NaturalGas Water Atmospheric Hot Water Boiler, 166MBHIP, Series 3

Williamson GWA‑166‑N‑T‑S3‑W – 166 MBH Cast‑Iron Atmospheric Gas Boiler (84 % AFUE)

The GWA‑166 is a factory-tested, cast-iron sectional boiler designed for natural gas (convertible to propane) hydronic heating systems. With a 166,000 BTU/hr input and 84 % AFUE, this Series 3 model provides 141,000 BTU/hr DOE output and 122,000 BTU/hr net I=B=R heating capacity :contentReference[oaicite:1]{index=1}.

???? Key Features for Contractors Efficient Heat Transfer: Long-lasting cast iron sections include a built-in air separator to optimize thermal performance forum.heatinghelp.com +10 williamson-thermoflo.com +10 williamson-thermoflo.com +10 . Quiet, High-Performance Burner: Stainless steel burner with spark ignition supports atmospheric chimney venting; equipped with an automatic vent damper to reduce off-cycle heat loss 24hr.supply +2 24hr.supply +2 ussupply.com +2 . Service Accessibility: One-piece front door provides fast access to all controls, circulator, pilot, and flueway for easier maintenance williamson-thermoflo.com +7 afsupply.com +7 generalplumbingsupply.net +7 . Thermal Protection: Heavy-gauge insulated jacket minimizes standby heat loss and includes a high-limit control and low-water safety cutoff ussupply.com +11 24hr.supply +11 williamson-thermoflo.com +11 . ???? Technical Specifications Model: GWA‑166‑N‑T‑S3‑W Fuel: Natural Gas (field-convertible to LP with accessory kit) Input: 166,000 BTU/hr DOE Output: 141,000 BTU/hr Net I=B=R: 122,000 BTU/hr AFUE: 84% Vent Type: Atmospheric; chimney vent with automatic damper included Controls: Taco‑007 circulator, low-water cutoff, pressure/temperature gauge, high-limit, and 30 PSIG relief valve included williamson-thermoflo.com +11 williamson-thermoflo.com +11 afsupply.com +11 orders.sidharvey.com +5 afsupply.com +5 24hr.supply +5 afsupply.com +3 24hr.supply +3 24hr.supply +3 . ???? Installation Highlights Factory-Assembled for Efficiency: Fully equipped and tested before shipment with all safety and hydraulic components installed . Compact Service Footprint: Despite its 166 MBH capacity, the boiler remains manageable in size (approx. 60.8″ H × 28″ W × 23.3″ D) and fits well in mechanical rooms . Ease of Use: All service points—pilot, circulator, and control wiring—are accessible from the front, reducing service time goatlantic.com +8 generalplumbingsupply.net +8 24hr.supply +8 . ???? Contractor Summary The Williamson GWA‑166 provides robust heating capacity in a compact, service-friendly design. Its combination of efficient cast-iron construction, airtight combustion, and easy access means it’s an excellent choice for contractors tasked with residential or light-commercial hydronic systems. The Series 3 configuration ensures reliable performance and compliance with safety standards.