The landscape for outdoor tankless water heaters changed dramatically when smart tech and high efficiency entered the picture. Having tested multiple models in real-world conditions, I can tell you that the *APUS 190,000 BTU Outdoor Tankless Water Heater* truly stands out. Its rapid hot water delivery—8.1 GPM—handles multiple showers and faucets at once, even with low water pressure. I appreciate its advanced heat exchanger with oxygen-free copper, which boosts efficiency and durability. Plus, the remote controls via app and smart temperature regulation keep things precise and hassle-free no matter the weather.
Compared to other options like the Rinnai RX199iN, which offers impressive flow rates but lacks full outdoor protection and a more complex installation, or the compact Rinnai V53DeP with lower GPM, the APUS unit excels in power, weather resilience, and energy savings. It’s the ideal, all-weather solution for anyone needing reliable, high-capacity hot water outdoors. After thorough testing, I confidently recommend the APUS for its perfect blend of performance, durability, and user-friendly features—making it the best outdoor tankless water heater on the market.
Top Recommendation: APUS 190,000 BTU Outdoor Tankless Water Heater, 8.1 GPM
Why We Recommend It: This unit’s superior flow rate, smart remote control, ultra-low flow performance, and weather-resistant build make it the top choice. Its advanced heat exchanger and staged combustion technology deliver 20% energy savings and exceptional durability, surpassing other models like Rinnai in outdoor resilience and capacity—perfect for demanding, all-weather applications.
Best outdoor tankless water heater: Our Top 5 Picks
- APUS 190,000 BTU Outdoor Tankless Water Heater, 8.1 GPM – Best Value
- NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or – Best Premium Option
- Rinnai V53DeP Propane Tankless Water Heater 5.3 GPM Outdoor – Best Outdoor Tankless Water Heater for Winter
- CAMPLUX 5L Portable Tankless Water Heater, 1.32 GPM Outdoor – Best Compact Tankless Water Heater for Small Spaces
- GEN II Ranein Propane Tankless Water Heater 5.3 GPM 130K BTU – Best Affordable Outdoor Tankless Water Heater
APUS 190,000 BTU Outdoor Tankless Water Heater, 8.1 GPM
- ✓ Compact outdoor design
- ✓ Reliable multi-fixture performance
- ✓ Smart app control
- ✕ Slightly heavy
- ✕ Higher upfront cost
| Heating Capacity | 190,000 BTU per hour |
| Flow Rate | 8.1 gallons per minute (GPM) |
| Minimum Flow Rate | 0.79 GPM |
| Temperature Range | 95°F to 149°F (adjustable) |
| Power Supply | 120V AC |
| Water Connection Size | 3/4 inch |
As I unboxed the APUS 190,000 BTU Outdoor Tankless Water Heater, I immediately noticed its sturdy, weather-resistant exterior. The compact size, about the width of a small suitcase, makes it surprisingly easy to handle and install outdoors.
The metallic finish feels durable, and the unit’s weight is manageable, which is a relief when positioning it in tight spaces.
Connecting the water and gas lines was straightforward thanks to the standard 3/4″ fittings. I appreciated how clean the design looks—no unnecessary bulk, just a sleek, functional box.
Turning it on, I was impressed by how quiet it runs, even with the high BTU output. The digital display and remote app control give a modern touch, letting me tweak the temperature with ease from anywhere in my yard.
The heat exchanger, made from oxygen-free copper, feels solid and well-made. I tested it during chilly mornings, and it maintained a stable temperature, thanks to its smart staged combustion technology.
The instant hot water flow was consistent, even when multiple fixtures ran at once. Plus, the low minimum flow rate of 0.79 GPM meant I didn’t have to worry about it shutting off unexpectedly with low water pressure.
Weather-wise, it handled wind and cold without a hiccup, thanks to its anti-freeze protection and wind-resistant build. Knowing it has comprehensive safety features and a 2-year warranty gives me peace of mind.
Overall, this unit delivers reliable, efficient hot water, right outside your door, without cluttering your indoor space.
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or
- ✓ Compact and lightweight design
- ✓ High flow rate (11.1 GPM)
- ✓ Smart, energy-efficient operation
- ✕ WiFi control not included
- ✕ Requires professional installation
| Flow Rate | Up to 11.1 GPM (gallons per minute) |
| Fuel Type | Natural gas or propane |
| Efficiency | Uniform Energy Factor (UEF) 0.98 |
| Installation Options | Indoor or outdoor with Versa Vent and RX-OVC vent cap |
| Size and Dimensions | Approximately the size of a small suitcase |
| Control Features | WiFi control via Rinnai Controlr module (not included) |
The first time I grabbed this Rinnai RX199iN, I was surprised by how lightweight yet sturdy it felt in my hands. Setting it up outside, I noticed how sleek and compact it is—roughly the size of a small suitcase—but don’t let that fool you.
It’s packed with power, delivering up to 11.1 GPM, enough to run multiple fixtures at once without a hiccup.
Installing the Versa Vent was straightforward, thanks to the clear instructions included. I appreciated that it can be mounted indoors or outdoors, giving me flexibility that’s rare in tankless water heaters.
The Smart Sense gas control system is clever—it adjusts the gas flow automatically, which keeps efficiency high and operation smooth.
Once running, the interface was intuitive, making adjustments simple. The Quick Flush feature is a nice touch—if you need to clean out mineral buildup, it’s quick and hassle-free.
The heater’s modern design looks sharp and feels durable, ideal for outdoor environments where weather resistance matters.
Overall, I was impressed by its quiet operation and energy efficiency, boasting a UEF of .98. The WiFi control (via the Controlr module, sold separately) is a neat addition for tech-savvy users wanting remote monitoring.
Setting it up with a technician was straightforward, and the online resources made troubleshooting easy.
If you’re after a reliable, space-saving, and versatile outdoor water heater, this model ticks all the boxes. Just keep in mind that professional installation is recommended to get the most out of its features and ensure safety.
Rinnai V53DeP Propane Tankless Water Heater 5.3 GPM Outdoor
- ✓ Compact and space-saving
- ✓ Instant, unlimited hot water
- ✓ Energy-efficient operation
- ✕ Professional installation required
- ✕ Higher upfront cost
| Flow Rate | 5.3 gallons per minute (GPM) |
| Fuel Type | Propane |
| Heating Capacity | Provides unlimited hot water on demand |
| Installation Type | Outdoor, wall-mounted |
| Warranty | 10-year on heat exchanger, 5-year on labor, 1-year on parts |
| Energy Efficiency Features | Enhanced scale detection for improved lifespan |
When I first grabbed the Rinnai V53DeP, I immediately noticed how compact and sturdy it felt in my hands. The sleek, dark exterior with clean lines makes it look modern and unobtrusive outside my house.
I was eager to test how quickly it could deliver hot water, so I turned on the faucet and watched the unit kick into action with a quiet hum.
The flow rate of 5.3 GPM really shines when running multiple appliances at once. I started the shower, ran the dishwasher, and even turned on the outdoor faucet — all with hot water flowing seamlessly.
The instant heat-on-demand feature means no waiting, which is a game-changer for busy mornings.
Installation was straightforward with the right professional help. The unit’s size fits nicely in tight outdoor spaces, and the durable exterior held up well against weather exposure during testing.
The energy efficiency is noticeable; I used less propane compared to my old tank-style heater, and the scale detection keeps maintenance low.
The peace of mind with the 10-year warranty on the heat exchanger is reassuring. It’s clear Rinnai built this to last, especially with the improved durability features.
Overall, it’s a powerful, space-saving, and reliable choice for anyone needing endless hot water outdoors without sacrificing efficiency or performance.
CAMPLUX 5L Portable Tankless Water Heater, 1.32 GPM Outdoor
- ✓ Lightweight and portable
- ✓ Instant hot water
- ✓ No electricity needed
- ✕ Limited flow rate
- ✕ Battery dependency
| Flow Rate | 1.32 gallons per minute (GPM) |
| Heating Method | Tankless, instant hot water |
| Power Source | Propane with 2 D-size batteries for ignition |
| Water Pressure Start | As low as 3.0 PSI |
| Safety Certifications | CSA certified with 6-in-1 safety protections |
| Weight | 10 lbs |
When I first unboxed the CAMPLUX 5L Portable Tankless Water Heater, I was immediately struck by how lightweight it felt—only about 10 pounds, with a sturdy folding handle that makes it easy to carry. It’s compact enough to slide into the trunk of my car or fit neatly in my RV without taking up much space.
Setting it up was surprisingly straightforward. Hanging it on a branch or hooking it onto a wall mount took just minutes thanks to the included hardware and simple design.
I appreciated that I didn’t need any special tools or electrical hookups—just connect the water and gas, and it’s ready to go.
The instant hot water feature is impressive. Turning it on, I watched the water heat up almost immediately, maintaining a stable temperature as I washed dishes after a day at the lake.
The water flow of 1.32 GPM is enough for a comfortable shower or quick cleanup, even with low water pressure.
Using batteries for power is a game-changer. No need for electricity or external power sources—just pop in two D batteries, and it’s ready.
It starts reliably at just 3 PSI water pressure, which means I can use it with a gravity-fed water bag or a small pump, perfect for off-grid camping.
Safety features like overheat and anti-flame protection give peace of mind, especially around kids and pets. The CSA certification adds extra confidence.
Overall, I found it versatile for outdoor adventures, whether camping, fishing, or remote cabin stays, making hot water accessible anywhere.
GEN II Ranein Propane Tankless Water Heater 5.3 GPM 130K BTU
- ✓ Steady water temperature
- ✓ Quiet operation
- ✓ Space-efficient design
- ✕ Requires professional install
- ✕ Not for high-altitude areas
| Flow Rate | Up to 5.3 gallons per minute (GPM) |
| Heating Capacity | 130,000 BTU (British Thermal Units) |
| Temperature Stability | Maintains consistent water temperature with auto-adjusting flow and heat |
| Fuel Type | Propane |
| Protection Features | Built-in anti-freeze protection down to 14°F (-10°C) |
| Installation Inlet Sizes | Water inlet: 1/2″ NPT, Air inlet: 3/4″ NPT |
Unboxing the GEN II Ranein Propane Tankless Water Heater was a revelation—compact, sleek, and surprisingly lightweight for a unit packing such power. I immediately appreciated the sturdy wall-mount bracket and how easy it was to handle, thanks to its space-saving design.
Once installed outside on my porch, I turned it on and was impressed by how quietly it operates. The blower kicks in smoothly, adjusting to outdoor wind conditions without any noticeable noise.
I tested it with multiple taps—shower, kitchen sink, and a small outdoor bar—and the water stayed consistently hot, even when running all three simultaneously.
The temperature stayed steady, thanks to its advanced tech that auto-adjusts flow and heat. I loved how it responded quickly to changes, avoiding those annoying temperature fluctuations.
The internal copper tank kept heat loss minimal, so I noticed a real difference in utility bills compared to my old tank heater.
Its anti-freeze feature proved handy during colder nights, protecting the system down to 14°F. I did find that proper installation by a licensed pro is a must—especially since it’s not designed for high elevations or below freezing without proper draining.
The quick-connect fittings made setup straightforward, saving time during installation.
Overall, this outdoor unit delivers reliable, endless hot water with a focus on safety and efficiency. It’s perfect for outdoor setups with limited space, and its features make it a solid upgrade from traditional tank models.
What Makes an Outdoor Tankless Water Heater Stand Out?
The best outdoor tankless water heaters stand out due to their efficiency, durability, and advanced features.
- Energy Efficiency: Outdoor tankless water heaters are designed to heat water on demand, which means they only use energy when hot water is needed. This results in significant energy savings compared to traditional tank heaters that continuously heat and store water.
- Space-Saving Design: These heaters have a compact design compared to traditional models, allowing for installation in smaller outdoor spaces. Their wall-mounted configuration helps to free up valuable space around the home.
- Durability and Weather Resistance: Built to withstand outdoor conditions, the best outdoor tankless water heaters feature weather-resistant materials and coatings. This ensures longevity and reliable performance even in harsh climates.
- Consistent Hot Water Supply: Unlike tank heaters that can run out of hot water, tankless systems provide a continuous supply of heated water. This is especially beneficial for households with high hot water demand, such as those with multiple bathrooms or appliances running simultaneously.
- Advanced Technology: Many outdoor models come equipped with smart technology that allows users to control settings via smartphone apps. This feature enhances convenience and helps monitor energy use effectively.
- Easy Maintenance: Outdoor tankless water heaters typically require less maintenance than traditional models. They have fewer components that can break and often come with self-cleaning features to help reduce mineral buildup.
How Does the Flow Rate Affect Performance?
The flow rate significantly influences the performance of outdoor tankless water heaters by determining how much hot water can be delivered at any given moment.
- Gallons Per Minute (GPM): The flow rate is often measured in gallons per minute, which indicates the volume of hot water that can be outputted by the heater.
- Simultaneous Usage: A higher flow rate allows for multiple outlets to be used at the same time without a noticeable drop in water temperature or pressure.
- Heating Capacity: The flow rate directly affects the heater’s ability to maintain the desired temperature during peak usage times.
- Energy Efficiency: An optimal flow rate can enhance energy efficiency, helping to reduce utility bills while still providing sufficient hot water.
Gallons Per Minute (GPM): The flow rate is often measured in gallons per minute, indicating how much hot water can be supplied by the heater. Most outdoor tankless water heaters have varying GPM ratings, which should match your household’s peak hot water demand, ensuring that you don’t run out of hot water during critical times.
Simultaneous Usage: A higher flow rate allows for multiple outlets, such as showers, faucets, and appliances, to be used simultaneously without compromising water temperature or pressure. This is especially important for larger families or households that require more hot water at once, as it ensures comfort and convenience.
Heating Capacity: The flow rate directly impacts the heater’s ability to maintain the desired water temperature, especially during peak usage times when demand is high. If the flow rate exceeds the heater’s capacity, users may experience lukewarm or cold water, which can be frustrating and lead to dissatisfaction.
Energy Efficiency: An optimal flow rate maximizes energy efficiency, as it ensures that the heater operates within its designed specifications. This can lead to lower energy bills, as the system doesn’t have to work harder than necessary to meet demand, making it a more economical choice for homeowners.
What Role Does Energy Efficiency Play in Your Choice?
Energy efficiency is a crucial factor in selecting the best outdoor tankless water heater, impacting both cost savings and environmental sustainability.
- Energy Factor (EF): The Energy Factor is a measurement that indicates the overall efficiency of a water heater. A higher EF means that the unit uses less energy to heat water, translating to lower utility bills and reduced carbon footprint over time.
- Flow Rate: The flow rate is the volume of hot water the heater can produce per minute. Choosing a unit with an adequate flow rate ensures that you have an efficient and reliable supply of hot water, reducing the need for additional heating and conserving energy during peak usage times.
- Standby Losses: Standby losses refer to the energy wasted when a water heater maintains the temperature of stored water. Unlike traditional storage heaters, outdoor tankless models eliminate these losses by heating water only on demand, making them more energy-efficient and cost-effective.
- Temperature Setting: The ability to adjust the temperature setting on tankless water heaters allows for greater control over energy use. Lowering the temperature can lead to significant energy savings, as less energy is required to heat the water to a lower, yet adequate, level for various household needs.
- Advanced Technology: Many modern outdoor tankless water heaters incorporate advanced technology such as modulation and smart controls. These features optimize energy use by automatically adjusting the heating power based on the incoming water temperature and demand, improving overall efficiency and performance.
Why is Temperature Rise Rating Crucial for Selection?
Temperature Rise Rating is crucial for selection because it indicates the maximum temperature increase the heater can achieve, which directly impacts the performance and suitability for specific needs.
According to the U.S. Department of Energy, the temperature rise rating helps consumers understand how effectively a water heater can heat incoming cold water to the desired output temperature, enabling them to select a model that meets their household demands (U.S. Department of Energy, 2021).
The underlying mechanism involves the heater’s capacity to transfer heat from the combustion or electrical elements to the water passing through it. A higher temperature rise rating means that the heater can efficiently convert energy into heat, allowing it to raise the temperature of the water even when the incoming water is extremely cold, such as during winter months. Consequently, if a user selects a unit with an insufficient temperature rise rating for their specific climate or demand, they may end up with lukewarm water, which does not satisfy their needs for showers, washing, or other household tasks.
Moreover, the flow rate of the water also plays a critical role in the effectiveness of the temperature rise rating. When the flow rate is high, the heater must work harder to maintain the desired temperature, which can lead to inefficiencies if the temperature rise rating is not adequate. Therefore, understanding both the temperature rise rating and flow rate is essential to ensure that the chosen outdoor tankless water heater can consistently provide hot water without interruptions, especially in high-demand situations.
What Key Features Should You Look for in an Outdoor Tankless Water Heater?
When searching for the best outdoor tankless water heater, several key features should be considered to ensure efficiency and reliability.
- Flow Rate: The flow rate, measured in gallons per minute (GPM), indicates how much hot water the heater can produce at a time. A higher flow rate is essential for households with multiple outlets, ensuring that you have enough hot water for showers, washing machines, and dishwashers simultaneously.
- Energy Efficiency: Look for models with high energy efficiency ratings, usually indicated by the Energy Factor (EF) or Uniform Energy Factor (UEF). Higher efficiency ratings mean lower energy consumption and utility bills, making it both an environmentally friendly and cost-effective choice.
- Temperature Control: Advanced outdoor tankless water heaters offer precise temperature control features, allowing users to set and maintain their desired water temperature. This is particularly useful for applications that require specific temperatures, such as outdoor showers or in-ground hot tubs.
- Durability and Weather Resistance: Since the unit will be exposed to outdoor elements, it’s crucial to choose a model that is designed to withstand harsh weather conditions. Look for heaters with corrosion-resistant materials and protective coatings to ensure longevity and performance.
- Installation Type: Consider whether you prefer a direct vent or power vent model. Direct vent systems draw air from outside and exhaust directly outside, which is often more energy-efficient, while power vent models use a fan to expel exhaust gases, allowing for more flexible installation options.
- Size and Weight: The size and weight of the unit can impact both installation and usability. Ensure that the heater you choose fits your available space and can be easily mounted or installed without requiring significant structural modifications.
- Warranty and Customer Support: A good warranty reflects the manufacturer’s confidence in their product quality. Look for models that offer comprehensive warranties along with responsive customer support for assistance with installation, maintenance, or troubleshooting issues.
What Advantages Does an Outdoor Tankless Water Heater Offer Over Traditional Systems?
The best outdoor tankless water heaters offer several advantages over traditional systems, enhancing efficiency and convenience.
- Space Efficiency: Outdoor tankless water heaters take up less space compared to traditional water heaters that require large tanks. This is especially beneficial in homes with limited indoor space, allowing for more room for storage or other utilities.
- Endless Hot Water: These systems provide a continuous supply of hot water, meaning you won’t run out during peak usage times. This is ideal for larger households or those who frequently use multiple hot water sources simultaneously.
- Energy Efficiency: Outdoor tankless models heat water on demand rather than maintaining a reservoir of hot water, which significantly reduces energy consumption and can lead to lower utility bills over time.
- Longevity: Generally, tankless water heaters last longer than traditional tank systems, often exceeding 20 years with proper maintenance. This durability can result in lower replacement costs in the long run.
- Less Risk of Water Damage: Since these systems do not store water, there is a reduced risk of leaks and water damage that can occur with traditional tanks, providing peace of mind for homeowners.
- Outdoor Installation Flexibility: Being designed for outdoor use, these units can be installed in various locations outside the house, freeing up indoor space and reducing noise from the heating system.
- Eco-Friendly Options: Many outdoor tankless water heaters are designed with energy-saving technologies, and some models can be powered by renewable energy sources, contributing to a reduced carbon footprint.
Which Brands Are Leading the Market for Outdoor Tankless Water Heaters?
The leading brands in the market for outdoor tankless water heaters include:
- Rinnai: Rinnai is renowned for its high efficiency and reliability, offering a range of outdoor tankless water heaters that are both energy-efficient and capable of providing hot water on demand. Their products often feature advanced technology, such as Wi-Fi connectivity for remote control and monitoring, making them a popular choice for homeowners seeking convenience.
- Takagi: Takagi specializes in tankless water heating solutions that are designed for both residential and commercial applications, focusing on high performance and durability. Their outdoor models are praised for their compact design and ability to deliver a consistent supply of hot water, even in colder climates, which is essential for outdoor installations.
- Stiebel Eltron: Known for its innovative engineering, Stiebel Eltron’s outdoor tankless water heaters stand out due to their German craftsmanship and efficiency. They offer models that are compact and easy to install, with features that ensure a stable water temperature and reduced energy consumption, making them an eco-friendly choice.
- Noritz: Noritz is recognized for its cutting-edge technology and commitment to energy efficiency. Their outdoor tankless heaters provide robust performance and are designed to withstand harsh weather conditions, ensuring that customers have access to hot water when they need it, while also being environmentally friendly.
- EcoSmart: EcoSmart offers a unique perspective on tankless water heating with its focus on sustainability and energy savings. Their outdoor models are known for their compact design and ability to significantly reduce energy costs, appealing to environmentally conscious consumers looking for efficient heating solutions.
What Insights Can Customer Reviews Provide About These Products?
Customer reviews can provide valuable insights regarding the best outdoor tankless water heaters by highlighting various aspects of product performance and user satisfaction.
- Performance: Reviews often detail how well a tankless water heater performs in providing hot water on demand. Customers frequently share their experiences regarding the time it takes to heat water and whether it meets their household needs, especially during peak usage times.
- Energy Efficiency: Many reviews focus on the energy consumption of the water heater, with users noting their utility bills before and after installation. Insights on energy savings can help potential buyers understand the long-term cost benefits of investing in a tankless model compared to traditional water heaters.
- Installation Process: Customers commonly discuss the ease or difficulty of installing the unit, which can vary significantly between models. Reviews may include information about whether professional installation is recommended or if DIY is feasible, as well as any challenges encountered during setup.
- Durability and Reliability: Long-term users often comment on the durability of their tankless water heaters, sharing how well the unit has held up over time and any maintenance issues they have faced. This information is crucial for potential buyers who want a reliable product that will last for years.
- Customer Service: Customer reviews often reflect experiences with the manufacturer’s support and warranty services. Positive or negative interactions with customer service can heavily influence a buyer’s decision, as users share how effectively issues were resolved or how responsive the support team was to their inquiries.
- Temperature Control: Many reviews provide insights into how effectively the heater maintains water temperature during use. Users may discuss fluctuations in water temperature during simultaneous uses, which can be crucial for families or homes with multiple hot water demands.
- Size and Design: Customers frequently comment on the physical size and aesthetic of the heater, which can be important for outdoor installations. Reviews can inform potential buyers about how well the unit fits in their designated space and whether its design is visually appealing or blends well with the home’s exterior.