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Propane Tankless Water Heaters Buying Guide

You’ve stumbled across the ultimate resource to help you choose the best tankless propane water heater for your home and needs! 

As homeowners and experts in home water quality products we’ve reviewed hundreds of water and energy products over the years. Our unbiased reviews are designed to help homeowners invest wisely in the right propane water heater solution for their needs. 

The US Dept of Energy outlines and implements both standards and procedures for energy-efficiency compliance by manufacturers. We’ve taken those standards into consideration along with a few of our own, read on and check out our propane tankless water heater reviews!

  • Freeze Protection
  • Low Carbon Emissions
  • Digital/Wi-Fi controls
  • Leak Detection
  • Low Carbon Emissions
  • Digital Remote
  • Dignostic Controls
  • Digital Remote
  • Overheat Protection
  • Water and Exhaust Temperature Control
  • Ion Flame Failure Protection
  • Manifold Auto-Protection
  • Over Water Pressure Protection
  • Manifold Auto Protection
  • Ion Flame Protection
  • Water Pressure Protection
  • Anti-Freeze Protection
  • Low NOx Emissions
  • LCD Temperature Display
  • CSA-Approved Gas Regulator
  • Flame Failure Protection
  • Freeze Protection

The 7 Best Propane Tankless Water Heater Reviews of 2024

Best Suited For: Large, 2 -3 bathroom home, indoor use only

Product Overview:

We begin our review with a powerhouse model from Rheem. The RTGH Direct Vent Propane Tankless Water Heater simply tops all others on our list for quality, performance (GPM), safety features, and its warranty coverage.

This compact unit is easily installed, minimizes cold water bursts to provide a continuous flow of hot water while remaining energy efficient. Once installed, activate the water savings setting to start saving on water flow and your heating bill. Designed for larger homes, Its industry leading low flow activation means you’ll enjoy a hot shower even when supply is low in your area. 

Powerful enough to heat your entire home, Rheem’s propane water heater will last for years thanks to a 12 year warranty and some convenient digital features. Connect remotely to your tankless Rheem unit with the EcoNet app. The self-diagnostic system monitors the efficiency and performance of your tankless water heater, and includes a digital remote as well. 

Its low-emissions design also means less propane fumes.

Main Features:

  • Up to .93 UEF (US)
  • 9.5 GPM Max
  • Serves up to 4 bathrooms
  • Self-diagnostic system for ease of maintenance
  • Stainless steel condensing heat exchanger
  • EcoNet Enabled
  • ½ inch gas line compatibility extends up to 24ft
  • Freeze protection up to – 30 degrees F
  • 34 kg
  • 12 year warranty



Awesome safety features

Expect 15 – 20 second lag in hot water temperature 

High energy efficiency

Requires periodic descaling for max efficiency

Low carbon emissions

Powerful 9.5 GPM provides limitless water supply

12 year warranty

Best Suited For:  mid-sized, 1 -2 bathroom home, indoor only

Product Overview:

World-class manufacturer Rinnai has created a powerful and energy efficient machine with their V75IP 7.5 GPM Indoor Low NOx model. 

This ultra-low emissions indoor tankless water heater by Rinnai ranks second in our review behind the Rheem because of its slightly lower energy efficiency rating. At 0.81 UEF, it’s still highly efficient, mind you, but better suited for small to mid-sized families, or 2 bathroom homes max.

The Rinnai model is a bit loud but its carbon dioxide emission levels are extremely low. Ventilation is required for indoor use, but installation is easy. There are warranties to cover labor, parts, and the heat exchanger, which really shows confidence in the quality of their tankless units.

 Main Features:

  • 0.81UEF
  • 7.5 GPM Max
  • 45.6 lbs (20.7kg)
  • ½ inch Gas line compatible
  • High altitude approved for up to 10,200 ft( 3109 m)
  • AHRI and CSA approved¾ inch inlet and outlet for water
  • Ultra Low Nox for extremely low carbon emissions
  • Leak detection
  • Wi-fi digital remote
  • Temperature range with controllers: 98ºF – 140ºF
  • mobile home installation
  • 1 yr warranty on labor, 5 year warranty on parts 10 YR warranty on heat exchanger



Great safety features

Direct Ventilation Kit must be purchased separately

Warranty covers parts, labor and heat exchanger

Can be a little loud

Energy efficient

Ultra low carbon emissions

Best Suited For: 1 – 2 bathroom home, outdoor unit

Product Overview:

If you’re looking for an economically-priced outdoor water heater with a high energy rating, Eccotemp makes some of the best tankless models out there!

Eccotemp’s outdoor liquid propane-powered N45H-LP is another one of the best tankless water heaters that compares well to other brands in terms of its efficiency. With an 80% energy rating and 6.8 GPM, the N45H-LP is ideal for small households, or 1 – 2 bathroom homes.

You’ll finally be able to enjoy an uninterrupted supply of hot water while the N45H works away. Installation is easy and its compact size means it can be mounted on any outdoor wall close to the water and gas inlets.

Main Features:

  • 0.80 UEF
  • 38 lbs
  • 6.8 GPM max
  • ¾ inch Gas line compatible (¾ inch inlet and outlet for water)
  • Wi-fi digital remote
  • CSA-certified
  • Elevation up to 3000 ft
  • 10 year warranty on heat exchanger, 5 year warranty on parts



High efficiency

Not suited for elevation above 3000 ft

10 yr and 5 yr warranty

No warranty on labor


Wifi control

Best Suited For: Mid-sized, 1 -2 bathroom home, 2 -3 bedroom apartment

Product Overview:

Slightly more powerful than the propane-fueled Takagi T-KJr2, the TK4 Indoor Tankless is designed for residential use in mid-sized homes or 2 -3 bedroom apartments. 

The Takagi T -K4-IN-LP provides a pretty impressive 8 GPM and can serve a 2-3 bathroom home with a constant flow of hot water. At just under 35 lbs, its compact size and weight means you’ll save a lot of space. We also like that it includes a number of safety features to prevent against overheating, freezing, as well as temperature controls.

We should warn you, however, that Takagi does not offer a warranty for their tankless propane heater. Several reviews have expressed dissatisfaction with the poor quality of customer service, and defective units are rarely replaced without exhaustive effort on your part.

Main Features:

  • 0.82 UEF
  • 8.0 GPM Max
  • 34.6 lbs
  • Air Fuel Ratio sensor
  • Water and Exhaust Temperature Safety Control
  • Temperature control systems
  • Overheat Cut-off Fuse
  • Freeze-Protection System
  • Manual reset high-limit switch
  • ¾ inch Hot/Cold Water Line Compatible
  • ¾ inch Gas Line Compatible 



Plenty of awesome safety features

No warranty

High energy efficiency

Poor customer service

Best Suited For: 1  bathroom home, single bathroom apartment

Product Overview:

No pilot light, no electrical hook-up, this liquid propane tankless water heater will reduce your gas bill and supply you with continuous hot water whenever you need it! 

Ranked 5th in our review, the TC-Home 4.8 has an 18 litre/mn capacity and an energy efficiency rating of 80% which is great. While the GPM is much lower than the other more expensive models, it’s priced economically and works best for a single bathroom home or apartment.

Sadly, the TC-HOME 4.8GPM is not covered by warranty. Tengchang doesn’t have a glowing reputation for customer service, but defects are rare. 

If you already have a water tank but want to install something smaller specifically for use in a single bathroom, the TC 4.8GPM is fairly easy to install and low maintenance. 

Main Features:

  • 0.8 UEF
  • 4.8 GPM
  • 18 L/mn capacity
  • ½ inch Gas Line compatible
  • Auto-ignition (Batteries Required ( 2 ‘D’)
  • Flame failure protection



Energy efficient

No warranty

18L/mn capacity heats water quickly

Good safety features

Portable, lightweight

Best Suited For: Single bath home or apartment

Product Overview

For those of you who aren’t fussy about GPM’s and just want an affordable alternative to your existing water tank, we decided to include the TC Propane Tankless Water Heater.

As you may have noticed by now, Tengchang is known for economically-priced gas and propane water heaters that are energy efficient but low on GPM. The TC 2.6GPM delivers the same of what you’d expect from Tengchang.

Designed for use in single bath households, this indoor unit is also fairly easy to install but doesn’t provide the safety features we like. Temperature control is also difficult to adjust but has a range between 8 degrees and 45 degrees F. 

The energy efficiency is rated 80% so you’ll definitely save on your gas bill. Its low GPM of only 2.6, however, makes it significantly less powerful. If saving on gas is your primary concern and you plan on only using it for baths, the Tengchang Propane Gas Tankless Heater should work for you.

We should mention that, once again, Tengchang Propane Gas Tankless Water Heater, is made in China, and is not covered by warranty.

Main Features:

  • 2.6 GPM 
  • >0.80 UEF
  • 9.5mm 3/8″ Gas Line inlet
  • Gas pipeline (outer diameter): 20mm rubber gas hose
  • Water Inlet: G1/2”
  • Water Outlet: G1/2”



Energy efficient

Limited application



Instant, continuous hot water

No warranty

Best Suited For: 1 – 2 bathroom home, outdoor unit

Product Overview:

Our review wouldn’t be complete if we didn’t include an affordable outdoor propane tankless water heater.  For those of you who need a portable solution for camping trips, cottage excursions, or an outdoor shower, the Marey GA30 OLP is an easy-to-install, energy efficient solution.

The 6.5 gpm at high temperatures means you’ll enjoy continuous hot water for your bath, shower, or dishwashing needs for as long as you need. Ideally suited for 1 -2 bathroom household, the safety features make it pretty hands-off once it’s installed. 

At 84% energy efficiency, the durable, UV-protected Marey GA30OLP starts saving you money soon after its activated. A digital display helps you easily monitor temperature, heat, and carbon emissions. Either propane or gas will work and the heat exchanger is covered by a 5 year warranty.

Main Features:

  • 0.84 UEF
  • 6.5 GPM max.
  • 52.91 lbs
  • ¾ inch gas line compatible
  • Low NOx emissions burner
  • Freeze protection
  • Max temperature 140 degrees F
  • Overheat protection
  • Digital display
  • 5 yr heat exchanger warranty, 1 yr labor warranty



Low emissions

Great safety features

Energy efficient

5 yr warranty for heat exchanger

Best Suited For: Camping excursions, cottage/cabin, outdoor shower

Product Overview:

To round out our list, we decided to go with yet another outdoor propane water heater, but this one is specifically for outdoor enthusiasts.  Camplux makes a whole range of products for making outdoor life easier, but the portable 10L is our favorite!

Wash your car, your pets, or enjoy an outdoor shower on your next camping trip. Lightweight, versatile, and easily installed, the Camplux 10L comes with a multifunctional showerhead and an energy efficient rating of 88%!. Weighing only 18 lbs, it also includes safety features to ensure the longevity and optimal performance of your tankless propane water heater for years to come.

The Camplux 10L gives you a constant, reliable flow of hot water whenever you need it, but what really stands out is the summer/winter settings for regulating energy efficiency based on season.  No other tankless water heater has such a feature, designed to adjust efficiency and gpm depending on climate.

Main Features:

  • 0.88 UEF
  • 2.64 GPM
  • 10.5 kg
  • Overheat protection
  • Freeze protection
  • Flame failure protection
  • Seasonal settings for summer/winter
  • Battery-powered ignition



Portable, lightweight

Requires outdoor ventilation

Includes shower head

No on/off switch on the shower head

Great safety features

Seasonal settings to maximize efficiency

What to know about propane tankless water heaters

Propane Tankless Water Heater Buying Guide

Key Criteria For Buying a Propane Tankless Water Heater:​

  • UEF: Uniform Energy Factor. Established June 12, 2017 as a universal standard, this is a metric for measuring energy efficiency. The higher the UEF, the more savings for you on your energy bill.

  • GPM: Gallons Per Minute, a measure of your water heater’s delivery Capacity. It’s the most critical decisioning factor that reflects the power of your water heater to deliver a constant flow across multiple rooms. GPM can vary, slowing as the temperature increases. Anything over 5.0 GPM, however, is above the standard.

  • Warranty: A propane-powered tankless water heater should be backed by a guarantee. If the manufacturer won’t stand behind the product, why should we?

  • Safety Features: Temperature controls, freeze protection, and low carbon emissions are additional features that impact both price and quality.

You’ll find a detailed review of each of our selections if you scroll below the table of our 8 top picks. All of the tankless propane water heaters on our list were chosen by our inhouse team. 

Why Switch To A Tankless Water Heater?

Imagine accessing hot water on demand, without having to wait for the water to heat to the desired temperature? No more line-ups for the bathroom in your home, no more running out of hot water in the middle of washing dishes – a tankless water heater is designed for greater convenience and efficiency.

combining automated controls for diagnostics and temperature, digital and wifi capabilities, and energy-efficient burners, a tankless water heater heats water and sustains your desired temperature with far greater efficiency than earlier tank-based models.

If you currently own a conventional water heater, then you already know how costly they are to maintain and repair, not to mention their comparably poor efficiency. New homeowners would do well to invest in a quality tankless water heater for a number of reasons. 

The table below provides a helpful comparison of the benefits of a tankless water heater and other energy products.

Comparison chart of water heaters
  • Energy Efficiency

Your typical tankless water heater can cut your energy bill down up to 60%.  The heater is designed to heat water rapidly while maintaining a continuous flow.  Propane also has a much higher BTU rate than gas (more than double). That means your hot water will require less energy to heat and stay hot.

  • Lower Emissions

A tankless propane water heater emits lower carbon emissions, and burns cleaner than natural gas, reducing your carbon footprint for the next generation.

  • Auto-Safety Features

Today’s top brands include LCD display, temperature controls and diagnostics to warn you of spikes in temperature, leaks, and other potential hazards. The water heater shuts off automatically when not in use, saving you money on your energy bill. 

Some models require batteries to operate the digital components that are not included. Others can be plugged into an electrical power source or battery-powered.

  • Better Flow Rate (GPM) 

The flow rate, measured as gallons per minute, (GPM) measures how well your tankless heater maintains the water temperature and flow to multiple devices or rooms simultaneously. 

A highly efficient tankless water heater delivers hot water efficiently to multiple rooms and devices without straining your energy bill or your heater. 

Shower head spraying water
  • Unlimited, on-demand hot water supply 

With a tankless propane water heater, your water is hot whenever you need it. You won’t have to wait for the water to heat up again after someone else has had a shower. You can wash dishes while someone else is having a bath, without any interruption in hot water.

  • Require less space

The typical tankless propane water heater is the size of a medicine cabinet, weighing anywhere between 25 – 45 lbs on average. They are usually wall-mounted, and take up much less room than your conventional water heater.

Because of its smaller size, a tankless unit can be installed close to a point of use or conveniently out of sight.  You can also install several units at different points of use to reduce the lag time as you wait for the tankless water heater’s internal combustion and exchange to activate.

  • Longevity

Due to its higher energy efficiency, a tankless propane water heater has a much longer lifespan than a conventional water heater. With proper installation and maintenance, your tankless water heater can last as long as 20 years!

    What is the Difference Between Tankless Propane & Natural Gas?

    Comparing the pros and cons of propane and gas can be tricky. There are benefits to both as well as drawbacks. 

    Propane and gas-powered products offer an alternative to electric tankless water heaters, giving you the capacity to function off-grid. Access to a reliable source of propane or gas, however, can vary greatly depending on your location, impacting the cost of your utility rates.

    In terms of energy efficiency, propane has a higher BTU rate than gas.  While both are fossil fuels, propane also burns cleaner.

    Utility rates for gas and propane will depend largely on your location and demand in your area. Gas can be continuously supplied via pipe inlets, whereas propane must be delivered and stored in a tank.

    How Do Tankless Heaters Work?

    Designed for efficiency and safety, tankless water heaters rely on combustion technology and digital tools to operate. 

    1. Unlike a conventional water heater, a tankless heater does not store any water. Instead it contains a heat exchanger that activates only when in use, heating water as it passes through. 

    2. The heat exchanger is typically housed inside a metal box that is much smaller in size and weight than a tank heater.

    3. Three inlet pipes provide the tankless heater with a supply of propane or gas, as well as water.

    4. A propane burner inside is fitted directly beneath the heat exchanger. Pipes coiled around the heat exchanger bring cold water in, and a third pipe sends the hot water out. 

    5. When the digital flow sensor detects the flow of cold water, it activates the burners. The propane burner, similar to the one on a gas stove, is typically made of copper. An intake located on the top draws air in to ignite the burner.

    6. Some units are fitted with recirculation technology to minimize the lag between activation and the desired temperature. The tankless heater keeps hot water pipes flushed with hot water, awaiting use on demand or at a scheduled time. A thermal bypass valve installed closest to the source of water pushes cold water into a return line, thus reducing water waste. 

    7. Finally a sealed vent directs combustible air in to the burners, and exhaust gases safely outside the home. 
    Diagram showing the parts and controls on a residential tankless water heater unit

      With a tankless water heater, there’s no risk of lime build up, corrosion, or frozen water. They function well in any climate, thanks to safety features like freeze protection and temperature controls that monitor flow as well as emission levels.

      Water Heater Cost-Savings 

      The initial cost of purchasing a tankless propane water heat and the cost of installation can represent a significant investment. Of course, the savings you generate over time from your reduced energy bill will certainly make your investment worth it.

      Choose wisely before deciding on the brand and type that’s right for you. In our next section, we’ll share with you some important criteria to consider before making your purchase.

      Choosing your propane tankless water heater

      How to Choose The Right Propane Tankless Water Heater For Your Household

      Cost isn’t the only consideration when it comes to getting the right propane tankless water heater for you. Too powerful, and your water usage could easily triple; not powerful enough, and your water heater will underperform. 

      • Household Size

      On average, larger families consume more water  and energy than single professionals. Households with young school aged children, in particular use more water for baths, showers, dishwashing and laundry. 

      • Lifestyle

      Many households also commute, leaving their homes vacant for much of the day. Usage peaks during the evenings and on weekends, which can result in higher utility rates for your propane or gas, as well as water.

      Note: If you happen to live in a remote area, say on a ranch or rural community, installing a reliable gas/propane line could be challenging. Gas line installation will incur an additional cost, but proximity to a reliable gas service is key. Should a problem occur with your propane/gas supply, you don’t want to have to wait for hours for repairs!

      • Number of Water Devices 

      Devices that rely on water are also a factor. Frequent use of your dishwasher, washer, specifically, will require a tankless water heater with a high flow rate, or GPM (gallons per minute), to provide continuous hot water simultaneously to each device.

      • Frequency of Use

      You should consider how frequently you use hot water in your household each week, as well as the activities in your routine. 

      Does your household have line-ups for the bathroom in the morning? Is your bath routine usually at night? A busy household needs a tankless propane water heater with high GPM. Activities that tend to frequently use large amounts of water include: 

      • Baths
      • Dishwashing
      • Laundry
      • Lawn care
      Pie chart showing the percentage breakdown of household water consumption

      Regional Water Consumption: What Is Water Consumption In Your Region?

      Before deciding on a propane tankless water heater, you should also consider the hot water usage in your region. Your utility rate depends on several local factors, and this will impact the amount of savings generated by your propane tankless water heater. 

       If your utility rates are high or fluctuating, you’ll see lower savings than someone with relatively rates. Your tankless water heater’s energy efficiency may also vary depending on local factors.

      Dry regions such as Nevada use less hot water than states in the midwest, but you may live on a remote ranch where access to municipal water is unreliable or simply not possible. Moderate climates and northern states have a higher reliance on a local CWS for their water, but the demand for hot water fluctuates depending on the season, time of day and population density. 

      Whether you choose gas or propane, we highly recommend you choose a  tankless water heater with the highest energy efficiency rating your budget allows. Since most tankless heaters are designed to last 5 – 10 years, it may be worth it to spring for a more powerful unit for large households with more than 2 bathrooms.

      In Conclusion: Propane Tankless Water Heaters

      When it comes to tankless propane water heaters, making the right investment can literally make or break you. You want a solution, not another problem, so do your homework and don’t rely on word-of-mouth alone to guide your decision.

      Research the water heater that interests you as well as the company behind it. Read what customers have to say about it. Ultimately, you’ll need to balance the pros and cons for yourself, but at least you’ll be informed.

      You’re always welcome to visit us at iWaterPurification for more insightful, in-depth reviews of the best water products for your home!