6 Best Rinnai Outdoor Tankless Water Heaters, Compared
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
Finding the best rinnai outdoor tankless water heaters requires comparing key specifications. We evaluated 6 models based on published listing data. The Rinnai 6.1 GPM Outdoor Propane Water Heater takes the top spot because its compact 14.1-inch width saves space without sacrificing performance. This guide helps you decide which unit fits your outdoor installation needs. You will see how flow rate, fuel type, and physical dimensions differ across the lineup. Read on to find the right match for your home.
Quick picks
The best fit for you
- You need the most compact outdoor propane heater Rinnai 6.1 GPM Outdoor Propane Water Heater It measures 10.8 inches long and weighs 49.2 pounds, making it the smallest unit listed.
- You want high flow for a large home Rinnai RU160eN 9 GPM Outdoor Natural Gas This natural gas model delivers 9 GPM, the highest flow rate in this group.
- You need a commercial grade propane solution Rinnai Commercial Outdoor 9 GPM Propane Tankless Heater It is rated for commercial use with a 9 GPM output and condensing venting.
- You want smart recirculation with natural gas Rinnai Smart-Circ Outdoor Natural Gas Water Heater This unit offers 7.9 GPM and includes built-in recirculation pump efficiency.
Our 6 picks
Rinnai 6.1 GPM Outdoor Propane Water Heater
Best for: compact outdoor propane hot water needs
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 6.1 GPM
- BTU
- 160k BTU
- Dimensions
- 24.6 x 14.1 x 10.8 in
- Venting Type
- Non-Condensing
View on Amazon: Rinnai 6.1 GPM Outdoor Propane Water Heater Affiliate link
This Rinnai RE160eP is a non-condensing propane water heater designed for outdoor installation. It delivers a flow rate of 6.6 GPM, supporting up to five fixtures simultaneously. The unit measures 24.6 by 14.1 by 10.8 inches and weighs 49.2 pounds. It features an LED screen for error codes and service reminders. This model suits homes needing reliable hot water in moderate climates.
Pros
- 6.6 GPM flow rate for multiple fixtures
- Compact outdoor design fits small spaces
- 15-year limited heat exchanger warranty
- LED screen displays error codes
Cons
- Lower flow rate than 9 GPM condensing models
- Non-condensing design requires specific venting
- WiFi control module sold separately
Good fit if
- You need a propane outdoor unit
- You want a compact footprint
- You prefer non-condensing technology
Skip if
- You need high flow for many fixtures
- You require indoor installation
- You want included WiFi control
Verdict: Rinnai RE160eP Propane Outdoor Tankless Heater offers a compact 6.6 GPM solution for outdoor propane needs. It fits buyers prioritizing space efficiency and durable non-condensing performance.
Rinnai 7.5 GPM Outdoor Propane Tankless Water Heater
Best for: outdoor propane homes needing 7.5 GPM
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 7.5 GPM
- Dimensions
- 35 x 14.5 x 22 inches
- Weight
- 63 pounds
View on Amazon: Rinnai 7.5 GPM Outdoor Propane Tankless Water Heater Affiliate link
The Rinnai RUS75eP is an outdoor propane tankless water heater delivering up to 7.5 GPM. It heats water only when you use it, saving energy and space. The compact unit measures 35 x 14.5 x 22 inches and weighs 63 pounds. It can serve up to six appliances simultaneously. This model is designed for outdoor installation and offers flexible venting options for easy placement.
Pros
- Delivers up to 7.5 GPM flow rate
- Serves up to six appliances at once
- Compact outdoor design saves space
- Energy efficient by heating only when needed
Cons
- Lower flow rate than other models on this list
- Requires professional installation for safety
- Standard warranty covers labor for only one year
Good fit if
- You need hot water for up to six fixtures
- You have an outdoor installation space
- You use propane as your fuel source
Skip if
- You require a flow rate higher than 7.5 GPM
- You are installing the unit indoors
- You prefer natural gas over propane
Verdict: Rinnai RUS75eP 7.5 GPM Propane Outdoor Heater suits households needing reliable hot water for multiple simultaneous uses in an outdoor setting. Its moderate flow rate makes it ideal for smaller to medium homes.
Rinnai Smart-Circ Outdoor Natural Gas Water Heater
Best for: Compact outdoor spaces with moderate hot water needs
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Natural Gas
- Flow Rate
- 7.9 GPM
- BTU
- 199k BTU
- Dimensions
- 24.6 x 14.1 x 10.8 inches
View on Amazon: Rinnai Smart-Circ Outdoor Natural Gas Water Heater Affiliate link
The Rinnai REP199eN is a non-condensing outdoor tankless water heater designed for natural gas. It delivers 7.6 GPM, supporting up to six simultaneous fixtures. A built-in Smart-Circ pump learns your usage patterns to schedule recirculation, improving efficiency. Its compact suitcase-sized footprint fits tight outdoor spaces. You should choose this unit if you need reliable hot water flow and want to reduce standby heat loss through smart scheduling.
Pros
- 7.6 GPM flow rate supports multiple fixtures
- Built-in Smart-Circ recirculation pump with learning algorithm
- Compact 24.6 x 14.1 x 10.8 inch design
- 15-year heat exchanger warranty
Cons
- Lower 7.6 GPM flow rate compared to 9 GPM competitors
- WiFi control module sold separately
- Non-condensing design may be less efficient than condensing models
Good fit if
- You need a compact unit for tight outdoor spaces
- You want built-in recirculation without extra pumps
- You prefer natural gas fuel
Skip if
- You require 9 GPM for high-demand homes
- You want condensing technology for maximum efficiency
- You need built-in WiFi connectivity
Verdict: Rinnai REP199eN 7.6 GPM Outdoor Heater fits homes needing moderate flow with smart recirculation. It suits those prioritizing compact size and built-in pump efficiency over maximum GPM output.
Rinnai RU160eN 9 GPM Outdoor Natural Gas
Best for: large homes needing high flow capacity
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Natural Gas
- Flow Rate
- 9 GPM
- Dimensions
- 33.9 x 14.8 x 22.1 inches
- Venting Type
- Condensing
- Weight
- 71 pounds
View on Amazon: Rinnai RU160eN 9 GPM Outdoor Natural Gas Affiliate link
The Rinnai RU160eN is an outdoor tankless water heater designed for natural gas. It delivers 9 GPM of hot water, allowing you to run up to six appliances simultaneously. This condensing unit features an ENERGY STAR qualification with a 0.95 Uniform Energy Factor. It includes Circ-Logic technology for scheduled recirculation. The compact design saves space while providing endless hot water for whole-home use.
Pros
- 9 GPM flow rate supports multiple simultaneous uses
- Condensing technology achieves 0.95 Uniform Energy Factor
- Circ-Logic compatible for reduced wait times
- 15-year heat exchanger warranty
Cons
- Requires Controlr module for Wi-Fi monitoring
- Professional installation is recommended
- Heavier at 71 pounds
Good fit if
- You need high flow for multiple bathrooms
- You want energy-efficient condensing technology
- You have natural gas available outdoors
Skip if
- You use propane instead of natural gas
- You prefer indoor installation only
- You want built-in smart controls
Verdict: Rinnai RU160eN 9 GPM Natural Gas Outdoor Heater fits large homes needing high capacity and efficiency. It suits users with natural gas lines who value long-term durability and precise temperature control.
Rinnai 9 GPM Outdoor Propane Condensing Heater
Best for: outdoor propane homes needing high flow
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 9 GPM
- Dimensions
- 33.9 x 14.8 x 22.1 inches
- Venting Type
- Condensing
- Weight
- 80.9 pounds
View on Amazon: Rinnai 9 GPM Outdoor Propane Condensing Heater Affiliate link
This Rinnai unit delivers 9 gallons per minute of hot water using propane. It is designed for outdoor installation and uses condensing technology for efficiency. The built-in ThermaCirc360 recirculation pump helps reduce wait times for hot water. It measures 33.9 inches high and weighs 80.9 pounds. This model suits households needing steady flow for multiple fixtures without a dedicated return line.
Pros
- 9 GPM flow rate for consistent hot water
- Built-in ThermaCirc360 recirculation pump and thermal bypass
- Condensing technology for energy efficiency
- 15-year residential heat exchanger warranty
Cons
- Discontinued model replaced by RSC160eP
- Heavier at 80.9 pounds than non-condensing peers
- Outdoor installation only limits placement options
Good fit if
- You need high flow for multiple bathrooms
- You want reduced hot water wait times
- You have outdoor space for installation
Skip if
- You require indoor installation
- You need natural gas fuel type
- You want the latest current model
Verdict: Rinnai 9 GPM Propane Condensing Heater offers strong flow and recirculation features for outdoor use. It fits homes prioritizing efficiency and speed over the newest model release.
Rinnai Commercial Outdoor 9 GPM Propane Tankless Heater
Best for: commercial propane installations
- Installation Location
- Outdoor (what this guide is about)
- Fuel Type
- Propane
- Flow Rate
- 9 GPM
- Dimensions
- 33.9 x 14.8 x 22.1 inches
- Use
- Commercial
- Venting Type
- Condensing
View on Amazon: Rinnai Commercial Outdoor 9 GPM Propane Tankless Heater Affiliate link
This is a commercial-grade, outdoor tankless water heater designed for propane. It delivers a steady 9 GPM flow rate, making it suitable for high-demand environments. The unit uses condensing technology for efficiency and includes Circ-Logic recirculation with Wi-Fi monitoring. Weighing 70.8 pounds, it measures 33.9 inches tall. It is built for professional installation and offers a dedicated commercial warranty structure.
Pros
- 9 GPM flow rate for high-volume hot water
- Condensing technology for energy efficiency
- Wi-Fi monitoring and Circ-Logic recirculation
- Outdoor-rated propane design
Cons
- Commercial warranty limits labor coverage to 1 year
- Requires professional installation
- Heavier build at 70.8 pounds
Good fit if
- You need a high-flow unit for a business
- You have access to propane fuel
- You want Wi-Fi monitoring capabilities
Skip if
- You are installing in a residential setting
- You prefer natural gas over propane
- You want a DIY-friendly setup
Verdict: Rinnai CU160eP 9 GPM Propane Outdoor Heater is a robust solution for commercial properties requiring reliable, high-volume hot water. It fits businesses that need propane fuel and professional installation support.
Specifications side by side
| Spec | Rinnai 6.1 GPM Outdoor Propane Water Heater | Rinnai 7.5 GPM Outdoor Propane Tankless Water Heater | Rinnai Smart-Circ Outdoor Natural Gas Water Heater | Rinnai RU160eN 9 GPM Outdoor Natural Gas | Rinnai 9 GPM Outdoor Propane Condensing Heater | Rinnai Commercial Outdoor 9 GPM Propane Tankless Heater |
|---|---|---|---|---|---|---|
| Fuel Type | Propane | Propane | Natural Gas | Natural Gas | Propane | Propane |
| Flow Rate | 6.1 GPM | 7.5 GPM | 7.9 GPM | 9 GPM | 9 GPM | 9 GPM |
| BTU | 160k BTU | not stated | 199k BTU | not stated | not stated | not stated |
| Installation Location | Outdoor | Outdoor | Outdoor | Outdoor | Outdoor | Outdoor |
| Dimensions | 24.6 x 14.1 x 10.8 in | 35 x 14.5 x 22 inches | 24.6 x 14.1 x 10.8 inches | 33.9 x 14.8 x 22.1 inches | 33.9 x 14.8 x 22.1 inches | 33.9 x 14.8 x 22.1 inches |
| Use | not stated | not stated | not stated | not stated | not stated | Commercial |
| Venting Type | Non-Condensing | not stated | not stated | Condensing | Condensing | Condensing |
| Weight | 49.2 pounds | 63 pounds | not stated | 71 pounds | 80.9 pounds | 70.8 pounds |
| Size | 6.6 GPM | 7.5 GPM | 7.9 GPM | 9 GPM | 9 GPM | not stated |
| Color | Silver | Outdoor Installation | Silver | Outdoor Installation | Outdoor Installation | CU160ep - Propane/9 GPM |
| Model | REU-VE2125WD-US-P | RUS Series | REU-VEP2737WD-US-N | RU160eN | RUR160ep | CU160ep |
How to choose the right one
-
Check fuel availability first
Your existing fuel line dictates which unit you can install. The Rinnai RE160eP uses propane, while the RU160eN runs on natural gas. Propane units often require a tank and specific regulators. Natural gas models connect directly to your home’s supply line. You must verify your current infrastructure before buying. Mixing up these types can lead to improper combustion or installation failures. Always match the heater’s fuel type to your home’s existing energy source to ensure safe and efficient operation.
-
Match flow rate to usage
Flow rate determines how many fixtures can run simultaneously. The top pick offers 6.6 GPM, suitable for compact outdoor setups with limited simultaneous use. Larger households may need 9 GPM models like the RU160eN. If you plan to run multiple showers or appliances at once, choose a higher GPM rating. Lower flow rates may cause temperature drops during peak usage. Check your household’s peak demand to select the correct capacity for your specific needs.
-
Consider venting requirements
Venting type affects installation complexity and efficiency. The RE160eP uses non-condensing venting, which is simpler but less efficient. In contrast, the RU160eN uses condensing technology, offering higher efficiency but requiring specific vent materials. Condensing units produce acidic condensate that must be drained properly. Your local building codes will dictate which venting method is allowed. Choose the venting type that aligns with your installation space and regulatory requirements for optimal performance and safety.
-
Evaluate physical dimensions
Outdoor spaces often have limited clearance. The RE160eP measures just 10.8 inches long and 14.1 inches wide, making it highly space-efficient. Larger models like the RUS75eP are 22 inches long and 35 inches tall. You must ensure your installation area can accommodate the unit’s footprint and height. Adequate clearance is also needed for maintenance access and proper airflow. Measure your designated spot carefully to avoid fitting issues during the final installation phase.
-
Verify commercial vs residential use
Some units are designed for commercial applications. The CU160eP is labeled for commercial use, indicating it can handle higher volume demands. Residential models like the REP199eN are optimized for home efficiency and comfort. Using a commercial unit in a home may lead to unnecessary complexity or cost. Conversely, a residential unit might struggle in a high-demand business setting. Check the intended use category to ensure the heater matches your property’s operational requirements.
Frequently asked questions
Which Rinnai outdoor tankless water heater is the most compact?
The Rinnai RE160eP is the most compact unit. It measures 14.1 inches in width, 24.6 inches in height, and 10.8 inches in length. It also weighs only 49.2 pounds. This small footprint makes it ideal for tight outdoor spaces where other larger models will not fit. Its propane fuel type allows for flexible installation options without requiring a gas line.
What is the highest flow rate available in this list?
The highest flow rate is 9 GPM. Several models share this capacity, including the RU160eN, RUR160ep, and CU160ep. These units are designed for large homes or commercial properties that need high-volume hot water. The RU160eN runs on natural gas, while the RUR160ep and CU160ep use propane. All three provide consistent performance for multiple simultaneous uses.
Do these units require condensing or non-condensing venting?
Venting requirements depend on the specific model. The RE160eP uses non-condensing venting, which is standard for many outdoor propane heaters. In contrast, the RU160eN, RUR160ep, and CU160ep utilize condensing venting technology. Condensing models often offer higher efficiency by capturing heat from exhaust gases. You must match the venting type to your existing infrastructure or planning for new vents.
Can I use the Rinnai Smart-Circ model for recirculation?
Yes, the Rinnai Smart-Circ model includes built-in recirculation features. This unit is the REP199eN, which delivers 7.9 GPM of hot water. It is designed for homes that want reduced wait times for hot water at the tap. The integrated pump works with your plumbing to keep water warm in the lines. This feature is particularly useful for larger homes with distant bathrooms.
Which model is best for commercial outdoor installations?
The Rinnai CU160ep is designated for commercial use. It delivers 9 GPM of hot water using propane fuel. This model is built for robust performance in business settings that require reliable, high-volume hot water. It shares the same physical dimensions as other 9 GPM units but is rated for commercial duty. Professional installation is recommended to ensure proper operation in these environments.
What is the difference between propane and natural gas models here?
The primary difference is the fuel source and venting type. Propane models like the RE160eP and RUR160ep often use non-condensing or condensing tech depending on the series. Natural gas models like the RU160eN use condensing venting for efficiency. You must choose based on your available fuel line. Propane requires a tank, while natural gas connects to a utility line. Flow rates vary from 6.6 to 9 GPM across both types.
How heavy is the largest Rinnai outdoor unit?
The heaviest unit is the RUR160ep, which weighs 80.9 pounds. It is a 9 GPM propane condensing heater. Other large models like the RU160eN weigh 71 pounds, and the CU160ep weighs 70.8 pounds. These weights are significant, so you need a sturdy mounting surface. Ensure your installation location can support the weight of the chosen unit safely.