Lochinvar SYNC (SBN, discontinued)

The SYNC is the commercial condensing boiler Lochinvar sold before the current FTXL and Crest generations. Its official support page carries the banner "Series Discontinued: SYNC Condensing Boiler" and documents three sizes: SBN1000 at 100-1,000 MBH input, SBN1300 at 130-1,300 MBH and SBN1500 at 150-1,500 MBH. The I&O ratings table prints gross outputs of 941, 1,237 and 1,444 MBH and AHRI net water ratings of 818, 1,076 and 1,256 MBH, with 8.4-11.4 gallons of water content, 3" outlet and (2)-2" inlet water connections, a 1-1/2" gas connection and 6" air and vent sizes.

The ratings table is reproduced on the model records here; the I&O's notes state that standard SYNC boilers operate from sea level to 4,500 ft with a 4% derate per 1,000 ft and that high-altitude builds cover 3,000-12,000 ft with a 2% derate per 1,000 ft. Lochinvar still hosts the complete document set — the Rev AA I&O, the "N" edition, the Rev K service manual and the Rev F user manual — so an owner of an installed SYNC can identify the unit and its control from the archived literature. The SYNC's commercial role is filled today by the FTXL and Crest lines on the current Commercial Boilers page.