Best Off Grid Water Heater Systems Explained with Recommendations
It’s possible today to live entirely off grid without sacrificing any of the comfort provided by modern amenities. One of the most vital of these modern comforts is easy access to hot water.
For those new to the off grid lifestyle, it can be hard to figure out the best way to heat your water, but by the end of this article, you’ll be armed with enough information about the best off grid water heater systems to confidently decide which is the best option for you.
How to Compare Off Grid Water Heaters
As we discuss the various off grid hot water heater options, you’ll need to keep the following considerations at the front of your thoughts to help determine which system will work most efficiently for your particular situation.
How Is the Water Heated?
One of the most prominent differences between off grid water heaters is the fuel source and manner in which they heat the water.
This is the oldest way of heating water, and it still works just as well today as ever before. If you put a container of water over a fire, you will eventually have hot water!
Propane water heaters also use fire to heat water, but they do so in a much more modern and controlled way, often with easy to use dials, ignitions, and safety features. These run on standard propane that can be used from small one pound canisters or larger 10+ pound canisters with the right adapters.
The downside to propane is that it’s not 100% off grid. You can’t produce it at home and you’ll have to purchase it from somewhere, but it’s still a good compromise to provide comfort amenities without your home being tied to utility companies.
We all enjoy swimming in the summer and not the winter because of what a great heat source the sun is. You can still harness that power today to heat your water, you just have to be a bit creative.
Electricity is one of the least efficient methods of heating water off grid. Electric water heaters require a lot of power to run, but the smallest units can still be manageable for off grid homes with substantial electrical storage and production capacity.
Biogas is an entirely natural fuel created by harnessing the power of composting organic material. What’s great about biogas is you can create it yourself, which makes it infinitely renewable and sustainable. However, it does take a lot of organic waste to produce, so this is best for families that either grow a lot of crops or have plenty of waste from raising animals.
How Much Hot Water Do You Need?
Everyone’s needs are different, and it’s important to consider what your needs really are before making a decision about which water heater to use for your off grid home.
A single person requires far less hot water than a whole family.
Similarly, a home with just one bathroom requires far less hot water than a home with three bathrooms.
Think about what you’ll use the water for as well. Is it just for showering? Or will you also use it for washing dishes, clothes, and more? Will these activities ever be done simultaneously, or will you only be using hot water for one task at a time?
If you’ll be sending hot water to multiple faucets or there’s a chance that hot water will be needed in several places at once, you’ll need a much larger supply of hot water than a home where the hot water is used solely for a single shower.
Some people have no problem working for their hot water every time they want a shower. Others will expect the convenience of on-demand hot water in their off grid home.
Neither way is wrong, but if you want convenience, then it’s going to rule out a few options like wood stove water heaters.
8 Types of Off Grid Water Heating Systems
From solar powered to electric and including everything in between, these eight options are the best off grid hot water systems available.
Tankless Portable Propane Water Heater
For the ultimate in convenience, the tankless portable propane water heater can be used just about anywhere. It’s small, portable, and can be easily hooked up to large propane cylinders or the small one-pound bottles.
With no water tank to warm up, your water is warmed on-demand. When you start to run the water, the heater kicks on and immediately heats the expelled water to the desired temperature. It takes all of about five seconds for that warm water to make it out of the line and provide you with comfortable water for showering.
This is definitely the best choice if your primary concern is hot water for a shower. Most models even include a shower head with an on/off switch (valuable for conserving water), so it’s practically an all-in-one solution.
Tankless Portable Propane Instant Water Heater
- LED display shows exact temperature
- Provides instant hot water on demand
- Tankless design is extremely efficient
- Includes showerhead with on/off switch
I personally have this Foruee model, as you can see from the photo. I use it strictly for showering, and a single one-pound propane canister lasts me months of daily showers.
It says outdoor, but I’ve used mine inside for nearly a year and never had an issue. Just make sure not to keep anything flammable near the front or sides, as per the instruction manual. I also keep a vent open when I use it, just in case!
Tankless Indoor Propane Water Heater
For anyone who’s in need of a water-heating solution that can meet the hot water demands of a larger home, a tankless indoor propane water heater is a great option.
These are designed to be permanently installed and can provide large volumes of hot water in an instant.
Since there’s no tank, these water heaters only use energy when you need hot water. They’re dormant the rest of the time, making them a very efficient way to fuel an entire home’s hot water needs.
On the downside, these are a bit pricey, and installation will probably cost even more. You’ll likely need to have this installed while your home is being built since the hot water pipes will need to be routed from this heater to each faucet in your home.
The Rinnai line of tankless indoor propane water heaters is a great choice, with models delivering up to 9.8 gallons per minute(GPM) of hot water. If you don’t need that much, they offer models with outputs as low as 5.3 GPM to meet any home’s water demands.
Propane Water Heater with Tank
An alternative to a tankless propane water heater is one with a holding tank. The water in the tank is kept at a constant warm temperature for use when you need it.
These do work, but they’re extremely inefficient, especially compared with on-demand propane water heaters that only burn fuel when you’re actively using hot water.
Many older RVs are already equipped with propane water heaters that have holding tanks. If you’re in such a situation, you might consider upgrading to a tankless design to reduce the amount of propane you go through.
For those who don’t currently have a tanked water heater, I would recommend skipping these and going with a tankless model instead, if you decide that propane is the right fuel source for your off grid water heating needs.
Barrel Over Fire
This is an undoubtedly primitive option, but it is an option nonetheless.
The most basic way to get hot water is to simply fill a metal barrel, tub, stock tank, or any similar holding device with water and place it over a fire.
You could be more elaborate with your setup, but it still follows the same basic premise.
Just make sure you mix the boiling hot water with cooler water to find the right temperature before you jump in for a bath! Also, only use a metal container. A plastic barrel will obviously melt!
Wood Stove Water Heaters
Wood stove heaters use the heat from a wood stove or similar heat source that’s already keeping the house warm to heat your water..
One way to do this is by taking a water pipe and wrapping it around the heat source, in this case the vent pipe coming from the wood stove. This device works by convection. The colder water at the bottom of your holding tank gets pulled in as the heat forces the water in the pipe to rise.
For this to work, you must have a wood stove or pellet stove installed for heating.
It’s not a very complex system, and if you already have a wood stove, it’s a great way to heat water whenever it’s running, without using any additional fuel or energy.
However, you are limited in that you probably won’t want to keep the wood stove stoked during the summer, which means no hot water! You’ll have to choose an alternative method during those warmer months.
Solar Water Heaters
Off grid homes can use solar for many things, including electricity, heating, and water heating.
Solar air heaters use the sun to heat air that can be used to keep your home warm, and solar water heaters can do the same basic thing with water.
Essentially, solar water heaters hold water in large tubes on your roof. The sun heats these tubes, and then the water is delivered into a holding tank inside.
A solar water heater can be used to augment other heat sources and reduce the amount of fuel needed. In some cases, you may even be able to use solar water heaters as your sole source of water heating, but you’ll need to have large heating tanks to accommodate that much water.
You can purchase solar water heaters, but they’re very large and expensive.
Another option is to build your own, and they’re not all that complicated.
You can recycle an old water heater that you can find for free at landfills and appliance shops. They’re difficult to dispose of and nobody wants them, so they’ll be happy to offload one to you!
Strip the heater down to just the holding tank. Secure it inside of a wooden box with reflective material lining it to focus the heat on the holding tank. You’ll need to connect hoses to the tank that run into and out of the box. Finally, install a piece of glass or a clear acrylic panel on the top and fill it with water. The sun will heat the tank and when you pump the water from the other side, it will be scorching hot. Be careful not to burn yourself!
You can have the tank empty into an existing water heater’s holding tank, or hook the tank into your whole system and have all your hot water pull directly from the tank.
Another type of DIY solar water heater that’s great for off grid homes involves coiling water pipes inside a clear case where the sun can heat them.
Point of Use Electric Water Heaters
In general, electric water heaters are a poor choice for off grid homes. They’re not efficient and they pull a lot of power. More power than many off grid dwellings can supply.
That doesn’t mean you have to completely overlook electric water heaters for off grid applications though.
Some small point-of-use electric water heaters use between 1400 and 2000 watts, which many personal microgrids are capable of supplying.
I do recommend, however, that you double check how much capacity your battery bank offers and ensure that such a high-wattage device won’t use more electricity than you have to spare.
Also, consider the power output of your inverter, which must also be sufficient to supply that much power since these units utilize 120-volt electricity.
The unfortunate issue with these small electric water heaters, at least when it comes to using them off grid, is that they’re not tankless. Their tanks are quite small, so not much liquid is kept heated, but there is a tank that will remain heated all day, wasting lots of precious electricity. If you’ve got the battery bank to handle that sort of drain, then it won’t be a problem. For most homes that aren’t grid tied, this is probably too much electricity to spare.
One way to circumvent this issue is to leave the heater unplugged until before you need it, plugging it to allow the tank to heat up when you’re ready to use it. But this isn’t the most convenient way to live. Moreover, some models can take quite a long time to heat the entire tank, even if it is small.
But if your heart is set on an electric water heater, I’d recommend this line from Camplux. They use 1440 watts, and you can choose tank sizes from 1.3 gallons up to 6.5 gallons to fit your needs.
Camplux Mini Tank Electric Water Heater
- Small tanks from 1.3-6.5 gallons
- Uses just 1440 watts
- Compact size easily fits under cabinets
- Adjustable temperature with overheat protection
Biogas Water Heating
Biogas is a natural gas similar to propane, only it cures the main issue with propane; you can make biogas at home! It’s actually pretty simple to do with 55-gallon barrels and compost.
The compost creates the biogas, which is then transferred into another container for use.
You can use food scraps and other biomaterial, but compost is what works best for making biogas.
Unfortunately, it takes quite a lot of biomaterial to create enough biogas to heat all of your home’s water, so this options is best for homesteads that raise livestock or grow a lot of crops.
If you decide to use biogas, propane appliances can often be retrofitted for use with biogas by drilling out the nozzles, but do this at your own risk!
Check out this video for more information about how biogas works.
What Is the Best Off Grid Water Heater?
Which off grid water heating system is best depends on the situation it will be used for.
If you’re a single person just looking to take hot showers in your off grid home, then I would recommend the portable propane water heater or a DIY solar air heater. A larger home for a whole family may require a sizable indoor propane water heater to provide hot water to multiple fixtures. If you’re already using a wood stove to heat your home, I would suggest harnessing its heat in the winter to warm your water, but that’s not a great solution in the summer when you’ll need to switch to a propane heater or start heating your water outside to prevent overheating your home, if you’re going to continue using fire.
An off grid water heater can vastly improve your quality of life when your home isn’t grid tied. Without a way to take warm showers, you aren’t living in the modern world!
When you’re living off grid, you have to think about keeping more than just your water warm though, especially as the colder months set in. Make sure to check out our guide to off grid heating so you can stay toasty all winter long.