Finding the right tankless hot water heater involves balancing flow rate, energy efficiency, installation requirements, and durability. This guide highlights five top options, spanning electric models from Orbek, Rheem, and EcoSmart, to help American homeowners compare performance, compatibility, and value. Each section links to an Amazon product page for quick review and potential purchase.
| Product | Type | Approximate GPM | Power/Voltage | Best For |
|---|---|---|---|---|
| Orbek 14kW Tankless Electric | Electric | Up to 3.38 | 240V | 2-3 fixtures |
| Rheem RTEX-24 24kW | Electric | Up to varies by location | 240V | Whole-home or multi-point |
| Orbek 18kW Tankless Electric | Electric | Up to 4.17 | 240V | 2-3 fixtures |
| Rheem 18kW 240V | Electric | Up to 4.4 | 240V | Higher demand |
| EcoSmart ECO 11 | Electric | Up to 1-2 GPM typical | 240V | Space-saving, point-of-use |
Orbek 14kW Tankless Electric — 3.38 GPM
Product details indicate this 14kW electric unit requires a 240V/60A two-pole breaker, 6 AWG wiring, and 1/2″ NPT water connections. It provides up to 3.38 GPM of on-demand hot water, suitable for 2-3 points of use simultaneously. The model emphasizes water-electricity separation to reduce scale and corrosion, with heat-up to hot water in about 3 seconds and potential energy savings relative to tank-style heaters.
Rheem RTEX-24 24kW 240V Electric
This unit requires 3 x 40-amp double-pole breakers and a 200-amp service recommended by the manufacturer. It delivers continuous hot water and its performance depends on supply conditions by location. The ON/OFF dial and adjustable digital temperature display allow precise settings from 80–140 degrees Fahrenheit, with performance being influenced by groundwater temperature and installation configuration.
Orbek 18kW Tankless Electric — 4.17 GPM
This 18kW model requires two 240V/40A two-pole breakers, plus two sets of 8 AWG wires and 3/4″ NPT water connections. It claims up to 4.17 GPM for 2-3 fixtures simultaneously, with rapid delivery of hot water and energy efficiency features that reduce scale and corrosion. Temperature stability is emphasized with rapid response times and a compact form factor suitable for indoor installation.
Rheem 18kW 240V Tankless Electric
Equipped with external digital thermostatic control and LED display, this model features adjustable self-modulation to meet hot water demand. It uses durable copper immersion heating elements and offers a flow rate up to 4.4 GPM. The device is described as field-serviceable, allowing maintenance with standard tools. It is designed to be compact and efficient for mid-sized households.
EcoSmart ECO 11 Electric Tankless Water Heater
EcoSmart’s ECO 11 uses patented self-modulating technology to adjust amperage, delivering endless on-demand hot water with efficiency. It is 90% smaller than traditional tank heaters and can be installed on a wall or at the point of use. Flow is typically suitable for smaller homes or apartments, with energy savings emphasized by continuous monitoring and precise temperature control. Dimensions and installation flexibility are highlighted features.
Buying Guide: Key Purchase Considerations
- Hot water demand: Calculate your peak GPM needs based on shower, faucet, and appliance use to choose a model with adequate flow.
- Electrical or gas supply: Electric units require dedicated breakers and proper wiring; gas-powered units require venting, gas line capacity, and space considerations.
- Power requirements and service capacity: Ensure your electrical panel can accommodate the unit’s amperage and consider whether service upgrades are needed.
- Energy efficiency: Look for self-modulating technology or advanced thermostatic control to minimize standby losses and reduce operating costs.
- Installation location: Consider indoor vs outdoor installation, space constraints, and venting (for gas units) or proximity to point-of-use fixtures.
- Maintenance and durability: Prefer units with durable heating elements (copper or stainless) and access for service; check warranty terms.
- System compatibility: Match the model’s maximum temperature and GPM with your typical climate and water temperature rise for reliable performance.
- Safety features: Temperature limits, anti-scald controls, and overheat protection improve reliability and user safety.