Best RV Tankless Water Heater in 2019 (Top 5 Reviews with Comparison)

Whether you’re in your house or your RV, you’ll be using a lot of water.

Cooking, drinking, and showering are all an essential part of everyday life, which means that water is integral to your daily habits and lifestyle.

In an RV, however, because all of the water onboard is put there, you have to be careful how you use it.

Nonetheless, one thing that you’ll need along with the water itself is a water heater.

Unfortunately, because space is always limited in your rig, having a bulky water heater isn’t usually the best idea.

Instead, many RVers choose to have a tankless unit so that they can get access to hot water while saving room and energy at the same time.

So, with that in mind, we want to take a look at the best RV tankless water heaters and see how they can improve life inside your rig.

COMPARISON CHART

IMAGEPRODUCT
 Rinnai RUC98iN review1. Rinnai RUC98iN
  • 199,000 BTU Rating
  • Ultra-Low Emissions
  • 96% Energy Efficiency
  • Rugged construction
LEARN MORE
 Camplux 5L review2. Camplux 5L 1.32 GPM
  • Max 114-Degree Heat
  • Flame failure device
  • Low Water Pressure Rating
  • Built-In Safety Protections
LEARN MORE
 Takagi T-KJr2-IN-NG review3. Takagi T-KJr2-IN-NG
  • High-BTU rating
  • Energy-efficient design
  • Gets water hot insanely fast
  • Only needs 6.6 gallons of pressure
LEARN MORE
 Eccotemp FVI12-LP review4. Eccotemp FVI12-LP
  • Activates at 3.6 GPM
  • Low noise output
  • Digital Temperature Display
  • Safe Electronic Ignition System
LEARN MORE

OUR TOP 5 PICKS

#1 Rinnai RUC98iN

 Rinnai RUC98iN review

Specifications

Weight

82 pounds

Product Dimensions

10 x 18.5 x 26 inches

Size

Twin Pipe/Ultra

Flow Rate

9.8 GPM

Water Consumption

9.8 gallons

Features

  • 199,000 BTU Rating
  • 96% Energy Efficiency
  • Compact design
  • Ultra-Low Emissions
  • Rugged construction
  • Durable

Once again, we’re looking at a standard indoor tankless water heater that can be converted for use inside an RV. However, this is one of the best models you can find on the market regardless, meaning that it’s worth the extra cost and installation parameters.

199,000 BTU Rating

When comparing different tankless water heaters, you want to be sure that you’re getting more than enough power for your money. Although this is one of the more expensive options out there, with a BTU rating of up to 199,000, you can be sure that it’s worth every penny.

To put it into perspective, you can get your water up to 140 degrees F, making this one of the most potent water heaters we’ve seen.

Ultra-Low Emissions

As with any standard tankless water heater, you need to make sure that you install it correctly, including with the proper ventilation so that you don’t breathe propane while taking a shower or washing the dishes.

Fortunately, this model from Rinnai has one of the lowest emission ratings you can find. Even if you don’t have the best ventilation, this model is so well built that you can still use it safely.

That being said, always strive for as much ventilation as possible. Low emissions aren’t the same as no emissions, and oxygen deprivation is a serious issue if it does occur.

96% Energy Efficiency

Even when comparing this tankless water heater to something built for RVs specifically, this unit may still be the better choice when it comes to energy usage.

With a 96% efficiency rating, this is one of the best tankless water heaters you can find. In fact, you may want to get two - one for your RV and another for your home.

  • WHAT WE LIKE
  • WHAT WE DON’T LIKE
  • PROS/CONS OVERVIEW

This is one of the most well-built and functional tankless water heaters on the market for RVs or otherwise. With low emissions, durable construction, and a highly efficient operating system, you’ll be glad that you installed this heater into your RV.

Video

#2 Camplux 5L 1.32 GPM

 Camplux 5L review

Specifications

Weight

10.8 pounds

Product Dimensions

11.4 x 5.5 x 14.6 inches

Size

pack of 1

Flow Rate

1.32 GPM

Features

  • Max 114-Degree Heat
  • Low Water Pressure Rating
  • Oxygen depletion shutoff sensor
  • Flame failure device
  • Built-In Safety Protections
  • Energy-saving design

Technically speaking, this water heater is designed as a camping model, meaning that it’s usually supposed to be portable. However, it does come with a wall mounting bracket, and it can work for some RVs, so if you’re up for a bit of a complex installation process, this unit can serve you well.

Low Water Pressure Rating

One of the things that you’ll realize about installing an RV tankless water heater is that you won’t have access to high-pressure water systems like you do at home. Since RVs have limited capacity, they restrict your water usage to ensure that you don’t run out after your first shower.

Fortunately, since this is a portable camping model, it has one of the lowest water pressure ratings on the market. It can operate with as little as 10 PSI and 1.2 gallons per minute of flow.

Simply put, it doesn’t take much to activate this tankless heater, which helps you save time and money in the process.

Max 114-Degree Heat

Don’t let this water heater’s size fool you - it’s still more than capable of delivering a piping hot shower. It has a temperature range of 48 to 114 degrees Fahrenheit, so if you like a toasty bathing experience, it can provide that in spades.

Built-In Safety Protections

One issue that comes from having a water heater on board your RV is that you have to rely on propane and fire to make it work. Also, because you’re in such a cramped space, you want to make sure that you’re not going to run into potential safety issues like fire hazards.

Thankfully, this heater has built-in protections to keep you and your family safe. First, it has a system that shuts off the whole thing if the flame goes out for any reason. Since you don’t want to suck down propane fumes, that can help save your life.

Speaking of breathing propane, there is an oxygen deprivation sensor in this heater as well. If, for whatever reason, the heater belches out too much propane, it will shut off automatically so that you don’t risk suffocation.

Finally, because you might be camping in some cold locations, this heater has anti-freezing protections as well.

  • WHAT WE LIKE
  • WHAT WE DON’T LIKE
  • PROS/CONS OVERVIEW

Because this is a camping water heater, making it work inside your RV can be a bit tricky to do. However, I appreciate the energy-saving design of this machine, as well as its built-in safety protocols. Also, the fact that you can light it with D batteries if necessary is a bonus.

Video

#3 Takagi T-KJr2-IN-NG

 Takagi T-KJr2-IN-NG review

Specifications

Weight

37 pounds

Product Dimensions

6.7 x 13.8 x 20.3 inches

Size

-1

Flow Rate

6.6 GPM max

Features

  • High-BTU rating
  • Gets water hot insanely fast
  • Relatively easy to install
  • Energy-efficient design
  • Only needs 6.6 gallons of pressure
  • Lightweight and compact design

As you’ll discover when comparing different tankless water heaters, not all of them are explicitly designed for RVs. Thus, if you do decide to get a model that is technically made for apartments or homes (like this one), you’ll want to make sure that it will work in your RV.

Pay close attention to things like flow rate (measured in gallons) and power requirements. If they exceed what your RV has to offer, then it won’t work, no matter how well you install it.

140,000 BTU Rating

Because this water heater is built for indoor use, it comes with all of the features you would expect for something inside your home.

Case in point, the heat level on this model is insane when compared to standard RV-type water heaters. With 140,000 BTUs, you can get your shower or faucet piping hot in much less time.

That being said, be aware of how quickly this can happen since it could pose a safety issue for you and your family. Don’t scald yourself because of this heater - be aware of its potential before installing it.

Inlet and Outlet Thermistors

One issue that plagues many compact tankless water heaters is that the temperature can be inconsistent. Fortunately, this model has thermistors and sensors on both the inlet and the outlet so that you can be sure it will stay the same at all times.

Energy-Efficient Design

Usually, I wouldn’t recommend installing an indoor tankless water heater into your RV, but since this model is so energy efficient and compact, it can work for many Class A motorhomes, as long as you know what you’re doing when installing it.

  • WHAT WE LIKE
  • WHAT WE DON’T LIKE
  • PROS/CONS OVERVIEW

Because this model isn’t made for RVs, it’s much more powerful and resilient than most water heaters that are. If you’re looking for power and performance, you’ve come to the right place.

Video

#4 Eccotemp FVI12-LP

 Eccotemp FVI12-LP review

Specifications

Weight

29.4 pounds

Product Dimensions

28 x 17 x 10.5 inches

Size

11-50 Gallons

Flow Rate

3.5 GPM

Features

  • Activates at 3.6 GPM
  • Digital Temperature Display
  • Fast and easy installation
  • Low noise output
  • Safe Electronic Ignition System
  • Highly efficient energy usage

As the name suggests, this next tankless water heater is economical and energy efficient. Best of all, it’s perfect for those who are on a budget since it costs way less than most other models in its class.

That being said, this is another standard indoor model that has to be converted for RV usage, so still be prepared for professional installation when putting it into your rig.

Activates at 3.6 GPM

Although this model doesn’t have the lowest water-pressure rating, it’s more than low enough for most mid to large-size RVs. Since it will activate at just 3.6 gallons, it’s an ideal choice for many RVers who value economy over power.

Digital Temperature Display

Depending on where you install this tankless water heater, you may really appreciate the fact that you can see what the temperature is at any given time. Best of all, you can adjust the heat level accordingly, based on your needs and how much power you have at any given time.

Safe Electronic Ignition System

Whereas other tankless water heaters ignite via manual or analog systems, this unit from Eccotemp uses electricity. Not only is this version more reliable, but it’s much safer for you and your family as well.

  • WHAT WE LIKE
  • WHAT WE DON’T LIKE
  • PROS/CONS OVERVIEW

If you’re going to install a standard tankless water heater into your RV, then you might as well use a model that is both energy efficient and lightweight. Fortunately, this model from Eccotemp is both (and more).

Video

BUYER'S GUIDE

Because having a tankless water heater in your rig can be such a rewarding experience, you want to make sure that you’re doing everything correctly. Also, since most RVs aren’t equipped with tankless heaters, you need to be ready for any complications that may arise during installation.

With that in mind, I wanted to go over some of the more crucial elements to consider before putting a tankless water heater into your RV.

Estimate Your Current Water Consumption

The first question you have to ask yourself is - do I need a tankless heater in the first place? Yes, these models provide a ton of benefits, from energy efficiency to economy of space. However, if you’re not using that much water to begin with, installing a new heater may be unnecessary.

Thus, before you proceed with anything, you should monitor your water use habits. Also, consider the difference between RVing full time vs. going out for vacation once or twice a year.

In the latter situation, it may be better to forgo a complicated installation process since you don’t use your RV that much. If you’re a full-timer, however, then a tankless unit may be the perfect solution for your rig.

I would suggest monitoring your water usage for at least a week or more before deciding on the right water heater unit. Also, keep in mind how much pressure your system needs as well, as that will limit which heaters you can put into your rig.

Do I have to use the shower head or is it okay to connect directly to the hot water side of a faucet?

With some portable water heaters (like the Camplux at the top of the list), they come with a shower head, not a standard water connector.

If you do decide to go with a portable model like that, you can usually decouple the shower head and connect the hose directly into your RV’s water system.

However, if you mostly need a new tankless heater for your showers (instead of cooking and cleaning), then it may be better to keep the shower head on instead. This way, you can attach the heater to your shower directly and keep the old unit installed for the rest of your RV.

While this tactic won’t save space in the long run, it could be much more efficient, not to mention much easier to implement.

Can I install a tankless water heater under an RV sink?

The short answer is yes, but the long answer is “it depends.” Because the space underneath your sink may be limited, some water heaters might be too large or bulky to install there.

However, if the model does fit, then you can usually benefit by putting the water heater next to the source that will use it the most.

Thus, if you’re mostly looking for a new RV tankless water heater for your shower, installing it under the sink is probably not the best option. However, if that’s the only place that works, keep in mind that the water temperature can fluctuate the longer the distance is between the heater and the output.

How to convert RV water heater to tankless?

Technically speaking, you don’t want to try and convert your RV to tankless by yourself. Instead, I highly recommend consulting with a professional beforehand for both safety and efficiency reasons.

Considering that you may be installing a standard indoor tankless water heater, consulting with a pro means that you can be sure that you won’t run into potential issues. Even if you’ve carefully calculated your water pressure and energy needs, there’s no guarantee that the model you’ve chosen will be compatible.

Overall, you want to be extra cautious and take your time when converting your RV. Also, if you’re not inside your rig that often, it may be too much of a hassle to do it anyway.

CONCLUSION

We’ve looked at some high-quality RV tankless water heaters, but I have to say that my favorite thus far was the Rinnai model. Although it’s relatively costly, it offers the best features of anything else on this list.

Low emissions, high energy efficiency, and one of the best BTU ratings are just a few of the reasons why I love this tankless heater.

However, if you’re more budget-minded, the highly portable Camplux Water Heater is by far the best way to go, especially if you’re looking for a quick and dirty way to improve the quality of your showers.

Last Updated on September 6, 2019