HTP’s EnduroTi is a large-mass, stainless-steel condensing boiler with a hyper-jet combustion system that includes a patented modulating inward firing burner. This high-mass, fire-tube design promotes improved heat transfer when used with its three-pass heat exchanger. The unit is up to 93% thermal efficient, with up to a 10:1 turndown ratio. It is available in 750,000 Btu and 1,000,000 Btu sizes. It is able to operate at altitudes of 4,500’ above sea level without additional parts or adjustments.