Buying Guide
6 Best RV Water Heater in 2026: A Practical RV Guide
Compare two Suburban 6-gallon tank heaters and four propane tankless RV water heaters by BTU, cutout size and 12V power needs.
By Hardcastle's RV Editors
10 min read6 products evaluated
RV water heaters come in two real types: a 6-gallon tank unit like the Suburban that stores hot water, and a propane tankless unit that heats on demand. The choice turns on how much hot water you use in a row, how big your existing cutout is, and whether you can supply the 12V control power a tankless unit needs.
This hub sorts six picks into those camps and explains what each trades away. Headline GPM figures mean little without the inlet and outlet temperatures, and propane tankless units typically still need 12V power, so read both before buying.
Hardcastle’s RV field notes
The Rig Fit Check
A quick way to connect the shortlist to the space, workload and ownership details that matter after the box arrives.
- Start with the job
- Suburban SW6DE 6-Gallon RV Water Heater leads this shortlist for Like-for-like tank swap. Use that fit as a reference point, then compare the alternatives against your own space and workload.
- Specs that separate the picks
- The first details to compare are 6 gallon, DSI and electric, 6 gallon, DSI, 2.5 GPM, 48,000 BTU. Confirm the exact model and included components before ordering.
- Trade-off to plan for
- 6 gallons runs out faster than tankless
The Practical Shortlist
A road-tested-thinking look at 6 options, organized around the job each one suits best.
Best Overall
Suburban SW6DE 6-Gallon RV Water Heater
Like-for-like tank swap
Our take Check price for Suburban SW6DE 6-Gallon RV Water Heater (opens in a new tab)
Best Basic Tank
Suburban SW6D 6-Gallon RV Water Heater
Budget tank replacement
Our take Check price for Suburban SW6D 6-Gallon RV Water Heater (opens in a new tab)
Best Value Tankless
FOGATTI InstaShower 7 RV Tankless Water Heater
Tank-to-tankless conversion
Our take Check price for FOGATTI InstaShower 7 RV Tankless Water Heater (opens in a new tab)
Best Premium Tankless
FOGATTI InstaShower 8 Plus RV Tankless Water Heater
Larger households
Our take Check price for FOGATTI InstaShower 8 Plus RV Tankless Water Heater (opens in a new tab)
Best High-BTU Tankless
ORBEK RV Tankless Water Heater
High-output on a budget
Our take Check price for ORBEK RV Tankless Water Heater (opens in a new tab)
Best Budget Tankless
MapleGrace RV Water Heater
Budget tankless
Our take Check price for MapleGrace RV Water Heater (opens in a new tab)
Why Each Pick Made the Cut
Best Overall1 of 6
Suburban SW6DE 6-Gallon RV Water Heater on Amazon (opens in a new tab)
Choose Suburban SW6DE 6-Gallon RV Water Heater for electric element gives a second heat source.
Best for
- Like-for-like tank swap
Why it made the shortlist
The Suburban SW6DE is a 6-gallon RV water heater with direct spark ignition and an electric element, built with a porcelain-lined steel tank. It has a replaceable anode rod and a flue tube design Suburban says improves heat transfer.
Against the Suburban SW6D, it adds the electric element so you can heat on campsite or generator power, for a higher price.
Best for owners who want a familiar tank unit with dual fuel.
Key dimensions & specs
- 6 gallon, DSI and electric
- Porcelain-lined steel tank
- Replaceable anode rod
Pros
- Electric element gives a second heat source
- Replaceable anode rod protects the tank
- Porcelain-lined steel tank
- Direct spark ignition
Cons
- 6 gallons runs out faster than tankless
Best Basic Tank2 of 6
Suburban SW6D 6-Gallon RV Water Heater on Amazon (opens in a new tab)
Suburban SW6D 6-Gallon RV Water Heater makes the shortlist because direct spark ignition.
Best for
- Budget tank replacement
Why it made the shortlist
The Suburban SW6D is a 6-gallon direct spark ignition water heater with a porcelain-lined steel tank and replaceable anode rod.
Versus the tankless units, it holds 6 gallons and heats slower.
Key dimensions & specs
- 6 gallon, DSI
- Porcelain-lined steel tank
- Replaceable anode rod
Pros
- Direct spark ignition
- Porcelain-lined steel tank
- Replaceable anode rod for corrosion
Cons
- Electric heating is optional
- Limited 6 gallon capacity
Best Value Tankless3 of 6
FOGATTI InstaShower 7 RV Tankless Water Heater on Amazon (opens in a new tab)
The strongest case for FOGATTI InstaShower 7 RV Tankless Water Heater is states 2.5 GPM and 48,000 BTU.
Best for
- Tank-to-tankless conversion
Why it made the shortlist
The FOGATTI InstaShower 7 is a propane tankless water heater listed at 2.5 gallons per minute and 48,000 BTU, with staged combustion and anti-scale protection. It has a high-altitude mode to 9,800 feet, a preinstalled 150 PSI valve and a 6.6 foot smart remote.
Compared with the InstaShower 8 Plus, it has less BTU and costs less.
Best for owners converting from a tank with three door options.
Key dimensions & specs
- 2.5 GPM, 48,000 BTU
- High altitude to 9,800 ft
- 150 PSI valve, 6.6 ft remote
Pros
- States 2.5 GPM and 48,000 BTU
- High-altitude mode to 9,800 feet
- Three door options in two colors
- Preinstalled 150 PSI valve
Cons
- GPM figure lacks a stated temperature rise
- Needs 12V control power
Best Premium Tankless4 of 6
FOGATTI InstaShower 8 Plus RV Tankless Water Heater on Amazon (opens in a new tab)
FOGATTI InstaShower 8 Plus RV Tankless Water Heater is the better fit when larger households.
Best for
- Larger households
Why it made the shortlist
The FOGATTI InstaShower 8 Plus is a propane, 12V DC tankless water heater with 55,000 BTU, listed for altitudes up to 9,800 feet. The opening is 13 by 13 inches and it is said to replace all RV water heaters.
Key dimensions & specs
- 55,000 BTU propane
- 12V DC, high altitude
- 13 x 13 inch opening
Pros
- 55,000 BTU burner for higher output
- High-altitude suitability to 9,800 ft
- 13 by 13 inch opening fits many cutouts
- Hot water lasts longer than a tank
Cons
- Needs 12V DC power
Best High-BTU Tankless5 of 6
ORBEK RV Tankless Water Heater on Amazon (opens in a new tab)
Choose ORBEK RV Tankless Water Heater for 60,000 BTU burner.
Best for
- High-output on a budget
Why it made the shortlist
The ORBEK RV Tankless Water Heater is a propane unit with a 60,000 BTU burner and 12V DC power. It lists oxygen-free copper heat exchangers, brushless DC fans, a high-altitude mode and optional black or white door panels.
Compared with the FOGATTI InstaShower 8 Plus, it states more BTU at a lower price.
Best for buyers who want high BTU on a budget.
Key dimensions & specs
- 60,000 BTU propane
- 12V DC power
- Oxygen-free copper exchanger
Pros
- 60,000 BTU burner
- Oxygen-free copper heat exchangers
- Optional door panels in black or white
- Standard NPT water connections
Cons
- Door panels sold separately
- Needs 12V DC power
Best Budget Tankless6 of 6
MapleGrace RV Water Heater on Amazon (opens in a new tab)
MapleGrace RV Water Heater makes the shortlist because cSA certification stated.
Best for
- Budget tankless
Why it made the shortlist
The MapleGrace is a 55,000 BTU propane tankless water heater that is CSA certified, with a digital display and touch panel. It has dual outlets, including an exterior outlet for outdoor use.
Versus the ORBEK, it states CSA certification, which is a plus for safety, and costs less. Versus the FOGATTI InstaShower 7, it lists higher BTU.
Best for budget tankless buyers who want a CSA mark.
Key dimensions & specs
- 55,000 BTU, CSA certified
- LED display, touch panel
- Dual outlets, exterior use
Pros
- CSA certification stated
- Digital display with touch control
- Dual outlets for exterior use
Cons
- Fit and cutout details are thin
- Needs 12V control power
How We Built This Shortlist
Each pick was assessed across 5 criteria weighted for real-world use.
- Heater type
- We separated 6-gallon tank units from propane tankless heaters because capacity and installation differ.
- BTU and flow context
- We noted BTU and GPM, and flagged flow figures that lack temperature rise.
- Power needs
- We checked 12V DC and 120V requirements.
- Fit and cutout
- We compared named opening sizes and door options.
- Safety marks
- We looked for named certifications such as CSA.
What Matters Before You Choose an RV Water Heater
Key buying criteria so you get the right fit the first time.
BTU and flow
BTU is heating power, while GPM is flow at a specific temperature rise, such as 40 or 60 degrees. A GPM number without the rise is incomplete. Look for both and compare them within the same type.
Tank versus tankless
A 6-gallon tank runs out after a limited amount of hot water and then needs time to recover, while a tankless heats continuously. Tankless units need adequate gas supply and flow. Match to your household.
12V power requirement
Many propane tankless units still need 12V DC to run the fan and control board. Your battery must support it. Check the listing for voltage and draw.
Cutout and venting
Your existing opening decides what fits, and doors and vents vary. A wrong fit means carpentry. Measure the opening and compare it to the 13 by 13 inch size named on some listings.
Altitude and freeze protection
Burners need adjustment above certain altitudes, and tanks can freeze in winter. That matters if you camp in the mountains or in winter. Look for an altitude rating, such as 9,800 feet, and freeze notes.
Certification and venting safety
Propane appliances produce combustion gases, so a named certification and correct venting matter. A poor install can be dangerous, not just inefficient. Look for CSA or similar marks and follow installation instructions.
Match an RV Water Heater to Your RV
By Household Size
| Your situation | Recommended pick | Why |
|---|---|---|
| One or two people, short showers | Suburban SW6D | 6 gallons covers short showers. |
| Want gas and electric | Suburban SW6DE | Adds an electric element. |
| Family, long showers | FOGATTI InstaShower 8 Plus | 55,000 BTU tankless. |
| Highest BTU | ORBEK 60K | 60,000 BTU propane. |
| Budget tankless | MapleGrace 55K | CSA certified at a lower price. |
Scroll sideways to see every column.
By Budget
| Budget | Recommended pick |
|---|---|
| $140 to $250 | MapleGrace 55K or ORBEK 60K |
| $410 to $440 | FOGATTI InstaShower 7 or Suburban SW6D |
| $500 to $520 | Suburban SW6DE or FOGATTI InstaShower 8 Plus |
Tank vs Tankless
- Tank
- The Suburban SW6DE and Suburban SW6D store 6 gallons and heat slowly, but are simple and have fewer power needs. They suit short showers.
- Tankless
- The FOGATTI InstaShower 7, FOGATTI InstaShower 8 Plus, ORBEK 60K and MapleGrace 55K heat on demand and need 12V power. They suit long showers and give more usable space.
Most owners with a Suburban cutout should choose the Suburban SW6DE unless the FOGATTI InstaShower 7 conversion appeals.
By Installation
| Install | Recommended pick |
|---|---|
| Existing Suburban opening | Suburban SW6D |
| 13 by 13 inch cutout | FOGATTI InstaShower 8 Plus |
| Door color choice | FOGATTI InstaShower 7 |
| Black or white panel | ORBEK 60K |
For High-Altitude or Cold-Weather Camping Specifically
- Look for
- A stated altitude rating, a freeze protection note and a 12V supply that stays charged, as the Suburban SW6DE listing shows.
- In this comparison
- The FOGATTI InstaShower 7 and FOGATTI InstaShower 8 Plus list a 9,800 foot altitude mode. Check freeze protection separately.
When to Spend More
- Spend more if
- Spend more on the FOGATTI InstaShower 8 Plus or Suburban SW6DE if you want higher output or dual fuel and expect heavy daily hot water use.
- Save if
- Save with the MapleGrace 55K or Suburban SW6D if you want a lower-cost fix and can accept limits.
Before You Bring One Home
Do tankless RV water heaters need 12V power?
Many do. The FOGATTI InstaShower 7 and ORBEK 60K list 12V DC. Confirm your battery can supply it.
How do I know a tankless heater will fit my cutout?
Measure the opening and compare it to the listing, such as the 13 by 13 inches on the FOGATTI InstaShower 8 Plus. Check the door options.
Is the FOGATTI InstaShower 8 Plus worth more than the FOGATTI InstaShower 7?
If you want 55,000 BTU and higher output, yes. For lighter use the InstaShower 7 costs less.
How should I maintain an RV water heater?
Flush the tank, check the anode rod on a Suburban, and descale tankless units. Drain before freezing weather.
Can I replace a tank heater with a tankless?
Often yes, with the right cutout and gas supply. Follow installation rules and have a qualified person check venting.
Bottom Line
Best overall: Suburban SW6DE 6-Gallon RV Water Heater — best overall pick in this roundup. See the full verdicts above for every pick, with pros, cons and who each one suits.
Browse all rv water heater on Amazon — Prime-eligible options with current pricing.