6 Best Alternatives to the Noritz NRC66DVNG Indoor Condensing Direct (2026)
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You are evaluating noritz nrc66dvng indoor condensing direct alternatives for your indoor natural gas hot water setup. The Noritz NRC66DVNG provides steady performance with a 6.6 GPM flow rate and high-efficiency condensing operation. It supports direct venting with Schedule 40 PVC pipe and fittings, which simplifies exhaust routing inside utility areas. The 38-pound unit also includes a remote thermostat and a six-foot power cord in a compact frame measuring 13.8 inches wide by 23.6 inches high.
You might still look for different equipment specifications depending on your household demands. Larger homes running multiple showers simultaneously may require higher flow capacities such as 9.0 GPM, 9.5 GPM, or 11 GPM. Other plumbing layouts may call for non-condensing venting, integrated WiFi connectivity, or a smaller 5.1 GPM footprint. These 6 alternatives were chosen because their specifications overlap with the original Noritz model, offering indoor natural gas configurations that align with different household sizes and venting preferences for 2026.
Our top pick: Noritz 6.6 GPM Indoor Natural Gas Tankless Heater.
Comparing Alternatives to the Noritz NRC66DVNG
Rinnai RE160iN 6.6 GPM Gas Water Heater
The Rinnai RE160iN matches the 6.6 GPM flow rate of the Noritz unit and runs on indoor natural gas, supplying up to five fixtures at once. It adds an integrated LED diagnostic display and offers 15-year warranty coverage on its heat exchanger. However, this model uses non-condensing venting rather than condensing technology, so you cannot take advantage of Schedule 40 PVC venting. At 48.5 pounds and 27.3 inches tall, it is also heavier and larger than the 38-pound, 23.6-inch-tall Noritz. Choose this heater if you want direct LED diagnostic readouts and extended heat exchanger coverage while keeping a standard 6.6 GPM output.
Rheem RTG 9.5 GPM Natural Gas Water Heater
The Rheem RTG provides a 9.5 GPM flow rate powered by a 199,900 BTU burner, outperforming the Noritz unit's 6.6 GPM capacity. It also adds built-in WiFi connectivity for system monitoring. In exchange for this increased flow, you step down to a non-condensing design with a 0.82 UEF rating, losing the PVC venting capability of the condensing Noritz. The Rheem is also heavier at 46.5 pounds compared to 38 pounds, though its width of 13.5 inches is slightly narrower. You should choose this model if your household runs multiple showers simultaneously and requires higher flow along with WiFi controls.
VancEpic 5.1 GPM Condensing Natural Gas Water Heater
The VancEpic unit retains condensing operation on indoor natural gas while offering a lighter 27-pound build and bundled venting. At 6.57 inches tall, it requires less vertical mounting space than the 23.6-inch-tall Noritz. What you give up is water volume: its 120,000 BTU burner produces 5.1 GPM, which is 1.5 GPM lower than the Noritz 6.6 GPM output. It also measures 14.2 inches in depth, which extends farther from the wall than the Noritz. Select the VancEpic if you are outfitting a smaller apartment or home where lower demand makes 5.1 GPM sufficient and you prioritize compact weight.
Rheem RTGH 9.0 GPM Natural Gas Tankless Heater
The Rheem RTGH increases output to 9.0 GPM while preserving condensing efficiency with a 0.93 UEF rating. It also features precise digital controls for water temperature management. Compared to the Noritz, it delivers 2.4 GPM more hot water for multi-fixture use. In trade, it requires more wall support and installation clearance, weighing 59.9 pounds against the 38-pound Noritz and measuring nearly four inches wider at 17.7 inches. It also omits the included remote thermostat bundled with the Noritz. Pick this unit if you need higher simultaneous volume for several indoor fixtures without sacrificing condensing efficiency.
Rinnai 9 GPM Indoor Condensing Natural Gas Heater
The Rinnai RU160in delivers 9 GPM and achieves a 0.97 UEF rating, exceeding the 6.6 GPM capacity of the Noritz. It also incorporates Circ-Logic capability, allowing you to pair the heater with an external pump for scheduled recirculation. To gain this efficiency and capacity, you accept a substantially larger footprint. The Rinnai weighs 72.5 pounds, nearly double the 38-pound Noritz, and stands 31.3 inches tall with an 18.5-inch depth. It is narrower at 11.5 inches wide. You should choose this model if your household has heavy simultaneous hot water demands and wants scheduled recirculation with top-tier condensing efficiency.
Rheem Prestige 11 GPM Condensing Water Heater
The Rheem Prestige provides an 11 GPM flow rate, offering 4.4 GPM more capacity than the 6.6 GPM Noritz. It integrates built-in recirculation, automatic leak shutdown, and digital usage tracking directly into the unit. What you give up is compact sizing. The Prestige measures 17.3 inches wide, 28.7 inches high, and 14.8 inches deep, requiring noticeably more installation space than the 13.8-by-23.6-by-10-inch Noritz cabinet. You will need a dedicated space that accommodates these larger dimensions. Choose this option if you manage a high-demand household running several fixtures at once and want built-in recirculation with automated leak protection.
Quick picks
Our 7 picks
Noritz 6.6 GPM Indoor Natural Gas Tankless Heater
Best for: indoor natural gas setups needing PVC venting
- Fuel Type
- Natural Gas
- Flow Rate
- 6.6 GPM
- Installation Location
- Indoor
- Venting Type
- Condensing
- Dimensions
- 6.7 × 13.8 × 23.6 inches
- Weight
- 38 pounds
View on Amazon: Noritz 6.6 GPM Indoor Natural Gas Tankless Heater
The Noritz 6.6 GPM Indoor Condensing Natural Gas Heater supplies endless hot water for indoor setups. This condensing unit delivers a 6.6 GPM flow rate and vents through standard Schedule 40 PVC pipe and fittings. It includes a remote thermostat and a six-foot power cord. At 38 pounds, it fits applications where you require dedicated indoor natural gas heating without needing higher flow capacities.
Pros
- Delivers a flow rate of 6.6 GPM
- Vents with Schedule 40 PVC pipe and fittings
- Includes remote thermostat and 6-foot power cord
- Lightweight 38-pound indoor condensing design
Cons
- Flow rate capped at 6.6 GPM
- Restricted to indoor natural gas installations
Good fit if
- You need an indoor condensing unit fueled by natural gas.
- You plan to vent using Schedule 40 PVC pipe and fittings.
- You find a 6.6 GPM flow rate sufficient for your household hot water needs.
Skip if
- You require an outdoor installation.
- You need a fuel source other than natural gas.
- You need flow rates above 6.6 GPM for high simultaneous demand.
Verdict: Noritz 6.6 GPM Indoor Condensing Natural Gas Heater delivers a balanced 6.6 GPM output with convenient PVC venting compatibility and an included remote control. It serves households seeking an efficient indoor natural gas system without demanding the higher capacity of 9.0 GPM models.
Rinnai RE160iN 6.6 GPM Gas Water Heater
Best for: homes needing up to five simultaneous fixtures
- Fuel Type
- Natural Gas
- Flow Rate
- 6.6 GPM
- Installation Location
- Outdoor
- Dimensions
- 27.3 x 14.1 x 10.8 inches
- Venting Type
- Non-Condensing
- Weight
- 48.5 pounds
This unit delivers up to 6.6 GPM of hot water, supporting up to five fixtures at once using natural gas. It features a non-condensing design measuring 27.3 by 14.1 by 10.8 inches and weighing 48.5 pounds. The built-in LED screen provides service reminders and error codes. This model suits you if you need a mid-size natural gas unit with a 15-year heat exchanger warranty.
Pros
- Maximum flow rate of 6.6 GPM serves up to five fixtures at once
- Limited 15-year warranty on the heat exchanger
- LED screen displays error codes and service reminders
- Compact dimensions of 27.3 by 14.1 by 10.8 inches
Cons
- WiFi control requires a separate Controlr module
- Does not include an internal recirculation pump
- Labor warranty drops from 5 years to 1 year without 90-day registration
Good fit if
- You need a natural gas heater sized for up to five simultaneous fixtures.
- You want clear diagnostic error codes and service alerts directly on an LED screen.
- You plan to register the heater within 90 days to keep the full 5-year labor warranty.
Skip if
- You need built-in WiFi monitoring included in the box.
- You require an integrated pump for water recirculation.
Verdict: Rinnai RE160iN 6.6 GPM Gas Water Heater provides practical non-condensing performance capable of handling up to five fixtures simultaneously. It offers direct diagnostic tracking via an LED display along with 15-year warranty coverage on the heat exchanger.
Rheem RTG 9.5 GPM Natural Gas Water Heater
Best for: large homes running multiple simultaneous showers
- Fuel Type
- Natural Gas
- Flow Rate
- 9.5 GPM
- BTU
- 199,900 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
The Rheem RTG 9.5 GPM Indoor Natural Gas Water Heater is a high-output, non-condensing unit built for whole-home demand. Delivering up to 9.5 GPM at a 35°F rise with a 199,900 BTU per hour gas burner, it supports three to four simultaneous showers. You get direct-vent indoor installation, built-in WiFi connectivity, and precise digital controls adjustable by 1°F increments. It suits you if you need maximum simultaneous hot water capacity indoors.
Pros
- 199,900 BTU/hr burner delivers up to 9.5 GPM flow rate
- Supports 3 to 4 simultaneous showers at 35°F rise
- Built-in WiFi capability and digital LED panel with ±1°F control
- 15-year heat exchanger warranty and 5-year parts warranty
Cons
- 0.82 UEF rating is lower than condensing models
- Non-condensing direct-vent design requires specific indoor venting
- Requires professional installation
Good fit if
- You run three to four water fixtures at the same time.
- You want built-in WiFi management and precision temperature controls.
- You have an indoor natural gas supply sized for 199,900 BTU/hr.
Skip if
- You require a condensing unit with an efficiency rating above 0.82 UEF.
- You use liquid propane rather than natural gas.
Verdict: Rheem RTG 9.5 GPM Indoor Natural Gas Water Heater delivers high flow capacity and WiFi connectivity for homes running several fixtures at once. Its non-condensing 199,900 BTU burner provides steady multi-shower performance with a 0.82 UEF rating.
VancEpic 5.1 GPM Condensing Natural Gas Water Heater
Best for: smaller homes and apartments with modest flow needs
- Fuel Type
- Natural Gas
- Flow Rate
- 5.1 GPM
- BTU
- 120,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- 95°F to 149°F
- Dimensions
- 14.2 x 14.2 x 6.57 in
View on Amazon: VancEpic 5.1 GPM Condensing Natural Gas Water Heater
This VancEpic indoor condensing natural gas water heater delivers up to 5.1 GPM with a 120,000 BTU heat rating. It uses a stainless steel heat exchanger to extract exhaust heat, venting through an included pipe. Its compact 14.2-inch square frame fits tight indoor spaces. If you need steady hot water for smaller homes or apartments running one or two fixtures simultaneously, this unit meets your daily demands.
Pros
- Stainless steel condensing heat exchanger with 120,000 BTU output
- Compact 14.2 by 14.2 by 6.57-inch dimensions and 27-pound weight
- Includes vent pipe and condensate drain line kit
- Integrated 114W anti-freeze heater for cold conditions
Cons
- Flow rate tops out at 5.1 GPM
- Limited 2-year warranty on parts and heat exchanger
Good fit if
- You live in an apartment or smaller home running one or two fixtures at once.
- You need a compact indoor unit that fits into shallow utility spaces.
- You want an indoor condensing heater that includes the vent pipe in the box.
Skip if
- You require more than 5.1 GPM for multiple simultaneous high-flow showers.
- You want manufacturer warranty coverage longer than 2 years.
Verdict: VancEpic 5.1 GPM Condensing Natural Gas Water Heater provides efficient condensing operation and bundled venting in a space-saving design. It serves smaller indoor installations that do not require high simultaneous flow capacity.
Rheem RTGH 9.0 GPM Natural Gas Tankless Heater
Best for: large homes running multiple simultaneous showers
- Fuel Type
- Natural Gas
- Flow Rate
- 9.0 GPM
- BTU
- 180,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTGH 9.0 GPM Natural Gas Tankless Heater
This indoor natural gas tankless water heater delivers up to 9.0 GPM at a 35°F rise using a 180,000 BTU/hr burner. It uses condensing direct-vent technology with a 0.93 Uniform Energy Factor to deliver hot water efficiently across multiple fixtures. If you need steady hot water for three to four simultaneous showers, this unit supplies high-capacity flow with precise digital temperature control accurate to within one degree.
Pros
- Delivers 9.0 GPM at a 35°F rise powered by 180,000 BTU/hr
- High-efficiency condensing operation with a 0.93 Uniform Energy Factor
- Digital LED temperature control accurate to within 1°F
- Built-in freeze protection and multi-point safety system
Cons
- This 9.0 GPM model variation lacks WiFi connectivity
- Heavier unit at 59.9 pounds requiring dedicated mounting support
- Restricted to indoor direct-vent installations
Good fit if
- You need enough hot water to run three to four showers simultaneously.
- You want an indoor condensing natural gas unit with a 0.93 UEF rating.
- You require precise temperature control within one degree.
Skip if
- You want built-in WiFi monitoring included on the unit.
- You cannot supply 180,000 BTU/hr of natural gas to the installation space.
Verdict: Rheem RTGH Series 9.0 GPM Tankless Heater provides high-capacity condensing natural gas performance for households running multiple fixtures at once. Its 0.93 UEF rating and precise digital controls make it an efficient indoor hot water solution.
Rinnai 9 GPM Indoor Condensing Natural Gas Heater
Best for: busy homes needing high flow and efficiency
- Fuel Type
- Natural Gas
- Flow Rate
- 9 GPM
- Installation Location
- Indoor
- Dimensions
- 31.3 x 11.5 x 18.5 inches
- Venting Type
- Condensing
- Weight
- 72.5 pounds
View on Amazon: Rinnai 9 GPM Indoor Condensing Natural Gas Heater
This indoor condensing tankless water heater delivers up to 9 GPM on natural gas, supporting up to six fixtures simultaneously. It features an energy-efficient 0.97 Uniform Energy Factor and built-in Circ-Logic technology for scheduled recirculation with an external pump. If you need higher flow rates and energy conservation for a busy household, this unit provides steady whole-home hot water without occupying floor space.
Pros
- 9 GPM flow rate supports up to 6 appliances at once
- High energy efficiency with a 0.97 Uniform Energy Factor
- Circ-Logic technology allows pairing with an external recirculation pump
- 15-year residential heat exchanger warranty
Cons
- Controlr Wi-Fi module is not included
- Requires an external pump for recirculation functionality
- Weighs 72.5 pounds and requires indoor wall space
Good fit if
- You need up to 9 GPM to run multiple fixtures simultaneously.
- You want an indoor condensing natural gas unit with a 0.97 UEF rating.
- You plan to run scheduled recirculation using an external pump.
Skip if
- You want built-in Wi-Fi monitoring included out of the box.
- You need an outdoor installation setup.
Verdict: Rinnai 9 GPM Indoor Condensing Tankless Water Heater delivers high-efficiency hot water for multi-fixture homes with its 0.97 UEF rating. Its Circ-Logic capability pairs well with an external pump if you want scheduled recirculation.
Rheem Prestige 11 GPM Condensing Water Heater
Best for: high-demand indoor natural gas homes
- Fuel Type
- Natural Gas
- Flow Rate
- 11.0 GPM
- Installation Location
- Indoor
- Dimensions
- 28.7 x 17.3 x 14.8 inches
- Venting Type
- Condensing
View on Amazon: Rheem Prestige 11 GPM Condensing Water Heater
This Rheem unit is an indoor condensing tankless water heater running on natural gas. Delivering up to 11.0 GPM of flow, it provides substantial capacity for simultaneous hot water demands throughout your home. It features built-in recirculation with auto-learn programming to track usage patterns, alongside automatic water and gas leak detection. If you need high flow rates and scheduled delivery from an indoor system, this model suits your setup.
Pros
- High flow rate reaching up to 11.0 GPM
- Built-in recirculation with auto-learn usage programming
- Water and gas leak detection with automatic shutdown
- Condensing natural gas design for efficient indoor operation
Cons
- Restricted to indoor installation only
- Compatible only with natural gas supplies
- Depth of 14.8 inches requires more wall projection than slimmer models
Good fit if
- You need a high flow rate up to 11.0 GPM for simultaneous hot water fixtures.
- You have an indoor utility space configured for natural gas venting.
- You want recirculation scheduling that automatically adjusts to your routine.
Skip if
- You require an outdoor-mounted water heater.
- You rely on liquid propane rather than a natural gas connection.
Verdict: Rheem 11 GPM Condensing Tankless Water Heater delivers high flow performance with built-in recirculation for indoor natural gas setups. Its automatic leak shutdown and usage-tracking features make it a capable high-capacity option.
Specifications side by side
| Spec | Noritz 6.6 GPM Indoor Natural Gas Tankless Heater | Rinnai RE160iN 6.6 GPM Gas Water Heater | Rheem RTG 9.5 GPM Natural Gas Water Heater | VancEpic 5.1 GPM Condensing Natural Gas Water Heater | Rheem RTGH 9.0 GPM Natural Gas Tankless Heater | Rinnai 9 GPM Indoor Condensing Natural Gas Heater | Rheem Prestige 11 GPM Condensing Water Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas |
| Flow Rate | 6.6 GPM | 6.6 GPM | 9.5 GPM | 5.1 GPM | 9.0 GPM | 9 GPM | 11.0 GPM |
| BTU | not specified | not specified | 199,900 BTU/hr | 120,000 BTU/hr | 180,000 BTU/hr | not specified | not specified |
| Installation Location | Indoor | Outdoor | Indoor | Indoor | Indoor | Indoor | Indoor |
| Temperature Control | not specified | not specified | ±1°F | 95°F to 149°F | ±1°F | not specified | not specified |
| Certification | not specified | not specified | CSA | not specified | CSA | not specified | not specified |
| Dimensions | not specified | 27.3 x 14.1 x 10.8 inches | 24.2 x 13.5 x 10.3 inches | 14.2 x 14.2 x 6.57 in | 23.7 x 17.7 x 9.8 inches | 31.3 x 11.5 x 18.5 inches | 28.7 x 17.3 x 14.8 inches |
| Venting Type | Condensing | Non-Condensing | Non-Condensing | Condensing | not specified | Condensing | Condensing |
| Features | not specified | not specified | WiFi | not specified | WiFi | not specified | not specified |
| Weight | 38 pounds | 48.5 pounds | 46.5 pounds | 27 pounds | 59.9 pounds | 72.5 pounds | not specified |
| Size | 13.8 inches (W) x 23.6 inches (H) x 10 inches (D) | 6.6 GPM | 9.5 GPM (WiFi) | 5.1GPM, 120,000BTU, NG | 9.0 GPM (No WiFi) | 9 GPM | 11 GPM |
| Color | White | Silver | Gray | Condensing | Gray | Silver | Gray |
| Model | NRC661-DV-NG | REU-VE2125FFD-US-N | RTG-95DVELN-3 | RH12KG-C-NG | RTGH-90DVLN-3 | RU160in | RTGH-RH11DVLN |
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Frequently asked questions
Which alternative to the Noritz NRC66DVNG provides the highest flow rate?
The Rheem RTGH-RH11DVLN offers the highest capacity among the listed options with an 11 GPM flow rate. This indoor natural gas condensing model supports demanding households. It also incorporates built-in recirculation, usage tracking, and automatic leak shutdown to manage high daily hot water demand across multiple fixtures.
What is the most compact indoor natural gas alternative available?
The VancEpic 5.1 GPM condensing heater provides the smallest footprint and lowest weight among the options. Measuring 14.2 inches by 6.57 inches by 14.2 inches and weighing 27 pounds, it is suited for compact indoor installations. It runs at 120,000 BTU and includes bundled venting for smaller apartments or modest hot water setups.
Which Noritz NRC66DVNG alternatives include WiFi connectivity?
The Rheem RTG 9.5 GPM and Rheem RTGH 9.0 GPM models list WiFi functionality. The Rheem RTG-95DVELN-3 delivers non-condensing operation using a 199,900 BTU burner and a 0.82 UEF rating. The Rheem RTGH-90DVLN-3 provides condensing performance with a 0.93 UEF rating and digital controls for larger household hot water requirements.
Which alternatives support hot water recirculation capabilities?
The Rheem 11 GPM and Rinnai RU160in models include recirculation features. The Rheem RTGH-RH11DVLN includes built-in recirculation alongside automatic leak shutdown. In contrast, the Rinnai 9 GPM model provides Circ-Logic capability, allowing you to pair the heater with an external pump for scheduled recirculation while delivering an energy-efficient 0.97 UEF rating.
Which condensing alternative has the highest energy efficiency rating?
The Rinnai RU160in delivers the highest efficiency rating on the list with a 0.97 UEF specification. It operates on indoor natural gas, delivers up to 9 GPM of hot water, and utilizes condensing venting. For comparison, the Rheem RTGH 9.0 GPM condensing unit achieves a 0.93 UEF rating.
What are the key spec differences between the 9 GPM alternatives?
The Rinnai RU160in and Rheem RTGH-90DVLN-3 both serve high-demand homes but differ in specs. The Rinnai model achieves a 0.97 UEF rating and weighs 72.5 pounds with Circ-Logic support. The Rheem model lists WiFi capability, digital controls, a 0.93 UEF rating, and a lower weight of 59.9 pounds.