In A Rush? Here's our winner
What’s the worst part about living in an RV? Well, probably the cramped living space when you have 3-4 people in one small area. But the second worst thing, hands down, is the hot water situation.
Coming back to your camper after a long, hot, sweaty day and realizing you’re going to need to wait an hour or more for the liquid to heat up so you can shower? Terrible. It is even worse if you drew the short straw and had to wait until everyone else is done to get clean.
That’s when you start thinking that installing a tankless heater might be the best idea you’ve ever had. But where do you start? There’s a ton of options on the market, and it’s hard to find the right information you need to start looking for the right unit. So let’s break down real quick the things you want to look for in any model, and the extra stuff you need to keep in mind.
How to choose
The best ones are going to cost you a pretty penny, at least if you plan to live out of your mobile home. We’re looking at an average of $500 to $1000, though we’ll be looking at some reasonable stopgap measures and cheap-ish portable options today as well.
On the bright side, they’re all cheaper than what you’d buy for a full-sized house, some of which can run you close to $2500 without factoring in installation.
That reminds me; all prices listed are without professional installation. While it is possible to install them yourself, I do urge you to consider getting a professional install. In almost all of these cases you’re dealing with something that runs on propane gas, and improper installation can lead to catastrophe.
It stands for “British Thermal Unit” and is what these products will list their heating capacity at, or will list them in BTUh (BTU per hour). For a simplified explanation, 1 BTU is enough to raise 1 lb. of water 1 degree, and a gallon of water is 8.3 lbs, so every 8.3 BTUs can increase the temperature of a gallon of water by 1 degree.
It will help you calculate how much heat you’re going to need based on where you’re traveling since groundwater temperature varies by location. Most of these models have an issue heating very cold groundwater, so keep that in mind.
Most of the products are going to hover in the 30k to 50k BTUh range, which is much smaller than most home units (that average about 140k to 199k) due to the size and power constraints. In other words, don’t be disappointed if you can’t quite match the flow and heat you’ve come to expect from a shower at home; your goal is to get close, but sometimes it’s just not possible.
There are three kinds of units we need to worry about: Propane, electric, and battery operated. They all have advantages and disadvantages, though I feel propane and battery units have a slight edge, as they allow portable units, while electric ones need to be fully integrated every time.
Space is at a premium in a trailer or camper. You should think about whether or not you have space at all to install one in your specific mobile home. Since sizes vary so much, I won’t be able to tell you whether a particular unit will fit in your space, but I’ll make a note of dimensions and whether they’re smaller or larger than average so you can decide for yourself.
There are two main types of mobile home units; The type you install, and portable products that can be used on the go anywhere. I’m going to organize this list to talk about the two almost separately, as they serve different purposes for different kinds of units (in particular, the portable types help camper trailers much better, as those do not have showers).
Many of the portable units on this list come with their shower heads, though some do not; those are meant (usually) to be used at campgrounds which have showers but no hot water.
We’ll start with the portable units, and move onto the installs afterward.
Gallons Per Minute
This number is used for two things: the maximum flow of the water, and as shorthand for how much of that can efficiently heat.
For reference, the average sink runs at 2.2 GPM, and the average shower at 2.1 GPM. If a unit has a 2.5 GPM rating, that means they can heat up to 2.5 GPM of fluid up to a particular temperature (usually 30-45 degrees above the groundwater temp at that flow).
Keep in mind that in a mobile home, your fluid flow is often going to be a lot lower than the standard home. The volume is 2 GPM or above, and sometimes may be as low as 1 GPM. It will be able to heat that much liquid a lot easier, so you’ll need to adjust the temperature down to compensate.
10 Best RV Tankless Water Heaters of 2019
Eccotemp returns to us again, this time with a non-portable unit. It is slightly smaller than average (15” x 24” x 4”) and runs on propane.
This one you can get an appropriate temperature in cold weather if you sacrifice your flow. It does offer up to 77-degree rise in temperature at 1.5 GPM, perfect for those places with groundwater at 30-40 degrees. For areas with naturally low pressure, you’re going to want to turn the temperature way down in warm regions to avoid scalding yourself. It hits 80k BTUh at max capacity, which is very impressive for a vehicle unit.
Speaking of scalding, this unit has a feature no other has: Child locking. While a niche feature, it can be a godsend for those with mischievous children that like to mash buttons and watch numbers go up and down. Its solid “gorilla glass” construction also helps in that regard, and for other household accidents.
It also prides itself on being an energy efficient unit, something to consider for those planning on camping in more remote campgrounds.
It is the unit for the more casual camper, who only needs a shower for a rinse or emergencies, or general handwashing on a trip.
While it’s not as powerful as anything else on this list, what it is is small, cheap, portable, and usable on its own. It only has a .8 GPM flow, but it comes with its pump as well as the heater, meaning you can take your shower anywhere: Perfect for camper trailers and small showerless units.
It runs off your car battery and a little propane. Hard to beat for little over $100.
Be prepared though, it’s a bit heavy (17 lbs), but that’s justified with everything (showerhead, hose, and all) included.
Let’s look at another extremely cheap option, with the unit again being barely over $100.
The cost isn’t the only thing that’s small. It is also very compact. It gives enough fluid for a shower (1.5 GPM, and a 30-35 degree rise in temperature) in a positively tiny 22” x 12” x 8” package, and weighs only 8 lbs.
The thing to keep in mind here is it doesn’t come with its showerhead like the Costway and most of the other options in this section; you’ll need an outside source.
However, it has a high enough flow rating to give you a satisfying shower and can be used in your trailer or at a campsite interchangeably; it’s a versatile and incredibly cheap that packs a lot of punch for its minuscule size.
This thing is a beast, for what it is. It’s a battery operated portable product that runs on liquid propane but uses two D batteries for ignition.
It has a surprising amount of power for something meant to be lugged around. It has an extraordinary 76, 000 BTUh (higher than any of our full install options, actually) and 2.6 GPM capacity, though it should be noted that 76k BTUh is hampered by a measly 76% efficiency rating; most propane units come in at 80% or above.
Still, for a portable machine that’s an impressive amount of hot fluid, and it can be used pretty much anywhere (though does come with mounts). I’d hesitate to take it hiking, as it’s a bulky, massive piece of equipment (8” x 14” x 25.5” and 27 lbs.; almost as large as many home units), but for a mobile home, it’s perfect.
It’s hard to argue with the price either, under $300 is very tempting, even if the safety shutoff (20 minutes) means you might have to rush your showers to get everybody through before it kicks off for a bit.
But there is one other I feel takes the cake…with an asterisk.
Another portable option, but this time far more on the mobile side of things. Both dimensions and weight are much lower than the EccoTemp (26” x 14.5” x 6”, and only 15 lbs), making it far more useful for both smaller homes and portable use.
It even has a higher flow rating of 3.1 GPM, though that does come with a much lower rise in temperature (on average a 45-degree increase). That means you have a bit of a tradeoff over the EccoTemp; Higher flow (you can run a sink and shower at the same time) at the cost of the ability to be used in colder climates.
To me it’s a fair tradeoff, having lived in a sub-tropical climate most of my life, but that trade might kill any interest for those wanting to take their vehicle on the road in colder places, or use this to heat the fluid in their winter cabin.
For those that don’t need to brave the cold though, it’s hard to beat at a little over $300, and the extra heat with a high flow makes it better for those with a few more occupants.
OPINION: All of these have merits, but especially the EccoTemp LP10 and EZ 202, which come down to a near tie. I admit a smidge of bias towards the EZ 202 because I live in a warm area (where the 45 degrees of heating is overkill) and love to feel the fluid pounding hard when I shower, but for those looking to go colder, the EccoTemp is the clear winner.
The other two have their uses, but these two go above and beyond as portable options that are just as functional as many installed, non-portable units.
RV Tankless Water Heaters with more Permanent Fixtures
Starting with a higher-end option, this is a relatively large (13.5” x 13.5” x 14.25”) vehicle propane unit that packs a lot of power. With a minimum flow of .5 GPM (and reaching optimum capacity at 1 GPM) this unit can output 55, 000 BTUh, enough to heat your water 90 degrees above the average temperature at that flow, and much lower at a higher rate.
It comes in two varieties (wall vent and floor vent), though I recommend the wall vent. The floor vent is harder to install and just uglier all around.
While it is propane powered, it has no pilot light to worry about, and is easily winterized; you just need to drain it and pour in about a pint of anti-freeze.
That power does come at a cost, however. About $1100 worth, not counting installation. I suggest this one primarily for larger vehicles operating in colder weather, where a 90-degree rise in temperature is a necessity rather than a luxury.
Think of this as the younger, stronger, hotter brother of the Girard 1GWHM.
At under $700 it sits somewhere in the mid-high range for performance but has a much better performance to cost ratio than the RV-550. It comes in at a roughly average size of 15.5” x 12.5” x 12.5”.
Even better, this thing is fully equipped for winter, having automatic monitors that detect incoming temperature and adjusting heat requirements accordingly, and that freeze protection comes standard. As a bonus, it’s very quiet, so you don’t have to worry about it chugging along in the night and making it hard to sleep.
It is also one of the best cold weather options out there (something we’ve struggled with in our research; too many units can’t correctly handle the cold), and the automatic adjustment of heat saves a lot of time and effort.
Be wary of one thing though: Mounting hardware is not included in this unit and will need to be bought separately. Other than that, no complaints about this one. It may not be the fanciest unit on the market, but it’s certainly the best all-rounder, being able to serve the needs of any RVer.
This model is a perfectly usable unit. It has one of the higher BTUh we’ll see today (60k) and runs on propane. Coupled with its built-in freeze protection (it runs a cycle automatically heating the water above freezing whenever temperatures drop) this makes it one of the best cold weather unit on the market.
It’s relatively bulky, weighing in at 22” x 15” x 15”, and its price is significant as well: Over $650.
The price ends up making it a more specialized unit, as the freeze protection is quite good, but isn’t necessary in many parts of the world. I’d suggest giving it a pass unless you’re tooling through the cold much of the time.
It is an older model, but it checks out. It’s a middle of the range unit, with a maximum BtuH of 34k. That means it’s a bit less winter ready than other models but is serviceable in most other climates.
For a full install unit it’s pretty small; 12.5” x 12.5 x 15.5” and weighing only 22 lbs. While the weight isn’t usually a concern for something installed in a large vehicle, I find it amusing that it is both smaller and lighter than the EccoTemp LP10 portable unit.
Priced at a little over $550, this one is good for those of you with budgetary concerns (or a smaller vehicle) but needs a more permanent fixture for their hot water (if you live full time in your van, mainly).
This one is versatile in a different way than the portable options: It’s enough power for a small house (or in our case, a large mobile trailer). Designed as a Point of Use model, it powers one sink or shower at a time, which is perfect for our purposes, and will only set you back around $350.
SioGreen was kind enough to do our math for us: at 2.2 GPM (the rough standard for a shower), it can raise the temperature by 30 degrees, or 60 degrees at a low 1.2 GPM. While this means I wouldn’t recommend it for colder regions, it can work just fine for a time there (if you’re just passing through, or the weather turns), and works excellently in warmer climates.
It comes in at 20” x 16” x 5”, which is reasonably small. It is an electric model so keep that in mind; it works by using infrared heat to heat the fluid without touching it. So as an added plus, you can tell people you have a device that shoots lasers at your liquid to heat it up, which is only mostly a lie.
While the RUR98iN is the winner by a simple fact of being the most versatile, powerful, and widely usable Rinnai tankless water heater, it was a close race.
Every tankless water heater on here is the best for somebody in some situation, with the possible exception of the RL75. Of particular note is the RUC98iN Ultra which lacks only one feature (albeit an important one) over the RUR98 and comes in significantly less expensive.
I can’t stress enough that if the recirculation system is not NECESSARY to you, the RUC98 is a far better deal, but simply having the option makes the RUR98 much, much better in the circumstance that you actually do need that extra efficiency.