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 Stiebel Eltron Tempra 36 Plus is a high-powered electric tankless water heater designed to provide continuous hot water on demand. Its 36 kW wattage supports a maximum flow rate of about 1.5 gallons per minute, which is ideal for point-of-use or smaller household setups but may struggle to supply multiple outlets simultaneously in larger homes. This model features advanced flow control and self-modulation technology that adjusts energy use to match the demand, making it energy-efficient and helping to reduce utility bills. The digital LED display allows for precise temperature adjustments, which is a convenient feature for users wanting consistent water temperature.

Being electric, it avoids the need for gas lines or ventilation, simplifying installation in many cases, though professional installation is still recommended due to electrical requirements. The compact size (approximately 16.6 by 14.5 inches) and wall-mount design make it space-saving, suitable for tight areas. Maintenance needs are relatively low compared to traditional tank heaters, but like all tankless units, it requires periodic descaling in hard water areas to maintain performance.

The Tempra 36 Plus is reliable and efficient, though its flow rate may limit its use in larger households with high simultaneous hot water demand. It is well suited for users looking for an eco-friendly, electric solution with precise temperature control and moderate flow capacity.