Electric Tankless Water Heaters for Shower Use

Endless cold showers are a thing of the past with an electric tankless water heater. These units heat water on demand, eliminating the need for a bulky storage tank and providing instant hot water for your shower.

In this roundup, we evaluate the best electric tankless water heaters that combine efficiency, performance, and ease of installation, ensuring you find the perfect fit for your home.

Comparison of Electric Tankless Water Heaters

Product	Best for	Flow Rate	Power	Dimensions	Price
Rheem 18kW 240V Tankless Electric Water Heater	Best Overall	4.4 GPM	18 kW	—	Check price
SIVUATEK 14kW 240V Tankless Water Heater	Best for Small Homes	—	14 kW	15.87″ x 11.14″ x 2.87″	Check price
LECLOC 3kW 120V Mini Tankless Water Heater	Best Point of Use	—	3 kW	7.1″ x 9.8″ x 2.8″	Check price
CAMPLUX 4.5kW 120V Tankless Water Heater	Best for Compact Spaces	1.0 GPM	4.5 kW	10.95″ x 2.52″ x 7.4″	Check price
Rheem 3.5kW 120V Point-of-Use Tankless Heater	Best for Single Fixture	0.5 GPM	3.5 kW	—	Check price

Top Electric Tankless Water Heaters for Shower Use

1

Best Overall

Rheem 18kW 240V Tankless Electric Water Heater

Best for: Households needing multiple simultaneous showers

The Rheem 18kW model delivers up to 4.4 GPM with advanced self-modulation that adjusts power to match demand, improving energy efficiency. Its dual copper immersion heating elements are durable and serviceable, while the external digital thermostatic control offers precise temperature management. This unit suits medium to large homes requiring steady, on-demand hot water for several outlets.

• Flow Rate4.4 GPM
• Power18 kW
• Dimensions—

Pros

• High flow rate supports multiple showers at once
• Precise temperature control with +/-1 degree accuracy
• Durable, serviceable heating elements
• Simple installation with standard 3/4 inch NPT connections

Cons

• Requires a 240V circuit and professional installation
• Larger footprint than point-of-use models

Skip it if: Skip if you only need hot water for one sink or small fixture.

Check price on Amazon

2

Best for Small Homes

SIVUATEK 14kW 240V Tankless Water Heater

Best for: 1–2 simultaneous usage points like a sink and shower

This 14kW heater offers nearly 100% thermal efficiency and instant hot water with no preheating or idle power use, cutting water heating costs by up to 50%. It includes smart temperature control with 1°F increments and safety features like leakage and overheating protection. It’s ideal for small homes or apartments with moderate hot water demand.

• Flow Rate—
• Power14 kW
• Dimensions15.87″ x 11.14″ x 2.87″

Pros

• Energy efficient with no standby heat loss
• Precise digital temperature control
• Advanced safety features including leakage protection
• Compact design with standard 1/2 inch NPT connections

Cons

• Requires a 60-amp circuit breaker
• Lower flow rate than larger models

Skip it if: Skip if you need hot water for multiple simultaneous showers.

Check price on Amazon

3

Best Point of Use

LECLOC 3kW 120V Mini Tankless Water Heater

Best for: Single sink or small fixture, not for showers

This 3kW 120V plug-in unit is designed for low-flow applications like kitchen or bathroom sinks. It provides endless warm water with a simple control knob and LED display. The compact size and multiple safety features make it easy to install under sinks or in small spaces, but it cannot supply a shower due to limited heating capacity.

• Flow Rate—
• Power3 kW
• Dimensions7.1″ x 9.8″ x 2.8″

Pros

• Plug-in design for easy installation
• LED display with simple temperature control knob
• Comprehensive safety features including IPX4 waterproofing
• Compact size fits small spaces

Cons

• Insufficient power for shower use
• Output temperature affected by inlet water flow

Skip it if: Skip if you need hot water for a shower or multiple fixtures.

Check price on Amazon

4

Best for Compact Spaces

CAMPLUX 4.5kW 120V Tankless Water Heater

Best for: Single sink requiring quick hot water

The CAMPLUX 4.5kW unit heats water instantly with a 1.0 GPM flow rate and a 50°F temperature rise, saving energy by heating only on demand. Its small size and wall-mount design fit tight spaces like kitchens and boats. The touch control panel and LED display make temperature setting easy, but it requires hard wiring and a 40A breaker.

• Flow Rate1.0 GPM
• Power4.5 kW
• Dimensions10.95″ x 2.52″ x 7.4″

Pros

• Instant hot water with fast temperature rise
• Compact and space-saving wall mount design
• Self-modulating power saves energy
• Easy touch controls with LED display

Cons

• Requires hard wiring and 40A breaker
• Limited to single sink use

Skip it if: Skip if you need a unit for showers or multiple outlets.

Check price on Amazon

5

Best for Single Fixture

Rheem 3.5kW 120V Point-of-Use Tankless Heater

Best for: One fixture applications like basement sinks or workshops

This 3.5kW 120V Rheem model fits small spaces and delivers up to 0.5 GPM, ideal for a single sink or outdoor kitchen. It features digital thermostatic controls with 1-degree increments and requires a 30-amp breaker. It saves energy by heating water only when needed, but cannot supply a shower due to low flow rate.

• Flow Rate0.5 GPM
• Power3.5 kW
• Dimensions—

Pros

• Compact size for small spaces
• Precise digital temperature control
• Energy-saving on-demand heating

Cons

• Low flow rate unsuitable for showers
• Requires a 30-amp breaker and proper wiring

Skip it if: Skip if you need a unit for multiple outlets or showers.

Check price on Amazon

How to Choose the Right Electric Tankless Water Heater

The best electric tankless water heater for shower use delivers hot water on demand without running out. Start by understanding flow rates, which measure gallons per minute (GPM). A typical shower needs about 1.5 to 2.5 GPM. Choose a heater that matches or exceeds your peak flow to avoid temperature drops.

Electric tankless water heaters require sufficient power. Most household models run on 240 volts and draw 12 to 18 kilowatts. Check your home’s electrical panel for capacity. Installation often needs dedicated breakers and proper wiring to handle the load safely.

Space for installation matters. Tankless units mount on walls and vary in size from compact point-of-use models to larger whole-house systems. Measure the available wall space and ensure clearance for ventilation and maintenance.

Energy efficiency features reduce operating costs. Look for self-modulating heaters that adjust power based on demand. This prevents wasted energy when water flow is low. A unit with a high energy factor rating converts more electricity into heat, saving money over time.

Sizing and Heat Output Considerations

Sizing a tankless water heater depends on your household’s hot water needs. Count the number of simultaneous users and fixtures. For example, two showers running at once need about 4 to 5 GPM combined.

Calculate required flow rates by adding the GPM of each fixture you expect to use simultaneously. Remember to include faucets or appliances if they run at the same time.

Temperature rise is the difference between incoming water temperature and desired output. In colder climates, ground water can be as low as 40°F. To reach 105°F for a shower, the heater must provide a 65°F rise.

Electric tankless water heater output per shower varies by model. A typical 18 kW unit can deliver about 4 to 5 GPM at a 60°F temperature rise. Smaller 14 kW models handle about 3 to 4 GPM at the same rise, suitable for one shower or a small household.

Safety Features and Certification

Electric tankless water heaters include several critical safety features to prevent hazards. Look for models with overheat protection that automatically shuts off the unit if the water temperature exceeds safe limits. Leakage detection is another key feature, stopping the heater if water escapes inside the unit.

Certification confirms a heater meets safety and performance standards. Check for UL, ETL or CSA listings. These certifications ensure the unit has been tested for electrical safety, fire risk, and proper operation.

Proper installation is essential for safety. Electric tankless water heaters require a dedicated circuit sized to the heater’s amperage. The manual will specify wiring and breaker requirements. Improper wiring or overloaded circuits can cause fire or damage.

1. Confirm circuit specifications
   Verify the electrical panel can support the heater’s amperage and voltage requirements.
2. Use a licensed electrician
   Have a professional install the heater to ensure code compliance and correct wiring.
3. Install proper grounding
   Grounding prevents electrical shock and is required by code.
4. Maintain clearance and ventilation
   Keep at least 3 feet of clearance around the unit and ensure any ventilation requirements are met.

Understanding Running Costs of Electric Tankless Water Heaters

The running cost of an electric tankless water heater depends on its power rating, usage hours, and your electricity rate. Calculate cost by multiplying watts ÷ 1,000 × hours used × price per kWh.

For example, a 14,000-watt (14kW) heater running 1 hour daily at $0.17 per kWh costs: 14,000 ÷ 1,000 × 1 × 0.17 = $2.38 per day. Multiply by 30 for monthly cost.

Electric tankless heaters use energy only when hot water flows, unlike traditional tank heaters that maintain temperature constantly. This on-demand operation reduces standby losses and can lower monthly energy bills despite higher wattage.

Frequently Asked Questions