Propane vs Natural Gas Tankless Water Heaters: Which Should You Buy?
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You are looking at propane vs natural gas tankless water heater options for different living spaces. Both models provide on-demand hot water without a storage tank. The main difference lies in their fuel source and intended use. One unit is designed for RVs and runs on propane. The other is built for indoor home installation and uses natural gas. These choices affect flow rate, power, and where you can place the unit.
Key differences
| Aspect | APUS 68,000 BTU RV Propane Water Heater | Ranein 5.3 GPM Natural Gas Tankless Water Heater |
|---|---|---|
| Fuel Type | Propane | Natural Gas |
| Use | RV | Indoor |
| Flow Rate | 3.9 GPM | 5.3 GPM |
| BTU | 68,000 BTU | 130,000 BTU |
| Voltage | 12V DC | not listed |
| Installation Location | RV Compartment | Indoor |
Which one should you choose?
Choose APUS 68,000 BTU RV Propane Water Heater if
- You need hot water for an RV or camper with limited space.
- Your vehicle uses a 12V DC electrical system for controls.
- You camp at high elevations up to 9,800 feet.
Choose Ranein 5.3 GPM Natural Gas Tankless Water Heater if
- You want to supply hot water to multiple indoor outlets.
- You have a natural gas line available for connection.
- You need a higher flow rate for family use.
Verdict: Choose the propane unit if you are outfitting an RV or need a compact, mobile solution. Select the natural gas model for indoor residential use where higher capacity and flow rate are priorities. Your fuel availability and installation site dictate the correct choice.
Propane RV vs Natural Gas Indoor
Fuel Type
Product A, the APUS 68,000 BTU RV Propane Water Heater, runs on propane. This fuel source is ideal for mobile living, allowing you to connect to standard RV propane tanks. Product B, the Ranein Natural Gas Tankless Water Heater, requires a natural gas line. This connection is typically fixed to a home’s gas supply. If you travel in an RV or camper, propane offers the portability you need. If you are installing the unit in a stationary home, natural gas provides a continuous fuel source without the need to refill tanks. Your choice depends entirely on your fuel infrastructure and whether the unit is for a vehicle or a house.
Capacity
The Ranein unit delivers 130,000 BTU of heating power, which is nearly double the 68,000 BTU output of the APUS propane model. This higher capacity allows the Ranein to heat water more aggressively, supporting higher flow rates. The APUS unit is designed for efficient heating in a compact space, prioritizing adequate performance for single-point RV use. For a large household with multiple simultaneous showers, the Ranein’s higher BTU rating provides more robust heating capacity. The APUS unit is sufficient for typical RV needs but lacks the raw power of the larger residential unit.
Flow Rate
Product B offers a maximum flow rate of 5.3 GPM, while Product A provides 3.9 GPM. This difference means the Ranein can supply hot water to more fixtures at once, such as a shower and a kitchen sink simultaneously. The APUS unit starts with a low minimum flow of 0.55 GPM, making it sensitive to flow changes but efficient for small RV bathrooms. If you need to run multiple outlets, the higher GPM of the natural gas model is advantageous. For a single shower in an RV, the propane unit’s flow rate is adequate and well-matched to the space.
Installation Location
The APUS heater is explicitly designed for RV compartments, fitting standard openings with a compact cutout size. It is built to withstand the vibrations and space constraints of travel trailers. The Ranein unit is rated for indoor installation in a home. It requires a fixed indoor space and connection to permanent gas lines. You cannot install the Ranein in an RV. Conversely, the APUS is not designed for permanent indoor residential use. Your installation location dictates which unit is viable, as they serve entirely different environments.
Voltage
Product A operates on 12V DC power, which is standard for RV electrical systems. This allows it to run directly from the vehicle’s battery or inverter without needing a dedicated household circuit. Product B requires standard household electricity for its internal blower and controls, which is not specified but implied by its residential indoor rating. If you are off-grid or in an RV, the 12V DC requirement of the APUS unit is a significant advantage. For a home with standard 120V outlets, the voltage difference is less relevant, as both can power their electronics.
Choose based on your space and fuel
RV owners needing compact propane heating
This APUS unit fits standard RV compartments with a 14.96-inch square footprint. It runs on propane at 68,000 BTU, delivering 3.9 GPM. The 12V DC power draws from your vehicle. It includes a remote control and operates up to 9,800 feet altitude. This makes it ideal for mobile living where space and gas availability are key constraints.
Homeowners with natural gas lines
The Ranein model uses natural gas for continuous supply without tank refills. It delivers 5.3 GPM at 130,000 BTU, supporting three to five outlets. The indoor design includes a blower for safe combustion. It connects via standard 3/4-inch NPT fittings. This unit suits fixed residences where high flow and gas line access are available.
Users prioritizing high flow rate
You get 5.3 GPM from the Ranein unit, which handles multiple simultaneous uses. The 130,000 BTU capacity ensures consistent temperature under load. It is designed for indoor installation in homes. The 38-pound build supports robust performance. This choice is best when you need maximum hot water volume for a family setting.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | APUS 68,000 BTU RV Propane Water Heater | RVers replacing standard tank heaters | Check price of APUS 68,000 BTU RV Propane Water Heater on Amazon |
| 2 | Ranein 5.3 GPM Natural Gas Tankless Water Heater | Indoor whole-home hot water needs | Check price of Ranein 5.3 GPM Natural Gas Tankless Water Heater on Amazon |
The products compared
APUS 68,000 BTU RV Propane Water Heater
Best for: RVers replacing standard tank heaters
- Fuel Type
- Propane (what this guide is about)
- Flow Rate
- 3.9 GPM
- BTU
- 68,000 BTU
- Voltage
- 12V DC
- Certification
- CSA
- Dimensions
- 14.96 x 14.96 x 14.18 inches
View on Amazon: APUS 68,000 BTU RV Propane Water Heater Affiliate link
This APUS unit delivers 68,000 BTU of heating power for propane-powered RVs. It provides up to 3.9 GPM of hot water, replacing standard 6 to 12-gallon tank heaters. The compact 14.96-inch design fits most standard RV compartments. It operates on 12V DC and includes a remote control for temperature adjustments. This heater is built for stable performance at elevations up to 9,800 feet.
Pros
- 68,000 BTU propane burner for continuous hot water
- 3.9 GPM flow rate supports showers and dishwashing
- Compact 14.96-inch square footprint fits standard RV openings
- CSA certified with multiple safety protections
- Includes remote control for interior temperature adjustment
Cons
- Lower flow rate of 3.9 GPM compared to 5.3 GPM home units
- Requires 12V DC power source for operation
- Maximum elevation limit of 9,800 feet
Good fit if
- You need a direct replacement for a standard 6 to 12-gallon RV tank heater
- You travel to high-elevation campsites up to 9,800 feet
- You want to adjust water temperature from inside your RV
Skip if
- You require a flow rate above 4 GPM for multiple simultaneous fixtures
- You are installing a fixed indoor unit for a house
- You need a unit rated for elevations above 9,800 feet
Verdict: APUS RV Propane Tankless Water Heater is a compact, CSA-certified solution for RVers who need to replace bulky tank heaters. It suits travelers who prioritize elevation stability and convenient remote temperature control over high-volume flow.
Ranein 5.3 GPM Natural Gas Tankless Water Heater
Best for: Indoor whole-home hot water needs
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 5.3 GPM
- BTU
- 130,000 BTU
- Installation Location
- Indoor
- Dimensions
- 23.2 x 14.2 x 14.2 in
- Use
- Whole House
View on Amazon: Ranein 5.3 GPM Natural Gas Tankless Water Heater Affiliate link
This Ranein unit delivers 5.3 GPM at 130,000 BTU using natural gas. It is designed for indoor installation and supports 3 to 5 outlet points. The blower sits underneath for safety and noise reduction. You get unlimited hot water without waiting. It fits standard 3/4 inch fittings. The compact design saves space. This model suits families needing steady hot water flow.
Pros
- 130,000 BTU heating capacity
- 5.3 GPM flow rate
- Under-mounted blower for safety
- Standard 3/4 inch NPT fittings
Cons
- Indoor installation only
- Not recommended above 2,000 feet
- 2-year warranty period
Good fit if
- You have natural gas available
- You need hot water for 3-5 outlets
- You are installing indoors
Skip if
- You live above 2,000 feet elevation
- You need outdoor installation
- You use propane fuel
Verdict: Ranein 5.3 GPM Natural Gas Tankless heater provides strong flow for whole-family use in standard indoor settings. It fits homes with natural gas lines that need reliable hot water for multiple sinks.
Specifications side by side
| Spec | APUS 68,000 BTU RV Propane Water Heater | Ranein 5.3 GPM Natural Gas Tankless Water Heater |
|---|---|---|
| Fuel Type | Propane | Natural Gas |
| Flow Rate | 3.9 GPM | 5.3 GPM |
| BTU | 68,000 BTU | 130,000 BTU |
| Installation Location | not stated | Indoor |
| Voltage | 12V DC | not stated |
| Certification | CSA | not stated |
| Dimensions | 14.96 x 14.96 x 14.18 inches | 23.2 x 14.2 x 14.2 in |
| Use | RV | Whole House |
| Weight | 24 pounds | 38 pounds |
| Color | White | Gray-NG |
| Model | AP-AWH-RV10W-NEW | RH13K-NG |
| Size | not stated | 5.3 GPM Indoor |
Frequently asked questions
Can I use a propane tankless water heater indoors?
You generally should not install propane units indoors unless they are specifically designed for it. The APUS 68,000 BTU RV Propane Water Heater is built for RVs, which are mobile and ventilated spaces. Indoor homes typically require natural gas models like the Ranein, which are rated for indoor installation. Always check the manufacturer's location specifications before deciding.
Which fuel type is better for a whole home?
Natural gas is usually the better choice for whole-home hot water needs. The Ranein 5.3 GPM Natural Gas Tankless Water Heater provides strong flow for multiple sinks in standard indoor settings. Propane units like the APUS are compact and suited for RVs, not whole-house distribution. If you have a gas line, natural gas offers consistent high-volume flow.
Do I need special ventilation for propane tankless heaters?
Yes, propane combustion requires proper ventilation to remove exhaust gases safely. The APUS unit is CSA-certified for RV use, where ventilation is managed through roof vents or windows. Indoor natural gas units like the Ranein also need specific venting. You must follow local codes to ensure exhaust does not accumulate in living spaces.
How much space does a propane water heater take up?
Propane RV heaters are designed to be compact to fit tight compartments. The APUS model measures 14.2 inches wide and 15 inches high, weighing only 24 pounds. This small footprint allows it to replace bulky standard tank heaters in RVs. Indoor natural gas units may be larger, so measure your available space carefully.
Is propane flow rate lower than natural gas?
Propane units often have lower flow rates because they are sized for smaller applications. The APUS RV heater delivers 3.9 GPM, which is sufficient for single-use scenarios in an RV. The natural gas Ranein model provides 5.3 GPM, supporting higher demand in homes. Your choice depends on whether you need high-volume flow or compact efficiency.
Can I switch from propane to natural gas?
You cannot simply switch fuel types on the same unit. The APUS is built for propane, while the Ranein is designed for natural gas. Each unit has specific internal components and regulators for its fuel source. You must purchase a new heater compatible with your available fuel line if you change sources.
What is the weight difference between propane and gas heaters?
Propane RV heaters are typically lighter due to their compact design. The APUS weighs 24 pounds, making it easy to mount in an RV. The indoor natural gas Ranein unit weighs 38 pounds. The extra weight comes from sturdier construction for permanent indoor installation. Consider your mounting surface strength when choosing.
Do I need an electrician for these units?
You likely need a professional for both fuel and electrical connections. The APUS RV heater draws 12V DC power from your vehicle. The Ranein natural gas unit requires a standard electrical outlet for controls. Gas line connections must be made by a licensed plumber to ensure safety and compliance with local codes.