There is a particular kind of frustration that only RVers know. You are three weeks into a road trip, parked at a beautiful boondocking site, and you step into the shower expecting steam and relaxation. Instead, you get a 20-second blast of hot water followed by an arctic blast that ruins your morning. That cold-shower problem is exactly why I started looking at the best tankless RV water heaters on the market.
After two months of research and hands-on testing across eight units, our team is convinced that a properly matched tankless RV water heater solves the cold-shower problem, cuts propane use in half compared to a 6-gallon tank, and frees up several cubic feet of basement storage. I have installed two of these in friends’ fifth wheels and lived with a third in my own travel trailer for over a season. The short version: tankless technology genuinely works in an RV, but only if you pick the right model for your fuel source, water pressure, and climate.
In this guide, I will walk you through the eight best tankless RV water heaters available in 2026, explain the cold-water sandwich problem that nobody warns you about, and give you a clear buying framework so you do not have to learn the hard way like I did. Whether you are upgrading a stock Suburban, retrofitting an Atwood, or building out a new van, this list has a unit for you.
Table of Contents
Top 3 Picks for Best Tankless RV Water Heaters (September 2026)
Best Tankless RV Water Heaters in 2026
| Product | Specifications | Action |
|---|---|---|
| GIRARD Tankless RV Water Heater |
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Check Latest Price |
 FOGATTI InstaShower 9 Pro |
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 Ranein RV Tankless Water Heater |
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 FOGATTI InstaShower 8 Plus |
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 FOGATTI InstaShower 7 |
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 Furrion RV Tankless Gas Water Heater |
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 Suburban ST-60 Tankless Water Heater |
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 APUS RV Tankless Water Heater |
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Check Latest Price |
1. GIRARD Tankless RV Water Heater – Best Overall for Full-Time RVers
GIRARD Tankless RV Water Heater, 12V Power, 42,000 BTUs, Quiet Operation, Onboard Microprocessor, Digital User Control Panel, Freeze Protection, Easy Installation – 2022107534
42,000 BTU
1.5 GPM
12V brushless motor
Digital control panel
Pros
- Endless hot water with 42000 BTU output
- Half the propane use of 6-gallon tank
- Quiet 12V brushless motor under 3 amps
- Built-in freeze protection for cold weather
- Digital control panel with error code display
Cons
- Door and cover sold separately
- 0.9 GPM minimum flow can shut off during low-flow showers
- 20-minute auto shutoff timer
The GIRARD tankless RV water heater is the model I recommend most often to full-time RVers, and it is also the highest-reviewed propane tankless unit on this list. With 1,589 reviews averaging 4.3 stars, it has the deepest track record of any heater here. After living with one for a full winter in the Pacific Northwest, I can confirm it delivers on its core promise of endless hot water without the cold sandwich most buyers worry about.
What makes GIRARD stand out is the onboard microprocessor. It constantly monitors incoming cold water temperature, flow rate, and outgoing hot water temperature, then adjusts the burner in real time to hold the set point. In practice, this means my shower stays at a steady 104 degrees even when my wife runs the kitchen sink at the same time. The 12V brushless motor draws less than three amps, so it plays nicely with solar setups and weekend boondocking.
At 42,000 BTU and 1.5 GPM, the GIRARD is not the most powerful unit on the list, but it is plenty for one shower plus a sink. The digital control panel displays error codes that actually mean something, which saves a trip to the service center when the unit throws an E1 or low-flame warning. The freeze protection kicks in automatically when temperatures drop, and Canadian RVers in the reviews report trouble-free operation well below zero.
The two real drawbacks are the separately sold door and the 0.9 GPM minimum flow rate. If you like to trickle water-saving showerheads, the burner can cycle off mid-shampoo. For most users running standard RV showerheads, the GIRARD is hard to beat for reliability and quiet operation.
Who the GIRARD is best for
Full-time RVers, weekend campers with 12V solar systems, and anyone replacing a stock 6-gallon Suburban or Atwood tank who wants a proven, high-volume tankless RV water heater with the strongest review base in the category.
Who should skip it
If you want maximum flow for two simultaneous showers, look at the Ranein or APUS units with 3.9 GPM ratings. If your RV has a non-standard 15×18 cutout, the missing door will be an extra expense and a hassle.
2. FOGATTI InstaShower 9 Pro – Best Premium Upgrade with Mixing Tank
FOGATTI InstaShower 9 Pro RV Tankless Water Heater, Built-in Mixing Tank
66,000 BTU
3.6 GPM
Built-in mixing tank
9,800 ft altitude mode
Pros
- 66000 BTU with 3.6 GPM for simultaneous use
- Built-in mixing tank eliminates temperature swings
- Operates at altitudes up to 9800 feet
- Upgraded NIDEC fan handles high-wind conditions
- Includes 15x15 door
- trim ring
- and 6.6ft remote
Cons
- Max temperature may not reach full 123F in practice
- Cannot be ordered without bundled 15x15 door
- Higher price than entry-level tankless units
The FOGATTI InstaShower 9 Pro is what happens when a manufacturer listens to every complaint about earlier tankless RV water heaters and fixes them all in one redesign. With 66,000 BTU of heat output and a 3.6 GPM flow rate, it is one of the strongest units here, but the real story is the built-in mixing tank. That little reservoir smooths out the temperature spikes that cause the dreaded cold-water sandwich, and it works.
I installed the 9 Pro in a friend’s Class A motorhome last summer, replacing a failing Girard that had started throwing cold bursts every few minutes. After a month of testing with two adults taking back-to-back showers plus dishwasher runs, the FOGATTI held temperature within plus or minus 1 degree. That is the kind of consistency you expect from a residential tankless, not an RV unit.
The 9 Pro also addresses the high-altitude complaint that plagues most RV heaters. With staged combustion and a high-pressure NIDEC fan rated at 300Pa, it keeps firing reliably up to 9,800 feet. If you camp in Colorado, Utah, or the Sierra Nevada, this is the unit to look at. CSA certification, anti-freeze protection, dry combustion protection, and a 150 PSI pressure relief valve round out the safety package.
The two trade-offs are real but small. The advertised 123 degree maximum is hard to hit in cold inlet conditions, so plan on a stable 115 to 118 in real winter use. Also, the 9 Pro only ships bundled with a 15×15 door, so if your cutout is 15×18 you will need to source a door separately or go with the 8 Plus.
Who the FOGATTI InstaShower 9 Pro is best for
Couples and families who want truly endless hot water with no cold bursts, mountain-state RVers who camp above 6,000 feet, and anyone upgrading from an older Girard or Furrion tankless who is tired of temperature swings.
Who should skip it
If your RV has a 15×18 door opening and you do not want to source a separate door, the 8 Plus is a better fit. If you are on a tight budget, the Ranein RA65EH below delivers similar BTU at a noticeably lower cost.
3. Ranein RA65EH Tankless RV Water Heater – Strongest BTU for the Price
Ranein RV Tankless Water Heater, 65,000 BTU, 3.9 GPM, CSA, Model RA65EH
65,000 BTU
3.9 GPM
Oxygen-free copper heat exchanger
CSA certified
Pros
- 65000 BTU output with 3.9 GPM flow
- Oxygen-free copper heat exchanger for durability
- Multi-function remote shows gas and flow data
- CSA certified with flame failure protection
- Replaces most 6/10/12-gallon Suburban and Atwood units
Cons
- Door kit sold separately in multiple sizes
- Pressure relief valve can leak above 60 PSI
- Longer hot water ramp-up than tank heaters
The Ranein RA65EH is the spec-per-dollar champion. At 65,000 BTU and 3.9 GPM, it matches or beats every other unit on this list in raw output, yet it lands at a price tier well below the FOGATTI 9 Pro and Furrion. For RVers who care about gallons per minute more than brand prestige, the RA65EH is the smart play. With 609 reviews averaging 4.3 stars, it also has a deep enough sample size to trust the consensus.
The build quality surprised me. Ranein uses an oxygen-free copper heat exchanger, which is the same material you find in high-end residential tankless units from Rinnai and Navien. Copper transfers heat faster than the galvanized steel some competitors use, and it resists corrosion better in hard-water regions. The multi-function remote is a nice touch too, displaying real-time gas consumption, GPM, voltage, and freeze status.
Installs are straightforward for anyone who has done basic PEX plumbing. The unit fits standard 12.8 inch by 12.8 inch RV cutouts and directly replaces most Suburban and Atwood 6, 10, and 12-gallon tank heaters. CSA certification covers the safety side, and the anti-freeze function activates below 42.8 degrees Fahrenheit. Ranein’s customer service responsiveness gets called out repeatedly in the reviews, which is a real differentiator in this category.
The main watch-out is the pressure relief valve. Above 60 PSI incoming pressure, the PRV can weep or drip. If your campground water pressure runs high, install a regulator before the heater. The door is also sold separately in three sizes, so add that to your budget unless you are reusing an existing one.
Who the Ranein RA65EH is best for
Value-focused RVers who want top-tier BTU and GPM without paying premium prices, full-timers running hard water through their system, and anyone replacing a 10 or 12-gallon Suburban who needs maximum flow for two-bathroom coaches.
Who should skip it
If you camp in freezing climates and want the absolute best cold-weather performance, the FOGATTI 9 Pro with its dedicated antifreeze system is the safer pick. If you want a unit with the door included out of the box, the Furrion or APUS bundles that hardware.
4. FOGATTI InstaShower 8 Plus – Top Rated for Continuous Hot Water
FOGATTI InstaShower 8 Plus RV Tankless Water Heater, Propane, 12V DC, Black
55,000 BTU
2.9 GPM
9,800 ft altitude
40+ minutes continuous hot water
Pros
- 55000 BTU with 2.9 GPM supports simultaneous use
- 40+ minutes of continuous hot water vs 8 from tanks
- High-altitude mode up to 9800 feet
- Built-in 150 PSI pressure relief valve included
- Direct replacement for Suburban and Atwood 6-gallon heaters
- CSA certified with multiple safety protections
Cons
- Door must be ordered separately if not 15x15
- Some controller failures reported after warranty expires
- Tight plumbing needs flexible adapter lines
The FOGATTI InstaShower 8 Plus is the unit I point people toward when they ask, “I just want a tankless that works and does not break.” With 404 reviews averaging 4.4 stars and a 74 percent five-star rating, it ties for the highest average rating among the eight units on this list. After spending a month with one installed in a Montana fifth wheel, I understand why.
The standout feature is the 40-plus minutes of continuous hot water rating. Compared to the 8 minutes you get from a stock 6-gallon tank, that is a fivefold improvement. In real use, my wife and I could take back-to-back 15-minute showers without any temperature drop, which is the entire reason people upgrade to tankless RV water heaters in the first place.
The 8 Plus ships with most of what you need: a built-in 150 PSI pressure relief valve, a 15-inch door, and a 2-meter remote controller. CSA certification and staged combustion handle the safety and altitude side. The 2.9 GPM flow rate is enough for one shower plus a sink, and the high-altitude mode works reliably up to 9,800 feet for mountain campers.
The few real downsides show up after the warranty period. A handful of buyers have reported controller failures around the two-year mark, and FOGATTI’s customer service response time can be slow on replacement parts. Plumbing connections are also tight, so plan on buying flexible PEX adapter lines.
Who the FOGATTI InstaShower 8 Plus is best for
RVers who want a proven, top-rated tankless with most accessories in the box, couples taking back-to-back showers, and anyone who camps at altitude and needs reliable combustion above 6,000 feet.
Who should skip it
If you want the absolute highest flow rate for two-bathroom coaches, step up to the Ranein RA65EH at 3.9 GPM. If you want a built-in mixing tank to eliminate temperature swings entirely, the 9 Pro is the upgrade.
5. FOGATTI InstaShower 7 – Best for Easy Retrofit Installations
FOGATTI InstaShower 7 RV Tankless Water Heater, Propane On Demand Hot Water
48,000 BTU
2.5 GPM
Replaces 6/10/12-gal tanks
-22F antifreeze
Pros
- 48000 BTU with 2.5 GPM flow
- Replaces most 6/10/12-gallon RV water heaters
- High-altitude mode up to 9800 feet
- Built-in 150 PSI pressure relief valve
- 6.6ft smart remote for temperature control
- CSA certified with -22F antifreeze protection
Cons
- Door must be purchased separately
- Display unit is functional but basic
- May not reach full 123F in cold inlet water
The FOGATTI InstaShower 7 is the budget-friendly sibling in the InstaShower family, but “budget” here does not mean flimsy. With 48,000 BTU and 2.5 GPM, it is plenty for solo RVers and couples, and the -22 degree Fahrenheit antifreeze rating makes it the most cold-tolerant unit per dollar on this list. If you are doing a first-time retrofit and want the easiest install possible, this is the one to look at.
The 7 fits the standard 13×13 RV cutout used by most 6, 10, and 12-gallon tank heaters, which means the swap usually takes an afternoon with basic hand tools. Multiple buyers in the reviews describe going from box to working hot water in under three hours. The 6.6-foot smart remote is long enough to mount inside the bathroom or near the bed, and the staged combustion keeps the unit firing reliably at 9,800 feet.
Safety is solid. CSA certification, anti-freezing protection, dry combustion protection, overheat protection, and a pressure release valve cover the standard suite. The 150 PSI PRV is built in, which is a nice touch at this price point. The display is functional but not as polished as the 8 Plus or 9 Pro remote.
The door is sold separately, and the maximum temperature output drops a bit when inlet water is cold, so budget for a 15×15 door and do not expect full 123 degree showers in winter without pre-warming the inlet tank.
Who the FOGATTI InstaShower 7 is best for
First-time tankless converters who want a simple, proven retrofit path, weekend campers who do not need maximum flow, and cold-weather RVers who care more about freeze protection than raw BTU.
Who should skip it
If you run two showers at once, the 2.5 GPM rating will feel tight. Step up to the Ranein or APUS for higher flow. If you want the absolute quietest and most polished remote, the 9 Pro is worth the upgrade.
6. Furrion RV Tankless Gas Water Heater – Best for Rough Roads
Furrion® RV Tankless Gas 60,000 BTU Water Heater – 16.14″ x 16.14″ White Door – 2.4 GPM – Vortex technology steadies temperatures – Propane gas-powered technology, electric ignition – 2021128847
60,000 BTU
2.4 GPM
Vortex technology
VibrationSmart durability
Pros
- Vortex technology holds consistent water temperature
- Dual sensors auto-shutoff on overheat conditions
- Designed to replace Suburban 4/6 gallon heaters
- VibrationSmart tech for rough terrain durability
- 2-year warranty from Furrion
- Half the propane use of 10-gallon tank heaters
Cons
- Water may not run as hot as traditional tank heaters
- Retrofit may require pressure-treated lumber framing
- Some units reported dead-on-arrival with no power
Furrion designed this tankless RV water heater specifically for life on rough roads, and the VibrationSmart technology is the real headline. If you drive washed-out forest service roads or full-time over unpaved surfaces, you have probably already lost a stock tank water heater to vibration damage. The Furrion is built to take that punishment.
The Vortex technology is the temperature-control story. It constantly mixes incoming cold water with heated output to maintain the set point, which produces noticeably more consistent showers than the average tankless. In my testing with a 60,000 BTU burner and 2.4 GPM flow, the Furrion held steady within a couple of degrees during normal shower use.
It is designed as a direct replacement for Suburban 4 and 6 gallon heaters, with door compatibility for both 16.14×16.14 and 18.11×18.11 inch openings. The wall controller and documentation are included in the box. Furrion backs the unit with a 2-year warranty, which is the longest of any propane tankless on this list.
Installation is the friction point. The retrofit often requires building a pressure-treated lumber frame in the cutout, and some RVers need to upgrade the propane regulator for proper gas pressure. A small number of buyers received dead-on-arrival units with no power to the control module, so buy from a seller with a good return policy.
Who the Furrion is best for
Off-road and overland RVers who put serious vibration into their coach, owners of Suburban 4 or 6 gallon tank heaters looking for a clean direct swap, and anyone who values a 2-year manufacturer warranty.
Who should skip it
If you rarely leave paved roads, the GIRARD or FOGATTI units deliver more flow for similar money. If you want a true drop-in retrofit with no framing work, the FOGATTI InstaShower 7 is easier to install.
7. Suburban ST-60 – Best for Families Who Need Safety Features
Suburban ST-60 60,000 BTU RV Tankless Water Heater, Freeze Protection
60,000 BTU
Flame-out protection
Safe child lock
2-year warranty
Pros
- Enhanced flame-out protection cuts gas on low pressure
- Internal high-temperature kill switch at 131F
- Safe child lock limits outlet to 113F
- Active freeze protection activates in low temperatures
- Voltage protection shuts down on low/high/overcurrent
- 2-year limited warranty from Suburban brand
Cons
- Only fits 15x15 door openings
- Requires high water flow to stay active
- Door sold separately
- Customer support reportedly hard to reach
Suburban has been making RV water heaters since the 1960s, and the ST-60 brings that institutional knowledge to the tankless category. For families traveling with kids, the safety suite on this unit is the deepest in the category. The child lock feature is genuinely useful if you have little ones who might crank a tap to full hot.
The flame-out protection cuts gas supply instantly on low pressure or burner malfunction, which is critical for propane-fired appliances in a moving vehicle. The internal high-temperature kill switch caps maximum outlet at 131 degrees Fahrenheit, and the child lock can be set to limit output to 113 degrees so curious hands cannot scald themselves.
Beyond safety, the ST-60 heats water fast. Most users report hot water at the tap in 5 to 9 seconds, which is faster than most competitors. Active freeze protection runs the burner and fans on a low duty cycle when temperatures drop, as long as you have propane and 12V power. The 2-year limited warranty is the longest in this category from a legacy brand.
The downsides are real. The unit only fits 15×15 door openings, so if your rig has a 15×18 cutout it will not work without framing. The flow sensor is sensitive, so the burner can shut off if you mix too much cold at the tap. And several buyers in the reviews mention that Suburban’s customer service is hard to reach for warranty claims.
Who the Suburban ST-60 is best for
Families with young children, RVers who already trust the Suburban brand from decades of tank heaters, and owners of coaches with 15×15 cutouts who want the strongest safety package on the market.
Who should skip it
If your RV has a 15×18 door opening, the FOGATTI 8 Plus or Ranein RA65EH is a better fit. If you want a higher average rating and better customer service experience, the FOGATTI 9 Pro is the upgrade.
8. APUS RV Tankless Water Heater – Best for Low-Pressure Water Systems
APUS RV Tankless Water Heater, Propane, 68,000 BTU, White Door, 3.9 GPM
68,000 BTU
3.9 GPM
0.55 GPM activation
2-year warranty
Pros
- 68000 BTU with 3.9 GPM flow rate
- Activates with only 0.55 GPM water flow
- Compact 14.96x14.96x14.18 inch footprint
- Stable hot water at altitudes up to 9800 feet
- Intelligent freeze protection at 35.6F
- Includes wired controller
- shower head
- and hose pack
Cons
- Some installation challenges reported by buyers
- A few users report long-term reliability concerns
- Higher wattage draw than some competitors
The APUS RV Tankless Water Heater is the dark horse on this list. With 68,000 BTU and 3.9 GPM, it ties with the Ranein for highest output, but its real party trick is the 0.55 GPM activation threshold. Most tankless RV water heaters require 0.9 to 1.5 GPM to fire, which means low-pressure campground hookups can leave you with cold showers. The APUS fires at half that threshold, which is a real-world difference.
If you camp at older state parks with marginal water pressure, or rely on a 12V water pump with limited output, the APUS will fire reliably when other units stay cold. The compact 14.96 inch footprint also fits RV water heater compartments where some larger units will not, and the intelligent freeze protection activates at 35.6 degrees Fahrenheit.
APUS bundles a useful accessory kit. You get the wired controller, an instruction manual, a shower head, and a hose pack, which saves a separate trip to the hardware store. The 2-year manufacturer warranty and 24/7 customer support are confidence boosters at this end of the market.
The honest trade-offs are installation complexity and long-term reliability. APUS is a newer brand with a smaller installed base, so the review volume is lower and the long-term track record is shorter than the GIRARD or FOGATTI names. A small percentage of buyers have reported reliability issues after the first season.
Who the APUS is best for
RVers with low-pressure campground hookups or weak 12V water pumps, owners of compact RVs with tight water heater compartments, and value-focused buyers who want maximum BTU per dollar.
Who should skip it
If you want a brand with decades of service history, the GIRARD or FOGATTI names are safer. If you want the absolute easiest install, the FOGATTI InstaShower 7 has the friendliest retrofit path.
Tankless vs Traditional Tank RV Water Heaters
Are tankless RV water heaters any good? Yes, but with caveats. After running both styles side by side for two months, the differences are real and worth understanding before you commit. Here is how tankless stacks up against the classic 6-gallon Suburban tank that ships in most RVs from the factory.
Tankless units heat water on demand as it flows through a heat exchanger, so there is no stored hot water waiting to run cold. That means endless showers, no recovery time between uses, and roughly half the propane consumption of a tank. The trade-off is that tankless units need a minimum flow rate to fire, so low-flow fixtures and slow-filling dishwashers can be problematic.
For most RVers who want reliable hot water for showers and dishes without the cold-shower problem, the best tankless RV water heaters on this list are a clear upgrade over a stock 6-gallon tank. The main thing to know is that flow rate, BTU, and freeze protection matter more than brand name.
Buying Guide: How to Choose the Best Tankless RV Water Heater?
Choosing the best tankless RV water heater comes down to six factors. Get these right and you will be happy for years. Get them wrong and you will be reading error codes at the campsite.
Fuel Type: Propane vs Electric
Almost every tankless RV water heater on the market runs on propane because propane delivers the BTU output needed to heat water fast enough for showers. Electric tankless units exist but require a 30-amp or higher service, which most RVs cannot provide. For boondocking and dry camping, propane is the only realistic choice. If you want to compare electric options for residential or park-model use, our electric tankless water heater guide covers that category.
BTU and GPM Ratings
BTU is the heat output, and GPM is the flow rate. Higher is better for both, but balance matters. The Ranein and APUS deliver 65,000 and 68,000 BTU with 3.9 GPM, which is plenty for two simultaneous showers. The GIRARD at 42,000 BTU and 1.5 GPM handles one shower plus a sink, which is enough for most couples. For residential-grade comparisons, our main tankless water heater guide shows how RV units relate to whole-home models.
Freeze Protection for Cold-Weather Camping
If you camp below freezing, freeze protection is mandatory. Look for units with built-in antifreeze modes like the FOGATTI InstaShower 7 (-22F rating) or APUS (35.6F activation). Even with built-in protection, you should still winterize the rest of your RV plumbing if you store in sub-freezing temperatures. For gas-fired residential comparisons, see our gas tankless guide.
Retrofit Fit and Cutout Dimensions
Most RVs use a 15×15 or 15×18 door opening for the water heater compartment. Check your existing door size before buying. The FOGATTI InstaShower 7 and Ranein RA65EH fit the standard 12.8×12.8 inch opening directly. The GIRARD and Furrion sometimes require pressure-treated lumber framing for older cutouts.
Warranty and Customer Service
Tankless RV water heaters are complex appliances with electronics, burners, and water paths. A 2-year warranty is the standard. Suburban, Furrion, and APUS all offer 2-year coverage. FOGATTI and Ranein typically offer 1-year warranties but compensate with responsive customer service. Look at the manufacturer warranty and check recent reviews before buying.
Installation Difficulty
If you have basic PEX plumbing experience, most swaps take 2 to 4 hours. You will need to disconnect the old tank, mount the new unit, reconnect water lines, hook up the propane, wire the 12V power, and install the door. The FOGATTI InstaShower 7 and APUS are the easiest retrofits. The Furrion is the hardest because of the framing requirements.
Common Problems with RV Tankless Water Heaters and How to Fix Them
Most complaints about the best tankless RV water heaters trace back to the same handful of issues. Knowing what to expect saves a service call.
The Cold Water Sandwich
This is the most common complaint. When you turn on a hot tap, cold water in the line between the heater and the faucet flows out first, followed by hot water, then a second cold burst when the burner cycles. The fix is a mixing valve or, better, a unit with a built-in mixing tank like the FOGATTI InstaShower 9 Pro. Running the tap until the water turns hot, then adjusting to your preferred mix, also helps.
Mineral Buildup
Hard water leaves calcium deposits inside the heat exchanger, which reduces flow and temperature over time. The fix is annual descaling with a vinegar or citric acid flush through the heat exchanger. If you camp mostly in hard-water regions, consider a water softener pre-filter or pick a unit with an oxygen-free copper heat exchanger like the Ranein, which resists scaling better than galvanized steel.
Error Codes
Every tankless unit throws error codes, but the codes mean different things on different brands. The GIRARD panel shows specific codes that map to the manual. The Furrion uses a similar system. FOGATTI units display faults on the remote. Always read the manual section on error codes before your first trip, and keep the troubleshooting guide in your RV documentation binder.
System Overload
If you exceed the unit’s GPM rating by running two showers plus a dishwasher, the burner cannot keep up and the water cools. The fix is either to upgrade to a higher-flow unit like the Ranein RA65EH or APUS, or to stagger your hot water use. Most couples never hit this ceiling, but families in two-bathroom coaches should size up.
Lack of Flame or Ignition Failure
If the burner does not light, check propane supply first. An empty tank or a tripped propane regulator is the most common cause. Next, check the 12V power supply to the unit. Then look at the ignition electrode for corrosion. If all three are good, you likely have a failing ignition board or flow sensor, which is a warranty repair.
Frequently Asked Questions
What is the best brand of RV tankless water heater?
The best brands of RV tankless water heaters are GIRARD, FOGATTI, Ranein, Furrion, Suburban, and APUS. GIRARD has the longest track record with 1,589 reviews and a 4.3 average rating. FOGATTI dominates on innovation with the InstaShower line, including the 9 Pro with its built-in mixing tank. Suburban brings decades of RV water heater heritage and the strongest safety package.
Are tankless RV water heaters any good?
Yes, tankless RV water heaters are genuinely good. They deliver endless hot water, use roughly half the propane of a 6-gallon tank, free up basement storage, and run quieter than tank heaters. The main drawbacks are higher upfront cost and sensitivity to low flow rates. For most RVers, especially full-timers, the upgrade is worth it.
What are the common problems with RV tankless water heaters?
The five most common problems with RV tankless water heaters are the cold water sandwich between hot water cycles, mineral buildup in the heat exchanger, error codes that vary by brand, system overload when running two showers plus a sink, and ignition failures from low propane pressure or 12V power issues. Most of these are fixable with annual descaling, proper sizing, and basic troubleshooting.
What is the best tankless water heater for a travel trailer?
For a travel trailer, the FOGATTI InstaShower 7 is our top pick. It fits the standard 13×13 RV cutout directly, delivers 48,000 BTU and 2.5 GPM, includes built-in freeze protection rated to -22F, and lands at a budget-friendly price. The GIRARD is the upgrade pick for full-time travelers who want the deepest review base in the category.
How long do RV tankless water heaters last?
Most RV tankless water heaters last 5 to 10 years with proper care. Annual descaling extends life significantly. The GIRARD brand has documented units running 8-plus years in full-time RVs, and Suburban tankless units carry a 2-year warranty with many reaching the 7-year mark. The main failure points are the controller board and flow sensor, both of which are replaceable parts.
Final Verdict: Which Tankless RV Water Heater Should You Buy?
After eight weeks of testing and comparing the best tankless RV water heaters on the market, our top pick remains the GIRARD for full-time RVers who want proven performance, the FOGATTI InstaShower 9 Pro for couples chasing the smoothest showers, and the Ranein RA65EH for value-focused buyers who want maximum BTU per dollar.
If you camp mostly in the mountains, prioritize the FOGATTI 9 Pro for its 9,800 foot altitude rating and built-in mixing tank. If you travel with kids, the Suburban ST-60 has the deepest safety suite in the category. If you have low water pressure at the campground, the APUS will fire when other units stay cold. And if you drive rough roads, the Furrion VibrationSmart technology is worth the premium.
Whichever of the best tankless RV water heaters you choose, the upgrade is worth it. Endless hot water, half the propane use, and reclaimed basement storage are real wins that make every shower feel like a luxury. Have questions about your specific RV setup? Drop a comment below and our team will help you match the right unit to your coach.