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    Rheem Tankless Water Heater Reviews

    Tankless Geek currently reviews 5 Rheem models. Each review separates our editorial score from Amazon customer ratings and links the source documents used for specifications, installation and warranty details.

    Specifications verified on the date shown in each review. Product availability and documents can change.

    Rheem IKONIC S84iN
    PREMIUM
    Premium

    Rheem IKONIC S84iN

    4.4

    Rheem's flagship IKONIC condensing natural-gas tankless — 157,000 BTU/h and 8.4 GPM at ~0.94 UEF, with built-in EcoNet Wi-Fi and LeakGuard automatic-shutoff leak protection. The smartest, best-protected tankless Rheem makes (non-recirculating; see SR84iN for a pump).

    Amazon customer rating as of the last specification review. Not the Tankless Geek editorial score.

    Flow Rate:8.4 GPM
    Energy Type:Natural Gas
    Installation:Indoor
    Best For:2–3 bathroom homes, Owners wanting leak protection and smart control, Tight installs needing a compact condensing unit
    $1899
    Rheem RTEX-24
    MID-RANGE
    Mid-Range

    Rheem RTEX-24

    4.5

    24 kW, 240 V whole-home electric tankless with self-modulating output and ±1 °F digital control (80–140 °F). Rated up to 5.9 GPM at minimal rise; a strong-value electric unit for warm climates or homes without gas — needs ~120 A of panel capacity.

    Amazon customer rating as of the last specification review. Not the Tankless Geek editorial score.

    Flow Rate:5.9 GPM
    Energy Type:Electric
    Installation:Indoor
    Best For:Homes without natural gas, Warm-to-mild climates, Small-to-medium homes with adequate electrical service
    $533
    Rheem RTG-70XLN-3
    MID-RANGE
    Mid-Range

    Rheem RTG-70XLN-3

    4.4

    Outdoor, non-condensing natural-gas tankless from Rheem's mid-efficiency RTG line — 160,000 BTU/h and 7.0 GPM at 0.82 UEF, with Hot Start Programming. Exterior mounting means no indoor venting; ideal for warm-to-mild climates.

    Amazon customer rating as of the last specification review. Not the Tankless Geek editorial score.

    Flow Rate:7.0 GPM
    Energy Type:Natural Gas
    Installation:Outdoor
    Best For:Warm-to-mild climates, Small-to-medium homes, Installs favoring outdoor mounting
    $899
    Rheem RTG-70DVLN-3
    MID-RANGE
    Mid-Range

    Rheem RTG-70DVLN-3

    3.9

    Indoor, direct-vent non-condensing natural-gas tankless from Rheem's mid-efficiency RTG line — 160,000 BTU/h and 7.0 GPM at 0.82 UEF, with Hot Start Programming. A value indoor gas unit for small-to-medium homes.

    Amazon customer rating as of the last specification review. Not the Tankless Geek editorial score.

    Flow Rate:7.0 GPM
    Energy Type:Natural Gas
    Installation:Indoor
    Best For:Small-to-medium homes, Indoor installs with proper venting, Budget-focused gas tankless buyers
    $899
    Rheem RTGH-84DVLN
    PREMIUM
    Premium

    Rheem RTGH-84DVLN

    4.3

    Indoor condensing natural-gas tankless from Rheem's super-high-efficiency RTGH line — 157,000 BTU/h and 8.4 GPM at up to 0.93 UEF (ENERGY STAR), with Hot Start Programming and lighter PVC/CPVC venting. IKONIC-level performance without the smart-first price.

    Amazon customer rating as of the last specification review. Not the Tankless Geek editorial score.

    Flow Rate:8.4 GPM
    Energy Type:Natural Gas
    Installation:Indoor
    Best For:2–3 bathroom homes, Efficiency-minded gas hot water, Installs favoring lighter PVC venting
    $1,769

    How to compare Rheem models

    Compare usable flow at your required temperature rise, energy input, installation requirements, efficiency, service access and written warranty. A maximum GPM value without its test conditions is not enough to size a system.

    Sizing guideDownload the specification dataset