Top-10 Electric On Demand Water Heater
Loved in the USA

The Stiebel Eltron Tempra 20 Plus Tankless Water Heater offers some impressive features that address key needs for an electric-on-demand-water-heater. It has a flow rate of up to 3.79 liters per minute, which should be sufficient for most households. The power rating of 19.2 kW ensures that it can deliver a significant temperature rise, keeping your showers hot even if demand fluctuates. The advanced flow control technology helps maintain a consistent water temperature, providing comfort and preventing interruptions during hot showers.

Energy efficiency is a strong point as well; the unit has auto-modulation and electronic flow control, and a savings monitor helps track energy costs, making it eco-friendly and potentially cost-effective in the long run. It's compact and wall-mountable, saving space without the need for venting, which can be a big advantage for smaller homes or apartments. The installation requires a minimum 125 A electric service, which might necessitate an upgrade for some homes. The digital temperature display and preset buttons make operation straightforward, and the unit runs quietly.

The warranty is robust, offering 7 years against leakage and 3 years for parts, which provides some peace of mind. However, the maximum flow rate of 3.79 liters per minute may not suffice for larger households with multiple simultaneous hot water demands. Additionally, while it is energy-efficient, the initial cost and potential need for electrical upgrades might be a consideration for some users. This unit is best suited for average-sized homes that require a reliable and efficient solution for on-demand hot water.

The WINTEMP Tankless Electric Water Heater offers a powerful 36 kW output with a 240V power supply, making it suitable for whole-house use, especially in homes needing 3-5 water usage points. It delivers up to 8.7 gallons per minute (GPM), which is enough to handle multiple showers or faucets simultaneously without running out of hot water. Its built-in technology keeps water temperature stable by adjusting power based on flow and incoming water temperature, which helps avoid sudden cold or hot bursts. This also means it uses energy efficiently, with claims of up to 99% savings by only heating water on demand, so you won’t waste electricity when hot water isn’t needed.

The unit’s compact, wall-mounted design saves significant space compared to traditional tank heaters and includes convenient WiFi control for adjusting temperature remotely. On the downside, the heater requires a high electrical capacity (150A maximum current and multiple 40A breakers), meaning your home’s electrical system must be able to handle this heavy load, possibly requiring professional upgrades for safe installation. It also needs specific wiring and a 300A household power supply, which might limit use in older homes.

Safety features like leakage, overheat, and dry-fire protection are reassuring, and it’s ETL certified, adding confidence in its reliability and safety. The product comes with a 2-year warranty and support, which is decent but not exceptional. This water heater is suited for homeowners looking for endless hot water with energy savings who have the electrical setup to support its demands, but it may not be the best fit if your home’s wiring can’t handle the power requirements or you want a simpler, lower-powered option.

The Rheem RTEX-36 is an electric tankless water heater boasting a powerful 36 kW capacity, designed to deliver hot water on demand. It features a maximum flow rate of 6 gallons per minute, making it suitable for households requiring a steady supply of hot water for multiple applications simultaneously. This capacity is generally adequate for a medium to large home, assuming simultaneous use is limited to a few fixtures.

The unit operates on 240 volts and is noted for its energy efficiency, with a remarkable efficiency rating of 99.8%. This high efficiency can lead to lower energy costs over time, appealing to environmentally conscious consumers looking to reduce their utility bills. The digital temperature control allows users to adjust the water temperature conveniently and precisely, enhancing user comfort and safety.

A compact and stylish design allows for easy wall-mounted installation, helping save space which is particularly beneficial for smaller homes or apartments. The Rheem RTEX-36 weighs 24.3 pounds and measures 24 x 21.1 x 6.3 inches, making it relatively easy to handle and install, provided that the necessary electrical and plumbing connections are in place.

Potential users should be aware of the installation requirements, as it may necessitate professional installation to ensure safety and optimal performance, especially if upgrading from a traditional water heater. Additionally, while the maximum temperature capacity of 140°F is sufficient for most domestic needs, those requiring higher temperatures should verify compatibility with their specific needs. The Rheem RTEX-36 is a compelling choice for users seeking an efficient, compact, and powerful tankless water heater solution.