Fully-modulating, fully condensing, compact, sealed combustion, low NOx and up to 98% efficient.

LAARS Heating Systems engineers designed the RHEOS+ boiler/water heater to provide ultra-high performance and superior efficiency. They are the ideal choice for demanding commercial jobs requiring 1.2 to 2.4 million BTU/hour. Seamless combustion modulation from 25 to 100 percent of full input maintains maximum efficiency and helps cut operating costs as much as 50 percent. The heart of eve