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Rheem EcoSense

Model # RETE 27

Internet # 202514587

Store SKU # 452893

RETE-27 - 27KW Electric Tankless Water Heater

This item has been discontinued.
The Home Depot no longer carries this specific product.

$619.99 /  each
  • Uses energy only when hot water is needed
  • Rugged brass/copper heat exchanger for longer life
  • Compact design allows simple installation almost anywhere


Model # RETE 27

Internet # 202514587

Store SKU # 452893

Store SO SKU # 1000114412

The Rheem EcoSense RETE-27 tankless Electric Water Heater features a rugged brass and copper heater exchanger that is designed to withstand tough water conditions for long life. Its lightweight and compact design enables simple installation in a variety of locations. It is designed to provide hot water for up to two bathrooms in warmer climates or a single bathroom in colder climates. Please click the “More Info” Tab and then “Specifications” to view the Rheem Brochure Guide to assist you in your purchasing decision.

  • Provides a maximum of 5.27 GPM continuous flow at a 35 degree Fahrenheit temperature rise
  • Designed to provide hot water for applications such as small homes, cottages, condos, apartments, workshops or offices
  • Flow rate provided by a tankless electric water heater is dependent on the difference in temperature of the incoming cold water supply and the desired hot water delivery temperature
  • 27 KW water heater requires 240 volt electric service, 2 separate 60 amp breaker(s) and 6 gauge copper wiring
  • Energy efficient, uses hot water only when needed
  • On-unit temperature controls and LED lights indicate active elements and system operation
  • Modulating control adjusts power consumption to meet the required hot water temperature and flow rate
  • Rugged brass and copper heat exchanger is designed to withstand tough water conditions for long life
  • Lightweight and compact design saves space and enables simple installation in a variety of locations
  • Requires 240 Volt Electrical connection
  • Equipped with ½ in. water connections for easy installation
  • Modulating Control adjusts power consumption to meet the required hot water / temperature flow rate

    How to Choose Your Rheem EcoSense Tankless Electric

    Choose your application, ie. shower, bath tub or vanity sink-faucet, kitchen sink faucet or washer. See chart below.

    For example: you choose a kitchen sink faucet.

    See application chart below and locate your flow rate. For example: your flow rate is 1.5 gpm.

    On the map, locate the average water temperature in your area.

    For example: your water temperature (in Atlanta) is 55°

    Use the water temperature and flow rate chart to determine the model you need.

    For example: 1.5 gpm flow rate + 55° = RETE 9.

Info & Guides

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Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Water Connection Size (in.) 
Amperage (amps) 
Electric Product Type 
Point of Use 
Finish Family 
Flow Rate @ 35 F Rise (gallons/min) 
5.27 gal (US)/min 
Flow Rate @ 45 F Rise (gallons/min) 
4.10 gal (US)/min 
Fuel Type 
Maximum Temperature (F) 
Minimum Activation Rate (gpm) 
Minimum Temperature (F) 
Product Weight (lb.) 
12 lb 
Residential/Commercial/industrial Use 
Residential or commercial 
Water Connection Location 
Water Heater Features 
No Additional Features 
Wattage (watts) 
Warranty / Certifications
Certifications and Listings 
2-UL Recognized 
ENERGY STAR Certified 
Labor Warranty 
No Warranty 
Part Warranty 
1 Year 


Rated 3.2 out of 5 by 35 reviewers.
Rated 5.0 out of 5.0 by Easy, Easy, Easy Works great for my 2 bath house. Solar installed and bill is still zeroed out. Gas bill cut in half. I installed the unit myself, wiring and plumbing. I don't do these for a living but have an understanding and respect. I had to adjust the flow for the faucet for my tub. 2 showers work great. More room in garage now! September 24, 2013
Rated 5.0 out of 5.0 by Good product My previous unit's manufacture is no longer in existence so I was not able to obtain replacement parts for it. Therefore, I chose a company that has been around for a long time. Another reason I purchased this unit was because it required very little flow rate to it to start and continue to heat water. This is a helpful feature if you need to have a small amount of water running for a long time. The only curious thing was the manual stated it required no maintenance but a paragraph later said it would last longer with preventive maintenance. Then, it never said what that the maintenance involved nor how to do it. When I plumbed the unit, I did so with cutoff valves before and after the unit. I also included two other valves so that I can "descale" the unit in place. The installation was relatively easy. I already had the electrical service to the unit and only had to change the breakers to match. This unit required fewer circuits (2) than my previous unit (4). Of course, the plumbing had to be modified. February 3, 2013
Rated 5.0 out of 5.0 by Works Great We built a small cabin at 2,200 feet elevation. We did not want a tank water heater to have to drain each winter. We researched the reviews on all the tankless electric heaters and this one had the most consistent results. We purchased the 27 kw model knowing the ground water temperature from our well in winter would be a challenge and we have more than enough hot water to handle a shower and washing machine running at the same time. This product met all our requirements. Saved space in a small cabin, no draining 40 gallons for winter and it provides hot water in the same time a tank heater takes to get the water to the tap. All things considered an excellent purchase for us. February 25, 2012
Rated 5.0 out of 5.0 by best thing i've bought in years. works great and never runs out. i bought the 27k electric rheem tankless water heater in feb. the installation was easier than expected. the hardest part was working with the 6 gage wire. don't try wire nuts, use the wire clamps that can be tightened. you should also use a large enough box to give space to work with the wiring and keep the clamps from touching. the plumbing is a piece of cake. be sure and put a shutoff on the cold water line just before it goes into the tank. after the plumbing ts done, let all of the hot water lines run for a few minutes to bleed the air and check for leaks. now you can let the wife go shower without her complaining about running out of hot water. March 27, 2012
Rated 2.0 out of 5.0 by wouldnt do it again this has been my first rheem product and it is NOT casting a favorable light on them from where I stand. this unit has not be good at maintaining a constant temperature and now it has stopped heating water at all in under 2 years of service. it has had a couple issues other than the tem control as well that required professional help. I would not advise getting one of these. I love the idea of tankless but I am strongly thinking of going back to a tanked water heater. October 4, 2014
Rated 1.0 out of 5.0 by Three of these failed for the same reason for us I installed this model in August 2011 at our cabin. It worked flawlessly for a year and then the Intake connection started leaking. Since it is a compression fitting, I gently removed, checked the fitting, added some liquid pipe thread seal, re-installed and it leaked worse. Tried a new pipe, new compression fitting and the leaking just got worse. Returned to HD, Rheem shipped me a new one. Easy swap out. 1 year later, same leak. same process, returned to HD, Rheem sent me a new one. 1 year later, leak again. I AM DONE WITH THIS HEATER. It is too bad as it works really well. My suspicion is since the cold water inlet on this heater is part of the actual heating chamber assembly (one solid unit in to out), that the temp extremes are just too much and the housing cracks at the inlet side. If this heater was being used at a gym or something and running 24X7, I could understand it might wear out but at a cabin that gets used every other weekend or less, it should not fail just sittng. January 10, 2014
Rated 5.0 out of 5.0 by We have only had it a couple of days but has done what we were hoping it would do. The product itself works wonderful. The only problem we had was that it did not have instructions on the wiring and did not specify that you actually need 2 double 60 amp breakers, and it took us a couple of phone calls to Tech support to get someone who actually knew what the problem was. January 13, 2015
Rated 4.0 out of 5.0 by A real improvement over tank type heater The product works great for our house, which has two bathrooms. There is plenty of hot water for showers, or baths. It may take a little longer to regulate, but the results are worth it. My only question is how long will it last. The workmanship, especially the wiring, looks suspect. I had a hard time connecting the #6 wires to the terminal strips. The terminal strips had only one screw holding each of them when they should have had two each. September 29, 2011
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