These can fire from 625000btu up to 1,125,000 btus and deliver domestic water as well. We also installed tekmar controls.
The old boiler we replaced burned approx 1200 gal./month in the summer!
These have been averaging between 500+600 gal./month this Winter! They are installed in a church where my daughters day care is and I check on them each morning to admire the work and monitor the oil consumption and run times. The way I figure it with oil prices the way they are these boilers will pay for the installation in less than 2 years.