RV tankless water heaters are worth the upgrade for full-time campers, families, and extended-stay RVers who value continuous hot water and reclaimed storage space. They are less attractive for weekend campers, strict boondockers, and owners focused on the lowest upfront cost because tankless units cost more, require minimum flow, consume water while warming, and need careful winterization.
Key Facts at a Glance
- A propane RV tankless water heater typically delivers about 1.5-2.4 gallons per minute, depending on temperature rise and incoming water temperature.
- A conventional RV water heater usually stores 6 or 10 gallons and needs roughly 20-40 minutes to recover after heavy use.
- Typical installed cost for an RV tankless replacement is about $650-$1,800, including a $450-$1,200 appliance and $200-$600 labor.
- Tankless operation reduces standby heating because the burner runs when water flows, but it does not eliminate propane use during showers.
- Most RV tankless units need about 0.4-0.5 GPM to activate, so very low faucet flow can produce cold water or a fault code.
- Freeze damage is a serious risk because the heat exchanger contains narrow passages that must be drained or protected.
What Is an RV Tankless Water Heater?
An RV tankless water heater is an on-demand appliance that heats water as it passes through a compact heat exchanger instead of storing heated water in a 6- or 10-gallon tank. Propane models use an LP burner and 12-volt controls, while electric models use shore power and place substantially greater demands on the RV electrical system.
A conventional water heater reheats stored water even when nobody is using a faucet. An on-demand model avoids that standby cycle, but the energy saving is most noticeable when the RV sits unused for long periods or when hot-water demand is intermittent. During a continuous shower, the burner can run for the entire shower.
“Endless hot water” means continuous supply at the unit’s rated flow and temperature rise. It does not mean unlimited water, propane, battery power, or gray-tank capacity. A family can keep showering, but the fresh-water tank and wastewater system still impose practical limits.
How Does an RV Tankless Water Heater Work?
An RV tankless water heater detects water movement, ignites a burner or energizes an element, transfers heat through a metal exchanger, and modulates output to maintain the selected temperature. The full process usually follows seven stages:
- Hot faucet opens: Water leaves the plumbing line and creates flow through the heater.
- Flow sensor activates: A turbine or electronic sensor measures movement.
- Control board responds: The board checks flow, temperature, 12-volt voltage, and safety switches.
- Ignition begins: A propane unit starts its combustion fan and igniter; an electric unit energizes its heating element.
- Heat exchanger transfers energy: Water passes through copper or stainless-steel passages around the heat source.
- Output modulates: Gas valves or electric controls adjust heat according to flow and incoming temperature.
- Hot water exits: The faucet receives heated water after the delay caused by the RV’s plumbing distance.
The water is not normally hot at the tap instantly. A 20-foot plumbing run can still contain cool water, so the first several seconds may be cold regardless of heater type. A recirculation feature can reduce that wait, but it adds cost, controls, and water or energy considerations.
Are RV Tankless Water Heaters Worth It for Most Owners?
RV tankless water heaters are worth the money when hot-water shortages create a recurring problem and the RV has reliable propane, water, and electrical systems. The upgrade is usually difficult to justify when the existing tank works, camping trips are short, and the owner rarely needs more than one consecutive shower.
The strongest case involves two or more people using hot water repeatedly. A 6-gallon tank may provide one long shower or several short uses before its temperature falls, whereas an appropriately sized tankless unit can keep supplying water as long as the burner, water source, and gray tank can keep up.
The weakest case involves dispersed camping with limited fresh water. Waiting for hot water at the shower can send usable water into the gray tank, and a tankless heater cannot create water that the RV does not carry. Tank models also provide a reserve of already heated water, which can be useful when the pump or generator is temporarily unavailable.
Quick Verdict by Camping Profile
| RV owner profile | Typical use | Verdict | Main reason |
|---|---|---|---|
| Full-time stationary RVer | 2-4 showers daily | Worth it | Continuous supply offsets higher purchase cost |
| Family campground user | 3-6 people per trip | Usually worth it | Faster back-to-back bathing |
| Weekend couple | 10-20 nights yearly | Usually not | Convenience rarely repays $650-$1,800 |
| Extreme boondocker | 20-40 gallons daily | Conditional | Water waste and gray capacity matter |
| Cold-climate seasonal camper | Freezing winters | Conditional | Winterization discipline determines survival |
How Do Tankless and Tank RV Water Heaters Compare?
Tankless models win on continuous supply, physical weight, and standby operation, while traditional tanks win on purchase price, simple behavior, and tolerance of low water flow. The correct choice depends more on household usage and camping infrastructure than on the heater’s advertised efficiency.
| Decision factor | RV tankless heater | 6-gallon RV tank | 10-gallon RV tank |
|---|---|---|---|
| Typical purchase price | $450-$1,200 | $250-$500 | $500-$900 |
| Typical installed cost | $650-$1,800 | $350-$900 | $600-$1,300 |
| Hot-water storage | 0 gallons | 6 gallons | 10 gallons |
| Typical recovery period | Continuous flow | 20-40 minutes | 25-45 minutes |
| Empty appliance weight | 15-25 pounds | 35-55 pounds | 45-65 pounds |
| Activation flow | 0.4-0.5 GPM | No minimum flow | No minimum flow |
| Typical LP output | 42,000-60,000 BTU | 8,800-12,000 BTU | 8,800-12,000 BTU |
| Typical life with maintenance | 10-15 years | 6-10 years | 6-10 years |
The weight comparison requires care. A tank contains several dozen pounds of water when full, but that water is already part of the RV’s payload calculation when the fresh tank is filled. Replacing a tank heater can reclaim appliance weight, yet the total trip weight changes only when the tank’s operating water load changes.
Which Heater Type Is Better, Propane or Electric?
Propane is usually the better RV tankless fuel because LP provides high heat output without consuming a 30-amp or 50-amp shore-power circuit. Electric tankless units suit stationary RVs with robust hookups, but many compact models deliver lower flow and can overload a small electrical panel.
| Heater type | Input requirement | Typical flow | Best environment | Main limitation |
|---|---|---|---|---|
| LP tankless | 12V controls, propane line, exterior combustion | 1.5-2.4 GPM | Boondocking and mixed camping | Requires LP and combustion maintenance |
| 120V electric | 15-30A circuit, shore power | 1.0-1.5 GPM | Full-hookup campground | High amperage reduces appliance capacity |
| 240V electric | Dedicated 30-50A circuit | 2.0-4.0 GPM | Permanent or specialized installation | Rarely practical in moving RVs |
| LP tank heater | 12V controls and propane | 0.8-1.5 GPM | Existing factory replacement | Limited stored-water volume |
| Electric tank heater | 120V element, commonly 1,440W | 0.8-1.5 GPM recovery equivalent | Quiet campground operation | Slow recovery and shore-power dependence |
A 1,440-watt electric element draws about 12 amps at 120 volts before other RV loads. A larger electric tankless unit can require 30 amps or more, leaving less capacity for air conditioning, battery charging, induction cooking, and refrigeration.
What Performance Should You Expect?
A typical RV propane tankless heater produces about 1.5-2.4 GPM, but maximum flow falls as the required temperature rise increases. A 40°F rise from cold mountain water to a comfortable shower temperature can reduce practical output below the headline specification.
| Operating condition | Incoming water | Target water | Approximate rise | Practical result |
|---|---|---|---|---|
| Warm campground supply | 65°F | 105°F | 40°F | Near rated flow |
| Mild spring camping | 55°F | 105°F | 50°F | Reduced flow or higher burner output |
| Cold well or mountain supply | 45°F | 105°F | 60°F | Lower shower flow likely |
| Winter hookup, protected lines | 35°F | 105°F | 70°F | Tankless performance becomes marginal |
| Low-flow handwashing | 55°F | 100°F | 45°F | Sensor may cycle below 0.4 GPM |
The temperature-rise relationship explains why two owners can report very different results from the same model. Incoming water temperature, showerhead restriction, water pressure, mineral scale, and propane pressure all affect delivered performance.
Typical LP consumption is approximately 0.5-0.75 pounds per hour during continuous burner operation, although cycling, set temperature, and water temperature change the result. A 30-minute shower therefore does not automatically consume the same amount of propane as a 30-minute full-output burn.
How Much Does an RV Tankless Upgrade Cost?
A typical RV tankless replacement costs $650-$1,800 installed, with the appliance accounting for approximately $450-$1,200 and labor adding about $200-$600. Extra charges arise when the cutout, gas line, electrical wiring, exterior door, venting, or plumbing connections require modification.
| Cost item | Typical low | Typical high | Cost driver |
|---|---|---|---|
| LP direct-fit unit | $450 | $900 | Capacity, controls, brand |
| Premium LP unit | $900 | $1,200 | Recirculation and diagnostics |
| Electric unit | $300 | $900 | Voltage and output |
| Professional labor | $200 | $600 | Access and conversion complexity |
| Door or trim kit | $50 | $250 | Cutout and exterior finish |
| Water treatment or descaling kit | $30 | $150 | Hardness and maintenance plan |
| Total installed replacement | $650 | $1,800 | Existing compatibility |
A direct-fit replacement can reduce labor when the new heater matches the old Suburban or Atwood cutout, door, gas connection, and plumbing orientation. A universal unit may appear cheaper but can require exterior fabrication, rewiring, or new controls.
For a realistic payback calculation, count convenience as the main return rather than assuming dramatic fuel savings. If an owner camps 20 nights per year and saves $10 per night in energy and replacement costs, a $1,000 upgrade would take five years to recover, before maintenance and repairs.
Will a Tankless Unit Fit Your RV?
An RV tankless heater fits safely only when the appliance dimensions, exterior door, gas capacity, electrical supply, plumbing connections, drainage, and combustion clearances match the RV installation. A nominal 12.5-inch replacement size does not guarantee compatibility across Suburban, Atwood, Dometic, Girard, Furrion, Fogatti, and Truma systems.
Measure and verify these items before ordering:
- Exterior cutout width, height, and depth, measured at multiple points.
- Existing door dimensions and hinge or latch location.
- LP pipe size, shutoff access, regulator condition, and approved fittings.
- 12-volt positive and negative wiring size, fuse rating, and polarity.
- Cold-water and hot-water connection locations.
- Exhaust direction, surrounding seal, and manufacturer clearance requirements.
- Drain points for winterization and service access.
- Control-panel wiring and whether the replacement includes a compatible wall pad.
A certified RV technician should inspect LP combustion and exhaust work. An incorrectly sealed exterior door or altered vent can expose occupants to combustion products, water intrusion, or fire risk.
What Are the Main Benefits?
The strongest benefits are continuous hot water, reduced occupied space, lower standby operation, and more consistent comfort for multiple users. Those benefits matter most when the RV remains connected to utilities or carries enough water and propane for repeated use.
Continuous Supply
A tankless heater can support consecutive showers without waiting 20-40 minutes for a storage tank to recover. The benefit disappears if the water pump cannot maintain pressure, the gray tank fills, or incoming water is too cold for the unit’s rated flow.
Reduced Storage and Weight
Many RV tankless appliances weigh approximately 15-25 pounds empty and occupy a compact cabinet or exterior compartment. Removing a full tank can reduce operating weight, but the actual payload gain depends on whether the RV would have carried that water anyway.
Less Standby Heating
A tankless burner does not maintain a hot reservoir overnight. That can reduce unnecessary LP consumption during idle periods, although the burner still uses substantial energy while water flows.
Better Control
Digital wall pads commonly allow users to select an exact temperature rather than mixing large amounts of cold water at the shower valve. Correct settings can help maintain enough flow to keep the sensor engaged.
What Problems Make Owners Regret the Upgrade?
The main drawbacks are higher purchase cost, minimum-flow behavior, cold-water delays, freeze vulnerability, scale sensitivity, and greater dependence on electrical controls. Tankless hardware solves the shortage of stored hot water, not every weakness in an RV plumbing system.
The Water Sandwich Effect
The water sandwich effect occurs when a faucet opens, closes, and reopens, sending separated pockets of cool and hot water through the plumbing. The effect becomes more noticeable when a shower is paused, a pump cycles, or the heater shuts down below its minimum flow.
Set the digital controller to the desired temperature and keep the shower valve sufficiently open. Repeatedly blending hot and cold at the faucet can lower hot-side flow enough to deactivate the burner.
Water Waste and Gray-Tank Capacity
Tankless heaters can waste water while occupants wait for the plumbing run to warm. A 20-foot line containing roughly 0.3-0.5 gallons may send that amount to the gray tank at each shower if the water is collected nowhere else.
A practical workaround is to collect initial cool water in a container for flushing or cleaning. Recirculating systems reduce the delay, but they add purchase cost and may use additional electricity or heat.
Freeze Damage
Thin heat-exchanger passages can freeze faster than a large tank’s water mass provides warning. Drain the heater according to the manufacturer’s instructions, disconnect power, shut off LP, open hot and cold faucets, and use approved antifreeze procedures where the manual allows them.
Do not assume ordinary RV plumbing antifreeze should pass through every heater. Some manufacturers prohibit antifreeze inside the heat exchanger or require bypassing the appliance.
Hard-Water Scale
Calcium scale narrows heat-exchanger passages, reduces flow, and causes unstable temperature. Owners in hard-water regions should install a sediment filter, monitor flow changes, and descale at the interval specified by the manufacturer, often annually or more frequently.
How Should You Maintain and Troubleshoot One?
RV tankless water heater maintenance should focus on winterization, water filtration, burner ventilation, electrical voltage, and flow screens. Most field complaints result from low flow, low 12-volt voltage, restricted water paths, air in the LP line, or incorrect installation rather than a failed heat exchanger.
| Symptom | Likely cause | First check | Corrective action |
|---|---|---|---|
| Water alternates hot and cold | Flow below threshold | Faucet or shower flow | Open valve farther, clean aerator |
| Low-flow error | Pump pressure or clogged screen | Pressure gauge and inlet filter | Restore about 30-45 PSI, clear restriction |
| Burner does not ignite | Air in LP line or low voltage | Stove flame and battery voltage | Purge LP line, charge battery above manufacturer minimum |
| Hot water has weak pressure | Scale or kinked hose | Inlet screen and plumbing | Descale, straighten hose, replace filter |
| Heater freezes | Water left in exchanger | Drain ports and bypass | Winterize completely before freezing weather |
| Unit shuts down outdoors | Exhaust obstruction or wind | Exterior vent and clearances | Remove obstruction, follow installation manual |
A battery reading near 11.5 volts under load can prevent some control boards from operating correctly, but the exact minimum varies by model. Measure voltage at the heater while ignition begins, not only at the battery terminals.
An RV water pump that reaches 30-45 PSI may still fail to deliver sufficient flow if the showerhead, inlet screen, or check valve restricts the line. Test flow directly at the heater before replacing electronic components.
Is an RV Tankless Heater Good for Boondocking?
An RV tankless heater can work well for boondocking because an LP unit needs comparatively little 12-volt power and avoids reheating a storage tank. The trade-off is water management: every warm-up delay, low-flow cycle, and long shower consumes fresh water and fills the gray tank.
Boondockers should prioritize:
- An LP model with low parasitic 12-volt draw.
- A stable flow sensor at the owner’s normal shower rate.
- An accessible drain and clearly documented winterization procedure.
- A water-saving showerhead that remains above the activation threshold.
- A method for capturing cool startup water.
- Recirculation only when its added power and cost fit the battery system.
A tank heater may be the better off-grid choice for short, carefully rationed uses because its stored water can be used without maintaining a minimum flow. The answer depends on whether the owner values long showers or maximum water efficiency.
Which Alternatives Deserve Consideration?
A conventional propane tank heater is the best alternative when low cost, simple operation, and low-flow reliability matter more than continuous supply. A hybrid approach, such as retaining a tank and adding better shower controls, can solve family-use frustration without the installation complexity of a conversion.
| Alternative | Typical cost | Hot-water behavior | Best use | Main trade-off |
|---|---|---|---|---|
| 6-gallon LP tank | $250-$500 | 6-gallon reserve, 20-40 minute recovery | Budget replacement | Limited consecutive showers |
| 10-gallon LP tank | $500-$900 | Larger reserve, 25-45 minute recovery | Larger families | More weight and space |
| Electric tank heater | $250-$700 | Stored water, slow 120V recovery | Quiet full hookups | Shore-power dependence |
| Premium LP tankless | $900-$1,200 | Continuous flow, digital control | Full-time RV living | High purchase price |
| Recirculating LP system | $1,000-$1,800 | Reduced startup waste | Stationary or water-conscious use | Added controls and maintenance |
A tankless unit is not automatically an upgrade over a functioning tank. Replacing a healthy six-gallon heater solely to pursue fuel savings can produce a long payback period, especially for an RV used fewer than 20 nights annually.
Which RV Owners Should Choose Tankless?
Full-time RVers and families should generally choose an LP tankless heater when the existing cutout is compatible and the installation can be completed safely. Weekend couples and water-limited boondockers should usually keep a tank unless continuous hot water solves a specific, frequent problem.
Full-Time Stationary RVer
Choose a premium LP unit with a digital control and, where practical, recirculation. Full-time use creates enough repeated demand for the convenience, space savings, and reduced standby heating to matter.
Family Camper
Choose tankless when three or more people regularly shower in sequence. Confirm that the unit can deliver the required flow at the campground’s coldest expected incoming-water temperature.
Weekend Couple
Keep the existing tank if it works reliably and the couple takes short trips. A tankless conversion becomes sensible when cabinet space, repeated showers, or frequent tank replacement is already an issue.
Extreme Boondocker
Choose tankless only if propane is plentiful and the water system can absorb startup waste. A low-flow showerhead, startup-water collection, and strict gray-tank planning are mandatory.
Cold-Climate Seasonal Camper
Choose tankless only with a written winterization routine and accessible drain points. One missed freeze-preparation step can destroy a heat exchanger that costs hundreds of dollars to replace.
The Bottom Line
Are RV tankless water heaters worth it? They are worth it for owners who repeatedly run out of hot water, camp for extended periods, or need to reclaim storage space. They are usually not worth it for occasional campers who want the cheapest reliable replacement or who conserve every gallon while boondocking.
The most broadly practical choice is a propane direct-fit model with digital temperature control, adequate flow at the expected temperature rise, accessible winterization, and a supported service network. Compare the full installed cost against your actual camping nights, family size, water limits, and tolerance for maintenance before ordering.
Frequently Asked Questions
Do RV tankless water heaters use more water?
RV tankless water heaters can use more water during startup because occupants may wait for cool water to clear the plumbing before showering. The heater itself does not require a fixed tank refill, but a long plumbing run, low-flow cycling, and repeated faucet operation can send additional water into the gray tank.
Can an RV tankless water heater run on a generator?
A propane RV tankless water heater can usually operate from a generator-supported 12-volt system, provided the control board receives adequate voltage and the LP system is correctly supplied. An electric tankless heater may exceed generator capacity because 120-volt models commonly require 15-30 amps or more.
How long do RV tankless water heaters last?
An RV tankless water heater typically lasts about 10-15 years when protected from freezing, descaled as needed, and maintained with clean water and correct LP pressure. Hard water, poor winterization, corrosion, and outdoor exposure can shorten service life substantially.
Can you install an RV tankless water heater yourself?
A mechanically experienced owner can complete a direct-fit installation in approximately 2-4 hours, but LP connections, combustion seals, venting, and electrical work create safety risks. Professional inspection is appropriate whenever the gas line, exterior door, exhaust path, or control wiring changes.
Why does my RV tankless heater shut off during a shower?
An RV tankless heater may shut off when flow drops below its activation threshold, commonly about 0.4-0.5 GPM, or when voltage, propane pressure, inlet screens, or temperature sensors fall outside operating limits. Open the shower valve farther, clean restrictions, verify battery voltage, and consult the model-specific fault code.
Does an RV tankless heater work in freezing weather?
An RV tankless heater can work in freezing weather only when the model’s freeze protection has power and the water system remains protected. Freeze protection is not a substitute for winterization during storage, especially when shore power or 12-volt power may be interrupted.
