Having endless hot water is a game-changer, especially when you need it outdoors. Whether it's for a detached garage, a pool house, an outdoor shower, or even RV setups, a reliable outdoor tankless water heater means no more chilly surprises. I've spent the last several weeks diving deep into what makes the Best Outdoor Gas Tankless Water Heater truly shine, looking at flow rates, fuel types, and durability.
After sifting through specs and real-world feedback, the APUS 190,000 BTU unit stands out for its robust performance and smart features. We'll walk through this and other top contenders to help you find the perfect fit for your needs.
Comparison Chart of Best Outdoor Gas Tankless Water Heater
List of Top 10 Best Best Outdoor Gas Tankless Water Heater
In our research, we focused on units that offer consistent performance, good energy efficiency, and features that make outdoor installation and use straightforward. We looked at models suitable for various flow rate demands and fuel types, from natural gas to propane.
Below are the list of products:
1. APUS 190 000 BTU Outdoor Tankless
1. APUS 190 000 BTU Outdoor Tankless
This APUS unit truly impressed with its capacity and smart capabilities. For anyone needing reliable hot water in a detached structure or for multiple outdoor applications simultaneously, this model is a top-tier choice, promising consistent performance.
Why I picked it
This heater's 190,000 BTU output and 8.1 GPM flow rate are seriously impressive, making it ideal for high-demand situations like multiple showers running at once or supplying a large workshop. The inclusion of WiFi and a remote control adds a modern convenience factor that’s hard to beat for an outdoor unit.
Key specs
- BTU Input: 190,000 BTU
- Flow Rate: 8.1 GPM
- Fuel Type: Natural Gas
- Installation: Outdoor
- Special Features: WiFi connectivity, remote control, supports up to 5 outlets
Real-world experience
Aggregate user feedback highlights its efficiency in keeping up with demand even during colder months, when water enters the unit at a lower temperature. The ability to adjust settings remotely is frequently mentioned as a key convenience for outdoor setups.
Trade-offs
Some users note that the initial setup requires specific venting, and professional installation is highly recommended to ensure safety and optimal performance. The unit's size might also be a consideration for very compact outdoor spaces.
2. Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor
2. Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor
Rheem is a name synonymous with reliable water heating, and this outdoor model doesn't disappoint. It offers a solid balance of performance and efficiency for moderate to heavy hot water needs in an outdoor setting.
Why I picked it
The RTG-70XLN-3 offers a strong 7.0 GPM flow rate for natural gas, which is ample for a typical household's simultaneous hot water needs in an outdoor application, like supplying a pool house and an outdoor kitchen. Its high-efficiency non-condensing design is a practical choice for many outdoor installations.
Key specs
- BTU Input: 180,000 BTU (maximum)
- Flow Rate: 7.0 GPM
- Fuel Type: Natural Gas
- Installation: Outdoor
- Vent Type: Direct vent (requires separate venting kit)
Real-world experience
User reviews consistently praise Rheem's easy integration with existing plumbing and its robust performance in providing continuous hot water. Many appreciate the digital display for easy temperature monitoring and adjustment.
Trade-offs
This is a non-condensing unit, meaning it's slightly less energy-efficient than condensing models. It also requires a specialized vent kit, which adds to the installation complexity and cost.
3. Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor
3. Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor
Stepping up slightly in flow rate from its sibling, this Rheem model offers a compelling combination of brand trust and performance for its class, making it a great value pick for many outdoor needs.
Why I picked it
With an 8.4 GPM flow rate and 180,000 BTU input, this unit is designed to handle more simultaneous hot water demands than smaller models. It’s a solid choice for properties that might be a bit larger or have more fixtures to supply outdoors.
Key specs
- BTU Input: 180,000 BTU (maximum)
- Flow Rate: 8.4 GPM
- Fuel Type: Natural Gas
- Installation: Outdoor
- Energy Factor: 0.82
Real-world experience
Verified buyer feedback indicates that this model provides a consistent and reliable stream of hot water, even when supplying multiple fixtures like a shower and sink concurrently. Its exterior construction is noted for its durability against weather elements.
Trade-offs
Similar to the RTG-70XLN-3, this is a non-condensing unit, so it doesn't offer the absolute peak energy efficiency of its condensing counterparts. Proper venting is also a must and adds installation cost.
4. Natural Gas Tankless Water Heater
4. Natural Gas Tankless Water Heater
This unit offers a good balance for residential outdoor use, providing sufficient flow for a single-family home's typical hot water needs with the convenience of a remote controller.
Why I picked it
The 130,000 BTU and 5.3 GPM flow rate are adequate for supplying hot water to one or two fixtures simultaneously, making it suitable for smaller outdoor spaces like a pool cabana or a single bathroom. The CSA certification offers an added layer of assurance for safety compliance.
Key specs
- BTU Input: 130,000 BTU
- Flow Rate: 5.3 GPM
- Fuel Type: Natural Gas
- Installation: Outdoor
- Certifications: CSA Certified
Real-world experience
Verified buyer comments often mention the unit's compact size and relatively straightforward installation for those comfortable with gas and water line connections. The included remote controller is a plus for convenient operation.
Trade-offs
While capable for its size, its flow rate might be insufficient for properties with multiple high-demand fixtures running at the same time. Users also point out that maximizing its efficiency requires proper venting, which is an additional installation consideration.
5. Ranein 18L Tankless Water Heater
5. Ranein 18L Tankless Water Heater
This propane-powered unit is a strong contender for locations where natural gas isn't available, offering a good flow rate for its fuel type and a compact design.
Why I picked it
The 18L designation typically refers to its capacity in liters per minute, and this model delivers a solid 4.74 GPM, making it suitable for a single shower or a couple of sinks. Its 85,300 BTU output is respectable for propane-powered units in this size.
Key specs
- BTU Input: 85,300 BTU
- Flow Rate: 4.74 GPM
- Fuel Type: Propane Gas
- Installation: Outdoor
- Capacity: 18L (approximately 4.74 GPM)
Real-world experience
Buyers often choose this for RVs, boats, or off-grid cabins where propane is the primary fuel source. The on-demand heating is appreciated for its efficiency when hot water is needed sporadically.
Trade-offs
Propane units, in general, can be more expensive to operate than natural gas, and tankless models like this require careful management of propane tank levels. Its flow rate, while good, may not be enough for very high-demand scenarios.
6. Ranein Propane Gas Tankless Water Heater
6. Ranein Propane Gas Tankless Water Heater
This Ranein model steps up the game for propane users, offering a higher flow rate and BTU input, making it suitable for more demanding applications.
Why I picked it
With a maximum flow rate of 8.5 GPM and a 190,000 BTU input, this unit is designed to handle significant hot water demand. It’s a great option for larger outdoor kitchens, multiple bathrooms, or even small commercial applications where propane is the required fuel.
Key specs
- BTU Input: 190,000 BTU (maximum)
- Flow Rate: 8.5 GPM
- Fuel Type: Propane Gas
- Installation: Outdoor
- Features: LED temperature display
Real-world experience
Users have noted its powerful performance in delivering hot water quickly and consistently, even when faced with challenging temperature drops due to cold incoming water. The LED display is a welcome feature for precise temperature control.
Trade-offs
As with most high-output propane units, ensuring adequate propane supply and proper ventilation are critical. Some reviews suggest that achieving peak performance may require a larger propane tank than typically used for smaller appliances.
7. Outdoor Tankless Water Heater
7. Outdoor Tankless Water Heater
This model boasts an impressive 5/5 rating from verified buyers, indicating strong satisfaction with its performance and reliability for outdoor use.
Why I picked it
This unit offers a 5.3 GPM flow rate and 130,000 BTU, making it a capable option for supplying hot water to a whole house in many scenarios, especially when paired with propane. The smart temperature control and CSA certification add to its appeal.
Key specs
- BTU Input: 130,000 BTU
- Flow Rate: 5.3 GPM
- Fuel Type: Propane Gas
- Installation: Outdoor
- Certifications: CSA Certified
Real-world experience
Verified buyer reviews frequently rave about the unit's ability to deliver consistent hot water and its robust build quality. The smart temperature control panel is often cited as a user-friendly feature for setting desired water temperatures.
Trade-offs
Users mention that installation, particularly gas line hookups and venting, is critical for safe and efficient operation. As with any propane unit, the cost and availability of propane are factors to consider.
8. Rheem RTG-70XLP-3 High Efficiency Non-Condensing Outdoor
8. Rheem RTG-70XLP-3 High Efficiency Non-Condensing Outdoor
For those needing a propane option from a trusted brand, this Rheem model provides a solid 7.0 GPM flow rate, suitable for many outdoor applications where natural gas isn't an option.
Why I picked it
This unit delivers 7.0 GPM with a 160,000 BTU input, making it a strong choice for applications like supplying an outdoor shower and sink, or even a small workshop. Rheem's reputation for reliability is a significant advantage here.
Key specs
- BTU Input: 160,000 BTU (maximum)
- Flow Rate: 7.0 GPM
- Fuel Type: Liquid Propane
- Installation: Outdoor
- Energy Factor: 0.82
Real-world experience
Verified buyers report consistent performance and ease of use, making it suitable for customers who prefer propane for their outdoor water heating needs. Its durable exterior is designed to withstand outdoor conditions.
Trade-offs
As a non-condensing unit, its energy efficiency isn't as high as condensing models. Like all propane appliances, managing fuel supply is a necessary consideration, and professional installation is recommended.
9. Rinnai CX199iN Condensing Smart Sense Commercial
9. Rinnai CX199iN Condensing Smart Sense Commercial
For high-demand commercial or very intensive residential outdoor applications, this Rinnai unit offers exceptional flow rates and advanced features.
Why I picked it
The CX199iN boasts an impressive 11.1 GPM flow rate and 199,000 BTU, making it one of the most powerful units available for outdoor use. Its condensing technology offers superior energy efficiency, and the "Smart Sense" feature learns usage patterns. This is geared towards heavy-duty applications or larger estates.
Key specs
- BTU Input: 199,000 BTU
- Flow Rate: 11.1 GPM
- Fuel Type: Natural Gas or Propane (check model variation)
- Installation: Outdoor
- Technology: Condensing, Smart Sense
Real-world experience
This unit is often chosen for commercial properties or large residential homes with extensive hot water demands. Its high flow rate and efficiency make it a standout for sustained hot water delivery.
Trade-offs
The premium performance and technology come at a higher price point. It also requires specialized venting for the condensing exhaust, and professional installation is absolutely essential.
10. Ranein × Vancepic Tankless Water Heater
10. Ranein × Vancepic Tankless Water Heater
This collaboration offers a significant BTU output and a respectable flow rate for natural gas applications, aiming for reliable outdoor hot water delivery.
Why I picked it
This unit offers a 190,000 BTU input and a 8.5 GPM flow rate, making it suitable for supplying multiple hot water points simultaneously. The inclusion of an LED temperature control panel provides user-friendly temperature management for outdoor settings.
Key specs
- BTU Input: 190,000 BTU
- Flow Rate: 8.5 GPM
- Fuel Type: Natural Gas
- Installation: Outdoor
- Features: LED temperature control panel
Real-world experience
Aggregate user feedback suggests this model is a strong performer for its price point, delivering consistent hot water for typical household needs. The detailed LED display is frequently cited as a convenient feature for precise temperature setting.
Trade-offs
While it offers a good flow rate, achieving maximum hot water delivery in colder climates might require careful consideration of the incoming water temperature. Proper venting is also a non-negotiable for safe operation.
How I picked
To narrow down the Best Outdoor Gas Tankless Water Heater options, I focused on several key criteria that genuinely impact performance and user satisfaction for an outdoor unit. My evaluation involved scrutinizing manufacturer specifications and cross-referencing aggregated user reviews, looking for consistent positive feedback on core functionalities.
I evaluated each unit on:
- Flow Rate (GPM): This is crucial for outdoor applications. I prioritized models offering at least 5 GPM for basic needs and looked for higher rates (7 GPM+) for more demanding scenarios like multiple fixtures or pool houses.
- BTU Input: A higher BTU input generally means the unit can heat water more quickly and maintain temperature under heavy load. I favored units with 130,000 BTU and above for reliable outdoor performance.
- Fuel Type: Both natural gas and propane models were considered, as availability varies by location.
- Installation Requirements: Outdoor units often have specific venting and clearance needs. I looked for models that provided clear specifications and noted any that seemed excessively complex to install.
- Durability and Weather Resistance: While direct physical testing isn't possible, I reviewed user feedback regarding the unit's construction and its ability to withstand outdoor elements.
- Certifications: Listings like CSA certification were noted as indicators of safety and compliance.
I deliberately did not test long-term durability beyond reviewing reported lifespans and warranty information. My focus remained on immediate performance, installation feasibility, and overall value based on available data.
Buying guide — what actually matters for Best Outdoor Gas Tankless Water Heater
When you're looking for an outdoor tankless water heater, there are a few things that really make a difference for getting hot water where you need it without hassle. It's not just about picking the cheapest one; it's about matching the heater's capabilities to your specific setup.
Flow Rate and Simultaneous Use
This is probably the most important factor. The flow rate, measured in gallons per minute (GPM), tells you how much hot water the heater can provide at once. If you're just supplying a small outdoor shower or a wash station, a lower GPM (around 3-5 GPM) might be fine. But if you're looking to serve a pool house with a shower and sink, or an outdoor kitchen, you'll need something with a higher GPM, often 7 GPM or more.
It's a balancing act: more GPM generally means a higher BTU input, which also impacts operating costs.
BTU Input and Efficiency
BTU (British Thermal Unit) input indicates the heating power of the unit. A higher BTU rating means it can heat water more aggressively, which is especially important in colder climates where the incoming water temperature is much lower. Outdoor units often need higher BTU to compensate for the ambient temperature. Efficiency is also key; look for higher Energy Factor (EF) ratings, though these are more common on indoor models.
For outdoor, consider the unit's design might prioritize robust heating over peak efficiency you'd find in an indoor appliance. Condensing tankless heaters are generally more efficient than non-condensing, but they also require special venting.
Fuel Type: Natural Gas vs. Propane
The biggest question here is what fuel is available at your installation site. Natural gas is often more cost-effective if you have a gas line running to the location. Propane is a great alternative when natural gas isn't an option, such as for remote cabins, RVs, or areas far from municipal gas lines. Propane units tend to have higher BTU inputs for equivalent sizes compared to natural gas, often providing robust heating.
Remember that propane requires storage tanks, which need refilling.
Installation and Venting
Outdoor tankless water heaters must be installed according to manufacturer specifications and local building codes. This typically involves proper gas line connection, water line connections, and importantly, venting. Venting for outdoor units is crucial for safely expelling exhaust gases. Some units are direct-vent and require a specific vent kit, while others might have simpler wall-mount configurations.
Always consult the manual and consider professional installation, especially if you're not experienced with gas appliance installations. Safety is paramount.
Size and Environmental Factors
Think about where you'll mount the unit. Outdoor units are designed to withstand weather, but it’s still wise to choose a location that offers some protection from direct, harsh elements if possible. Check the unit's dimensions and clearances required for safe operation and maintenance. Some units are exceptionally compact, while others are larger, especially higher-output models.
Frequently Asked Questions (FAQ)
Is an outdoor tankless water heater worth the investment?
Yes, an outdoor tankless water heater can be a fantastic investment if you frequently use hot water away from your main home. It provides on-demand hot water for detached garages, workshops, pool houses, outdoor showers, or even RVs, eliminating the need to run plumbing from your main house. The instant hot water and energy efficiency often make up for the initial cost over time.
Can I use a natural gas tankless water heater in a very cold climate?
You absolutely can, but you need to choose a unit with a high enough BTU input and flow rate to handle the colder incoming water temperatures. The temperature rise (the difference between incoming cold water and desired hot water temperature) is critical. A unit rated for 8 GPM might only deliver 5 GPM if the incoming water is very cold and you want a significant temperature increase. Check the manufacturer’s specifications for performance at various temperatures.
What maintenance is required for an outdoor tankless water heater?
Regular maintenance is key to ensuring your outdoor tankless unit performs well for years. This typically involves flushing the unit annually or bi-annually to remove mineral buildup, especially in hard water areas. Checking the vent for obstructions (leaves, nests, etc.) and ensuring connections are secure are also important. Some manufacturers recommend checking the igniter and gas pressure.
How do I choose between a condensing and non-condensing outdoor unit?
Condensing tankless water heaters are more energy-efficient because they capture heat from the exhaust gases, reheating incoming water. This leads to lower operating costs. However, they require specialized PVC venting and are generally more expensive upfront. Non-condensing units are typically less expensive and may have simpler venting requirements, but they are less energy-efficient.
For outdoor use, the decision often comes down to budget, energy efficiency goals, and installation complexity.
What is the typical lifespan of an outdoor tankless water heater?
With proper installation and regular maintenance, most high-quality tankless water heaters, including outdoor models, can last between 15 to 20 years, sometimes even longer. This is often longer than traditional tank water heaters, which typically last about 10-12 years. Key factors influencing lifespan include water quality, frequency of use, and adherence to manufacturer maintenance schedules.
Final verdict
For unparalleled outdoor hot water performance, the APUS 190,000 BTU Outdoor Tankless Water Heater is our top pick. Its robust flow rate, smart features, and high BTU output make it ideal for almost any demanding outdoor application.
If you're looking for a reliable option from a brand with a long-standing reputation, the Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor is an excellent choice, offering strong performance for everyday needs. For those on a tighter budget who still need dependable heating, the Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor delivers great value.
Affiliate disclosure: This post contains affiliate links. If you buy through one of these links, I may earn a small commission at no extra cost to you. It never changes my recommendation, I only suggest gear I'd actually buy myself.
