If you’re anything like me, no day feels quite right without a nice hot shower to start it off with.

For tiny dwellers and others living off the grid, finding the best way to heat water can be a bit daunting. Most of the water heaters you would use in a traditional home simply won’t cut it for a tiny home.

That’s why we put this comprehensive guide together.

In our guide below, you will find our rankings for the top 7 tiny house water heaters so you can easily determine which one is best for your needs and budget. 

For those who want a quick overview, below is our comparison table:

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Our Pick For the Overall Best Tiny House Water Heater: Rinnai RL Series HE+ Tankless Hot Water Heater

Tankless Water Heater
Our rating
Rinnai RL Series HE+
Rinnai RL Series HE+
  • Best overall water heater for tiny homes
  • Provides hot water instantly
  • Multiple can use simultaneously
  • uses 40% less water than traditional tanks
  • Comes with a 10-year warranty
  • About the size of a carryon suitcase
Our Rating
Our #1 Rated (For Best Overall Pick)
5 out of 5

The Rinnai RL Series HE+ Rl75EP is a propane-powered tankless water heater. It’s designed to provide all the water needed for a two- to three-bedroom home, plenty for use in a tiny home or off-grid cabin.

It provides 7.5 GPM (gallons per minute) of instant-on hot water and has a number of really cool features. To start with, it’s possible to program the heater to warm the water in your pipes at the optimal times for your schedule. 

Rinnai RL Series HE+

This allows you to have truly instant hot water when you go to take a shower, wash dishes or relax in a hot bath. You can even connect it to your home Wifi for easier programming.

It’s designed to be mounted externally to allow for safe and effective venting. For a tiny house, this is a great way to free up some extra space inside your home. 

Rinnai RL Series HE+ Review

For those living in a tiny home or off the grid, I can’t suggest the Rinnai Rl75EP enough. 

Our #2 Rated Tiny House Water Heater: Rheem RTG-84XLN-1 (Best For Cold Winter Climates)

Tankless Water Heater
Our rating
Rheem RTG-84XLN-1
Rheem RTG-84XLN-1
  • Rated to -30°F for safe use in very cold winter climates
  • Rated for use with up to three bathrooms, plenty for a tiny home
  • Hot Start Programming allows truly instant hot water
  • Great for use off-the-grid
  • Powered by tanked propane
  • Meets SCAQMD safety standards with an ultra-low NOx burner
Our Rating
Our #2 Rated
4.8 out of 5

The Rheem RTG series of instant water heaters are mid-efficiency condensing water heaters designed for instant and continuous hot water.

They run on propane and offer great features for the tiny dweller, both on and off the grid.

Just two feet tall and a little over a foot wide, the Rheem RTG installs easily on the front or back of your tiny home or cabin. It requires outdoor installation, something I generally recommend for tiny dwellers.

Having your water heater outside your home helps you save space on the inside for storage or use as part of your bathroom space. 

Rheem RTG-84XLN-1

One thing I really loved was how resilient it is. The RTG functions perfectly all the way down to -30°F. If you’re planning on taking your tiny home to wintery locations, this is an absolute must.

It also means you can use the Rheem RTG even in cold climates for homesteads.

The RTG uses Rheem’s exclusive Hot Start Programming that constantly keeps the system in a state of readiness. This allows you to get truly instant hot water at the flip of a knob.

The Rheem RTG offers a good combination of features, durability, and temperature resistance. It’s a great option if you want a traditional hot water experience no matter where you find yourself.

Our #3 Rated Tiny House Water Heater: Rinnai V Series V65iP HE (Best For Most Advanced Features)

Tankless Water Heater
Our rating
Rinnai V Series V65iP HE
Rinnai V Series V65iP HE
  • Indoor installation allows for use in colder climates
  • Up to 6.5 GPM flow rate
  • Can be turned on and off from your phone to better fit your schedule and save on fuel costs
  • About the size of a carryon suitcase
  • SCAQMD safety standards approved
Our Rating
Our #3 Rated
4.5 out of 5

The Rinnai V series is an indoor line of propane-powered tankless water heaters. They offer some of the most advanced features on the market and are easy to fit into any tiny home or off-grid cabin design.

The V65iP comes Wifi ready out of the box and is fully programmable. You can set up timers, build daily schedules, and even put the system into vacation mode from a distance.

Rinnai V65IP Tankless Water Heater

This gives you considerable flexibility in how you use your hot water and can help you save even more on your energy costs.

It’s an indoor-only water heater and requires adequate venting. This cuts into your interior space a bit but does ensure that your water heater is well protected from winter conditions and other incidents that can occur on the outside of your home.

Rinnai V65IP Rewiew

Depending on the ambient temperature of your water, it can provide up to 6.5 gallons per minute of instant hot water. If you have colder water, you’ll get a lower flow since it takes longer for it to warm it up.

The Rinnai V65iP is an efficient and highly effective tankless water heater. It works well in tiny homes but does require interior installation, which is why it didn’t get a higher ranking on our list. 

Our #4 Rated Tiny House Water Heater:  The Camplux 5L (Best Budget Option)

Tankless Water Heater
Our rating
The Camplux 5L
The Camplux 5L
  • Portable design allows use indoors or outdoors
  • Includes a shower head hose
  • Provides up to 1.32 GPM flow rate
  • Can raise water temperature by up to 114.8 °F
  • Includes oxygen depletion safety shut off
  • Extremely compact and easy to move around
  • Powered by D-cell batteries
Our Rating
Our #4 Rated
4.3 out of 5

If you’re looking for the ultimate low profile tiny house water heater, the CampLux 5L may be the setup for you.

It’s designed for use in RVs and campsites to provide on-the-go hot water for showering.

It runs off propane and is designed with portable use in mind.

Camplux 5L 1.32 GPM

For the tiny dweller looking to travel, this can be a seriously nice feature. On cold winter days, you can shower indoors, while on beautiful summer nights you can shower under the open sky.

Even better, the little power it uses comes from D-cell batteries. You end up with a fully functional water heater that requires no wiring and no plumbing.

There are a couple of things to keep in mind though.

The Camplux 5L isn’t going to be permanently plumbed into your home. It’s basically a camping water heater that can be hooked up to a hose or tap and quickly heat water.

Camplux 5L 1.32 GPM Amazon Rating

It has a much lower flow rate than the other water heaters on this list and definitely won’t be sending water to multiple taps at once. 

As long as you’re aware of what you’re getting into though, it can be an ideal choice.

It offers one of the most affordable ways to get hot water for bathing and cleanup in a tiny home. Just don’t expect to get traditional home levels of performance.

Our #5 Rated Tiny House Water Heater: Eccotemp i12-LP Tankless Water Heater 

Tankless Water Heater
Our rating
Eccotemp i12-LP Tankless Water Heater
Eccotemp i12-LP Tankless Water Heater
  • Runs on propane
  • Plugs into a standard wall outlet
  • Digital display makes power button and temperature controls easy to use
  • Sleek tempered glass look
  • Can be installed indoors with proper venting
  • Uses just 1.07 amps when in operation
Our Rating
Our #5 Rated
4.1 out of 5

The Eccotemp i12-LP is a propane-powered tankless water heater designed for use in a small space. It can produce up to 4.8 GPM of hot water depending on conditions and draws just 1.07 amps.

One of the best things about the i12-LP is how easy it is to install and use. It comes with a stainless steel venting vent kit and plugs into a standard outlet rather than requiring hard wiring.

Eccotemp i12-LP water heater

The control surface is made of tempered glass and allows you to instantly adjust the temperature, turn the unit on and off, and set a child lock. This makes it easy to adjust the system exactly to your liking.

The combination of low power draw, easy installation, and effective water heating makes the Eccotemp i12-LP one of the better water heaters for tiny homes and off-grid living.

Eccotemp i12-LP Rewiew

Our #6 Rated Tiny House Water Heater: Camplux Pro 26L Tankless Water Heater

Tankless Water Heater
Our rating
Camplux Pro 26L Tankless Water Heater
Camplux Pro 26L Tankless Water Heater
  • Designed for exterior installation
  • Provides up to 6.86 GPM flow rate
  • Includes automatic heating device to protect against cold temperatures
  • Produces low NOx emissions
Our Rating
Our #6 Rated
4 out of 5

The Camplux Pro is a higher capacity version of the popular portable Camplux outdoor propane water heater. It’s designed for permanent installation on the exterior of your house and has a maximum flow rate of 6.86 GPM.

It includes a digital control on a 3.3 ft cable that allows you to adjust the temperature from the comfort of your home. Because of its high flow rate, it’s capable of providing water to multiple taps simultaneously.

Camplux Pro

Our #7 Rated Tiny House Water Heater: Stiebel Eltron Tempra 12 Plus Tankless Electric

Tankless Water Heater
Our rating
Stiebel Eltron Tempra 12 Plus Tankless Electric
Stiebel Eltron Tempra 12 Plus Tankless Electric
  • Engineered in Germany 
  • Operates silently and without the need for venting 
  • Highly durable and corrosion-resistant copper tubing
  • Advanced Flow Control system maintains constant temperature and flow rate over time
Our Rating
Our #7 Rated
3.9 out of 5

The Stiebel Eltron Tempra 12 is an electrically powered tankless water heater. It can heat water up to 140°F depending on your groundwater temperature.

It uses corrosion-resistant copper tubing that offers maximum reliability and near-silent operation. Water temperature and flow are monitored via their Advanced Flow Control system to maintain a consistent temperature and flow rate.

Stiebel Eltron

The Tempra 12 runs entirely on electric power. It requires 12 kW and at least 100 amps of electric service. That’s way too much to run on an affordable home solar system.

If your tiny home is grid-connected, though, the Tempra 12 is a viable and affordable option.

Tankless Water Heaters vs Traditional Hot Water Heaters 

One of the biggest decisions to make with a tiny house water heater is whether to go tankless or not. Traditional water heaters have a water storage tank that is kept at a constant temperature.

These give you a reservoir of hot water to draw on when you need it. The downside to this is that they draw power/gas continuously and take up a pretty large footprint. Plus, water is heavy, so you need to cite a tank water heater in a reinforced area that’s balanced with the rest of your home.

Tankless water heaters, also known as instantaneous hot water units, are a relatively new invention. They use an instant heating system that provides on-demand hot water.

They’re much smaller, lighter, and easier to install than traditional water heaters and take up a much smaller footprint. Because they rely on an instant design they also offer significant energy savings.

For tiny dwellers who choose to go with an off-grid solar system, this is a major consideration. 

For me, this one’s pretty much a no-brainer. Tankless water heaters are smaller, lighter, and require less energy.

Propane/Natural Gas Water Heaters vs Electric Water Heaters

The next big decision to make is whether to go with an electric water heater or a gas one. There are good options available in both tankless and traditional water heaters that run on either source of power.

Electric Water Heaters

Electric water heaters are generally cheaper upfront but cost more to operate on a day to day basis. They also take longer on average to heat water than a similar gas water heater.

If you’re grid-connected this can be an acceptable tradeoff, but not if you’re off-grid. The average electric hot water heater draws 4,000 watts per hour. That’s just not attainable on a reasonably sized off-grid solar system.

Pretty much the only major benefit electric water heaters offer is safety. There’s no chance for a gas leak with an electric water heater. So long as a gas heater is properly installed, this is a minuscule risk, but still, something to keep in mind.

Gas/Propane Water Heaters

Gas/propane water heaters are more expensive upfront but cost less to operate. Some still require a small amount of power to operate but others are designed to run entirely without power.

There are models designed to run on natural gas, propane or both. This gives you considerable flexibility in both on and off-grid situations. For THOW’s a propane water heater is probably going to be your best overall choice.

It allows you to carry substantial fuel storage in a very small space. This is especially beneficial if you plan to spend substantial amounts of time off-grid.

Alternative Water Heating Options 

If you’re looking for really sustainable options there are several other ways you can heat water for your tiny home.

Solar Water Heater 

Solar water heaters also called solar domestic water heaters, use the heat of the sun to passively warm water. They come in a variety of different forms but generally require both a solar collector and an insulated water storage tank.

Under the right conditions, they’re able to provide comfortably hot water on demand. It’s relying on those ‘right conditions’ that becomes the problem.

Thus, on cloudy or cold days solar water heaters just don’t work. In these situations, having a backup water heater is a must. 

Wood Water Heater

If you want to go really old school you can buy or build a wood fired water heater. In the most basic cases, this is just a large kettle or pot suspended over a wood fire.

More advanced models use a series of copper coils to circulate water through convection. If you have substantial wood resources and are willing to put in the time this can be a low-cost and sustainable option for heating water.

It definitely doesn’t offer the instant-on convenience of traditional water heaters though.

Exterior vs Interior Installation

One of the most important things to keep in mind is how your tiny house water heater can be installed. Some units, especially propane or natural gas ones, can only be installed on the exterior of your home.

This can be a space-saving measure but you need to make sure it can handle your local climate. Those who live in areas with seriously cold winters need to get a water heater that’s rated for their climate.

Interior units are generally smaller. Some are actually designed to provide water for a single tap, usually a shower.

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Full Home Water Heater or Tap Mounted Instant Water Heater

Depending on your needs you may be able to get away with a tap mounted instant water heater. These water heaters are hooked directly onto a single tap and provide instant hot water.

The benefit of these is their substantially lower cost and the lack of any pipe temperature loss. The downside is that they generally provide very low water flow and often have limited use times before a cool-down period.

They’re only available electrically powered, and some people don’t like the idea of electricity right next to their shower tap.

Josh Davidson

Josh is a freelance writer and avid outdoorsman. He graduated from the University of Georgia with a B.A. in Political Science and has done his best since to live location-independent. He's been a firm supporter of the tiny movement, new homesteaders, and sustainable alternative living and used his knowledge of these topics to convert a 1999 Dodge Ram van to explore as much of Wild America as he could reach.

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