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Rheem Tankless Outdoor

Gas Water Heaters

Available in 5.3 and 7.4 GPM Outdoor Models

10-Year Limited Warranty on Heat Exchanger*  

3-Year Limited Warranty on Parts*

New!

UMC-117 remote control is included and can be set

from the out-of-the-box 120 degrees – up to a 140
degree maximum 

(additional remote control thermostats are available

– sold separately)

New!

EZ-Link

cable connects two tankless 

units to operate as one – now available for high 
demand applications

Exclusive!

Guardian SBT

sensing burner technology

Exclusive!

Guardian OFW

overheat film wrap

Exclusive!

Two high-altitude options – up to 6,560 or

9,840 ft. elevations above sea level 

(altitude chip required 

– sold separately)

Exclusive!

All Rheem tankless models are third-party

certified by GAMA

Exclusive!

All Rheem tankless models qualify for up to a

$300 federal energy tax credit 

(refer to your tax advisor for details)

Exclusive!

All Rheem models can be linked in up to 20

unit manifold installations by using the optional MIC-180
and MICS-180 manifold control assembly

Continuous hot water

Energy saving design

Compact, space saving design 

Intelligent electronic controls designed to increase energy
efficiency and safety

Self diagnostic program

Digital display shows temperature setting and
maintenance codes

Built-in electric blower

Environmentally friendly Low NOx  burner meets
SCAQMD rule 1146 requirements

Features freeze protection to -30°F on RTG-74, 
-20° F on RTG-53

Rheem Water Heating

• 101 Bell Road, Montgomery, Alabama 36117-4305 • www.rheem.com

P R I N T E D   I N   U . S . A

0 7 / 0 6   W P

F O R M   N O . 1 0 1 - 4 1

In keeping with its policy of continuous progress and product improvement, Rheem reserves the right to make changes without notice.

These units are designed to meet 
or exceed ANSI (American National
Standards Institute) requirements and have
been tested according to D.O.E. test proce-
dures and meet or exceed the energy effi-
ciency requirements of NAECA, ASHRAE
standard 90, ICC Code and all state energy
efficiency performance criteria for energy
consuming appliances.

Before purchasing this appliance, read
important energy cost and efficiency
information available from your supplier.

DESCRIPTION

FEATURES

ROUGHING IN DIMENSIONS (SHOWN IN INCHES)

ENERGY INFO.

GAS 

WATER FLOW RATE

SHIP.

D.O.E.

INPUT

TEMP.

GPM @ 77° GPM @ 45°

CONNECTION

VENT

WEIGHT

ENERGY

ANN.

MODEL NUMBER

BTU/HR.

TYPE

RANGE*

RISE MAX.

RISE MAX.

WATER       GAS

HEIGHT

WIDTH

DEPTH

DIAMETER

(LBS.)

FACTOR

OP. COST

RTG-53XN

21,600 -

Outdoor

100° to

3.1

5.3

3/4

3/4

20-1/2

13-3/4

5-1/4

N/A

36

.82

$167 Nat

141,000

140° F

$246 LP

RTG-74XN-1

19,000 -

Outdoor

100° to

4.3

7.4

3/4

3/4

25-3/8

14-7/8

11-1/8

N/A

55

.82

$167 Nat

199,900

140° F

$246 LP

Available in Natural Gas and Propane (LP). For Propane replace the N 
with a P when ordering. 

* Factory set maximum temperature is 120° F.
• For installations above 3,280 feet a high altitude chip is required. 

Refer to Rheem price list or consult factory for details.

• Consult factory for information on sizing the application.

Temperature Rise (°F)

Model Number

35°

45°

50°

60° 70°

77° 80° 90° 100°

RTG-53X Water Flow (GPM)

6.8

5.3

4.7

3.9

3.4

3.1

3.0

2.6

2.4

RTG-74X Water Flow (GPM)

8.5

7.4

6.6

5.5

4.7

4.3

4.1

3.7

3.3

Above estimates are for sizing purposes only.

Proper gas pressure must be ensured to supply tankless gas water heaters – up to
145,000 BTU for RTG-53 models and up to 199,900 BTU for RTG-74 models. 
(Consult your gas supplier)

*See Residential Warranty Information Brochure for complete warranty information.

If the water heater is installed anywhere other than a single family dwelling, such
as a commercial application, or in any system in which the water is recirculated,
the applicable warranty periods will be limited to one (1) year.

Energy Factor and Average Annual 
Operating Costs based on D.O.E.
(Department of Energy) test
procedures. D.O.E. national average
fuel rate natural gas 91¢/therm;
LP $1.23/gallon

.

®

Recess Box for Rheem
Tankless Outdoor Units
Now Available

Contact your wholesale or local
Rheem representative for the recess
box that meets your application.

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