When multiple boilers are staged and rotated, the last stage can be fixed to fire last. A common application is to allow a second boiler plant, such as a DHW boiler plant, to assist with the heating when the DHW system is satisfied. Another common application is to front end load an older inefficient boiler with several higher efficiency boilers. Most of the heating load can be satisfied by the higher efficiency boilers and only during extreme conditions will the old boiler be allowed to fire. This function allows for added flexibility when designing or retrofitting a boiler plant.