SUGGESTED SPECIFICATION
The hot water supply boiler(s) shall be an A. O. Smith Genesis® Model GW ___________________ having an input rating of __________________ BTU/hr.
and capable of supplying no less than _________________GPH at a 100ºF temperature rise when fired with Natural/Propane gas. The boiler shall bear
the ASME “H” stamp and shall be National Board registered for 160 PSI working pressure. The boiler shall be test certified at 84% thermal efficiency
by CSA per ANSI Z21.13/CSA 4.9 Harmonized Standard Latest Addenda. The boiler’s copper fin tube heat exchanger shall be a horizontal, single row,
two pass design. The solid copper tubes shall have integral extruded copper fins spaced at “7” fins per inch, and be rolled into heavy steel tube sheets.
High temperature silicone “O” rings shall provide a watertight seal between each tube and the ASME code Bronze/Cast Iron headers. Headers must
be field removable to allow complete inspection of all waterways. Non-removable headers, with tubes rolled directly into the headers, shall not be
acceptable. The low mass, low water volume heat exchanger shall be explosion-proof and immune to thermal shock.
The combustion chamber shall be fully lined with high temperature ceramic fiber insulation, rated to 2,300°F. The jacket panels shall be coated with
a baked-on powder-coat finish, suitable for outdoor service. The jacket shall be of tight construction, and weather- and water-resistant.
The hot water supply boiler(s) shall be supplied with a factory supplied, sized and wired boiler-circulating pump.
The boiler shall employ a fan induced premixed multi-burner system firing into a pressurized combustion chamber. Atmospheric or power burners will
not be acceptable. Only stainless steel/titanium alloy burners will be acceptable. All boiler functions shall be controlled, operated, and monitored by
a microprocessor-based control. The microprocessor shall control the boiler temperature and be accurate to within plus or minus 1°F. The hot surface
ignition system shall employ a separate flame sensor for maximum reliability.
The boiler shall be supplied with a remote tank thermistor for sensing and controlling the hot water storage tank temperature up to 1,000 feet away.
Provisions for connecting a remote thermistor, alarm bell, pump, and alternate temperature controller must be provided.
Factory mounted and wired flow, blower prover, and blocked flue switches shall be provided. The gas train shall meet or exceed the requirements
of ANSI Z21.13 and include gas pressure regulator, manual gas cock, redundant safety gas valve, operating control valve, and plugged pressure test
tapings. The ASME rated pressure relief shall be factory installed.
The boiler shall be certified for direct horizontal through-the-wall venting, or direct vertical venting; in addition to sidewall or conventional vertical
venting. The boiler must be field convertible from top mounted venting to rear mounted venting. The boiler shall be capable of horizontal sidewall
or direct venting up to 35 equivalent feet without the aid of any optional sidewalll vent fans or blowers.
For Technical Information and Automated Fax Service, call 800-527-1953. A.O. Smith Corporation reserves the right to make product changes or improvements without prior notice.
Commercial Gas Boilers
Revised November 2008
PG 4 OF 4
www.hotwater.com
AOSDG25200
July 2011R
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