% of its output, and modulating a second boiler stage to operate at less than 100% of its output; wherein the first and second boiler stages are modulated while both boiler stages are active.