10 Best Rheem Gas Water Heater of 2026 For Endless Hot Showers

1

Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water

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  9.7
• Brand
  Rheem

Key specs3

Outdoor Installation

Mounting the unit on an exterior wall eliminates indoor exhaust venting requirements and saves indoor living space.

Shower Output

3 to 4 simultaneous showers at 8.4 GPM

Warranty Coverage

Rheem covers the heat exchanger for 15 years and replacement parts for 5 years.

Pros & cons42

Pros

• Outdoor cabinet setup removes the need for indoor venting penetrations through walls or roofs
• Delivers 8.4 GPM at a 35 degree Fahrenheit rise with 180,000 BTU output for 3 to 4 showers
• Backed by a 15-year heat exchanger warranty and 5-year parts coverage
• Digital LED panel permits exact 1-degree temperature adjustments

Cons

• Requires outdoor mounting so it is unsuitable for homes in regions with severe freezing winters
• Does not offer built-in WiFi connectivity for smartphone temperature adjustments

2

WV8840C1406 - OEM Upgraded Water Heater Natural Gas Valve Fits

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  9.4
• Brand
  Rheem

Key specs2

Replacement Purpose

This item is an upgraded natural gas control valve replacement part, not an entire water heater appliance.

Physical Dimensions

7 x 7 x 7 inches and 4 pounds

Pros & cons32

Pros

• Direct OEM replacement valve engineered specifically for compatible Rheem natural gas water heaters
• Compact 7-inch cube profile simplifies handling during burner control repairs
• Restores factory gas regulation without requiring a complete water heater replacement

Cons

• Component gas valve only, not a complete water heater unit
• Requires verifying specific tank model compatibility before ordering

3

Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water

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  9.3
• Brand
  Rheem

Key specs3

Outdoor Installation

Engineered specifically for outdoor mounting with a metal cabinet that requires no indoor chimney or vent pipe.

Flow Rate Capacity

7.0 GPM at 35 degree F rise

Household Demand

• Powers 2 to 3 showers simultaneously
• 160,000 BTU maximum gas input
• Non-condensing 0.82 UEF rating

Pros & cons42

Pros

• Exterior wall mount requires zero indoor ductwork or venting pipes
• Supplies 7.0 GPM at a 35 degree Fahrenheit rise to handle 2 to 3 fixtures simultaneously
• Non-condensing design delivers 160,000 BTU per hour with a 0.82 Uniform Energy Factor
• Includes multi-point safety features such as flame failure and freeze protection

Cons

• Lower 7.0 GPM flow rate can limit hot water availability in large multi-bathroom homes
• Outdoor placement exposes the cabinet to local ambient weather conditions

4

Rheem RTG-70DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water

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  8.9
• Brand
  Rheem

Key specs3

Venting Setup

Requires direct-vent indoor installation to route combustion air and exhaust directly through an exterior wall.

Leak Defense

LeakGuard internal water leak detection

Fixture Capacity

2 to 3 simultaneous showers at 7.0 GPM

Pros & cons42

Pros

• Built-in LeakGuard detection senses internal water leaks to help prevent utility room damage
• Direct vent configuration allows safe indoor installation in utility closets or basements
• Produces 7.0 GPM hot water flow rate supporting up to 3 fixtures running concurrently
• Space-saving wall-mount design frees up valuable floor space

Cons

• Requires dedicated direct-vent exhaust ducting routed through an exterior wall
• 7.0 GPM capacity may cause flow drops if more than 3 fixtures draw water at once

5

Rheem Prestige Condensing Tankless Gas Indoor Natural Gas Water Heater

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  8.8
• Brand
  Rheem

Key specs3

Recirculation System

Features built-in recirculation to deliver instant hot water at fixtures and reduce overall water waste.

Peak Demand Capacity

11.0 GPM high-flow indoor performance

Leak Defense

Integrated safety monitoring shuts down the unit and provides error codes if a gas or water leak occurs.

Pros & cons42

Pros

• High 11.0 GPM capacity comfortably powers multiple simultaneous hot water demands
• Built-in recirculation pump reduces wait times at the faucet for faster hot water delivery
• Auto-Learn programming tracks household usage patterns to optimize heating schedules
• Automatic shut-down system responds to detected water or gas leaks with clear error codes

Cons

• Requires dedicated indoor direct-vent ducting and drainage for condensing operation
• Larger 28.7-inch tall cabinet requires more installation clearance than non-recirculating units

6

Rheem RTG-84DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water

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  8.7
• Brand
  Rheem

Key specs3

Venting Setup

Direct-vent design draws combustion air from outdoors and vents exhaust fumes through dedicated piping.

Shower Output

3 to 4 simultaneous showers at 8.4 GPM

Gas Input Demand

180,000 BTU per hour

Pros & cons42

Pros

• Supplies 8.4 GPM at a 35 degree rise to keep 3 to 4 showers running without temperature drops
• Direct-vent design safely draws outside combustion air for indoor closet or basement placement
• Delivers 180,000 BTU per hour with a 0.82 UEF rating to reduce natural gas consumption
• Protected by a 15-year warranty on the heat exchanger and 5-year parts warranty

Cons

• Requires running dedicated direct-vent piping to an exterior wall or roof
• Standard model does not include built-in WiFi connectivity

7

Rheem RTG-70XLP-3 High Efficiency Non-Condensing Outdoor Tankless Liquid Propane Water

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  8.7
• Brand
  Rheem

Key specs3

Propane Requirements

Factory-configured exclusively for liquid propane tanks and will not operate on natural gas utility lines.

Venting Requirement

Zero indoor venting needed due to outdoor mount

Flow Rate Capacity

7.0 GPM supporting 2 to 3 showers

Pros & cons42

Pros

• Specifically engineered for liquid propane connections rather than standard natural gas lines
• Outdoor cabinet installation completely bypasses the need for interior venting ducts
• Produces 7.0 GPM with 160,000 BTU output to support 2 to 3 hot water taps at once
• Protected by built-in freeze defense and automatic flame failure monitoring

Cons

• Incompatible with municipal natural gas supplies without a proper conversion kit
• Outdoor wall placement is not suitable for severe sub-zero climates

8

Rheem SP20867C Natural Gas Water Heater Control Valve Kit

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  8.6
• Brand
  Rheem

Key specs2

Replacement Purpose

Authentic factory-authorized control valve kit designed for repairing existing Rheem natural gas tank heaters.

Compatible Models

• XG40T06EN38U1 and 6G40-38FN4
• PRO+G40-38U RH62 EC1 -1
• XG75T06EN76U1
• PROG40-38U RH62 EC1 TT -1

Pros & cons32

Pros

• Genuine factory-authorized Rheem replacement valve restores tank burner operation
• Confirmed compatibility with multiple Rheem, Ruud, and Richmond gas tank water heaters
• Kit includes the complete valve assembly and detailed installation instructions

Cons

• Standalone control valve only, not a complete replacement water heater
• Coverage is limited to a 1-year warranty compared to multi-year heater warranties

9

Rheem RRTGH84DVLN3701171 Rheem RTGH Series 8.4 GPM 157,000 BTU 120

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  8.4
• Brand
  Rheem

Key specs3

Condensing Efficiency

Condensing heat exchange delivers a 0.93 Uniform Energy Factor to extract more heat from 157,000 BTU input.

Emissions Compliance

Meets ultra-low NOx emission standards

Warranty Coverage

Includes a 15-year warranty on the heat exchanger and 5-year coverage for parts.

Pros & cons42

Pros

• Condensing technology achieves an efficient 0.93 UEF rating using 157,000 BTU per hour
• Delivers 8.4 GPM at a 35 degree rise, capable of powering 3 to 4 simultaneous showers
• Direct-vent indoor installation meets strict ultra-low NOx emissions standards
• Digital LED controls permit precise temperature adjustments in 1-degree increments

Cons

• Heavier 59.88-pound unit weight requires secure wall anchoring during installation
• Condensing operation generates liquid runoff that requires a dedicated drainage connection

10

Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water

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  7.3
• Brand
  Rheem

Key specs3

Gas Input Demand

Requires an existing or upgraded natural gas line capable of delivering up to 199,900 BTU per hour at full firing rate.

Simultaneous Demand

9.5 GPM for 3 to 4 simultaneous fixtures

Efficiency Rating

0.82 UEF non-condensing direct vent

Pros & cons42

Pros

• Generates 199,900 BTU per hour delivering up to 9.5 GPM flow rate for demanding homes
• Direct-vent indoor design safely exhausts combustion gases through an exterior wall
• Supports 3 to 4 simultaneous showers with reliable non-condensing 0.82 UEF performance
• Includes a 15-year heat exchanger warranty and 5-year coverage on internal parts

Cons

• High 199,900 BTU firing rate requires confirming adequate natural gas pipe diameter
• Requires dual-pipe or concentric direct venting infrastructure through exterior walls

Last update on 2026-10-06 / Affiliate links / Images, Product Titles, and Product Highlights from Amazon Product Advertising API

How do flow capacities like 7.0, 8.4, 9.5, and 11.0 GPM compare for home hot water demand?

Your fixture demand determines whether a 7.0, 8.4, 9.5, or 11.0 GPM unit prevents sudden drops in water temperature. Rheem rates these tankless models based on a 35-degree Fahrenheit temperature rise. The 7.0 GPM units deliver up to 160,000 BTU, while 8.4 GPM non-condensing heaters operate at 180,000 BTU. For higher household demand, the 9.5 GPM model provides 199,900 BTU, and the condensing RTGH-RH11DVLN reaches 11.0 GPM with built-in recirculation to minimize wait times.

Do I need an outdoor tankless model or an indoor direct-vent unit?

Installation location dictates venting requirements. Outdoor heaters such as the RTG-70XLN-3 and RTG-84XLN-3 mount directly on exterior walls, venting combustion gases straight into open air without dedicated interior pipe runs. If you want exterior placement to save utility room space, an outdoor tankless water heater avoids wall and ceiling flue penetrations. Indoor direct-vent units like the RTG-70DVLN-3 and RTG-95DVLN-3 require dedicated intake and exhaust piping through an exterior wall or roof to operate safely inside living spaces.

What separates non-condensing 0.82 UEF models from condensing 0.93 UEF units?

The difference lies in thermal efficiency ratings and burner specifications. Non-condensing Rheem units carry a 0.82 Uniform Energy Factor (UEF) and save up to 34% on energy costs compared to standard 50-gallon electric tank heaters. In contrast, condensing models like the RTGH series achieve a 0.93 UEF for reduced gas consumption. For example, the 8.4 GPM condensing RRTGH84DVLN3701171 operates at 157,000 BTU per hour on a 120-volt connection while meeting ultra-low NOx emissions standards.

Can a natural gas Rheem tankless water heater run on liquid propane?

No, Rheem gas water heaters are engineered for one specific fuel source at the factory and cannot be interchanged without proper factory conversion hardware. The RTG-70XLN-3 is manufactured specifically for natural gas, whereas the RTG-70XLP-3 is built for liquid propane, delivering 7.0 GPM at a 35-degree Fahrenheit rise. Connecting natural gas equipment to propane creates severe combustion and pressure hazards. Check your supply line before ordering, particularly if you maintain a dedicated propane heater for home fuel storage.

What is the difference between a replacement control valve and a complete water heater?

A gas valve is a standalone repair part for an existing storage tank, not an entire water heating unit. Components like the WV8840C1406 valve and the Rheem SP20867C control valve kit are designed to service specific standing tank models, including the XG40T06EN38U1, 6G40-38FN4, and PRO+G40-38U RH62 EC1 -1. If your existing storage tank body is functional and only the thermostat or gas control fails, installing a replacement valve kit restores function. If you want continuous hot water on demand, you need a complete tankless heater.

How much wall space and weight support does an indoor Rheem tankless heater require?

Indoor Rheem tankless units require sturdy wall mounting to support their physical footprint. Standard non-condensing direct-vent models, such as the RTG-70DVLN-3, RTG-84DVLN-3, and RTG-95DVLN-3, measure 10.27 by 13.5 by 24.2 inches and weigh 46.5 pounds. High-capacity condensing options require more space: the 8.4 GPM condensing model weighs 59.88 pounds with dimensions of 9.8 by 17.7 by 23.7 inches, while the 11.0 GPM model measures 14.8 by 17.3 by 28.7 inches. Always measure your mounting area and confirm framing support before installation.