Best Tankless Water Heaters for on-Demand Hot Water
Tankless water heaters provide hot water on demand without a bulky storage tank. This guide identifies top options for American homes, highlighting energy efficiency, install considerations, and performance. Below you’ll find five well-reviewed models with key features to help compare fits for point-of-use or whole-house applications.
| Product | Brand | Key Feature |
|---|---|---|
| EcoSmart ECO 11 Electric Tankless Water Heater | EcoSmart | Self-modulating technology for efficiency |
| Rheem 18kW 240V Tankless Electric Water Heater | Rheem | Digital thermostat control with self-modulation |
| Tankless Water Heater Electric 110V, 3000W | xwdzswgs | Under-sink, compact and fast hot water |
| ECOTOUCH 14kW 240V Tankless Water Heater | ECOTOUCH | Self-modulating with high flow for 2–3 points of use |
| Rheem 11kW 240V Tankless Electric Water Heater | Rheem | Self-modulating with compact footprint |
EcoSmart ECO 11 Electric Tankless Water Heater
The EcoSmart ECO 11 uses patented self-modulating technology to adjust energy use based on hot water demand. It delivers on-demand hot water with temperature control within one degree of the selected setting, optimizing energy use and space. Its compact design (about 11.5 x 8 x 3.75 inches) makes it suitable for wall mounting or point-of-use installation, and operation is particularly efficient in smaller households or locations with limited space.
Rheem 18kW 240V Tankless Electric Water Heater
This Rheem model features external digital thermostatic control with an LED display for precise temperature settings. It employs advanced self-modulation to match power output with hot-water demand and includes durable copper immersion elements. A convenient, high-efficiency option for households seeking reliable on-demand hot water with straightforward serviceability. Typical flow performance reaches up to 4.4 GPM.
Tankless Water Heater Electric 110V, 3000W (Under Sink)
This compact under-sink unit provides instant, endless hot water at the point of use with a 3000W power rating. It supports temperatures up to high practicality for kitchen or bath applications and features a visual display to monitor operation. Note that higher flow rates may require multiple fixtures or careful flow management to maintain desired temperatures.
ECOTOUCH 14kW 240V Tankless Water Heater
The ECOTOUCH ETL-certified model delivers up to 3.38 GPM, suitable for two to three point-of-use fixtures. It requires a 60A double-pole breaker and proper wiring (6 AWG) for full 240V operation. Smart control and self-modulating heat help maintain stable water temperatures while reducing energy waste. It emphasizes safety with built-in protections and durable construction for long-term use.
Rheem 11kW 240V Tankless Electric Water Heater
This 11kW Rheem model features a user-friendly ON/OFF dial control with an adjustable digital temperature display and self-modulating power control. It supports flow up to 2.68 GPM, making it a practical option for small apartments or single fixtures where compact form and reliable on-demand hot water are priorities.
Buying Guide
Selecting a tankless water heater involves balancing output, energy use, and installation considerations. Key factors include:
- Flow rate and temperature rise: Evaluate your typical hot-water demand (shower, faucets, dishwasher) and the unit’s GPM rating at a given temperature rise. Higher-demand homes may need larger models with multi-point capacity.
- Electrical requirements: Many electric models require dedicated circuits and significant amperage. Confirm panel capacity and whether new breakers, wiring, or electrical upgrades are needed.
- Self-modulating technology: Self-modulating units adjust energy use to the demand, increasing efficiency and reducing standby waste.
- Size and installation: Tankless units are compact but still require proper venting (for gas models) and safe clearance. Wall mounting can save space, while under-sink options suit point-of-use needs.
- Durability and safety features: Look for ETL/UL certifications, leak protection, dry-fire protection, and overheat safeguards to ensure reliable operation.
- Point-of-use versus whole-home: Point-of-use heaters are ideal for a single sink or small area; whole-home units serve multiple fixtures but may require higher capacity and electrical service.
- Compatibility with home electrical system: Confirm breaker size and wire gauge. Some models require 60A circuits and 6 AWG wiring for full capacity at 240V.
- Maintenance and serviceability: Check element construction, accessibility for service, and warranty terms when selecting a model.
When choosing among these options, consider whether you prioritize maximum GPM for simultaneous fixtures, the desire to install in a compact space, or the ease of installation with existing wiring. Self-modulating features are common across the top models and tend to improve energy efficiency and consistent performance during peak usage.