Choosing a Tankless Water Heater for Your RV

Are you trying to decide if a tankless water heater for your RV is right for you? Keep reading for tips on things to consider when shopping for one, plus costs and which one I decided was right for my rig in the end.

After winterizing my travel trailer a few months ago, I didn’t know if my water heater was going to last the winter. It was one of the few original fixtures we decided to keep when we were going through the complete renovation process. Not exactly the smartest thing to do, come to find out, but it lasted us for well over a year at least.

Winterization Shouldn’t Be This Hard, Right?

Now that we’ve moved back to Arizona from South Dakota and the old water heater decided to thaw out (despite my endless efforts to empty it prior to Winter), I’ve been on the prowl for a new water heater setup.

Tankless water heaters are all the rage in the tiny living community, so I knew I wanted to give it a shot and take back some of that cabinet space that the current water heater was using in the kitchen. 

Here’s how I decided on my next water heater to help you think through the process before diving into the first one you see online. (And also prevent you from having a leaky water heater next winter!)

What to Consider When Choosing a Tankless Water Heater

There are a handful of things to take into consideration before deciding on a tankless water heater for your RV that can help you decide what size you need and if it’s a good fit physically in your very limited space.

Number of Water-Using Areas

The tankless water heater size you need is highly dependent on how many areas in your rig need and use water regularly. For us, we only have one sink and a bathtub area that rarely uses water unless we’re hooked up somewhere. For others, this can be multiple sinks, a shower, and a toilet or two. 

You should consider how much water is needed and how often you use it in these areas to determine what size tankless water heater you need. This will ensure you get adequate volume and flow.

You can easily figure out the total flow rate, as the tankless water heater community phrases it, by looking at your fixtures for each water-using area and then adding those numbers together. For example, if my kitchen faucet had a 1.0-gallon per minute flow rate and my shower head had a flow rate of 3.0 gallons per minute, my total flow rate would be 4.0 gallons per minute. 

If you don’t know what the flow rate is on each of your fixtures, the manufacturer should have some information online to help you. If your flow rates are high, you can also look at installing low-flow water fixtures or adapters to your current setup to reduce your total water needs. This will potentially allow you to downsize the water heater.

Water Temperature

Though tankless water heaters turn your water from cold to hot quickly, not all are made to pump out consistently hot water. If you live in a warmer climate, which most of us do or aim to do when living on the road, you won’t require an insanely high temperature to keep your water warm enough. But if you plan to use your rig in mild to heavy winters, you’ll want to up the ante on a tankless water heater.

For reference, you should at any given time hope that your water comes out between 105-115 degrees when you’re in the shower. Keep this in mind when you look at temperatures on each water heater.

Gas or Electric

Depending on how your rig is set up, you may want to consider a gas over an electric tankless water heater. Gas tankless water heaters are not only great for boondocking, but they also heat water more quickly. If you’re off the grid enough, a gas tankless water heater is probably better, but if you’re always hooked up to shore power somewhere an electric one should work well, too.

My Tankless Water Heater Options

After much research, I settled on a few tankless water heater options based on what I know of my current water pump’s capabilities. I also took into account the above considerations I listed previously.

My High-End Options

Truma AquaGo

One of the most ranted and raved about tankless water heaters is the Truma AquaGo. I have to say after my research that I’m impressed by how easy it is to winterize this water heater after the endless struggle I had with my original setup.

Here are a few of the specs to give you a closer look at what this setup has to offer:

• 12V DC power at roughly 2.5 amps
• Weighs roughly 35 lbs
• Fuel type: Propane only
• Water Operating Pressure: 65 PSI max
• Some packages offer freeze protection, while others don’t 

This is one of the better tankless water heaters for travel trailers and RVs because most individuals who use them, like myself, are pretty conscious about how much water they use. Unlike some of the other tankless water heaters I’ve seen, the AquaGo does a good job of heating up small amounts of water even if you’re turning the water on and off repeatedly or only letting your faucet trickle a bit as you wash dishes or brush your teeth.

Because the Truma AquaGo is so easy to manipulate, winterize, and use in your rig the price of this setup is much higher than you’ll see on many other tankless water heaters. You’re looking at over a thousand dollars for a basic setup, which is the main reason why I decided to not pull the trigger on the AquaGo. There are just so many other great options out there for a lot less money.

Girard Tankless Water Heater

The Girard Tankless Water Heater is another great option at a little over $500 for a setup. I’ve watched several YouTube videos about installing this particular unit and it seems relatively straightforward. In case you didn’t know, this is a huge plus when you’re diving into a DIY RV or travel trailer project.

Trust me, I should know.

Here’s a little bit about the Girard Tankless Water Heater to give you a closer look:

• 12V DC power at less than 3 amps
• Weighs roughly 24 lbs
• Fuel type: Propane only
• Water Operating Pressure: 125 PSI max
• Designed for all-season use

The Girard system is one that I have seen time and again in RV forums and Facebook groups. It seems to fit in just about any water heater space in any kind of rig. Some people have mentioned that certain flow rates have prevented the water heater from heating up small amounts of water, so if you’re interested in a Girard setup I suggest talking to a dealership about it before purchasing one for your rig. You’ll want to make sure you can adapt your current setup somehow to meet the minimum requirements.

Side Note: This particular kit comes with the water heater, but not the door setup, so be sure you add the right door to your cart before purchasing one.

Because I’m selling my travel trailer, I decided not to go with the Girard system either. Mostly because of cost, but also because I didn’t want to have to spend any more of my budget revamping my plumbing fixtures prior to the sale. I honestly think this is the best system to purchase if you intend to keep your rig for a long time, but for me, it doesn’t make sense right now to spend that much until I get another recreational vehicle!

My Mid to Low-End Options

Thermomate Tankless Water Heater

Here are a few extra details about the Thermomate Tankless Water Heater:

• 12V DC power at less than 3 amps
• Weighs roughly 10 lbs
• Fuel type: Propane
• Water Operating Pressure:  2.5 PSI minimum up to 110 PSI maximum
• Can be used indoors and outdoors with anti-freezing properties

This particular setup is often used outdoors, but several RVers have seen success by mounting the heater underneath a window and cracking it prior to hopping in the shower or washing dishes. 

Even though this setup seems to have the lowest PSI minimum, which makes it ideal for RVs and trailers, I’m not entirely convinced that this water heater is worth the money at $199.

If you see a promo or discount on this water heater, you may want to scoop it up right away. Either way, I do recommend that you do your due diligence and see if it might be a good fit for your situation.

Camplux 5L 1.32 GPM Outdoor Portable Tankless Water Heater

For about $160, you can have this portable tankless water heater do the job if you only use water sparingly. This particular setup needs ventilation, like most other tankless water heaters, but this one in particular will also require an easily accessible location. It needs to be somewhere handy where you can adjust the temperatures and allow it enough oxygen to prevent it from turning on and off while you’re using hot water.

Here are a few details about the Camplux to help you decide for yourself:

• 12V DC power at less than 3 amps
• Weighs roughly 14 lbs
• Fuel type: Propane
• Water Operating Pressure:  3 PSI minimum up to 110 PSI maximum
• Can be used indoors and outdoors with anti-freezing protection

The Camplux 5L has better consumer reviews than its 10L counterpart, but I preferred this one myself because it requires very little PSI to get going and still gives you up to a 114 degree Fahrenheit change in water temperature to keep your water hot wherever you are and whenever you need it.

Which One Did I Choose?

After spending many hours down the tankless water heater rabbit hole, I finally decided on the Camplux 5L.

Not only is it relatively inexpensive, it also has great reviews and meets our particular needs (and the needs of our travel trailer’s future owners!) based on the number of areas that need hot water and how large our water tank reserve is.

The Camplux 5L is also propane-based for boondocking purposes, which made the most sense for us as you can use it anywhere without being hooked up to electricity.

We’ve put our order in for the Camplux 5L and will report back in due time after we get everything set up and test it out for a bit prior to selling our rig, Lorelai!

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