6 Best Alternatives to the MAREY Tankless Water Heater Gas (2026)

How Each Alternative Compares

Rinnai RUCS75iP 7.5 GPM Propane Heater

The Rinnai RUCS75iP matches the Marey’s 7.5 GPM flow rate and propane fuel type for indoor use. It offers a similar high-capacity solution for busy households. However, the Rinnai is taller at 35 inches and wider than the Marey’s 26.2-inch height. It also weighs more, tipping the scales at 57.3 pounds compared to the Marey’s 40.8 pounds. You should choose this unit if you prefer a premium brand with a robust warranty. The larger footprint may limit where you can install it. Both units provide endless hot water for multiple fixtures. The Rinnai’s vertical design might fit better in some utility closets despite the extra height.

Rinnai RE160iP 6.6 GPM Propane Indoor

The Rinnai RE160iP reduces the flow rate to 6.6 GPM while maintaining propane fuel for indoor heating. It is shorter than the Marey unit at 27.3 inches tall, though it shares a similar width. This model weighs 48.5 pounds, which is heavier than the Marey. It features non-condensing venting, a specific technical detail you should verify for your installation. Choose this alternative if you need steady performance without the highest possible flow rate. The lower GPM may be sufficient for homes with fewer simultaneous water demands. It suits users who prioritize durability and warranty coverage over maximum output. The compact width helps in tight spaces, but the weight requires sturdy mounting.

FOGATTI 7.5 GPM Propane Tankless Heater

The FOGATTI InstaGas Comfort provides 7.5 GPM of hot water using propane, matching the Marey’s capacity. It is designed for indoor use, just like the original. However, it is significantly deeper at 16.3 inches compared to the Marey’s 7.3-inch depth. The height is slightly shorter at 25 inches. This unit weighs less, making it easier to handle during installation. Select this option if you prioritize flow rate and temperature stability over a slim profile. The deeper body may affect clearance requirements in your utility space. It is a strong budget choice for large households needing high output. The gray finish offers a different aesthetic than the Marey’s white exterior.

Rheem RTG Series 7.0 GPM Propane Tankless Water Heater

The Rheem RTG Series drops the flow rate to 7.0 GPM while keeping propane fuel for indoor installation. It is narrower and shorter than the Marey unit, measuring 24.2 inches in height. It weighs 46.5 pounds, which is heavier than the Marey. This model features non-condensing venting and includes WiFi connectivity for remote control. Choose this alternative if you want smart features for temperature management. The slightly lower flow rate may impact performance in very large homes. The WiFi capability adds convenience for monitoring usage. The compact width helps fit into tighter spaces. It is a solid choice for multi-bathroom homes that value precise temperature control and digital management.

MIZUDO 7.9 GPM Indoor Propane Tankless Heater with WiFi

The MIZUDO HW180A0W-LP increases the flow rate to 7.9 GPM and boosts BTU output for indoor propane heating. It includes WiFi control for added convenience. The unit is deeper at 16.3 inches, similar to the FOGATTI, and slightly shorter at 25 inches. It weighs less than the Marey at 39.6 pounds, making it lighter to install. Pick this model if you need the highest flow rate and smart connectivity in this group. The higher GPM supports larger households with multiple simultaneous uses. The WiFi feature allows you to adjust settings remotely. The white finish matches the Marey’s aesthetic. It is ideal for users prioritizing capacity and modern control features over a slim profile.

Ranein 4.3 GPM Indoor Propane Tankless Water Heater

The Ranein 4.3 GPM unit significantly reduces flow rate to 4.3 GPM while maintaining propane fuel for indoor use. It is shorter at 22.5 inches and narrower than the Marey. This model weighs less, making it easier to mount. Choose this alternative if you have lower hot water demands or a smaller household. The reduced GPM may not support multiple fixtures running simultaneously as well as the Marey. It focuses on precise temperature control and anti-freeze safety features. The compact size fits well in tight spaces. It is a practical choice for users who do not need high-volume output. The gray finish offers a neutral look for utility areas.

Quick picks

Our 7 picks

1 Best overall

Marey GA24CSALP 7.5 GPM Propane Heater

Best for: High-flow indoor propane needs

Fuel Type

Liquid Propane

Flow Rate

7.5 GPM

BTU

170,000 BTU

Installation Location

Indoor

Certification

CSA

Dimensions

26.2 x 17.1 x 7.3 inches

View on Amazon: Marey GA24CSALP 7.5 GPM Propane Heater

The Marey GA24CSALP delivers 170,000 BTUs and a 7.5 GPM flow rate for indoor propane use. Its compact 26.2 x 17.1 x 7.3-inch design mounts easily on walls. CSA certification ensures safety with multiple protective layers. This unit supports three to four simultaneous use points. It suits households needing high-volume hot water without the bulk of a traditional tank.

Pros

• 170,000 BTU heating capacity
• 7.5 GPM flow rate
• CSA certified for safety
• Compact wall-mounted design
• 5-year limited warranty

Cons

• Not recommended for elevations above 2,000 ft
• Heavier at 40.8 pounds than competitors
• Requires professional installation

Good fit if

• You need high flow rates for multiple bathrooms
• You have standard 3-inch exhaust venting
• You want CSA certified safety features

Skip if

• You live above 2,000 ft elevation
• You prefer outdoor installation options
• You want a lighter unit under 40 pounds

Verdict: Marey GA24CSALP 7.5 GPM Propane Heater handles high-demand households with ease. Its robust 170,000 BTU output makes it ideal for homes requiring simultaneous hot water at multiple fixtures.

2 Best premium

Rinnai RUCS75iP 7.5 GPM Propane Heater

Best for: High-flow indoor propane needs

Fuel Type

Propane

Flow Rate

7.5 GPM

Installation Location

Indoor

Dimensions

35 x 14.5 x 22 in

Weight

57.3 pounds

View on Amazon: Rinnai RUCS75iP 7.5 GPM Propane Heater

The Rinnai RUCS75iP is an indoor propane tankless water heater delivering up to 7.5 GPM. It measures 35 by 14.5 by 22 inches and weighs 57.3 pounds. This unit supports simultaneous use by up to six appliances. It offers flexible venting options, including PVC or CPVC configurations. You get a 12-year heat exchanger warranty, five years on parts, and one year on labor. It suits homes needing high flow rates for multiple fixtures.

Pros

• High 7.5 GPM flow rate for multiple appliances
• Compact indoor design with flexible venting options
• 12-year heat exchanger and 5-year parts warranty

Cons

• Requires professional installation
• Indoor-only placement restriction
• Heavier at 57.3 pounds

Good fit if

• You need hot water for up to six fixtures
• You want a long-term warranty on the heat exchanger
• You have space for a larger indoor unit

Skip if

• You prefer outdoor installation
• You want a smaller footprint
• You are looking for a DIY-friendly unit

Verdict: Rinnai RUCS75iP 7.5 GPM Propane Heater delivers high capacity for busy households. It fits homes with multiple simultaneous hot water demands and durable warranty needs.

3 Best 6.6 gpm

Rinnai RE160iP 6.6 GPM Propane Indoor

Best for: Indoor propane homes needing 6.6 GPM

Fuel Type

Propane

Flow Rate

6.6 GPM

Installation Location

Indoor

Dimensions

27.3 x 14.1 x 10.8 inches

Venting Type

Non-Condensing

Weight

48.5 pounds

View on Amazon: Rinnai RE160iP 6.6 GPM Propane Indoor

The Rinnai RE160iP delivers 6.6 GPM of hot water using propane. It measures 14.1 by 27.3 by 10.8 inches and weighs 48.5 pounds. This non-condensing unit is designed for indoor installation. It includes a 15-year heat exchanger warranty. The LED screen shows error codes. You get reliable performance for up to five fixtures. Professional installation is recommended for safety and compliance.

Pros

• 6.6 GPM flow rate supports five fixtures
• 15-year heat exchanger warranty
• Compact indoor design fits tight spaces
• LED screen displays error codes

Cons

• Lower flow rate than 7.5 or 7.9 GPM competitors
• WiFi control module sold separately
• Non-condensing venting requires specific installation

Good fit if

• You need reliable indoor propane heating
• You want a long heat exchanger warranty
• You prefer a compact unit under 50 pounds

Skip if

• You need more than 6.6 GPM flow
• You want built-in WiFi connectivity
• You are installing outdoors only

Verdict: Rinnai RE160iP 6.6 GPM Propane Heater suits homes needing steady indoor propane heat with strong warranty coverage. It fits users who prioritize durability over maximum flow rates.

4 Best budget

FOGATTI 7.5 GPM Propane Tankless Heater

Best for: indoor high-flow propane needs

Fuel Type

Propane

Flow Rate

7.5 GPM

BTU

170,000 BTU

Installation Location

Indoor

Voltage

120V AC

Temperature Control

±1°F

View on Amazon: FOGATTI 7.5 GPM Propane Tankless Heater

The FOGATTI InstaGas Comfort delivers 7.5 GPM at 170,000 BTU for indoor propane use. Its compact 25 x 16.3 x 7.3 inch frame fits tight spaces. Advanced water servo technology maintains temperature within ±1℉. It handles 15-150 PSI water pressure and requires a 120V AC connection. This unit suits households needing high flow rates without the bulk of traditional tanks.

Pros

• 7.5 GPM flow rate supports 3-5 simultaneous outlets
• 170,000 BTU heating power for rapid hot water
• ±1℉ temperature precision via water servo technology
• CSA certified for safety standards
• Operates with low water pressure starting at 15 PSI

Cons

• Indoor installation only
• Recommended for altitudes below 2000 feet
• Requires active anti-freeze measures below 5℉

Good fit if

• You need high flow for multiple bathrooms
• You have limited indoor space
• You want precise temperature control

Skip if

• You require outdoor installation
• You live above 2000 feet altitude
• You need natural gas compatibility

Verdict: FOGATTI 7.5 GPM Propane Tankless Heater provides powerful indoor heating for large households. It fits buyers who prioritize flow rate and temperature stability over outdoor versatility.

5 Also great

Rheem RTG Series 7.0 GPM Propane Tankless Water Heater

Best for: Whole-house propane heating without WiFi

Fuel Type

Liquid Propane

Flow Rate

7.0 GPM

BTU

160,000 BTU/hr

Installation Location

Indoor

Temperature Control

±1°F

Certification

CSA

View on Amazon: Rheem RTG Series 7.0 GPM Propane Tankless Water Heater

This Rheem unit delivers 7.0 GPM at 160,000 BTU/hr for indoor propane use. It features a non-condensing design with a 0.82 UEF rating. The digital panel offers ±1°F precision control. It includes built-in freeze protection and flame failure safety. This model suits homes needing reliable hot water for two to three simultaneous showers without WiFi connectivity.

Pros

• 160,000 BTU/hr output for high flow
• Digital LED control with ±1°F precision
• Built-in freeze and flame failure protection
• Space-saving wall-mount design

Cons

• No WiFi connectivity in this 7.0 GPM variant
• Heavier at 46.5 pounds
• Requires professional installation

Good fit if

• You need precise temperature control for whole-house use
• You prefer a non-condensing indoor unit
• You want reliable safety features without smart connectivity

Skip if

• You require WiFi remote monitoring
• You need more than 7.0 GPM flow
• You are installing outdoors

Verdict: Rheem RTG 7.0 GPM Propane provides stable hot water with precise temperature control for multi-bathroom homes that do not need smart features.

6 Also great

MIZUDO 7.9 GPM Indoor Propane Tankless Heater with WiFi

Best for: large households with propane access

Fuel Type

Propane

Flow Rate

7.9 GPM

BTU

180,000 BTU/h

Installation Location

Indoor

Voltage

120V AC

Temperature Control

±1°F

View on Amazon: MIZUDO 7.9 GPM Indoor Propane Tankless Heater with WiFi

The MIZUDO 7.9 GPM Propane WiFi Heater delivers 180,000 BTU/h for indoor use. It maintains temperature stability within ±1°F using a copper heat exchanger. WiFi app control lets you adjust settings remotely. The sealed combustion system draws air from outside. This model suits larger households needing steady hot water across multiple fixtures.

Pros

• 7.9 GPM flow rate for high demand
• 180,000 BTU/h input power
• WiFi app control for remote adjustments
• ±1°F temperature stability
• Sealed combustion for indoor safety

Cons

• 2-year unit warranty is shorter than typical 5-year standards
• Propane-only fuel type limits versatility
• Indoor installation only

Good fit if

• You need high flow for multiple bathrooms
• You want remote temperature control via app
• You have a propane supply for indoor use

Skip if

• You require natural gas compatibility
• You need outdoor installation capability
• You prefer a longer standard warranty

Verdict: MIZUDO 7.9 GPM Propane WiFi Heater offers strong performance for large households. Its high BTU and WiFi control make it ideal for users prioritizing convenience and capacity.

7 Best 4.3 gpm

Ranein 4.3 GPM Indoor Propane Tankless Water Heater

Best for: Indoor multi-fixture propane hot water needs

Fuel Type

Propane Gas

Flow Rate

4.3 GPM

BTU

100,000 BTU

Installation Location

Indoor

Temperature Control

95°F-155°F

Use

Whole House

View on Amazon: Ranein 4.3 GPM Indoor Propane Tankless Water Heater

The Ranein 4.3 GPM propane water heater delivers 100,000 BTU of heating power for indoor use. It supports three to four simultaneous water points with a temperature range of 95°F to 155°F. The unit includes an oxygen-free copper heat exchanger and anti-freeze protection down to 14°F. It features four preset modes and an LED display. This model suits households needing reliable hot water for multiple fixtures.

Pros

• 4.3 GPM flow rate supports 3-4 water points
• 100,000 BTU heating capacity for on-demand hot water
• Oxygen-free copper heat exchanger for durability
• Anti-freeze protection down to 14°F
• Four intelligent preset modes for different uses

Cons

• Lower flow rate compared to 7.5 GPM alternatives
• Indoor installation only, not suitable for outdoor use
• Not recommended for elevations above 2,000 feet

Good fit if

• You need a propane heater for indoor installation
• You require hot water for multiple simultaneous fixtures
• You want anti-freeze protection for cold climates

Skip if

• You need a flow rate higher than 4.3 GPM
• You plan to install the unit outdoors
• You live at an elevation above 2,000 feet

Verdict: Ranein 4.3 GPM Propane Indoor Heater offers solid performance for indoor households needing multi-fixture support. It fits buyers who prioritize anti-freeze safety and precise temperature control over maximum flow rates.

Specifications side by side

Frequently asked questions

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