A.O. Smith GCN-75, GCN-100 User Manual

COMMERCIAL-GRADE

RESIDENTIAL GAS WATER HEATERS

PROLINE® ULTRA-LOW NOx HIGH RECOVERY

COMMERCIAL-GRADE RESIDENTIAL

CODE COMPLIANCE

• The Ultra-Low NOx atmospheric vent
residential gas water heater meets the
thermal efficiency and standby loss
requirements of the U. S. Department of
Energy and Current Edition ASHRAE/IES 90.1.

FULLY AUTOMATIC CONTROLS WITH
SAFETY SHUTOFF

• Accurate, dependable control system requires
no electric connections. Fixed automatic
gas shutoff device for added safety. Not
recommended for 180°F sanitizing.

HEAVY GAUGE STEEL JACKET

• Finished with baked enamel over bonderized
undercoat.

GLASSLINED TANK

• Maximizes tank life.

FOAM INSULATION

• Saves fuel, helps reduce standby heat loss.

ULTRA-LOW NOX EMISSIONS

• Complies with SCAQMD Rule 1146.2 and
other Air Quality Management Districts with
similar requirements of 14 ng/j or 20 ppm.

COREGARD™ ANODE ROD

• Our anode rods have a stainless steel core
that extends the life of the anode rod
allowing superior tank protection far longer
than standard anode rods.

MAXIMUM WORKING PRESSURE

• 150 psi.

MAXIMUM GAS INLET PRESSURE

• 14” W.C.

FEATURES

• Anodic protection

• Equipped with gas pressure regulator

• Integral automatic gas shutoff system
prevents excessive water temperature

• CSA certified and ASME rated T&P relief valve

• The GCN-75 comes standard with side
loop fittings for use with hydronic heating
applications.

6-YEAR LIMITED TANK AND PARTS
WARRANTY

• For complete warranty information, consult
written warranty or contact A. O. Smith.

EASY-TO-INSTALL

• Completely factory-assembled. Only gas,
water and vent connections need to be
made. All connections are located in front
and top of heaters for ease-of-installation
and service.

DRAFT HOOD

• Low profile draft hood furnished as standard
equipment.

© February 2017 A. O. Smith Corporation. All rights reserved.

www.hotwater.com | 800-527-1953 Toll-Free USA | A. O. Smith Corporation | 500 Tennessee Waltz Parkway | Ashland City, TN 37015

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AOSRG45820

COMMERCIAL-GRADE

RESIDENTIAL GAS WATER HEATERS

Recovery Ratings

Model Input Rate Recovery in US Gallons/hr or Liters/he at Indicated Temperature Rise in Fahrenheit or Celsius

75,100 BTU/h

GCN-75**†

22 kW

75,100 BTU/h

GCN-100*

22 kW

*Recover rating based on 81% thermal efficiency
**Recover rating based on 80% thermal efficiency
†The GCN-75 comes standard with side loop fittings for use with hydronic heating applications

Model Units A B C D E F G H J K L M

GCN-75

GCN-100

Inches 62-1/16 58 29-1/2 25-1/4 15-7/8 4 15-1/4 16 2 1 1/2 12-1/2 285 lbs

Inches 70-1/2 66-1/2 30-15/16 27-3/4 15-3/16 4 15-3/4 16 1-1/4 1-1/4 1/2 11-15/16 350 lbs

°F 30 40 50 60 70 80 90 100 110 120 130 140

GPH 243 182 146 121 104 91 81 73 66 61 56 52

°C 17 22 28 33 39 44 50 56 61 67 72 78

LPH 919 689 551 459 394 345 316 276 251 230 212 197

°F 30 40 50 60 70 80 90 100 110 120 130 140

GPH 246 184 147 123 105 92 82 74 67 61 57 53

°C 17 22 28 33 39 44 50 56 61 67 72 78

LPH 930 698 558 465 399 349 310 279 254 233 215 199

Dimensions

CM 157.6 147.3 74.9 64.1 40.3 10.2 38.7 40.6 5.1 NPT NPT 31.8 129.2 kg

CM 179.1 168.9 78.6 70.5 38.6 10.2 40 40.6 3.2 NPT NPT 30.3 158.8 kg

K

DRAIN
VALV E

HOT WATER

OUTLET

J

A

E

M

F

D

K

COLD WATER

INLET

B

TEMPERATURE
AND PRESSURE
RELIEF VALV E

G

DRAIN VALV E

TOP VIEW

HOT

GAS INLET

H

C

COLD

L

Approx.

Shipping

Weight

SPECIFICATION

Water heater(s) shall be Model ________________ as manufactured by A. O. Smith or an approved equal. Water heater(s) shall be of
glasslined design, equipped to burn __________ gas and design certified by UL. Heaters must meet all applicable energy codes and comply
with ultra-low NOx emissions of 14 ng/j or 20 ppm. Heaters shall have an input rating of _____ BTU/H and a recovery capacity of _____ GPH
at a temperature rise of 100°F with a storage capacity of _____ gallons. Heater shall have a working pressure of 150 psi. Heater(s) shall be
provided with an automatic gas shutoff device and safety shutoff in event pilot flame is extinguished; a gas pressure regulator set for the type
of gas supplied; an approved draft hood, and extruded anode rod rigidly supported for cathodic protection. A CSA Certified and ASME Rated
T&P Relief Valve shall be furnished and installed by the manufacturer. The tank shall be foam insulated. The outer jacket shall have a baked
enamel finish over a bonderized undercoating. Fully illustrated instruction manual. All internal surfaces of the heater(s) exposed to water shall
be glasslined with an alkaline borosilicate composition that has been fused-to-steel by firing at a temperature range of 1400° to 1600°F.
Heater tank shall have a six year limited tank and parts warranty against corrosion and tank failure due to sediment build-up as outlined in the
written warranty. Heater(s) shall be design certified by UL. Operation of the heater in a closed system where thermal expansion has not been
compensated for with a properly sized expansion tank will void the warranty.

For technical information call 800-527-1953. A. O. Smith Corporation reserves the right to make product changes or improvements without prior notice.

www.hotwater.com | 800-527-1953 Toll-Free USA

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AOSRG45820