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visit Rheem.com/HotWater4Life
for more information.
SELLING GUIDE | Water Heaters | Rheem Marathon
For more information, call 1-800-621-5622,
visit Rheem.com/HotWater4Life or see your local distributor.
THE RHEEM
®
MARATHON—BUILT TO LAST.
WARRANTIED FOR LIFE.
RHEEM
®
MARATHON
®
A LIFETIME OF
HT WATER
OUTLASTS
STANDARD
ELECTRIC
WATER
HEATERS
DESCRIPTION DIMENSIONS (IN.)
GAL.
CAP.
MODEL
NUMBER
ELEMENT
WATTAGE
VOLTAGE
HEIGHT
TO T&P
DIAM.
15 MR15120 2000 120 35-3/4 21-3/4
19.9 MR20120 2000 120 34-1/2 23-1/2
19.9 MR20230 3000 240 34-1/2 23-1/2
Uniform Energy Factor based on Department of Energy (DOE) requirements.
Canadian models have different model numbers than U.S. models. Add a “C” before the model
number (e.g. CMR40245C) when ordering. Water heaters furnished with standard 240 or 120
volt AC, single phase non-simultaneous wiring and 4500 watt upper and lower heating elements.
3000 and 3800 watt elements are also available. If heating elements of different wattages than
those shown are demanded, they must be specifically requested. For height to top and T&P
and heat traps add 3-1/2” to the height to water connection. Maximum test pressure: 300 PSI.
Maximum working pressure: 150 PSI.
1
Warranty is provided to original customer in a residential application after online product
registration is complete. Registration must be completed within 90 days of installation. See
warranty certificate for complete information.
2
See warranty certificate for complete information.
3
Savings based on comparison of Marathon tank with 25 year life and standard tank type water
heater with 6-year warranty with cost of $359. Registration required for lifetime warranty.
4
“Water heaters needed over lifetime” assumes this to be the period between the median age of
first-time homebuyers (32.5 according to zillow.com) through the U.S. life expectancy
(78.8 according to the CDC) divided by the life of the warranty.
In keeping with its policy of continuous progress and product improvement, Rheem
reserves the right to make changes without notice.
DESCRIPTION DIMENSIONS
ENERGY
INFO
NOMINAL
GAL.
CAP.
MODEL
NUMBER
FIRST HR.
RATING
GPH
HEIGHT
TO T&P
(IN.)
DIAM.
(IN.)
APPROX.
SHIP. WT.
(LBS.)
UNIFORM
ENERGY
FACTOR
30 MR30238C 38 49-1/2 21-5/8 75 0.88
30 MR30245C 38 49-1/2 21-5/8 75 0.88
40 MR40245C 51 65-1/2 21-3/4 90 0.92
50 MR50245C 57 66-3/4 23-1/2 100 0.91
50 SHORT MSR50245C 41 47-1/4 28-1/4 95 0.90
85 MRG85245C* 77 70-1/4 28-1/4 134 0.92
100 MRG105245C* 83 70-3/4 30-1/4 152 0.90
MARATHON
®
SPECIFICATIONS
MARATHON
®
POINT-OF-USE SPECIFICATIONS
PRINTED IN U.S.A. • 09/18 • WP • FORM NO. 104-8 Rev. 5
* This water heater is intended only for use as part of an electric thermal storage or demand
response program. This water heater will not provide adequate hot water unless enrolled in such a
program and is activated by your utility company or another program operator. Please confirm the
availability of such a program in your local area before purchasing or installing this product.