Oil-Fired Chimney Vent Water Boiler, 100MBHOP , 84% AFUE, Series 3

Williamson OWB‑3‑T‑S3‑W – 98 MBH Cast‑Iron Oil Boiler, 87 % AFUE

The OWB‑3‑T‑S3‑W is a factory-assembled, three-section cast-iron boiler delivering 98 MBH input with net outputs between 75–86 MBH, depending on models, at 87 % AFUE efficiency. It features an insulated steel jacket and integrated Taco‑007 circulator for hydronic heating systems :contentReference[oaicite:1]{index=1}.

✅ Contractor Key Features High-Efficiency Oil Burner: Equipped with a solid-state ignitor, PSC motor, and solenoid valve, designed for reliable combustion afsupply.com +11 sidharvey.com +11 24hr.supply +11 . Cast-Iron Heat Exchanger with Separator: Built-in air separator supports efficient system operation and pressure ratings up to 50 PSIG afsupply.com +15 williamson-thermoflo.com +15 24hr.supply +15 . Service-Friendly Access: Features a swing-away burner door, plug-in wiring harness, and top cleanout cover for quick maintenance sidharvey.com +11 williamson-thermoflo.com +11 afsupply.com +11 . Enhanced Safety Controls: Includes thermal limit control, probe-type low-water cutoff, and pre-purge protection 24hr.supply +9 williamson-thermoflo.com +9 generalplumbingsupply.net +9 . Flexible Venting: Rear chimney flue collar standard; optional top-flue kit available; compatible with 6″ round or 8″×8″ chimney oswaldsupply.com +2 williamson-thermoflo.com +2 oswaldsupply.com +2 . ???? Technical Specifications Specification Detail Input 98,000 BTU/hr (0.70 GPH oil) Net Output 75–86 MBH (model dependent) AFUE 86–87 % Sections 3 cast-iron Venting Chimney vent (rear or top) Controls LWCO, limit control, circulator Jacket Insulated steel ???? Installation & Maintenance Notes Factory-Assembled: Boiler ships complete with jacket, circulator, wiring, and control components—ready for gas hook-up and vent connection. Combustion Air Requirement: Must be installed with proper chimney height, draft per -0.01″ to -0.02″ w.c., and gas-tight installation per NFPA 31 & 211 williamson-thermoflo.com +2 24hr.supply +2 24hr.supply +2 sidharvey.com +2 sidharvey.com +2 orders.sidharvey.com +2 afsupply.com +4 oswaldsupply.com +4 generalplumbingsupply.net +4 ebirdsall.com . Service Access: All mechanical components are accessible from the front and top, reducing labor during routine servicing. Clearances: Ensure proper chimney clearances and combustible distances as per installation instructions and local codes. ???? Contractor Summary The OWB‑3‑T‑S3‑W is a durable, efficient oil-fired boiler designed for residential and light commercial hydronic systems. Its cast-iron durability, oil-fired reliability, full vent options, and straightforward service design make it a top choice for contractors. It’s well-suited for new installs or replacement scenarios where proven performance and ease of service are priorities.