There are few better ways to spend the summer than camping or exploring the countryside in your RV. However, after a long day of roaming the wilderness, you probably look forward to a warm shower.
If you travel with a large group, a standard 6-gallon RV water heater tank just won’t cut it. An RV tankless water heater heats water instantly, so the last person in line doesn’t get stuck with a freezing rinse.
With so many units on the market, finding the right one is tough. We reviewed the top models available to help you upgrade your rig and keep the hot water flowing.
- Self-modulating technology
- Easy-to-use digital thermostat
- Under 12 inches tall
- Produces 1.3 gallons per minute
- 0.99 energy factor
- Whisper quiet
- Off-grid camping with propane
- Large handle for hanging or moving
- Includes most required equipment
- Sleek digital design
- Touch panel and remote control
- Easy to install
- Attractive blue finish
- Self-modulating technology
- Compact 17 inch height
How to Choose an RV Tankless Water Heater
A tankless water heater is a massive upgrade for any rig. They connect to your onboard plumbing to provide hot water on demand. Before you dive into the reviews, here is what you need to know.
Water Capacity and Recovery Time
Standard RV water heaters hold about 6 to 10 gallons. Once that hot water is gone, you have to wait.
The biggest issue with tank heaters is recovery time. A 10-gallon tank can take up to an hour to reheat. If you travel with family, this means waiting hours for everyone to cycle through the shower.
Tankless heaters eliminate recovery time. They heat water instantly as it passes through the unit. When you turn on the faucet, the burner ignites and heats the water immediately.
While the initial price tag is higher than a tank unit, the convenience is unbeatable for groups. You also save on propane or electricity since you aren’t paying to keep a tank of water hot 24/7.
Flow Rate (GPM)
You need to know how much water you use to pick the right heater. Buying a unit that is too small results in lukewarm showers, while an oversized unit is a waste of cash.
Think about your usage patterns. The bathroom shower is the biggest water hog, but you also need hot water for dishes or perhaps an onboard washing machine.
Tankless heaters are rated by Gallons Per Minute (GPM). Most RV units provide between 2 to 6 GPM.
- Low Demand: 1.5 to 2.5 GPM is usually enough for one faucet or shower at a time.
- High Demand: If you want to run the shower and the kitchen sink simultaneously, look for 3+ GPM.
Fuel Type
You have two main choices for powering your heater: electric or gas (propane).
1. Electric
An electric tankless water heater is eco-friendly and quiet.
These are great if you mostly stay at campsites with shore power (hookups). However, they draw a massive amount of amperage. You need to ensure your RV’s electrical panel can handle the load, which often requires 50-amp service. They are generally not suitable for boondocking unless you have a massive generator.
2. Gas (Propane)
Since you likely don’t have a natural gas line, this type of heater runs on propane.
Propane units are the standard for RVs. They heat water faster than electric models and are more efficient for high-flow needs. They are also perfect for boondocking since they don’t rely on shore power for heat, though they still need a 12V battery connection for the ignition and control board.
Don’t Forget
Safety Features
RVs deal with vibration, varying water pressure, and changing climates. Look for a unit with built-in safety features.
- Freeze Protection: Essential if you camp in winter. This prevents the heat exchanger from cracking in freezing temps.
- Flame Failure Device: Cuts the gas if the flame goes out.
- Overheating Protection: Shuts the unit down if water temps get dangerously high.
Types of RV Tankless Water Heaters
You also need to decide on the form factor. Do you want a permanent install or something you can move around?
Portable
A portable tankless water heater is usually hung outside the RV or on a tree. These are popular with teardrop campers, van lifers, and tent campers who want an outdoor shower.
Pros
- Versatile: You can set it up anywhere. Many come with a showerhead attachment included.
- Easy Setup: No cutting holes in your RV wall. Just hook up a propane tank and a garden hose.
- Affordable: These are significantly cheaper than installed systems.
Cons
- Outdoor Only: Most portable units are not vented, meaning you cannot use them inside the RV safely due to carbon monoxide risks.
Installed (Whole-RV Systems)
This replaces your existing 6-gallon tank heater. It mounts permanently into the sidewall of your RV. If you want a residential experience where you just turn the knob and get hot water, this is the way to go.
Pros
- High Performance: Designed to handle the water pressure and demand of a full RV plumbing system.
- Convenience: Works exactly like a home water heater. Many come with digital wall controllers to set the precise temperature.
Cons
- Complex Installation: Requires plumbing, gas line work, and 12V electrical wiring. You might need a professional installer.
Product Reviews
We analyzed flow rates, power requirements, and durability to find the top units for your rig. Here are our five favorite RV tankless water heaters.
EcoSmart 8 KW Electric Tankless Water Heater
Best Tankless Water Heater for Eco-Friendly Camping
Spending time in your RV is about enjoying nature, so an eco-friendly electric heater makes sense. The EcoSmart 8 KW is a powerful electric option that eliminates the need for propane.
We love the smart technology here. It uses self-modulating logic to adjust energy input based exactly on how much hot water you demand. This prevents energy spikes and wasted electricity.
It features a digital temperature control that lets you dial in heat in 1-degree increments. The footprint is tiny, measuring just 12 by 8 inches, making it easy to tuck into a cabinet or storage bay.
While designed as a residential point-of-use heater, it works well in RVs with robust electrical systems. It heats around 1.5 gallons per minute (GPM) to 105 degrees Fahrenheit.
Just remember, this is electric. It requires significant amperage, so ensure your campsite hookups can handle the load.
What We Like
Smart Self-Modulation
This unit is brilliant at energy management. It only draws the power necessary to heat the water flowing through it. If you only turn the tap on halfway, it uses less electricity.
It also features durable copper and stainless steel components that resist corrosion, which is vital for longevity.
Digital Precision
The external digital thermostat allows for 1-degree adjustments. You can set it to the exact temperature you like for a shower without having to mix in a bunch of cold water.
Space-Saving Size
This EcoSmart model saves serious room. It is only about the size of a standard sheet of paper and less than 4 inches deep. This frees up valuable storage space compared to a bulky 6-gallon tank.
Note that this requires a 40-amp double pole breaker. You need a 50-amp RV service to run this safely alongside other appliances.
What We Don't Like
Struggles in Freezing Weather
Electric heaters rely on groundwater temperature. If the incoming water is freezing (below 45 degrees F), the unit has to work much harder, and the flow rate will drop significantly. It works best in climates where the inlet water is 57 degrees F or higher.
Product Specs
| Measurements | 11.5 inches by 8 inches by 3.75 inches |
| Flow rate | 1.5 gallons per minute |
| Temperature range | 80 to 140 degrees Fahrenheit |
| Weight | 5.3 pounds |
| Warranty | Limited lifetime warranty |
Our Ratings
Stiebel Eltron 12 Plus Tempra Tankless Water Heater
Best Tankless Water Heater for Larger RVs
If you have a large fifth wheel or Class A motorhome, you need a heavy hitter. The Stiebel Eltron Tempra 12 Plus is a sleek, high-output electric unit capable of keeping up with high demand.
This is technically a whole-house unit, meaning it has the muscle to run a shower and a sink at the same time.
Depending on your groundwater temperature, it pushes a flow rate of 1.3 to 2.5 GPM. It boasts an energy factor of 0.99, meaning virtually no energy is wasted. The “Plus” in the name refers to its advanced flow control, which automatically slows water flow to maintain temperature if demand gets too high.
Stiebel Eltron is a German engineering giant with 90 years in the game. The unit is whisper-quiet, which is a massive plus in the tight quarters of an RV.
What We Like
Advanced Flow Control
This is the standout feature. If you demand more hot water than the unit can heat, lesser heaters simply give you lukewarm water. The Tempra Plus automatically slightly reduces the flow of water to ensure the temperature stays hot. No more cold shocks.
Incredible Efficiency
With a 0.99 energy factor, it is as efficient as it gets. The auto-modulation technology scales power usage instantly, ensuring you don’t trip breakers unnecessarily.
Silent Operation
Old tank heaters can rumble and hiss. This electronic unit is completely silent. You won’t even know it is running until the steam hits your mirror.
Informative Digital Display
The front display gives you real-time info on temperature and potential savings. It also features preset memory buttons, so you can save your preferred shower temperature.
What We Don't Like
Professional Installation Recommended
This is a high-voltage, high-amperage electrical appliance. While the plumbing is standard, the wiring is complex and requires a heavy-duty circuit. Unless you are an electrician, hire a pro to install this in your rig to avoid fire hazards.
Product Specs
| Measurements | 14.5 inches by 16.2 inches by 4.5 inches |
| Flow rate | 1.3 gallon to 2.5 gallons per minute |
| Temperature range | 86 to 140 degrees Fahrenheit |
| Weight | 13.5 pounds |
| Warranty | Seven-year warranty |
Our Ratings
Camplux 2.64 GPM Tankless Propane Water Heater
Best Tankless Water Heater for Off-Grid Camping
Boondocking is all about freedom, and the Camplux 2.64 GPM heater is the ultimate off-grid accessory. This is a portable propane unit, not a permanent install, making it versatile for outdoor showers.
It functions as an instant outdoor shower system. You hang it up, connect a standard propane tank and a water hose, and you have hot water in seconds.
This is perfect for small trailers, teardrops, or van builds that don’t have an internal shower. It includes an integrated handle for easy transport. Since it runs on D-cell batteries for ignition, you don’t even need an electrical hookup to use it.
What We Like
Truly Portable
You can move this unit wherever you need it. Use it to wash the dog, rinse off muddy hiking boots, or take a shower behind a privacy tent. It weighs about 18 pounds, so it is easy to stow away when travel days arrive.
Battery Powered Ignition
No generator? No problem. The ignition runs on two D-cell batteries. This makes it the most reliable option for deep wilderness camping where electricity is scarce.
Complete Kit Included
Camplux includes almost everything you need to get started right out of the box:
- Showerhead with on/off switch.
- 5-foot shower hose.
- CSA-approved gas hose and regulator.
- Garden hose adapters (quick connects).
- Mounting hardware.
What We Don't Like
Outdoor Use Only
This unit is not vented. It consumes oxygen and produces carbon monoxide. You must strictly use this outdoors or in an open-air environment. Do not install this inside your sleeping quarters.
Included Hose is Basic
The included shower hose is plastic and can kink. We recommend upgrading to a longer, flexible stainless steel hose for a better experience.
Product Specs
| Measurements | 12.8 inches by 6.1 inches by 21.65 inches |
| Flow rate | 2.64 gallons per minute |
| Temperature range | Not specified |
| Weight | 18 pounds |
| Warranty | N/A |
Our Ratings
EcoTouch Tankless Water Heater Electric
Best Tankless Water Heater for High-Tech RV's
If you love sleek gadgets, the EcoTouch electric heater will fit right in. It is compact, roughly the size of an oatmeal box, and features a modern black finish that looks great in renovated RV interiors.
It uses a touch control panel rather than clunky knobs. The installation is surprisingly simple for an electric unit, making it a favorite for DIYers.
The smart modulation prevents scalding. If someone flushes a toilet or pressure drops, the EcoTouch adjusts power instantly to keep the temperature stable. It’s a point-of-use heater, best suited for a single sink or a low-flow situation.
What We Like
Modern Aesthetic
The black glass faceplate looks premium. It is lightweight (5 pounds) and smooth, making it easy to wipe clean. It eliminates the “utility” look of traditional white metal boxes.
Touch Controls and Remote
The touch panel is responsive and waterproof. It lets you tap in your desired temperature effortlessly.
Even better, this model comes with a remote control. You can install the heater deep inside a cabinet to save space and mount the remote on the wall to control the temperature without crawling under the sink.
Easy Installation
EcoTouch designed this for easy setup. It comes with 0.5-inch NPT pipe fittings and the power cord is pre-wired, so you don’t have to strip wires yourself.
Smart Safety
The modulation technology hits 99.8% energy efficiency. It also cuts power immediately if water flow stops, preventing the unit from burning out or overheating the remaining water.
What We Don't Like
Low Flow Rate
This is a small unit. It produces about 1 to 1.5 GPM depending on inlet temperature. While great for washing dishes or hands, it struggles to provide a high-pressure hot shower unless you are in a very warm climate.
Product Specs
| Measurements | 15.74 inches by 10.24 inches by 2.05 inches |
| Flow rate | 1 gallon to 1.3 gallons per minute |
| Temperature range | 67 to 115 degrees Fahrenheit |
| Weight | 10.78 pounds |
| Warranty | N/A |
Our Ratings
Eemax EEM24018 Electric Tankless Water Heater
Best Aesthetically Pleasing Tankless Water Heater Unit
The Eemax EEM24018 stands out with its distinctive metallic blue casing. But it isn’t just about looks; this is a robust 240-volt heater designed to provide consistent hot water.
It uses direct heating elements to warm water quickly. Like the others, it employs self-modulating technology to keep energy bills in check.
Eemax markets this as capable of running a sink and shower simultaneously. In a residential setting with warm groundwater, that is true. In an RV setting, it serves as a reliable main source of hot water, provided you have the 240V electrical capacity to run it.
What We Like
Durable Design
The metallic blue finish is tough and protects the internal components well. The digital interface is simple, allowing you to toggle settings easily. It is compact enough (17 x 14 inches) to fit in most RV utility closets.
Self-Modulating Power
The unit reads the water flow and temperature inlet, adjusting the power draw in real-time. This prevents the “sandwich effect” (bursts of cold water) often found in older tankless models.
Fast Heating
Because it draws significant power (18kW), it heats water faster than the smaller 110V units. If you have a rig with 50-amp service and 240V capability, this offers a shower experience closest to a sticks-and-bricks home.
What We Don't Like
High Electrical Requirements
This is a 240-volt unit. Many RVs only run on 120 volts. You must verify your rig is wired for 240V appliances before buying this, or it simply will not work.
Performance Variations
While powerful, user reports vary on simultaneous use. If the incoming water is very cold, you may have to choose between a hot shower or washing dishes, not both at once.
Product Specs
| Measurements | 17 inches by 14 inches by 3.75 inches |
| Flow rate | 2.3 gallons per minute |
| Temperature range | 80 to 140 degrees Fahrenheit |
| Weight | 14.47 pounds |
| Warranty | Five-year warranty on leaks, one year on parts |
Our Ratings
| Product | Award | Measurements | Weight (lbs) | Temp. Range (F) | Flow rate (GPM) | Warranty |
|---|---|---|---|---|---|---|
| EcoSmart 8 KW | Best For Eco-Friendly Camping | 11.5″ x 8″ x 3.75″ | 5.3 | 80 – 140 | 1.5 | Limited lifetime |
| Stiebel Eltron 12 | Best For Larger RVs | 14.5″ x 16.2″ x 4.5″ | 13.5 | 86 – 140 | 1.3 – 2.5 | 7 years |
| Camplux 2.64 GPM | Best For Off-Grid Camping | 12.8″ x 6.1″ x 21.65″ | 18 | N/A | 2.64 | N/A |
| EcoTouch | Best For High-Tech RVers | 15.74″ x 10.24″ x 2.05″ | 5.7 | 67 – 115 | 1 – 1.3 | N/A |
| Eemax EEM24018 | Best Aesthetically Pleasing | 17″ x 14″ x 3.75″ | 11.25 | 80 – 140 | 2.3 | 5-year on leaks, 1 year on parts |
FAQs
How Should I Install a Tankless Heater in My RV?
Location is key. You usually mount the unit to the sidewall (where the old tank was) or the floor. You must connect the cold water inlet, hot water outlet, and power source (gas or electric).
If you use a gas unit, installing the flue is critical. The flue directs dangerous carbon monoxide outside (1). Improper venting can be fatal (2). Always seal connections with teflon tape and check for leaks with soapy water. If you aren’t confident, hire a pro.
Can I Install a Tankless Heater Under an RV Sink?
Yes, and it is a great idea for efficiency. Installing a small electric “point-of-use” heater directly under the kitchen or bathroom sink reduces the travel time for the water. This means you get hot water instantly rather than waiting for it to travel from the back of the RV. Just measure your cabinet space first to ensure it fits.
Are RV Tankless Water Heaters Worth It?
Absolutely, especially for families or full-timers. They provide an endless supply of hot water, meaning no more military-style navy showers. They also weigh less than a tank full of 6 to 10 gallons of water (which weighs over 80 lbs), helping you stay under your GVWR. The fuel savings from not heating a standby tank also add up over time.
What Is the Best RV Tankless Water Heater?
The Furrion 2.4GPM Tankless RV Gas Water Heater is widely considered the top dedicated RV unit. It handles freezing temperatures well, has a high heating capacity, and fits into the standard cutout of most OEM tank heaters. It also features advanced safety sensors that shut off gas immediately if issues arise.
How Much Is an RV Tankless Water Heater?
Portable outdoor units cost between $150 and $250. Permanent, whole-RV systems generally range from $500 to $1,000 depending on the brand and flow rate. While the upfront cost is higher than a tank heater, the longevity and lack of maintenance often balance it out.
How Big of an RV Tankless Water Heater Do I Need?
Size depends on your flow rate (GPM). Add up the GPM of your fixtures. A standard RV shower head uses about 1.5 to 2.0 GPM. A sink uses about 1.0 GPM. If you want to shower while someone does dishes, you need a unit rated for at least 3.0 GPM. If you only use one thing at a time, a 2.0 GPM unit is sufficient.
Do I Need to Winterize My Tankless Water Heater?
Yes, winterizing is crucial. Even a small amount of water left in the heat exchanger can freeze, expand, and crack the copper tubing, ruining the unit. To winterize, you must drain all water from the unit and blow out the lines with compressed air, or pump non-toxic RV antifreeze through the system.
