A six-gallon RV water heater can turn a relaxing shower into a race against the clock. One moment the water feels warm, and the next it bites like a mountain stream. An RV on demand water heater removes the small storage tank and heats water as it passes through the unit.
The best RV on demand water heater must match the camper’s propane supply, 12-volt power, water pressure, wall opening, door size, and cold-weather use. Burner size matters, but steady temperature control matters just as much. A powerful heater can still produce hot and cold swings when the water pump pulses or the shower flow drops too low.
High-End Pick: Truma AquaGo Comfort
The Truma AquaGo Comfort is the premium choice for RV owners who want steady shower temperatures and strong low-flow performance. It uses a small 0.35-gallon mixing vessel that softens the temperature swings found in many basic tankless units.
The burner adjusts from 20,000 to 60,000 BTU per hour. This wide firing range helps the AquaGo handle a gentle sink stream, a normal RV shower, or more than one open faucet. Truma states that the heater can work at flow rates below 0.4 gallon per minute.
Low-flow operation matters inside a camper. RV shower heads often use less water than household models, and campground pressure can change from one site to the next. A heater that needs a strong flow may shut the flame off when the user slows the shower to save fresh water.
The AquaGo Comfort runs on propane and 12-volt DC power. It draws less than 2.5 amps while operating and has a very low standby draw. The cabinet weighs about 34.2 pounds and measures roughly 12.5 inches wide, 12.5 inches high, and 15.5 inches deep.
The standard outlet temperature is 120°F. A microprocessor changes burner output based on water flow and inlet temperature. The small mixing vessel then smooths the hot-water delivery before it reaches the faucet.
Truma also gives the AquaGo an easy drain lever and a built-in decalcification process. The owner can clean mineral deposits with Truma tablets rather than removing the whole appliance. This is useful for full-time RVers who move through campgrounds with hard water.
The AquaGo Comfort can replace many sidewall-mounted six-gallon, ten-gallon, and older tankless heaters. Truma handles aftermarket sales through trained partners and factory retrofit sites. A full professional retrofit may reach or pass $2,000 once the heater, door, plumbing changes, labor, propane work, and shop fees are counted.
Check Truma AquaGo Comfort listings and parts on Amazon
Best Overall Value: Furrion 2.4 GPM Tankless RV Water Heater
The Furrion 2.4 GPM Tankless RV Water Heater is the best overall choice for many travel trailers, fifth wheels, and motorhomes. It combines a 60,000 BTU burner, a listed 2.4 gallon-per-minute output, an interior thermostat, and several retrofit door sizes.
Furrion uses an internal mixing design to reduce cold spots and sudden bursts of very hot water. The wall controller lets the user select the outlet temperature and watch the heater’s operating status. It also displays a warning when water flow becomes too low.
The heater has automatic freeze protection when propane and electrical power remain available. It also has over-temperature protection, blower monitoring, a pressure-relief valve, and automatic shutdown.
Three common door sizes are sold for retrofit work. The choices include roughly 16.14 by 16.14 inches, 18.11 by 16.14 inches, and 18.11 by 18.11 inches. These doors help cover openings left by older Atwood and Suburban tank heaters.
The Furrion weighs about 31.3 pounds with the listed configuration. Its one-year warranty is shorter than the coverage on the Suburban ST-60, but Furrion parts and Lippert service channels are easy to find in many RV markets.
This model works well for couples and small families who camp with full hookups. It can also suit boondocking, though an endless heater does not create an endless fresh-water supply. A long shower can drain the fresh tank and fill the gray tank quickly.
Check Furrion 2.4 GPM RV water heater listings on Amazon
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Best RV On Demand Water Heater Comparison
| Model | Burner Output | Power | Best Use | Warranty |
|---|---|---|---|---|
| Truma AquaGo Comfort | 20,000 to 60,000 BTU | 12V DC, under 2.5A | Premium temperature control | Dealer terms apply |
| Furrion 2.4 GPM | 60,000 BTU | 12V DC | Best overall value | 1 year |
| Suburban ST-60 | 60,000 BTU | 12V DC | Cold-weather camping | 2 years |
| Fogatti InstaShower 9 Pro | 66,000 BTU | 12V DC | High shower flow | Check seller terms |
| Girard GSWH-2 | 42,000 BTU | 12V DC, under 3A | Lightweight retrofit | 1 year retail listing |
| RecPro 60,000 BTU | 12,000 to 60,000 BTU | 12V DC, about 3A | Lower-cost retrofit | Check current terms |
Suburban ST-60: Best for Cold-Weather Camping
The Suburban ST-60 is a strong pick for RV owners who camp during chilly spring mornings, late fall trips, or mild winter weather. Its propane burner reaches 60,000 BTU per hour, and the included digital wall control sets the desired water temperature.
Active freeze protection guards the heater when propane and 12-volt power remain connected. This feature can protect the appliance during an unexpected cold night, but it does not replace winterization. The owner must drain the heater and plumbing before storage in freezing weather.
The ST-60 also has flame-out protection. It stops propane flow after a burner fault or a drop in gas pressure. Fan monitoring shuts the gas valve when combustion airflow becomes blocked.
A high-temperature switch guards against scalding after a thermostat fault. The control also has a child lock that limits the selected outlet temperature. Maximum water temperature reaches 131°F when the lock is not active.
The cabinet measures about 13.125 inches wide, 13.125 inches high, and 13 inches deep. Its square body can fit many common RV water-heater spaces, though the old cutout and new door must be measured before purchase.
Suburban gives the ST-60 a two-year limited warranty. That is one reason it stands above many lower-cost camper tankless water heaters with one-year coverage.
Check Suburban ST-60 listings on Amazon
Fogatti InstaShower 9 Pro: Best for High Flow
The Fogatti InstaShower 9 Pro is aimed at RV owners who want a stronger shower stream. Fogatti rates the burner at 66,000 BTU and lists output as high as 3.6 gallons per minute under favorable water conditions.
A built-in mixing tank helps hold the selected temperature within a narrow band. This can reduce the hot-cold wave that appears when the shower head is briefly closed and opened again.
The larger burner gives the heater more room when incoming water is cold. It may also handle a shower and a small faucet at the same time. Actual flow falls when winter water needs a larger temperature rise.
The InstaShower 9 Pro is attractive for a fifth wheel, toy hauler, or large travel trailer with a residential-style shower. Before ordering, check the exterior opening, door size, propane pressure, water-line position, electrical plug, and exhaust clearance.
Fogatti sells several door sizes and heater packages. Read the exact package details before checkout because a listing may include the heater without the door needed for the RV wall.
Check Fogatti InstaShower 9 Pro listings on Amazon
Girard GSWH-2: Best Lightweight Retrofit
The Girard GSWH-2 is a compact propane RV water heater with a 42,000 BTU burner. Its light body and familiar 12.5-inch square face make it a common replacement for older six-gallon tank units.
The heater weighs close to 23 pounds in its normal setup. That can save weight compared with a steel storage tank filled with six or ten gallons of water.
A brushless 12-volt motor draws less than three amps during use. The digital controller lets the owner set water temperature from 95°F to 124°F. It also displays outlet temperature and fault codes.
The internal controls watch inlet temperature, outlet temperature, and water flow. Burner output changes as those conditions move. The aim is a steady shower without constant faucet adjustment.
The Girard has less burner power than the 60,000 BTU models above. It may feel weaker when cold campground water enters the RV during winter. Couples who camp in warm or moderate weather may find its output fully adequate.
Conversion doors are sold for common six-gallon and ten-gallon openings. Measure the old flange and wall cutout before choosing a kit. A door that is too small will leave screw holes and wall gaps exposed.
Check Girard GSWH-2 listings on Amazon
RecPro 60,000 BTU: Best Lower-Cost Pick
The RecPro 60,000 BTU RV Tankless Water Heater gives buyers a lower-cost path to stronger burner power. Its propane input changes from about 12,000 to 60,000 BTU per hour based on water demand.
The unit runs on 12-volt DC power and draws about three amps. It comes with a wired controller for power, temperature selection, Fahrenheit or Celsius display, and fault codes.
Safety controls include flame-out shutdown, low-voltage and high-voltage shutdown, blower monitoring, freeze protection, and a pressure-relief valve. Freeze protection needs propane and electrical power. It cannot guard an RV that is parked without power during a hard freeze.
RecPro sells the unit with 15-inch and 18-inch door choices. White and black doors are available. The buyer can also add a backflow preventer and an installation kit.
This model suits an older camper where the owner wants 60,000 BTU output without paying premium retrofit prices. Service access should be checked before purchase, especially for full-time travel far from the seller.
Check RecPro 60,000 BTU RV heater listings on Amazon
How an RV Tankless Water Heater Works
An RV tankless water heater starts when a flow sensor detects moving water. The control opens the propane valve, starts the fan, and lights the burner. Heat passes into the water through a metal exchanger.
The burner shuts down when the faucet closes. There is no six-gallon tank that stays hot between uses. This can reduce propane use during long periods when nobody needs hot water.
The heater still needs 12-volt power. The control board, igniter, fan, gas valve, sensors, freeze guard, and wall display rely on the RV battery system. A weak battery or poor converter can cause ignition faults.
Water flow also matters. Every model has a minimum activation rate. When the flow drops below that point, the burner stops. A clogged shower head, weak pump, dirty inlet screen, or nearly closed faucet can cause unwanted cold bursts.
RV Tankless vs. Six-Gallon Tank Water Heater
A tankless model can supply hot water for as long as propane, water, and battery power remain available. This is ideal at a campground with full hookups. One person can shower after another without waiting for a small tank to recover.
A six-gallon tank gives hot water at very low flow. It can also run on propane, shore power, or both when fitted with gas and electric heating. Its stored water acts as a small cushion when campground pressure changes.
Tankless heaters ask for steadier water flow. They may also waste fresh water while the burner lights and warm water travels through the pipes. Premium models with small mixing vessels reduce this delay.
Boondockers must watch tank capacity. Endless hot water can empty a 40-gallon fresh tank faster than expected. A navy shower may still be needed when water and dump access are limited.
How Much Burner Power Does an RV Shower Need?
A 42,000 BTU heater can handle a normal RV shower in warm and moderate weather. It works best when incoming water is not extremely cold and only one hot-water fixture runs.
A 55,000 to 60,000 BTU heater gives more room for colder inlet water. It can also hold temperature better when shower flow rises or a sink opens nearby.
A 66,000 BTU model may suit a larger RV with a high-flow shower head. Burner size alone does not decide comfort. Water control, mixing design, flow sensor quality, and propane pressure also affect the shower.
A heater cannot deliver its full rating when the regulator or propane line is undersized. A technician should test gas pressure while the burner runs at high fire.
Check the Wall Opening and Door Size
Do not order an RV tankless heater by the old tank’s gallon rating. A six-gallon Atwood, six-gallon Suburban, ten-gallon tank, and factory tankless unit can leave different wall openings.
Measure the cutout width, cutout height, wall thickness, cabinet depth, flange area, and screw pattern. Check the space behind the heater for water lines, propane tubing, wiring, flooring, and nearby cabinets.
The new exterior door must cover the old opening and screw holes. A larger conversion door can hide marks left by the previous flange. A smaller door may require wall repair or a custom trim plate.
The exhaust must remain clear of windows, slide rooms, awnings, storage doors, and propane components. Follow the heater manual and RV rules for the final location.
Water Pressure and Pump Performance
A tankless heater works best with steady pressure. Campground water can surge or fall as other campers use the line. A pressure regulator can protect the RV plumbing and calm some swings.
The onboard pump should also provide smooth flow. A worn pump may pulse every few seconds, which can make the burner chase a moving target. An accumulator tank can soften pump cycling in some RV plumbing setups.
Clean the heater’s inlet screen when flow becomes weak. Mineral flakes, pipe debris, and sediment can block the screen. A dirty shower head can create the same problem.
Do not mix large amounts of cold water at the shower valve unless the heater maker directs that method. Set the wall controller near the desired shower temperature and use mainly the hot side. This keeps enough flow moving through the heater.
Cold Weather and Freeze Protection
Freeze protection is not the same as winterization. Built-in heaters can warm selected parts only when propane, battery power, and the heater’s controls remain active.
Exterior water lines, valves, filters, and fittings may still freeze. A long power outage can also stop the protection circuit. Hard freezes can split the heat exchanger and create an expensive leak.
Drain the heater before winter storage. Follow the exact maker steps because tankless models can trap water in small passages. Some units have a drain lever, while others need plugs or compressed air.
RV antifreeze must be used only as directed by the heater maker. The wrong method can leave water inside the exchanger or place fluid where it should not go.
Installation Cost
A simple swap can be affordable when the new heater matches the old opening and all connections sit nearby. Labor rises when the door size changes, propane tubing must move, wiring needs repair, or the cabinet needs new bracing.
A premium Truma retrofit may pass $2,000 as a completed shop job. Mainstream Furrion, Girard, Suburban, Fogatti, and RecPro swaps often cost less, though body repair can add a large charge.
Ask the shop to price the heater, conversion door, sealant, propane work, wiring, plumbing fittings, wall repair, leak test, burner test, and old-unit disposal.
Propane appliances should be installed and tested by a qualified RV technician. A poor exhaust seal can send combustion gases into the camper, while a poor propane joint can create a fire risk.
Care and Cleaning
Hard water leaves scale inside the heat exchanger. Scale can slow water flow and reduce heat transfer. Full-time campers may need descaling more often than weekend users.
Clean the inlet screen, inspect the exterior vent, and remove insect nests or road debris. Check the propane flame and fault history when the heater begins shutting down.
Drain the unit before freezing storage. Inspect the exterior door seal after long trips because vibration can loosen screws and crack old sealant.
Carry the model number, manual, fuse details, and basic spare parts during long trips. A flow sensor, fuse, drain plug, or controller cable can be hard to find in a remote town.
Common Buying Mistakes
Choosing by BTU Rating Alone
A large burner helps with cold water, but steady flow control matters just as much. Compare activation flow, mixing design, controls, and service access.
Forgetting About the Fresh and Gray Tanks
An on demand heater can run longer than a storage heater. The fresh tank and gray tank may become the new limits.
Buying the Wrong Door
The heater may fit inside the cabinet while the exterior door fails to cover the old opening. Measure before ordering.
Expecting Freeze Protection During Storage
Freeze protection needs power and propane. A drained heater is safer during long winter storage.
Using Too Much Cold Water at the Shower Valve
Heavy cold-water mixing reduces flow through the heater. The burner may shut off and send a cold wave through the shower.
Skipping the Propane Pressure Test
A weak regulator or narrow line can starve a 60,000 BTU burner. Test pressure while the heater runs.
Final Verdict
The Truma AquaGo Comfort is the best premium RV on demand water heater. Its 20,000-to-60,000 BTU burner, small mixing vessel, low-flow operation, easy draining, and decalcification process make it a polished choice for full-time RV use.
The Furrion 2.4 GPM is the best overall value for many campers. It pairs a 60,000 BTU burner with several retrofit door sizes, freeze protection, a digital thermostat, and a listed 2.4 GPM output.
The Suburban ST-60 is the better pick for cold-weather travel and buyers who want a two-year limited warranty. The Fogatti InstaShower 9 Pro suits larger RV showers that need more flow.
The Girard GSWH-2 is a light and familiar retrofit choice for moderate climates. The RecPro 60,000 BTU gives budget-minded buyers strong burner power and flexible door choices.
Before ordering, measure the wall opening, cabinet, exterior flange, propane line, water connections, and electrical plug. Check the minimum flow rate and cold-weather plan. The right camper tankless hot water heater should turn a cramped RV shower into a calm place rather than another race against a cooling tank.