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Best Rheem Water Heaters

Explore Rheem's tankless water heaters, delivering endless hot water with superior efficiency for residential use. Gas and electric models for indoor/outdoor installation.

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Rheem RTG-84XLN-3 Tankless Natural Gas Water Heater: 8.4 GPM Outdoor High Efficiency, 180K BTU for 3-Bath Homes

The Rheem RTG-84XLN-3 is an outdoor non-condensing tankless natural gas water heater with 8.4 GPM flow rate and 180,000 BTUs, supporting up to 3 bathrooms. Its Hot Start Programming eliminates cold water bursts during back-to-back uses, ideal for busy households needing endless hot water.

  • Endless hot water for simultaneous showers, laundry, and dishes without running out
  • Saves up to 25% energy and 1,100 gallons of water yearly with efficient design and Water Saving Setting
  • Compact wall-mount design frees up space in tight areas with minimal installation clearance
  • Hot Start Programming prevents cold bursts for seamless back-to-back hot water use
  • Overheat Film Wrap protects the heat exchanger for long-lasting reliability up to 2.5x a tank

High 8.4 GPM capacity handles 3-bathroom homes during peak demand. Up to 34% more efficient than 50-gallon tanks, lowering energy bills. Durable outdoor build with easy wall mounting for space savings.

Designed exclusively for outdoor installation, not suitable for indoor use. Requires professional qualified installer for safe setup. Natural gas only, no liquid propane option for this model.

Rheem RTGH-84DVLN-3 8.4 GPM 157K BTU Indoor Natural Gas Tankless Water Heater - Super Efficient Continuous Hot Water

The Rheem RTGH-84DVLN-3 is a high-efficiency indoor condensing natural gas tankless water heater with 8.4 GPM flow for up to 3 bathrooms and 157,000 BTU output. Its Hot Start Programming eliminates cold bursts, making it perfect for families wanting endless hot water with energy and space savings.

  • Endless hot water for multiple showers and appliances without running out
  • Up to 34% more energy efficient than traditional 50-gallon tanks, slashing utility bills
  • Compact wall-mount design frees up floor space in tight closets or utility areas
  • Water-saving mode cuts waste by up to 1,100 gallons yearly while waiting for hot water
  • Hot Start Programming prevents cold water sandwiches during back-to-back use

High 8.4 GPM flow supports 3 bathrooms simultaneously. Super high efficiency reduces energy use and greenhouse gases. Industry-leading slim clearance for easy small-space installs.

Requires natural gas line and proper venting for indoor use only. Needs 120V electrical connection and professional installation recommended. Higher initial setup complexity compared to tank models.

Rheem RTG-70DVLN-3 Tankless Natural Gas Water Heater: 7.0 GPM Indoor High Efficiency, 160K BTU for 2-3 Baths

The Rheem RTG-70DVLN-3 is a high-efficiency non-condensing indoor tankless natural gas water heater with 7.0 GPM flow rate and 160,000 BTUs, ideal for 2-3 bathroom homes needing continuous hot water. Its Hot Start Programming eliminates cold water bursts during back-to-back uses, perfect for busy families.

  • Delivers endless hot water at 7.0 GPM for simultaneous showers, laundry, and dishes in 2-3 bathroom homes
  • Saves up to 25% energy and qualifies for rebates compared to traditional tank heaters
  • Hot Start Programming prevents cold bursts for seamless back-to-back hot water use
  • Compact wall-mount design frees up closet or storage space with minimal clearance needed
  • Water Saving Setting reduces waste by up to 1,100 gallons yearly while waiting for hot water

High 0.82 EF efficiency cuts energy bills and emissions. Powerful 160,000 BTU input handles peak household demand. Easy indoor installation in tight spaces.

Requires professional installation by qualified technician. Natural gas fuel type limits flexibility. No built-in WiFi for remote monitoring.

Rheem RTEX-13 13kW 240V Tankless Electric Water Heater - Endless Hot Water, 99.8% Efficient, Gray

The Rheem RTEX-13 is a 240V residential tankless electric water heater providing continuous hot water on demand for single or multiple points of use. Its 99.8% energy efficiency and precise digital thermostatic control with +/-1°F accuracy make it ideal for homeowners needing reliable, space-saving hot water solutions.

  • Delivers endless hot water on demand for showers, sinks, or multiple fixtures
  • Achieves 99.8% energy efficiency to slash utility bills and reduce waste
  • Precise digital LED temperature control adjustable in 1°F increments for perfect comfort
  • Simple DIY-friendly installation with included 1/2" adapters and compression fittings
  • Durable, field-serviceable copper heating elements for long-lasting reliability

Exceptional energy efficiency at 99.8%. Accurate temperature control with LED display. Easy installation and serviceable components.

Requires 240V and 54A electrical service, needing professional wiring. Best for point-of-use or smaller homes, not whole-house in large setups. Higher upfront electrical demands than traditional tank models.

Rheem 6.5kW 240V Tankless Electric Water Heater - Point-of-Use Thermostatic, Endless Hot Water for Sinks & Fixtures

This Rheem 6.5kW 240V point-of-use thermostatic tankless electric water heater provides continuous hot water up to 1.6 GPM for 2 sinks without running out. Homeowners needing compact, energy-saving hot water at sinks or lavatories should buy it for its space efficiency and quick delivery.

  • Endless on-demand hot water that never runs out for sinks and light fixtures
  • Saves up to 50% on water heating costs by heating only when needed
  • 90% smaller than tank heaters, perfect for under-sink or closet installation
  • Eliminates water waste with instant hot water at the point of use
  • Energy modulation ensures efficient performance within 1 degree of set temperature

Compact size frees up storage space. Significant energy and water savings. Consistent temperature control and fast hot water delivery.

Limited flow rate suits only 2 sinks, not showers or whole home. Requires 240V circuit and 30A breaker for installation. Professional electrician recommended for wiring.

Rheem RTEX-11 11kW 240V Tankless Electric Water Heater - Endless Hot Water, Energy Saving Point-of-Use Unit

The Rheem RTEX-11 is an 11kW 240V tankless electric water heater providing up to 2.68 GPM for one shower and two sinks. Its self-modulating power and compact design make it perfect for point-of-use installs under sinks, delivering continuous hot water while saving energy and space.

  • Endless on-demand hot water for showers and sinks without running out
  • Saves up to 50% on water heating costs compared to tank models
  • Ultra-compact size fits under sinks or in closets, freeing up space
  • Energy modulation uses only needed power for maximum efficiency
  • No venting required for flexible indoor installation anywhere

Continuous hot water supply at up to 2.68 GPM. Saves energy, money, water, and space versus traditional tanks. Self-modulating technology optimizes power usage.

Requires 240V circuit and 50A breaker for installation. Best suited for point-of-use, not whole-home in cold climates. Professional electrical setup recommended.

Rheem RTEX-18 18kW 240V Tankless Electric Water Heater - Endless Hot Water, Energy Saving for Whole Home or Showers

This Rheem 18kW 240V tankless electric water heater delivers up to 4.4 GPM for single showers or multiple sinks in Midwest climates. Its self-modulating technology provides continuous hot water while saving up to 50% on energy costs, perfect for space-conscious homeowners seeking efficient on-demand heating.

  • Endless hot water on demand for showers and sinks without running out
  • Saves up to 50% on energy bills with self-modulating technology that heats only when needed
  • Compact design 90% smaller than tanks, installs under sinks or on walls to free up space
  • No venting required for flexible indoor installation anywhere in your home
  • Digital thermostatic control for precise temperature adjustment with LED display

High flow rate up to 4.4 GPM supports multiple fixtures simultaneously. Energy-efficient modulation lowers operating costs compared to tank heaters. Easy installation with 3/4-inch NPT connections and no venting needed.

Requires 2 x 40 AMP breakers, needing professional electrical upgrade. Best for warmer climates like Midwest; lower performance in very cold groundwater areas. Higher upfront power demands may not suit all electrical panels.

Upgrade your home's hot water system with Rheem tankless water heaters, the gold standard for on-demand hot water. This collection features seven high-performance models, including powerful natural gas units and compact electric options, designed for residential indoor and outdoor use. Whether you're remodeling or seeking energy savings, Rheem delivers reliability and efficiency that outperforms traditional tanks.

Why Rheem Stands Out in Tankless Water Heaters

Rheem has built a reputation over decades for durable, innovative plumbing solutions. Their tankless water heaters heat water only when needed, slashing energy costs by up to 50% compared to tank models. Key strengths include stainless steel heat exchangers for longevity, advanced modulation technology for precise temperature control, and easy integration with smart home systems. These units provide endless hot water, ideal for families with high demand.

Gas vs. Electric Rheem Tankless Models

Rheem offers both natural gas and electric tankless heaters to suit different setups. Gas models excel in whole-home applications with higher flow rates, while electric ones are simpler to install where gas lines aren't available.

  • High-Capacity Gas Models: The RTGH Series 8.4 GPM indoor unit (157,000 BTU) handles multiple fixtures simultaneously, perfect for larger homes. The RTG-84XLN-3 outdoor version (8.4 GPM, 180,000 BTUs) thrives in vent-free installs, and the RTG-70DVLN-3 (7.0 GPM, 160,000 BTUs) suits mid-sized households with its indoor efficiency.
  • Electric Options: The 18kW and 11kW 240V models deliver robust whole-house performance. The RTEX-13 provides reliable heating for medium demands, and the 6.5kW point-of-use unit fits under sinks for instant hot water at a single faucet.

Choose gas for maximum flow (up to 8.4 GPM) or electric for ventless convenience. All models feature self-diagnostic controls and freeze protection.

Key Features to Consider When Buying

Selecting the right Rheem tankless heater involves matching specs to your needs:

  • Flow Rate (GPM): 6.5-8.4 GPM covers 2-5 fixtures; higher for simultaneous use.
  • Energy Rating: Non-condensing gas units offer 80%+ efficiency; electrics up to 99%.
  • Installation Type: Indoor for sheltered spaces, outdoor for space-saving.
  • BTU/kW Rating: 157k-180k BTU for gas; 6.5-18kW for electric to match household size.
  • Additional Perks: WiFi connectivity on select models, low NOx emissions, and 5-year warranties on heat exchangers.

For broader plumbing needs, explore our Plumbing section. If parts are required, check Water Heaters & Parts.

Use Cases and Model Recommendations

Whole-Home Heating: Opt for the 8.4 GPM gas models like RTGH84DVLN or RTG-84XLN-3 for busy families. The 18kW electric handles similar loads without gas.

Point-of-Use: The 6.5kW electric is compact for bathrooms or kitchens.

Medium Homes: RTG-70DVLN-3 or 11kW electric balance cost and capacity.

Compared to competitors, Rheem's build quality edges out options like EcoSmart Water Heaters in durability, while matching GE Appliances Water Heaters in efficiency. For alternatives, see our main Water Heaters category.

Frequently Asked Questions

What is Rheem's warranty on these tankless water heaters?

Rheem provides a 5-year limited warranty on heat exchangers, 1-year on parts, and lifetime coverage on tanks where applicable. Register your unit for extended protection.

Gas or electric: which Rheem model should I choose?

Gas for higher flow and lower operating costs in large homes; electric for easier installs in apartments or additions. Calculate your GPM needs based on fixtures.

How does Rheem compare to other brands?

Rheem leads in reliability and service network, outperforming budget brands like VEVOR in longevity. For premium rivals, see Westinghouse Water Heaters.

Can I install a Rheem tankless heater myself?

Electric models are DIY-friendly for handy users, but gas units require professional venting and plumbing to meet codes. Always consult local regulations.

What maintenance do Rheem tankless heaters need?

Annual flushing prevents scale buildup. Self-cleaning features on newer models simplify care; Rheem offers support via their app and hotline.