A. O. Smith GBO-1000 User Manual

Hydronic Heating Boilers

GB/GBO-1000

HYDRONIC HEATING BOILERS

FEATURES

84% THERMAL EFFICIENCY - The absolute highest thermal effi ciency possible by a
non-condensing boiler.

Low NOx - Precise amounts of gas and air are premixed through special Pre-Jet Orifi ces and
forced through stainless steel burners that provide complete and clean combustion. Complies
with Air Quality Management Districts of California requirements for low NOx emissions.

EXCLUSIVE EMC-5000 W/STAGED FIRING - The EMC-5000 is a complete

microprocessor based boiler control. Every electrical boiler function, from starting
the blower, to igniting and stage fi ring the main burner, to controlling the
boiler temperature, is controlled and monitored by the onboard computer. A
comprehensive display panel includes LEDs that indicate current operating
and fault status. A digital LED displays temperature set points, outlet
temperature, current inlet/outlet differential (ΔT), loop temperature, and
additional numerical fault codes. Precise temperature management is plus or
minus 1°. In addition, the EMC-5000 provides true self-diagnostic capabilities,
eliminates guesswork, and reveals exactly where the problem is.
Troubleshooting has never been easier.

iCOMM™ Compatible and can be monitored from remote
locations. Call 1.888.WATER02 for more information.

STAGED FIRING – All second family Genesis boilers are staged fi red. The

boiler automatically adjusts its fi ring rate and Btu output to maintain a
precise system temperature control. Each stage is user programmable;
allows the boiler to be tailored to the installation and adjusted for optimum
boiler performance and overall system effi ciency. Models GB-1000 thru
GB-1500 have three stages; Models GB-1850 thru GB-2500 have four stages.

through

GB/GBO-2500

HIGH EFFICIENCY HIGH HEAT TRANSFER – A. O. Smith’s distinctive double-row

integral-fi nned copper heat exchanger provides maximum heat transfer and utilizes a
self-baffl ing staggered tube design, that assures 84% thermal effi ciency. Heavy -duty
cast iron glasslined headers are standard on all models.

SECONDARY BOILER PUMP (Optional) - Units are available with the optional

Integral Rear Header Mounted Boiler Pump; eliminates fi eld wiring and secondary
pump sizing concerns.

UNMATCHED VENTING FLEXIBILITY - Multiple venting options; choose from

several conventional or direct venting options. Multiple openings options; choose from
exhaust outlet leaving the top of boiler or exhaust outlet-leaving the rear of boiler.

STACKABLE SPACE SAVING DESIGN - Up to 5 million BTUs in the space of a single

2.5 million BTU boiler.

OTHER FEATURES - CSA Certifi ed and ASME Rated T&P Relief Valve #50

Remote Loop Sensor Alternate (24V) ThermostatTerminals Manual Reset High Limit
Blocked Flue Switch Fan Proving Switch Adjustable Secondary Pump Delay

OPTIONS -

Headers Stack Rack Low Water Cut Off Extended Power Venting Kits Dry Contacts
For Any Boiler Failure Direct and Sidewall Vent Terminal Kits Integral Rear Header Mounted
Boiler Pump (For Primary/Secondary Piping Systems) EMS converter (Allows Energy Management
Controls systems to manage the stage fi ring.)

Code Options: CSD-1, California Code

Alarm Bell Outdoor Models Bronze

Mounted Flow Switch

TEN-YEAR LIMITED HEAT EXCHANGER WARRANTY

FACTORY START-UP INCLUDED-Required for activating warranty and assuring maximum
operating performance. Contact your local sales representative or Authorized Start-Up Agent
to arrange a FREE Certifi ed Start-Up.
contact A. O. Smith

June 2011R

For complete information, consult written warranty or

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Hydronic Heating Boilers

All Dimensions in Inches

Model

GB-1000 2 1/2 2 10 8 47 40 1/2 14 12 1/2 36 1/4 31 3/4 20 3/4 64
GB-1300 2 1/2 2 12 10 57 1/2 40 1/2 24 3/4 12 1/2 36 1/4 31 3/4 18 74 1/2
GB-1500 2 1/2 2 12 10 64 1/2 40 1/2 30 12 1/2 36 1/4 31 3/4 19 3/4 81 1/2
GB-1850 2 1/2 2 1/2 14 10 78 3/4 43 1/4 27 3/4 11 1/2 35 1/4 32 1/2 34 1/4 95 3/4
GB-2100 2 1/2 2 1/2 14 12 85 1/2 43 1/4 31 11 1/2 35 1/4 32 1/2 35 3/4 102 1/2
GB-2500 2 1/2 2 1/2 16 12 99 1/2 43 1/4 38 10 1/2 35 1/4 32 1/2 42 3/4 116 1/2

Maximum gas supply pressure is 13.8” W.C. for both Natural and Propane Gas.
The minimum supply gas pressure is 7” W.C. for Natural Gas.
The minimum supply gas pressure for Propane is 11.0” W.C.
Requires: 120V, 60 Hz, 30 Amps, Dedicated Breaker.

Model

GB

-1000 990,000 831,600 83 5.1 55 2.7 42 1.5 154 12.2 11 42 1.5 40

GB

-1300 1,300,000 1,092,000 109 72 73 4.2 55 3.2 154 14.5 14 55 3.2 40

GB

-1500 1,500,000 1,260,000 126 10.1 84 8.3 64 4.3 154 16.3 17 64 4.3 40

GB

-1850 1,850,000 1,554,000 154 19 104 10.1 78 6.4 154 16.5 20 78 6.4 40

GB

-2100 2,100,000 1,764,000 N/A N/A 116 14.5 89 8.3 154 21.3 23 89 8.3 40

GB

-2500 2,490,000 2,091,600 N/A N/A 139 16.5 105 11.6 154 23.2 26 106 11.6 40

Notes:
Flow rates and pressure drops shown above are through the boiler only and include no fi eld piping. The fi eld piping must also
be considered when sizing system pumps.

The optional factory supplied integral rear header mounted pump (for primary/secondary pumping) is sized for the boiler and
up to additional 50 equivalent feet of fi eld piping.

Water

Connections

Input Rating BTU/Hr.

Natural & Propane (LP) Gas

Connections

BTU lnput/Output

Gas

Natural & Propane (LP) Gas

Vent InletAir

Hydronic Boiler BTU Input/Output And Flow Rates

Output Rating BTU/Hr.

A Width

WO/Pump

20 Deg. F Rise 30 Deg. F Rise 40 Deg. F Rise Maximum Flow Rate Minimum Flow Rate

GPM

B Height C D E F G

Boiler Rate of Flow and Pressure Drop

PD-Ft.

Head

GPM

PD-Ft.

Head

GPM

PD-Ft.

Head

GPM

PD-Ft.

Head

Deg.F

Rise

GPM

W/Pump

PD-Ft.

Head

Width

Deg.F

Rise

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.

June 2011R

www.hotwater.com

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