Tankless water heater for an RV provides a convenient source of continuous hot water without the constraints of a limited tank capacity. Tankless RV water heaters heat water directly on demand rather than storing already heated water. This “endless” supply of hot water makes tankless heaters a popular upgrade option for recreational vehicles.
Installing a tankless or on-demand RV water heater opens up possibilities for long hot showers, doing dishes, laundry and other tasks without worrying about running out. Tankless operation also saves storage space compared to bulky tank heaters. This guide covers how tankless RV water heaters work, types of heaters, installation considerations, sizing requirements and recommendations of the best tankless models to provide unlimited hot water for your travels.
- Tankless heaters provide a constant supply of hot water – never run out halfway through a shower!
- More cost effective than tank heaters over time with energy savings.
- Compact size saves interior RV space.
- Propane and electric tankless models available for off-grid use.
- Requires proper sizing based on flow rate and temperature rise.
- Professional installation recommended to integrate with plumbing.
- Need adequate electrical service and wiring for an electric model.
How Tankless Water Heaters Work
Tankless or on-demand RV water heaters operate quite differently than traditional tank water heaters that most RVs come equipped with. Rather than maintaining a large reservoir tank that keeps 40-50 gallons of water constantly heated to your desired temperature, tankless heaters use high-powered burners or electrical heating elements to heat water directly on demand as it flows through the unit.
This difference in operation provides some significant benefits. In a tankless heater, cold incoming water from the RV’s fresh water hookup enters the unit. Then as soon as any hot water is called for at a faucet or shower, the heaters activate to rapidly warm only the amount of water being used. The now heated water immediately flows from the tankless unit to the tap, showerhead, or appliance needing hot water. So heat is applied directly on demand rather than being maintained in reserve.
This tankless operation offers several benefits compared to traditional tank water heaters:
- It provides a practically endless supply of continuous hot water whenever needed, meaning you’ll never run out halfway through a shower or dish session again. The water keeps flowing hot even for very long showers or tasks.
- Energy efficiency and cost savings arise since you’re only expending fuel or electricity to heat water at the moment it’s required rather than constantly keeping an entire tank hot 24/7. Tankless heaters use less propane or electricity over time.
- The compact size of tankless units frees up interior RV space since you no longer need a large water heater tank consuming 40-50 gallons. This recovered space can be used for storage or other purposes.
- Advanced computer modulation in the tankless system maintains a consistent temperature with only quick spikes of intense heat when more hot water is called for. This increases efficiency and avoids scalding.
- Tankless heaters enjoy a long lifespan expectancy around 15-20 years since they aren’t subjected to the mineral corrosion and leaks associated with constantly heated tank reservoirs. Less repairs or replacements needed.
The only caveat is being sure to size your tankless water heater adequately to provide sufficient hot water flow for peak demand times when water usage in the RV is highest. But with the right tankless size, you’ll enjoy reliable continuous hot water.
Types of Tankless RV Water Heaters
For RV applications, there are two main types of tankless water heaters to choose from:
Propane Tankless Water Heaters: Propane-fired tankless units are a popular choice for RV owners who frequently camp off-grid with no electric hookups. Operating off the RV’s propane supply, they can be installed almost anywhere with proper ventilation.
Electric Tankless Water Heaters: Electric tankless heaters simply plug into shore power when at an RV park, eliminating the need for venting. They provide on-demand hot water without propane. Just be sure your electric service can handle the amp draw.
Many models offer dual fuel options with connections for both propane and electric. This provides the most flexibility in how you power the tankless heater.
Sizing a Tankless Water Heater for an RV
One of the most important considerations when selecting a tankless water heater for an RV is properly sizing the unit to ensure it can deliver sufficient hot water for peak demand. The key factors involved in determining the right tankless water heater size include:
- Temperature rise needed – This is the increase required from the cold water inlet temperature to the target hot water output temperature. For example, if cold water enters at 50°F and you want output at 120°F, then you need a 70° rise. The greater the temperature rise, the more heating power needed.
- Flow rate – This refers to the maximum volume of water in gallons per minute (GPM) that flows through the RV’s plumbing system when hot water is called for at multiple fixtures simultaneously. Carefully calculating the peak simultaneous demand is crucial for sizing.
- Power supply – The tankless unit must have an adequately powerful gas burner or electrical heating element to heat the expected water volume to the desired temperature rise. Gas tankless heaters require sufficient propane supply. Electric models need adequate amperage.
With these considerations in mind, RV tankless water heater models range from small 2.5 GPM units meant for simple needs up to 8 GPM or even higher capacity models for very large motorhomes with multiple bathrooms. Have a professional technician experienced in tankless sizing help select the right model for your particular RV’s peak hot water requirements and electrical capabilities. Undersizing the tankless leads to disappointment when sufficient hot water can’t be maintained.
Where to Locate a Tankless Water Heater in an RV
One great benefit of tankless water heaters is their small, compact size compared to traditional tank-style heaters. This provides flexibility in positioning the unit. However, the installation location still requires some careful thought. You need to ensure:
- Easy connections to the existing plumbing lines for cold water intake and hot water output. The layout must enable direct hookups.
- Convenient accessibility for future maintenance, repairs and servicing of the unit. Technicians will need regular access.
- Proper ventilation for gas/propane fired models. Exhaust must safely vent outdoors and intake air is needed.
- Sufficient clearances from combustible materials if applicable. Maintain the unit’s specified spacing.
- Adequate structural support and mounting at the install location. Often special brackets are required.
Some common tankless water heater installation locations in RVs include dedicated utility compartments, under the RV in heated compartments, inside a garage bay if present, or under a kitchen galley sink. Just be sure to consult the manufacturer’s guidelines for required clearances and talk through positioning with your RV technician to determine the optimal placement for your particular model. This ensures the best performance and safety.
Benefits of a Tankless RV Water Heater
Switching from a conventional water heater tank to an on-demand tankless model offers several benefits:
Endless hot water – Never run out during long showers, doing dishes, laundry, etc. Enjoy the convenience of continuous supply.
Space savings – Compact tankless units free up interior space compared to bulky tanks. Easier to fit during remodels.
Propane efficiency – Only burn fuel when heating water on demand. No maintaining temperature of a tank.
Electric efficiency – Sophisticated sensors and modulation tailor heating precisely to demand.
Lightweight – Weigh less than traditional water heater tanks for easier handling and installation.
Digital controls – Adjust to your precise temperature preference and operate with electronics.
Long lifespan – Tankless heaters last up to 20 years vs 6-10 years for tank heaters.
Tankless offers many benefits for RV owners looking to upgrade beyond limited tank capacity and lifespan.
Important Installation Considerations
While installing a tankless water heater in a recreational vehicle may seem straightforward, there are several important installation considerations that should be addressed to ensure optimal performance, safety, and longevity of the unit.
It is highly recommended to have a professional contractor or plumber with experience installing tankless water heaters in RVs handle the installation. This will ensure the system is properly integrated with the existing plumbing infrastructure and set up according to manufacturer specifications. A qualified professional will be familiar with the nuances of sizing, positioning, venting, wiring, and configuring the electronics of tankless heaters for RVs specifically. Attempting a DIY installation as an amateur could result in subpar performance or even hazardous operating conditions if configured improperly.
Sizing and Positioning
The tankless water heater must be appropriately sized and located within the RV to deliver sufficient hot water at the desired temperature to all water fixtures. A unit that is too small will not be able to meet hot water demands, while an oversized unit is wasteful and unnecessary. The installer should calculate the peak hot water requirements based on the number of fixtures, flow rates, and incoming ground water temperature. The tankless heater should then be installed as close to the point of use as possible to minimize heat loss in the pipes.
Electric tankless water heater models have significant power demands, often requiring a 200 amp or greater dedicated circuit. The RV must have adequate electrical service and panel capacity to accommodate the load. Running a new circuit directly from the main panel may be necessary. The installer should provide a proper shutoff switch as well. Insufficient electrical infrastructure can lead to tripped breakers, inability to reach desired water temperature, and damage to the unit.
Gas Supply and Venting
Gas-fired tankless heaters require proper gas line sizing to supply adequate propane volume to meet heating needs. Undersized gas lines will restrict flow and limit the hot water capacity. The exhaust venting must also be configured correctly to safely remove combustion byproducts. Improper venting can lead to hazardous carbon monoxide buildup. Intake vents should also be installed if required by the manufacturer. A professional installer is best equipped to handle the gas and venting demands of propane tankless heaters.
Digital Controls and Thermostats
Most modern tankless water heaters include digital controllers, thermostats, and temperature sensors to fine-tune operation and provide diagnostics. The installer must properly integrate these components with the existing plumbing and power systems for automated control and monitoring. Temperature should be set appropriately to help prevent scalding. Professional configuration of the electronics maximizes the convenience and capabilities of the new tankless heater.
Addressing these key installation considerations by having a qualified professional handle the tankless water heater installation helps ensure optimal safety, performance, and longevity. While the system may seem straightforward in principle, the nuances involved mean DIY installation is not recommended. Spending the time and money on a proper installation is worth the investment for reliable operation for years to come.
Best Tankless RV Water Heaters
Here are some top recommended tankless water heater models to consider for RV installation:
Girard 2GWHAM (propane) – Compact, entry-level on-demand unit great for smaller RVs
Eccotemp i12-NG (propane) – Midrange gas model good for tight spaces
Truma AquaGo (propane) – High-capacity continuous flow heater for larger motorhomes
EZ 202 (electric) – Affordable plug-in electric model for fast install when shore power allows
Eemax SP2412 (electric) – Good electric option using minimal power but providing rapid heat
Girard Tankless Water Heater (propane & electric) – Flexible dual power for off-grid use or plugin operation
Consult manufacturer sizing guidelines and talk to RV technicians to select the right tankless model for your particular RV’s on-demand hot water needs.
Cost of Installing a Tankless RV Water Heater
What’s the typical cost for parts and professional installation of a tankless RV water heater?
- Tankless unit cost – $200 to $1000 depending on size and fuel type
- Installation labor – $40 to $100 per hour
- Misc parts, wiring – $50 to $200, more for electrical upgrades
- Total installed cost – $500 to $1500+
Get multiple installation quotes. Prices vary greatly based on model, technician rates, complexity and required changes to plumbing and electrical.
Conclusion of RV Tankless Water Heaters
Installing a tankless water heater is a great way to upgrade an RV to enjoy endless hot water for showering and tasks. Tankless heaters provide water on demand rather than storing heated water. When properly sized and installed, propane or electric tankless heaters offer convenience, space savings, efficiency and reliability. Consult technicians to select the right tankless model to meet your RV’s hot water needs and say goodbye to running out of hot water!
Frequently Asked Questions
Here are answers to some common questions about switching to a tankless water heater in an RV:
How does an RV tankless water heater work?
Tankless heaters use burners or heating elements to rapidly heat water on demand as it flows through the unit. This provides endless hot water without storage.
What size tankless water heater for an RV do I need?
Carefully calculate your RV’s peak hot water flow rate and temperature rise needed. Size your tankless heater accordingly. Get professional help sizing.
Where is the best place to install a tankless water heater in an RV?
Install in a utility compartment, under the RV, under the galley, or in garage bays. Ensure access and adequate venting/clearances.
Can you replace an RV water heater tank with a tankless one?
Yes, a tankless water heater can directly replace a tank model. Some plumbing modifications may be needed for proper install and performance.
How long do tankless RV water heaters last?
Tankless units last 15-20 years generally, compared to 6-10 years for tank heaters. Their longevity makes them a smart investment.
Do RV tankless water heaters save space?
Yes, tankless designs are much smaller than conventional tank heaters freeing up interior space for other uses. Easier to fit during remodels.
Are tankless water heaters energy efficient?
More efficient than storage tanks since they only heat water directly when demanded rather than maintaining a temperature.
Do you need better electrical service for a tankless RV water heater?
Likely yes – consult an electrician. The heating elements typically require more amps than an existing water heater.
How do I get endless hot water for my RV?
Installing an on-demand tankless propane or electric water heater provides unlimited hot water for showers, dishes and more.