A.O. Smith AOSRG45700 User Manual

Residential Gas Water Heaters

DIRECT-VENT

ProMax® Direct-Vent Features

DIRECT-VENT DESIGN

One-pipe, dual-channel closed-combustion system draws all make-up air
from outside the home, eliminating problems caused by insufficient indoor
ventilation, and is FVIR compliant

Horizontal air intake and venting on all models up to 80 inches from
outside wall, with no electrical power needed.

A. O. SMITH DYNACLEAN™ DIFFUSER DIP TUBE

Helps reduce lime and sediment buildup, maximizes hot water output.
Made from long-lasting PEX cross-link polymer.

GREEN CHOICE™ GAS BURNER

Patented “eco-friendly” design reduces NOx emissions up to 33% and
complies with Southern California and Texas requirements.

PUSH BUTTON PIEZO IGNITER

Makes lighting pilot fast and easy with one hand push button spark
ignition.

HEAT TRAP NIPPLES Factory installed.

DURABLE TAMPER-RESISTANT BRASS DRAIN VALVE

A. O. SMITH PERMAGLAS®GLASS COATING

Protects steel tank from rust.

FACTORY-INSTALLED TEMPERATURE & PRESSURE (T&P)
RELIEF VALVE

6-YEAR LIMITED TANK & PARTS WARRANTY

For complete information, consult written warranty or A. O. Smith Water
Products Company.

CODE COMPLIANCE: UBC, CEC, SBCC, CABO, HUD, BOCA
NATIONAL CODES, ASHRAE/IES 90.1-1999 AND 2004 NAECA

DESIGN-CERTIFIED BY CSA INTERNATIONAL

According to ANS Z21.10.1 standards governing storage-type water
heaters.

Revised April 2008

Page 1 of 2

AOSRG45700

Residential Gas Water Heaters

DIRECT-VENT

MODEL

NUMBER

FIRST
HOUR

RATING

GALLONS

ENERGY
FACTOR

GAL.
CAP.

BTU

INPUT

PER HOUR

RECOVERY

90ºF RISE

GALLONS

PER HOUR

DIMENSIONS IN INCHES

A B C D E F

VENT

OUTLET*

APPROX.

SHIPPING

WEIGHT

(LBS)

GDV-40 73 .62 40 38,000 41 68 54-3/4 22-1/4 16 12-1/4 45-1/4 Co-Axial 167

GDV-50 87 .60 50 42,000 45 76 63-3/4 22-1/4 16 12-1/4 54 Co-Axial 185

GDVT-50 88 .59 50 50,000 55 76 64-3/4 22-1/4 16-1/4 12-1/2 55-1/2 Co-Axial 187

GDV-75 131 .59 75 55,000 60 76 65-3/4 26-1/4 16-1/4 12-1/2 55-1/2 Co-Axial 310

Recovery capacities based on actual performance tests.
* Dual-channel system has 3˝ vent pipe inside 6˝ air intake pipe, for the 40 & 50 gallon models.

The 75 gallon model uses a 4” x 7” co-axial pipe.
All Models Have 2” Foam Cavity.
Water connection 3/4” male all models.
75 gallon water connections are 12” on center.

Important! Vent Installation and Termination Requirements

n Maximum horizontal vent distance is 80” to outside of exterior wall.
n Minimum horizontal vent distance is 17” to outside of exterior wall.
n Vent pipes may be trimmed (cut) for short vent installations.
n For vent installation less than 30” the vent restrictor is required.

Place restrictor over the flue outlet on heater before installing the outlet vent
pipe to the heater.

n Recommended installation height for the heater vent pipe should be

68” for 40 gallon models and 76” for the 50-gallon and 75-gallon
models (vent height).

n Offset Vent Arrangement

1. When replacing an existing direct vent model,
the new vent pipe may drop from the minimum
vent height as much as 7 1/4” to exit through the
existing vent opening in the exterior wall.

2. Vent may have one horizontal 90 degree turn before
exiting through exterior wall (Do not combine both
offset vent arrangements in one installation) (See
examples in the installation manual)

n High Rise Vent Arrangement

3. When vent termination is more than 80” above the
base of the heater. The horizontal vent run must be
a minimum of 22” from the center of the heater to
the outside exterior wall surface. (See example in the
installation manual)

n Vent termination clearance hole through the exterior

wall should be approximately 7” diameter.

n Snow accumulation and drifting should be considered

when locating the termination.

n An optional wire grill vent cap protector is available

through the parts department. Part number 9006627.

n See the installation manual for complete installation

and venting requirements.

A

B

D

6” DIA. on 40 & 50 Gal. Models

7” DIA. on 75 Gal. Models

C

E

40 & 50 gal.

MIN VENT

17

MAX VENT

80

6 DIA.

F

25-1/4

25-1/4

75 gal.

29-1/2

TOP

T&P

42°

47°

EXTERIOR

WALL

DRAIN

75 gal. vent
termination
cap is not
interchangeable
with vent cap
on 40 & 50 gal.
models

FRONT

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.

Revised April 2008

www.hotwater.com

Page 2 of 2

AOSRG45700