10 Best Tankless Water Heaters 2026 in the United States

The Fogatti InstaShower 8 Plus is designed specifically for RV users and campers looking for a reliable, propane-powered tankless water heater. It delivers up to 2.9 gallons per minute, which is quite good for RV use, allowing multiple showers without running out of hot water quickly. The unit is energy efficient with 55,000 BTUs and runs on propane, so you don’t have to worry about electrical hookups while traveling. It’s also high-altitude ready, working effectively up to 9,800 feet, which is a useful feature if you camp in mountainous areas.

Installation is flexible with three door size options to retrofit existing water heater openings, making it a practical choice for replacing older tank or tankless models from popular brands. The water heater includes helpful safety features like automatic gas shut-off and frost protection, plus it has a built-in pressure relief valve and remote controller for ease of use. Its maximum temperature is limited to 123°F, which might be lower than some users prefer, and while the flow rate is solid for RV needs, it may not meet the demands of larger households or full-time RVers requiring higher water volumes.

The unit’s size at 15”x15” is compact but may require door modification for larger replacements. Maintenance is simplified by built-in protections; however, as a propane device, it requires regular checks for safe operation. This heater is well-suited for families and campers who want continuous hot water without the wait of tank heaters, offering easy installation and strong safety features tailored to RV lifestyles.

The Rheem RTEX-24 24kW 240V Electric Tankless Water Heater offers a robust solution for continuous hot water supply with its impressive flow rate of up to 5.9 gallons per minute, making it suitable for households with moderate to high hot water demands. One of its standout features is the 99.8% energy efficiency, which helps in reducing energy costs and promoting eco-friendliness. The electric fuel type simplifies installation and maintenance compared to gas models, although it does require a 240V electrical connection, which some homes may need to upgrade to accommodate.

The compact dimensions (17.63”W x 18.25”H x 3.5”D) and wall-mount design make it space-efficient and ideal for small utility areas, while the digital temperature display and ON/OFF dial control provide ease of use and precise temperature adjustments. Additionally, the self-modulating power control enhances efficiency by only using the necessary amount of power based on the water flow rate.

However, the temperature rise might be limited during peak usage in colder climates, potentially requiring additional units for larger homes. Potential buyers should consider the installation requirements and whether their household electrical setup can support the unit. Those looking for a reliable, energy-efficient, and continuous hot water supply will find the Rheem RTEX-24 a compelling option, especially in moderate climates and homes with appropriate electrical infrastructure.

The FOGATTI InstaShower 9 Pro is a high-output propane tankless water heater designed especially for RVs, providing a strong 3.6 gallons per minute flow rate. This allows it to supply hot water simultaneously to both bathroom and kitchen without waiting, which is ideal for families or frequent users. It features precise temperature control within ±1°F and a built-in mixing tank that helps keep water temperature stable, enhancing comfort during showers. With a 66,000 BTU power rating, it is suitable for colder climates or higher altitudes, supported by a robust fan system that operates effectively even in windy conditions and up to 9,800 feet elevation.

Installation is fairly straightforward for RV owners replacing a tank water heater, as it fits common opening sizes and includes a 15x15 inch door and trim, plus a wired remote control for convenient temperature adjustments from inside the RV. Safety features like automatic gas shut-off, anti-freeze protection, and a pressure relief valve are built in, reducing additional costs and concerns. However, it runs on liquid propane, requiring a compatible fuel source and proper venting, which may be a consideration for those who prefer electric models.

The unit weighs around 31 pounds and is compact in size (15 inches square), but it is not smart home compatible, so remote control is limited to the included wired controller. Maintenance is simplified thanks to a dust and sand filter screen, though periodic checks and cleaning are necessary to ensure safe operation. This heater suits RVers who need reliable, instant hot water with strong flow and precise temperature control, especially when traveling in varying weather and altitude conditions.