Best Electric Tankless Water Heaters for Quick Hot Water on Demand
If you need instant hot water without a bulky tank, these top-rated electric tankless water heaters deliver reliable on-demand warmth for homes and apartments. This guide highlights five models that balance power, efficiency, and installation considerations. Ideal buyers include small to mid-size homes, point-of-use upgrades, and households seeking energy savings. The table below summarizes key details to compare at a glance.
| Product | Key Feature | Best For |
|---|---|---|
| Rheem 18kW 240V Tankless Electric Water Heater | 18 kW, self-modulating, LED temp display | Powerful whole-home use with compact footprint |
| Orbek 14kW Tankless Water Heater | 3.38 GPM, 240V, ETL Certified | 2-3 fixtures, budget-friendly upgrade |
| EcoSmart ECO 11 | 13 kW, self-modulating, compact | Space-saving, efficient point-of-use |
| Rheem RTEX-24 | 24 kW, 240V, adjustable 80–140°F | Whole-home use with higher demand |
| WINTEMP 27kW 240V | 27 kW, up to 6.5 GPM, WiFi control | Larger households and showers with multiple uses |
Rheem 18kW 240V Tankless Electric Water Heater
The Rheem 18kW unit uses external digital thermostatic control with an LED display and self-modulating technology to match power output with hot water demand. It features copper immersion elements and is field serviceable for maintenance. This model is best for mid-sized homes needing reliable whole-house hot water without a storage tank. A limitation is that it requires a compatible electrical panel and proper clearances for installation, which may influence where you place it in your home.
Orbek 14kW Tankless Water Heater
The Orbek 14kW model provides up to 3.38 GPM, suitable for 1–2 fixtures. It notes a high current requirement of 150 amps minimum from your main panel and specifies a 240V/60A double-pole breaker with 6 AWG wiring. This makes it a practical choice for smaller homes or apartments upgrading from a traditional heater. A potential limitation is the need for a robust electrical service to support the unit’s demand.
EcoSmart ECO 11 Electric Tankless Water Heater
The EcoSmart ECO 11 uses patented self-modulating technology to heat water only as needed, offering up to 54 A draw and a compact form factor. It’s ideal for space-constrained installations or point-of-use applications, such as under a sink or in a small apartment. It’s best for households with modest hot water needs; it may struggle with simultaneous high-flow demands in larger homes. A limitation is its lower maximum flow compared with higher-kW models.
Rheem 11kW 240V Tankless Electric Water Heater
The Rheem 11kW model offers an adjustable digital temperature display and self-modulating power control, with a flow rate up to 2.68 GPM. It’s suitable for small homes or apartments needing modest hot water or for point-of-use adds like a bathroom vanity or kitchen sink. A limitation is its lower output, which may not support multiple simultaneous uses in a larger household.
Rheem RTEX-24 24kW Tankless Water Heater
The RTEX-24 delivers 24 kW at 240V, with a recommended 200-amp service and three 40-amp double-pole breakers. It features a dial control and adjustable temperature from 80–140°F. This model suits larger homes with higher hot water demands, but it requires careful electrical planning and a spacious electrical panel to accommodate the power load. Consider capacity and panel space before purchasing.
WINTEMP 27kW Electric Tankless Water Heater
The WINTEMP unit operates at 27 kW (113A max) and requires three 40A breakers and 8 AWG wiring. It can provide up to 6.3 GPM, making it suitable for households with higher simultaneous hot water use. It also supports WiFi control for convenient monitoring. A caution is the need for a substantial electrical service and professional installation due to high power requirements.
Buying Guide
What should you consider before buying an electric tankless heater?
- Hot water demand: Estimate GPM needs based on showers, sinks, and appliances used simultaneously. Higher GPM models handle more simultaneous uses.
- Electrical service: Review your home’s electrical panel capacity. Many high-output models require 200+ amps and multiple dedicated circuits.
- Space and installation: Consider whether you’ll mount the unit on a wall in a utility area or near fixtures. Self-modulating models save energy and reduce peak power.
- Temperature stability: Look for units with precise digital controls and memory features to maintain steady temps.
- Efficiency and cost: Self-modulating technology reduces energy consumption. Compare the total electrical load and potential savings over time.
- Maintenance: Field-serviceable parts and copper heating elements can simplify future service needs.
FAQ
- What does “tankless” mean for hot water supply? It heats water on demand, so there is no standby energy loss from a storage tank.
- Do these units require professional installation? Yes, especially for wiring and electrical service upgrades. An electrician should verify compatibility with your panel.
- Which model is best for small apartments? The EcoSmart ECO 11 or Orbek 14kW are common choices for limited spaces and modest hot water needs.
- Can a single unit supply hot water to multiple bathrooms? It depends on GPM requirements; larger homes may need higher-kW units or multiple heaters.
- Do self-modulating heaters save energy? Generally, yes, because they adjust power to match flow, reducing unnecessary energy use.
- Is installation hardware included? Most listings show required electrical and water connections; check your kit contains necessary fittings or plan for extras.