RV tankless water heaters serve a specific niche — replacing the traditional 6-gallon or 10-gallon storage tanks that most US travel trailers and motorhomes ship with. The advantages versus storage are real (weight, footprint, freeze-protection during winter storage, endless hot water), but the install constraints are specific to RV plumbing and propane systems.
Top RV tankless picks
Best overall RV tankless: Furrion FWH09BL 2.4 GPM
60K BTU propane, 2.4 GPM peak, sealed exterior venting, 12V DC ignition. Specifically engineered for travel trailers and fifth wheels. About $600 unit, $300–$500 install. The most-installed aftermarket RV tankless in the US.
Best for larger RVs and Class A: Truma AquaGo Comfort Plus
Premium European-engineered. Hybrid tankless + small buffer for instant hot at startup. Higher BTU output. About $1,700 unit, $500–$800 install. Right answer for high-end coaches and longer-duration full-timers.
Best for replacing Atwood/Dometic storage tanks: PrecisionTemp RV-550 NSP
55K BTU propane tankless, fits in most existing Atwood G6 series cutouts with trim plates. 1.5 GPM peak. About $800 unit. Direct conversion path for existing 6-gallon Atwood installs.
Best budget option: Camplux 5L Outdoor Portable
Not a permanent install — a portable outdoor tankless that sits beside the RV at the campsite. 50K BTU, 1.32 GPM. Battery-ignited, propane-fed. About $200. Right answer for occasional weekend camping where permanent conversion is overkill.
Why convert from storage to tankless in an RV
Weight savings
6-gallon storage tank: ~50 lbs full of water. Tankless: ~15 lbs total. The 35-lb savings matters for trailers near their cargo capacity limits and for motorhomes managing front-axle weight.
Footprint and storage
The exterior cutout where the storage tank lived (typically 12" × 12" × 16" deep) is freed up for storage when converted to tankless (which is much smaller and mounts inside the cabinet). For a small RV where every cubic foot counts, this matters.
Winterization simplicity
Storage tanks must be drained completely for freeze protection in winter storage. A tankless has no reservoir to freeze (just the small heat exchanger path). Winterization is simpler — flush the exchanger with RV antifreeze and you're done.
Endless hot water for longer showers
A 6-gallon storage tank delivers about a 4-minute shower at typical RV flow rates (1.5 GPM). After that, you wait 20+ minutes for the tank to recover. Tankless provides continuous hot water — particularly useful at campgrounds without strict water restrictions where longer showers are practical.
Install considerations specific to RV
Propane regulator sizing
RV propane regulators are typically sized for the existing storage tank's 8,800 BTU burner. A 55–60K BTU tankless requires roughly 7× the propane flow. The regulator may need to be upsized or a high-flow regulator added. Verify before install or experience flame-out under load.
12V power requirements
RV tankless units use 12V DC for ignition and control board (no 120V required, which is the advantage over residential tankless). Verify the existing 12V wiring to the storage tank's compartment is adequate amp for the new unit — typically 5–10 amps continuous.
Plumbing connections
RV plumbing typically uses PEX with 1/2" PEX fittings. The new tankless will have 1/2" NPT or 3/8" SAE flare fittings — verify the adapter situation and have the right connections on hand before install.
Exterior venting
The combustion vent location is fixed by the existing cutout. The new tankless's vent termination must align — most retrofits include a trim plate that adapts the new unit to the existing cutout. Verify trim availability before purchase.
When not to convert
Three scenarios where keeping the storage tank is the right call:
- Older RV (pre-2000) with marginal plumbing. The conversion exposes weak points in older PEX joints and propane regulators. Cost can spiral beyond the value of the conversion.
- Storage tank still has 5+ years of expected life. Don't replace a working unit. Convert at next failure.
- Owner uses RV exclusively at campgrounds with full hookups. Hot water is rarely an issue at full-hookup sites; the conversion benefits are smaller than for boondocking-focused use.
