Best Propane Tankless Water Heater: Indoor and Outdoor

Finding the perfect propane tankless water heater can be a game-changer for your home, offering endless hot water, energy efficiency, and a compact design. With so many models available on the market, it’s easy to feel overwhelmed by the options. In this guide, we’ve tested and reviewed the top propane tankless water heaters on the market to help you make an informed choice. Whether you’re upgrading your current system or making the switch for the first time, this guide will help you choose the best unit based on your unique needs, preferences, and budget.

List of the Best Propane Tankless Water Heater:

Check out the thorough review of the best propane tankless water heater below.

1. Rinnai RX199iN Indoor or Outdoor Propane Tankless Water Heater

The Rinnai RX199iN Condensing Smart Sense Tankless Water Heater is an innovative, high-performance solution for homeowners seeking efficient and versatile water heating. With a robust flow rate of up to 11.1 gallons per minute (GPM) and a powerful heating capacity of 199,000 BTUs, this unit effortlessly supports up to seven fixtures simultaneously, making it ideal for larger households. Its Smart Sense gas control system allows seamless operation with either propane or natural gas, while the Versa Vent feature ensures flexible installation indoors or outdoors. Measuring just 18.5 inches wide and 30.11 inches high, this compact unit fits neatly in tight spaces without compromising performance.

With an ultra-high Uniform Energy Factor (UEF) of 0.98, the RX199iN is designed for optimal energy efficiency, helping homeowners save on utility bills. Its modern design includes a user-friendly interface and a Quick Flush function for simplified maintenance. Additionally, the system is compatible with the Control-R Wi-Fi module (sold separately) for remote monitoring and control. Backed by Energy Star certification, this water heater delivers reliable performance while contributing to sustainability.

Key Features, Pros, and Cons

Key Features

• Flow rate of 11.1 GPM supports up to 7 fixtures simultaneously.
• Smart Sense system allows propane or natural gas operation.
• Ultra-high UEF of 0.98 for exceptional energy efficiency.
• Compact design with flexible indoor/outdoor installation using Versa Vent.
• Optional Wi-Fi control via Control-R module for added convenience.

Pros

• Powerful heating capacity suitable for large households.
• Extremely energy-efficient with a UEF of 0.98.
• Compact and versatile design fits various installation needs.
• Simplified maintenance with Quick Flush function.
• Supports propane or natural gas, offering flexibility.

Cons

• Outdoor installation requires additional RX-OVC vent cap.

2. Ranein Indoor Propane Gas Tankless Water Heater

The Ranein Propane Gas Tankless Water Heater is a compact and efficient on-demand water heating solution, offering a heating capacity of 80,000 BTU and a maximum flow rate of 3.6 gallons per minute (GPM). Designed to support 2-3 water supply points simultaneously, it is ideal for small households or spaces like kitchens, bathrooms, and bar areas. Unlike traditional water heaters, this unit eliminates preheating times, delivering instant hot water when you need it.

The water heater features four user-friendly temperature modes—Dish (100°F), Fruit (95°F), Elderly (104°F), and Infant (107°F)—making it versatile and convenient for various applications. With high water pressure protection and an oxygen-free copper water tank, the unit ensures durability while reducing heat loss and energy consumption. Its compact dimensions of 19.09″W x 7.67″H make it a space-saving option for indoor installations. Additionally, the included vent pipe simplifies setup and reduces extra costs.

Key Features, Pros, and Cons

Key Features

• Flow rate of 3.6 GPM with 80,000 BTU capacity for instant hot water.
• Four temperature modes for customized use: Dish, Fruit, Elderly, Infant.
• High water pressure protection and oxygen-free copper water tank.
• Compact design with vent pipe included for easy installation.
• Standard 1/2″ NPT water fitting and gas inlet for compatibility.

Pros

• Provides instant hot water with no preheating required.
• Compact and space-saving design.
• Versatile temperature modes for different needs.
• Durable materials reduce heat loss and improve efficiency.
• Includes vent pipe, saving additional costs.

Cons

• Not suitable for areas over 2,000 feet altitude.

3. Rinnai Outdoor Propane Tankless Hot Water Heater

The Rinnai V53DeP Tankless Hot Water Heater is a high-efficiency, propane-powered system designed for outdoor installation. Compact yet powerful, this unit delivers a maximum flow rate of 5.3 gallons per minute (GPM), ensuring consistent hot water for up to four appliances simultaneously. Its tankless design eliminates the need for a bulky water tank, freeing up valuable space while providing endless hot water on demand.

Energy-efficient by design, this unit heats water only when needed, reducing energy waste and lowering gas bills. The enhanced scale detection system protects the heater from long-term damage, ensuring durability. Made from stainless steel and weighing only 33 pounds, it’s lightweight and weather-resistant, ideal for outdoor installations. For convenience, the heater is Wi-Fi capable (with the Controlr module, sold separately), allowing users to monitor and control settings remotely. Backed by a robust warranty—10 years on the heat exchanger, 5 years on labor, and 1 year on parts—it guarantees reliability and peace of mind.

Key Features, Pros, and Cons

Key Features

• Delivers 5.3 GPM to support up to four appliances simultaneously.
• Outdoor installation saves space and eliminates indoor venting needs.
• Energy-efficient design heats water only when required.
• Enhanced scale detection protects the unit from long-term damage.
• Wi-Fi capable for remote monitoring and control (module sold separately).

Pros

• Provides endless hot water on demand.
• Compact and lightweight design saves space.
• High efficiency reduces energy waste and utility bills.
• Durable stainless steel construction for outdoor use.
• Backed by an extensive warranty for long-term reliability.

Cons

• Wi-Fi Controlr module must be purchased separately.

4. Orbek Indoor Propane Tankless Water Heater

The Orbek 80,000 BTU Residential Indoor Propane Tankless Water Heater is a compact, high-performance solution for on-demand hot water. Designed for indoor use, it delivers a flow rate of up to 3.6 gallons per minute (GPM), supporting 1-3 fixtures simultaneously, making it ideal for small to medium-sized households. With a heating capacity of 80,000 BTU and crafted from high-quality oxygen-free copper, this water heater ensures efficient heat transfer and corrosion resistance, reducing energy costs over time.

Equipped with advanced safety features, such as dry combustion protection, flame failure protection, and high water pressure protection, the unit is CSA-certified for reliable performance. Its built-in chip adjusts heating power 20,000 times per second, maintaining water temperature within 1°F, providing a stable and comfortable hot water experience. The LED digital display allows users to set temperatures between 95°F and 149°F with ease, and its power outage memory function ensures consistent performance.

Key Features, Pros, and Cons

Key Features

• Provides 3.6 GPM and 80,000 BTU, serving 1-3 fixtures simultaneously.
• Built-in chip ensures stable water temperature within 1°F.
• Compact design saves 50% of space compared to traditional tanks.
• LED display with adjustable temperature range (95°F-149°F).
• CSA-certified with multiple safety protections.

Pros

• Delivers on-demand hot water with steady temperature control.
• Energy-efficient design reduces long-term costs.
• Compact and space-saving for easy indoor installation.
• Advanced safety features ensure reliable operation.
• Affordable price with strong warranty and customer support.

Cons

• Maximum flow rate may not support larger households.

5. Rheem Outdoor Tankless Liquid Propane Water Heater

The Rheem RTG-70XLP-3 High Efficiency Outdoor Tankless Liquid Propane Water Heater is an exceptional solution for providing continuous, energy-efficient hot water. With a maximum flow rate of 7.0 gallons per minute (GPM), this unit can comfortably handle multiple applications, such as a shower and dishwasher running simultaneously, making it ideal for medium to large households. Its Hot Start Programming ensures the heater remains in a ready state, eliminating cold water bursts during back-to-back uses.

Designed for efficiency, this tankless water heater operates only when needed, reducing energy costs. Its water-saving setting conserves up to 1,100 gallons of water per year, an eco-friendly benefit that also helps lower utility bills. Measuring just 13.5 inches wide and 20.75 inches high, and weighing 39.25 pounds, the compact design allows for easy wall-mounted installation while saving valuable floor space. The unit’s industry-best side-to-side clearance makes it adaptable to tight outdoor spaces.

Key Features, Pros, and Cons

Key Features

• Delivers 7.0 GPM for continuous hot water across multiple fixtures.
• Hot Start Programming eliminates cold water bursts during repeated use.
• Water-saving setting reduces water waste by up to 1,100 gallons annually.
• Compact design with 22% reduced weight for easy outdoor installation.
• Overheat Film Wrap protects the heat exchanger for enhanced durability.

Pros

• Provides consistent hot water for multiple applications.
• Energy-efficient operation reduces utility bills.
• Compact and lightweight, saving space during installation.
• Eco-friendly with significant water savings annually.
• Durable stainless steel construction ensures long-term reliability.

Cons

• Non-condensing design may result in less heat recovery efficiency.

6. MIZUDO Indoor Propane Gas Tankless Water Heater

The MIZUDO Propane Gas Tankless Water Heater is an efficient and compact indoor solution for providing instant hot water. With a maximum heating capacity of 80,000 BTU and a flow rate of up to 3.6 gallons per minute (GPM), it can meet the hot water demands of small to medium households, supporting multiple fixtures with precise temperature control. Certified by CSA, this unit incorporates essential safety features, such as overheating and flameout protection, ensuring reliable and worry-free operation.

Designed with an oxygen-free copper water tank, the MIZUDO heater minimizes heat loss while maximizing efficiency and durability. Its Uniform Energy Factor (UEF) of over 0.81 ensures energy conservation, as it only consumes power during heating. Measuring 20.5 inches high and 13 inches wide, this tankless water heater saves over 50% of space compared to traditional tank models, making it an ideal choice for smaller homes or tight installations.

Key Features, Pros, and Cons

Key Features

• Provides 3.6 GPM with precise temperature control and no temperature fluctuations.
• Compact design saves over 50% of space compared to tank systems.
• CSA-certified with overheating and flameout protection for safety.
• Features an oxygen-free copper water tank for high efficiency and durability.
• UEF above 0.81 ensures energy conservation and cost savings.

Pros

• Instant and endless hot water supply for small to medium households.
• Energy-efficient with reduced heat loss.
• Lightweight, compact design for easy installation.
• Durable materials ensure long-lasting performance.
• Affordable and backed by a solid warranty with 24/7 support.

Cons

• Limited to 3.6 GPM, unsuitable for larger households.

How to Choose the Best Propane Tankless Water Heater?

Are you tired of running out of hot water in the middle of a shower or waiting endlessly for your water heater to do its job? A propane tankless water heater might just be the game-changer you need.

Understand Your Hot Water Needs

The first step in finding the best propane tankless water heater is understanding your household’s hot water demand. Ask yourself:

• How many people live in your home?
• How often do you use hot water simultaneously (e.g., showering while running a washing machine)?
• What’s the climate like in your area?

Propane tankless water heaters are measured by their flow rate (in gallons per minute or GPM). For instance, a family of four might need a unit with a flow rate of at least 8–10 GPM to handle multiple showers and appliances running at the same time. On the other hand, if you’re a couple or living solo, a lower GPM (4–6) could suffice.

Determine Where You’ll Install It

Next, decide where the unit will be installed. This is crucial because propane tankless water heaters come in both indoor and outdoor models.

• Indoor Units: These are compact and ideal for homes with limited outdoor space. However, they require proper ventilation systems to expel exhaust gases safely.
• Outdoor Units: These are perfect if you live in a mild climate and have space outside your home. They don’t need extra venting, making installation easier and more cost-effective.

For colder climates, ensure the unit is protected against freezing temperatures. Many models come with freeze protection, but always double-check before purchasing.

Check the Efficiency Ratings

When it comes to energy efficiency, propane tankless water heaters outperform traditional storage tanks. However, efficiency ratings can vary between models. Look for units with high Energy Factor (EF) or Uniform Energy Factor (UEF) ratings.

A higher EF/UEF means the unit converts more propane into hot water, saving you money in the long run. For an eco-conscious choice, consider ENERGY STAR-certified models—they not only reduce energy consumption but might also qualify you for rebates.

Consider the Budget—But Think Long-Term

It’s tempting to choose the cheapest option, but remember: the cheapest isn’t always the most cost-effective. A quality propane tankless water heater may cost more upfront, but its energy savings and longer lifespan (up to 20 years!) make it a wise investment.

Budget considerations should also include installation costs. Some units require professional installation, while others are DIY-friendly. Check the manufacturer’s recommendations to avoid surprises.

Focus on Key Features That Match Your Lifestyle

Not all propane tankless water heaters are created equal. Look for features that align with your lifestyle:

• Digital Controls: These allow you to adjust the water temperature precisely and monitor system performance.
• Built-in Recirculation Pumps: These ensure instant hot water, eliminating the wait.
• Wi-Fi Connectivity: Some models can be controlled through your smartphone, making adjustments effortless.
• Durability: Choose models made from stainless steel or high-quality materials to ensure longevity.

Think about what features would make your daily life easier and more comfortable, then prioritize those.

Don’t Forget About Maintenance

While propane tankless water heaters are low-maintenance compared to traditional water heaters, they still require some care to perform optimally. Consider the following:

• Look for models with easy-to-replace parts.
• Check if the unit has a built-in descaling system to reduce mineral buildup, especially if you live in an area with hard water.
• Understand the warranty coverage—longer warranties often indicate a manufacturer’s confidence in their product.

Why Propane? The Benefits Are Worth It

By now, you might be wondering why propane is a better choice than electric or natural gas. Propane is highly efficient, heats water quickly, and is ideal for off-grid or rural homes where natural gas isn’t available. Plus, propane heaters are known for their durability and consistent performance, even in power outages.

Frequently Asked Questions When Selecting the Best Propane Tankless Water Heater

1. What is a propane tankless water heater, and how does it work?

A propane tankless water heater is a water heating system that uses propane gas to heat water on demand, rather than storing it in a tank. When you turn on a hot water faucet, cold water flows through the heater’s unit, where a propane-fueled burner rapidly heats it. This ensures you get a continuous supply of hot water without waiting for a tank to refill. It’s energy-efficient and compact, making it an excellent choice for modern households.

2. What are the main benefits of a propane tankless water heater?

The key benefits include:

• Endless Hot Water: It heats water on demand, so you never run out.
• Energy Efficiency: These systems only heat water when needed, saving energy and reducing utility bills.
• Compact Design: Without a bulky tank, these units save space in your home.
• Durability: Propane tankless water heaters can last up to 20 years with proper maintenance.
• Eco-Friendliness: Propane is a clean-burning fuel, making these systems environmentally friendly.

3. How do I determine the right size propane tankless water heater for my home?

To choose the correct size, calculate your household’s hot water demand in gallons per minute (GPM). Add up the flow rates of appliances and fixtures that you might use simultaneously. For example:

• Shower: 2–3 GPM
• Kitchen faucet: 1–2 GPM
• Washing machine: 2–3 GPM
  If you plan to use multiple appliances at once, ensure the heater has a flow rate that can handle the combined demand. For a family of four, a unit with at least 8–10 GPM is typically recommended.

4. Are propane tankless water heaters better than electric ones?

Propane tankless water heaters have some advantages over electric models:

• Faster Heating: Propane heaters deliver hot water more quickly.
• Higher Flow Rates: They can handle larger households with higher water demand.
• Energy Efficiency: Propane is generally more efficient and cost-effective in the long run, especially in areas with high electricity costs.
• Off-Grid Use: Propane units are ideal for remote locations without access to electricity or natural gas.

However, electric models might be better for smaller homes with lower hot water needs and areas where propane is not readily available.

5. Can I install a propane tankless water heater myself?

While some models are DIY-friendly, professional installation is often recommended, especially for indoor units. Proper installation ensures safe ventilation, correct gas line connections, and optimal performance. Improper installation can lead to safety hazards, inefficiency, or voided warranties. Always check the manufacturer’s instructions and local building codes before attempting a DIY installation.

6. How much does a propane tankless water heater cost?

The cost of a propane tankless water heater varies depending on its size, features, and brand.

• Unit Price: Typically ranges from $500 to $2,000.
• Installation Costs: Can range from $300 to $1,500, depending on whether additional work (e.g., venting or plumbing upgrades) is needed.
  Though the upfront costs are higher than traditional water heaters, the energy savings and long lifespan make it a cost-effective choice in the long term.

7. Are propane tankless water heaters suitable for cold climates?

Yes, many propane tankless water heaters are designed to perform well in cold climates. Look for models with:

• Freeze Protection: Prevents the unit from freezing in low temperatures.
• High BTU Ratings: Ensures sufficient heating power for colder incoming water.
  Additionally, insulating pipes and the unit itself can improve performance in extreme weather conditions.

8. What features should I look for in the best propane tankless water heater?

Here are some must-have features:

• Flow Rate (GPM): Matches your household’s hot water demand.
• Energy Efficiency: High UEF or ENERGY STAR certification.
• Digital Controls: For precise temperature adjustments.
• Safety Features: Includes automatic shutoff and overheat protection.
• Durability: Units made of stainless steel or high-quality materials last longer.
• Recirculation Pumps: For instant hot water without delay.
• Warranty: A longer warranty is a good indicator of quality and reliability.

9. Do propane tankless water heaters require maintenance?

Yes, regular maintenance ensures optimal performance and extends the unit’s lifespan. Tasks include:

• Descaling: Remove mineral buildup, especially in areas with hard water.
• Cleaning the Filter: Prevent clogs by cleaning the water inlet filter.
• Inspecting Gas Lines: Ensure there are no leaks.
  It’s best to follow the manufacturer’s maintenance schedule and hire a professional for annual inspections.

10. How do propane tankless water heaters compare to natural gas models?

Both propane and natural gas tankless water heaters operate similarly, but the main difference lies in the fuel source:

• Availability: Natural gas is connected to a utility line, while propane is stored in tanks. If you live in a rural area, propane is often the better option.
• Cost: Natural gas is usually cheaper per unit, but propane burns more efficiently, so the difference in operational cost is often negligible.
• Portability: Propane heaters are ideal for off-grid homes or RVs, as they don’t rely on a fixed gas line.

11. How long do propane tankless water heaters last?

With proper care and maintenance, propane tankless water heaters can last up to 20 years or more. Their longer lifespan compared to traditional water heaters (10–15 years) makes them a worthwhile investment.

12. Are propane tankless water heaters safe?

Yes, propane tankless water heaters are safe when installed and maintained properly. Key safety features include:

• Flame sensors to prevent gas leaks.
• Overheat protection.
• Automatic shutoff mechanisms.
  Ensure proper ventilation and regular inspections to maintain safety and efficiency.

13. What are the top brands for propane tankless water heaters?

Some of the most trusted brands include:

• Rinnai: Known for reliability and advanced technology.
• Takagi: Offers compact, energy-efficient models.
• Rheem: Popular for its affordability and robust performance.
• EcoSmart: Focuses on eco-friendly, budget-friendly options.
  Each brand has unique features, so compare models based on your specific needs.

14. Can I use a propane tankless water heater in an RV or mobile home?

Yes! Many propane tankless water heaters are specifically designed for RVs and mobile homes. Look for compact, lightweight models with a low GPM suitable for limited water usage. Additionally, ensure the unit is compatible with your RV’s propane system and has proper ventilation.

15. Where should I install my propane tankless water heater?

Installation depends on the model:

• Indoor Models: Require proper ventilation and a suitable space for gas line connections.
• Outdoor Models: Ideal for mild climates and don’t require venting.
  Consult a professional to determine the best location based on your home’s layout and local building codes.

Conclusion

Choosing the best propane tankless water heater doesn’t have to be a daunting task. By considering factors like your household’s hot water demand, climate, efficiency, and desired features, you can find a unit that perfectly fits your needs. Our in-depth reviews highlight the top-performing models that have been tested for reliability, performance, and value.

Enjoyed this guide of the best propane tankless water heater? Then be sured to check out our other heating guides.

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