10 Best Compact Tankless Electric Hot Water Heaters 2026 in the United States

The EcoSmart ECO 11 is a compact and efficient tankless electric water heater designed mainly for small applications like a bathroom, office sink, or breakroom. It delivers a flow rate between 1.3 and 3.1 gallons per minute, which is suitable for low-flow needs but won’t support multiple large water outlets simultaneously. Its 13,000-watt power rating and 240-volt operation enable it to heat water consistently with a temperature control accurate within 1 degree, reaching up to 140°F. One of its standout features is the patented self-modulating technology, which adjusts energy use based on your hot water demand, making it very energy efficient at about 99%, and helping you save on electricity bills.

The unit is also notably small—about 11.5 by 8 inches—and wall-mounted, saving valuable space compared to traditional tank heaters. Installation is straightforward for point-of-use situations, but because it draws 54 amps, your electrical system must be compatible and may need professional setup. The ECO 11 includes a lifetime warranty on the electronics and heating elements, which adds peace of mind, though labor costs aren’t covered.

Due to its limited flow rate, this model is best suited for single fixtures rather than whole-house use, and the relatively high amperage requirement can complicate installation in some homes. For those needing a compact, energy-saving unit for small or occasional hot water needs, this product provides reliable and consistent performance with easy temperature control.

The Ecosmart ECO 24 is a compact and sleek electric tankless water heater designed for residential use. It delivers a strong power output of 24 kW at 240 volts, which supports a maximum flow rate of about 5.8 gallons per minute. This makes it a good choice for smaller homes or apartments where moderate hot water demand is typical. Its temperature can rise up to 130°F, which is sufficient for everyday uses like showers and sinks. One standout feature is its high energy efficiency at 99.8%, meaning it wastes very little electricity and can help reduce utility bills over time. The unit’s slim size (17 x 17 x 3.5 inches) and wall-mount design also make it easy to install even in limited spaces.

Additionally, it includes a digital temperature display for easy monitoring. The lifetime warranty on electronics and heating elements provides extra peace of mind, although it doesn’t cover labor or incidental costs. Its flow rate may be limiting if you need hot water simultaneously from multiple outlets or for larger households. Since it requires a 240V electrical supply and a 100A circuit, installation might need professional help if your home isn’t already set up for this.

The Ecosmart ECO 24 suits individuals or small families looking for an energy-efficient, space-saving electric water heater with consistent temperature control, but it might not fit larger homes or high-demand situations.

The EcoSmart ECO 18 is a compact electric tankless water heater designed for residential use in moderate climates where incoming water temperatures are around 62°F or higher. It offers a power rating of 18 kilowatts at 240 volts, which is quite strong for its size (14" x 17" x 3.5") and enables it to provide a maximum flow rate of about 3.5 gallons per minute. This means it can comfortably supply hot water for one or two fixtures simultaneously, such as a bathroom sink and a shower, but might not be enough for larger households needing multiple hot water sources at once.

One of its convenient features is the digital temperature control with 1-degree increments, allowing precise adjustments for comfort. The patented self-modulating technology helps maintain energy efficiency at an impressive 99.8%, which can help reduce electricity costs compared to traditional water heaters. Installation is relatively straightforward due to its compact design, though it requires a 240-volt electrical connection and is best suited for homes with compatible wiring. The unit comes with a lifetime warranty on electronics, exchanger, and heating element, which offers good peace of mind, although the warranty does not cover labor costs or incidental damages.

A drawback is that it’s optimized for warmer incoming water and may struggle in colder climates without additional units or pre-heating, limiting its versatility. The EcoSmart ECO 18 serves as a solid choice for small households or point-of-use scenarios looking for energy-efficient, on-demand hot water in a compact form.