Best Propane Tankless Water Heaters in 2022

As more people look for greener, energy-saving ways to heat their water, propane tankless water heaters are becoming one of the most popular options for home and RV heating.

With up to twice the lifespan of traditional heaters and no bulky tank to worry about, tankless heating systems can be installed pretty much anywhere.

They also produce hot water on demand by activating when faucets are turned on. This saves energy and prevents waste, leading to reduced utility bills.

Propane is often a more flexible and efficient fuel choice than natural gas and is usually cheaper than heating water with electricity.

What’s on this page?

If your home runs on propane, a tankless heater is the best way to save on fuel. But choosing a product from the multiple brands and models available isn’t easy.

To help, we’ve analyzed the best-selling and most popular propane heaters online by key features such as flow rate, capacity, efficiency, and more. Here are the results!

How to choose a Propane Tankless Water Heater

Deciding on a few essential features will help identify the ideal tankless water heating system for your home.

Flow Rate (GPM)

Flow rate is an important metric that indicates how many gallons of water a propane heater is able to produce per minute. Selecting a heater with the right GPM for your home is key to avoid slow faucets and cold showers.

The majority of homes with 2 or fewer bathrooms operate on a flow rate of between 4 and 6 GPM, while larger homes may need up to 10. For reference, most faucets require around 1 GPM, laundry machines and other kitchen appliances use 2-3, and showers draw 2-4 GPM.

If you’re planning on using your propane heater for just a single appliance, such as a shower, then a flow rate of 2-4 GPM is likely to be enough for your needs.

However, factors such as incoming water temperature and the distance between the heater and the outlet also affect overall flow rate. Heaters installed in colder areas of the US are likely to underperform by several GPM, so it’s important to take your climate into account when shopping.

Heating capacity (BTU)

Propane heaters are able to deploy a certain about of heating power, listed in British Thermal Units. One BTU is enough to heat one pound of water by one degree.

Whole-house heaters need a capacity of at least 150,000 BTUs to ensure that they can keep the hot water running when multiple appliances are being used at the same time. Point-of-use devices, such as portable heaters, can function on around half that capacity.

Capacity and flow rate are closely related. They determine how much water a heater provides and how much energy they draw. Large heaters, such as the Rinnai Sensei series, have very high flow rates but draw up to 200,000 BTUs. Heaters like the Camplux, on the other hand, draw around 60,000 BTU, but can only supply a flow rate for a single outlet.


While electric tankless heaters are the most efficient type of heater available, propane units are often more energy-saving than natural gas options. Most propane tankless heaters achieve between 80-95% efficiency, with the best pushing 99%, deploying practically all of their fuel towards heating water.

Indoor or outdoor heater

Indoor tankless propane heaters can be as small as a piece of carry-on luggage, meaning they can fit inside cupboards and other small spaces. But they do need to be vented outdoors, as well as connected to the propane tank, which will likely be outside.

Outdoor and portable heaters don’t need special venting, and they often ignite using batteries rather than electricity, so the only input into your home is the hot water pipe. If you’re planning to install your heater outside, however, make sure it contains technology that protects it from freezing temperatures, wind, and rain.

Venting and installation

While it’s relatively easy to mount a tankless heater, installing gas lines and proper venting requires a good deal of DIY experience. When it comes to permanent propane tanks, professional help may be legally required, and heater companies will often extend your warranty if your heater is fitted by a certified pro.

Indoor heaters require venting to bring in air and expel carbon dioxide. It’s important to correctly vent your heater to avoid health risks—however, modern units have super low NOx emissions, making them safer and more environmentally friendly.

Warranty and other features

Look for manufacturers that offer warranties for at least 10 years on the heat exchanger. This ensures that the most critical component in your heater is covered for a good portion of its lifespan.

Depending on how and where you plan to use your tankless heater, you might want to look for some other specific features. For example, if you need a portable heater, consider units with simple propane hookups and lightweight designs.

Heaters that are installed in visible areas of the house might need child locks and an aesthetically friendly look. A programmable memory is often convenient in areas with big seasonal temperature changes.

Our top picks

1. Best propane Tankless Water Heater – Rinnai V65iP

  • Reviews: 4.6 out of 5 from 1,800+ global Amazon ratings

  • Capacity: 150,000 BTUs

  • Flow rate: Up to 6.5 GPM

  • Efficiency: 82%

  • Type: Whole-house Indoor

We think Rinnai’s V series heaters are the best tankless propane devices on the market right now—mostly because of their great balance of features and retail price. The Rinnai V65iP is designed for indoor installation in homes with 1 or 2 bathrooms and is the most popular heater in this line. The V65iP contains flow rate sensors that activate at just 0.26 GPM, which means the unit is able to detect small adjustments of hot water faucets or shower controls, so you won’t encounter annoyingly hot or cold bursts while bathing. With a maximum output of 6.5 GPM and a capacity of 150,000 BTU, it’s not the most powerful heater around, but can easily match the heating needs of the average household. It does this using Rinnai’s renowned copper elements and microprocessors, which achieve 82% efficiency, wasting very little propane. Rinnai offers a 10-year heat exchanger warranty on V series heaters, as well as wifi remote control and internal scale protection.

We recommend this heater for:

  • Smaller homes up to 2 bathrooms
  • High-efficiency propane heating
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Read our full review of the Rinnai V65iP

2. Best RV/camping propane heater – Camplux 10L Outdoor

  • Reviews: 4.6 out of 5 from 90+ global Amazon ratings

  • Capacity: 68,000 BTUs

  • Flow rate: Up to 2.64 GPM

  • Efficiency: 88.5%

  • Type: Point-of-use

The Camplux 10L Outdoor might just be our favorite road trip buddy. An awesome companion for RVs, camping expeditions, or even cabins and cottages, it produces 2.64 gallons of water per minute through its integrated shower attachment (or hose). While it can only handle 68,000 BTUs of propane, this is ample for single-use applications, and will provide plenty of hot water for bathing or washing down objects and pets. It ignites via batteries rather than a mains outlet, includes antifreeze and dry combustion protection, and has an Eco performance option to max out that 88.5% energy factor, helping preserve fuel when traveling. The Camplux outdoor line offers several heaters at different power points, with this 10L version being the most popular among Amazon customers.

We recommend this heater for:

  • RVs, boats, camping
  • Efficient heating on-the-go
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Or read our full review of the Camplux 10L Outdoor

3. Best for large homes – Rinnai RUR199iP

  • Reviews: 4.5 out of 5 from 430+ global Amazon ratings

  • Capacity: 199,000 BTUs

  • Flow rate: Up to 11 GPM

  • Efficiency: 96%

  • Type: Whole-house | Indoor

Considering it’s not much bigger than your average roller suitcase, the propane-fueled Rinnai RUR199iP is a specs beast, with a maximum flow rate of 11 GPM and a capacity of just under 200,000 BTU. This heating ability makes the RUR199iP the most powerful unit in the brand’s Sensei SE+ line, capable of running large households with over 3 bathrooms and multiple simultaneously running appliances. Rinnai supply this unit with their ThermaCirc360 technology, which is a recirculation pump that helps to efficiently deploy propane, so only 4% of the energy inputted is not converted into heat. The RUR199iP is also Energy Star certified, Wifi compatible, and comes with a huge 15-year warranty on the heat exchanger.

We recommend this heater for:

  • Super efficient heating
  • High power for large families and 3+ bathrooms
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Or read our full review of the RUR199iP

🔥Other popular Propane Tankless Heaters

Best budget propane heater – Marey GA10LP

As one of the most popular propane heaters currently on Amazon, the Marey GA10 packs a flow rate of 3.1 GPM and an energy factor of 87% into a simple, no-frills unit that we think is excellent value for money. The GA10 can’t match some of the more highly powered heaters on this page, but it should work well for apartments or single-use applications. It also uses a battery-powered ignition, so it’s a viable off-grid option.

Learn more at Amazon >

Runner up shower attachment – VIVO Outdoor Portable Water Heater

Like the Camplux 10L, this portable water heater from VIVO has an integrated shower and hose, so you can hook it up and start using it straight away. With a GPM of 1.6, it’s not the most powerful point-of-use heater around—however, it’s enough for quick showers or washing jobs while outside of the home, and we think its lower retail price makes the VIVO a worthwhile option.

Learn more at Amazon >

Sleek design for high footfall areas – Eccotemp i12-LP

As one of the best-looking tankless units we’ve seen, the Eccotemp i12 is worth considering if you need to install your heater in a more visible spot, such as the hallway or kitchen. This model has a respectable flow rate of 4 GPM, which is enough to run a small home. Its good looks are matched by a neat user interface, with an LED display and automatic temperature controls housed behind black tempered glass. There’s also an energy-saving mode and a child lock.

Learn more at Amazon >

Popular on a tight budget – VEVOR 12L Propane Hot Water Heater

While the Marey GA10 is our budget pick, the VEVOR 12L is another very popular value heater with Amazon shoppers, mostly thanks to its insanely low price. For just over $150, the VEVOR supplies 3.2GPM through a tin-plated copper heating element, which helps reduce rust and scale buildup. Despite its low price, the VEVOR also still achieves an energy factor of 80%.

Learn more at Amazon >

Hand Washing, Soap, Wash, Hygiene, Clean, FaucetBest Propane Tankless Water Heater – Buying guide

Calculating water usage needs

To work out how much hot water your home might need at any one time, survey how many water outlets are running simultaneously during your peak usage periods. This might be in the mornings when multiple people are showering, or in the evenings when the laundry machine and dishwasher are running while the kids take a bath.

Once you’ve noted down your peak usage period, check the flow rate of each outlet that’s being used. Some appliances will list their GPM requirement on their label, while you may need to perform a quick google search to find out others. For example, here are some common flow rates for household appliances.

To get a steady stream of hot water that won’t be affected when multiple outlets are turned on, you’ll need a tankless heater that can match your maximum GPM needs. Of course, the incoming flow rate for many homes won’t meet this number in the first place, so your heater may only be able to go so high.

How many GPM (flow rate) for a propane tankless hot water heater do I need?

  • If you live in a mild climate, in an apartment or small townhouse, a heater with a flow rate of 3-5 GPM will be adequate (for average usage habits).
  • If you live in a mild climate, in a small to mid-size home, a heater with a flow rate of 4-6.5 GPM will meet your needs (for average usage habits).
  • If you live in a mild climate, in a large home, or with a large family, look for a heater with a flow rate of 6-10 GPM (for average usage habits).
  • If you live in a colder climate, add 1-2.5 GPM to the above.

Water pressure

When choosing a propane tankless water heater, check the minimum and maximum water pressure requirements of each unit, as heaters need a certain incoming pressure to properly process your water.

If your incoming water pressure is too low for your heater (a common problem with well water), you may need to purchase and install an electric pump. A pressure regulator will help deal with an incoming pressure that’s too high.

How much propane does a tankless water heater use?

Most homes with tankless water heaters will use between 0.5 and 2 gallons of propane per day, leading to average annual propane needs of between expect to use somewhere between 200-700 gallons of propane per year for hot water.

This variance is mostly due to the number of people within the home, as well as the seasonal climate. A family of two may only use 10-15 gallons per month, whereas those with teenage or adult children may go through 40-55 gallons.

Temperature Rise

The difference between incoming and desired water temperature is often known as “temperature rise” and is a key factor in propane consumption. The bigger the temperature rise, the more energy a heater will need to deploy.

You can easily find out the temperature rise in your area by identifying your ideal water temperature and deducting the local groundwater temperature from that figure.

Most homes receive water that’s between 40 and 70 degrees. Here’s a heat map from Rinnai to help you estimate your local climate.

How long do 100 gallons of propane last?

When thinking about how much propane heaters need, it’s also important to consider heater efficiency. Most tankless heaters have efficiency levels between 80-95%, so your choice of product will affect how quickly you’ll go through 100 gallons.

Propane consumption also depends upon the types of appliances a heater is running. Taking a shower might cost you between 12,000 and 17,000 BTUs, and there are about 85-95,000 BTUs for every gallon of propane (again, depending upon efficiency). As a result, 100 gallons of propane could last for 500+ showers, if that was the only appliance you used.

Is propane cheaper than electric power?

In most areas, it’s currently cheaper to heat your water using propane than electricity—however, as we move towards a greener economy, this may not always be the case.

It’s also worth considering that electric tankless heaters are often slightly cheaper to buy and install than gas models, meaning that any propane bill savings are initially offset by the initial retail and installation price.

How to maintain a tankless propane water heater

All popular tankless water heaters are longer-lasting and more reliable than traditional tank water heaters. In fact, the US Department of Energy estimates the lifespan of tankless heaters and +20 years.

Hard water & flushing

To reach that full lifespan, heaters should be regularly maintained, with the most common job being to remove a buildup of scale from the heating elements. All copper heating coils are susceptible to scale, as they attract hard minerals like calcium and magnesium in water as they heat them.

Leaving scale around heating elements can drastically reduce heater performance. To remove it, you’ll need to use a circulating pump to run a descaling solution through the heater.

Descaling solutions are available at hardware stores, or you can make your own using vinegar or bleach.


Alongside scale buildups, heater components can begin to corrode, especially if incorrectly fitted. We recommend having a professional service your heater on a semi-regular basis, as they’ll be able to swap out any corroded parts before they seriously affect hot water function.

Modern Minimalist Bathroom, Bath, Bathtub, LuxuryFAQ – Best Propane Tankless Water Heater

How does a tankless water heater work?

Tankless water heaters are famous for “never running out” of water. They create the impression of an endless stream of heated water by sensing when you turn on a faucet of a water-drawing appliance. These flow sensors detect the draw of water and communicate with the propane ignition components via a simple microprocessor.

The heater then opens the gas valve, ignites the burner, and turns on a fan to compost the propane. The heat created is transferred to a heating element, which is most tankless heaters consists of several copper coils thanks to their efficient conductivity. Water is heated as it comes into contact with the heating element.

Finally, the heater will sense water temperature and release the water when it reaches the set level. Depending, upon the model, heaters may contain other technology, such as condensers, which capture emitted heat a redistribute via a secondary heating element to increase energy efficiency.

When the flow sensors detect that an outlet has been switched off, the heater shuts down, meaning that no hot water is wasted. This is in contrast to traditional tank heaters, which fill up large, built storage tanks with costly hot water, no matter the demand level within the home.

How big of a propane tank do I need for a tankless water heater?

​​Working out how much propane you need to power your heater is often a process of making several guesstimations. You need to take into account the flow rate, efficiency, and BTU capacity of your heater—as well as how hard the heater needs to work to bring your water to the desired temperature (temperature difference).

In general, however, 25-35 gallons of propane per month is usually considered sufficient for an average family, while two-person households may be able to get away with 15-20 gallons.

For those using whole-house propane heaters, permanent propane tanks can be installed, which are usually 100-500 gallons in size. These offer millions of BTUs in heating power and will last up to a year.

How much does it cost to install a propane tankless water heater?

According to the home advisor, tankless water heater installation costs range from $1,175 to $3,365, depending upon where you live and the complexity of your heating unit. When transitioning to a tankless heater from a traditional model, it’s worth checking for any tax incentives you may qualify for.

If you’re using your heater for point-of-use purposes (e.g. to run a single shower or sink), then the installation is likely to be cheaper and simpler. Installation may only cost $100-$300 in these cases.

What is the best propane tankless water heater for RVs?

We think the best propane heater for RVs and other outdoor or portable use is the Camplux 10L Outdoor.

We like this heater because of its small size and weight, as well as its integrated shower attachment. Reviews suggest the Camplux provides a steady flow rate that’s adequate for showering and other common needs, and is also able to use propane efficiently.

What is the best propane tankless hot water heater?

Based on our research, the Rinnai V65iP provides the best balance of price and features for most households. Here are the current most popular brands of propane tankless water heaters according to Amazon customers:

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