A tankless water heater only draws power while hot water is flowing, but the size of that draw still matters. Whole-home electric units pull 18kW to 36kW and often need several 40-amp breakers. If you only need warm water at one sink, a 3.5kW, 120-volt point-of-use model keeps the load small and can often run on a single circuit. These three are the lowest-wattage tankless heaters we recommend.
We compared wattage, voltage, flow, controls and safety features using manufacturer specifications and owner feedback. If you need more flow, see the best tankless water heater energy efficient guide or start with the best tankless water heater; our Editorial Policy explains how we choose. Electric tankless heaters must be wired to code; have a licensed electrician confirm your panel, breaker and wire size before you buy.
Top 3 Low-Power Tankless Water Heaters
GE Appliances GE04SNLPDG 3.5kW 120V Point-of-Use Tankless Water Heater
- 3.5kW, 120V
- Remote control
- 0.7 GPM
Eemax SPEX3512 FlowCo 3.5kW 120V Point-of-Use Tankless Water Heater
- SafeStart
- Self diagnostics
- Any orientation
LECLOC C3500 3.5kW 120V Under-Sink Tankless Water Heater
- Knob + LED
- Error codes
- Overheat protection
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Low-Power Tankless Water Heaters Compared
| # | Product | Key Features | |
|---|---|---|---|
| 1 |  GE Appliances GE04SNLPDG 3.5kW 120V Point-of-Use Tankless Water Heater |
| Check Latest Price |
| 2 |  Eemax SPEX3512 FlowCo 3.5kW 120V Point-of-Use Tankless Water Heater |
| Check Latest Price |
| 3 |  LECLOC C3500 3.5kW 120V Under-Sink Tankless Water Heater |
| Check Latest Price |
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1. GE Appliances GE04SNLPDG 3.5kW 120V Point-of-Use Tankless Water Heater
Best Overall
- Draws only 3.5kW on a 120V supply
- Up to 0.7 GPM, enough for one faucet
- Touch screen plus remote control from up to 30 feet
- LED temperature display
- Sized for one faucet, not showers
- Low flow in cold climates
- Power: 3.5kW, 120V
- Flow: up to 0.7 GPM (72°F in, 105°F out)
- Model: GE04SNLPDG
GE’s 3.5kW unit gives a sink warm water on demand while keeping the electrical load modest.
The remote is handy when the heater is tucked inside a cabinet.
Who the GE 3.5kW fits best
Kitchen, bar or bathroom sinks.
Who should skip the GE 3.5kW
Anyone who needs a shower.
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2. Eemax SPEX3512 FlowCo 3.5kW 120V Point-of-Use Tankless Water Heater
Best Simple Unit
- 3.5kW at 120V
- SafeStart technology and self diagnostics
- Mounts in any orientation
- Compact, activates only on demand
- Output temperature depends on flow
- Cold water inlet only
- Power: 3.5kW, 120V
- Rise: 41°F at 0.5 GPM
- Model: SPEX3512
Eemax’s FlowCo is a simple, compact point-of-use heater for low-flow sinks.
The maker recommends 10-gauge wire.
Who the Eemax FlowCo 3.5kW fits best
Hand-washing sinks.
Who should skip the Eemax FlowCo 3.5kW
Users who want a set temperature display.
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3. LECLOC C3500 3.5kW 120V Under-Sink Tankless Water Heater
Best Display
- 3.5kW, 120V hard-wired
- Self-modulating power
- Overheat, leakage and dry heating protection, IPX4
- Big knob and LED display with error codes
- Needs a 30–40A single-pole breaker
- Low-flow use only
- Power: 3.5kW, 120V
- Install: hard-wired
- Model: C3500
LECLOC’s C3500 adds clear controls and fault codes to a low-wattage design.
It is not meant for showers or several taps at once.
Who the LECLOC C3500 fits best
Under-sink installs.
Who should skip the LECLOC C3500
Multi-tap use.
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How to Keep Power Use Low
- Match wattage to the job: one sink rarely needs more than 3.5kW.
- Use a low-flow aerator so the heater can reach temperature.
- Set the lowest comfortable temperature.
- Check that your panel can supply the required breaker.
Frequently Asked Questions
What is the lowest-power tankless water heater?
Point-of-use models around 3.5kW at 120V, like the GE GE04SNLPDG.
Can a 3.5kW heater run a shower?
No, these units are sized for one sink.
Do tankless heaters use power on standby?
Only a small amount for controls; heating happens when water flows.
Do I need an electrician?
Yes, have a licensed electrician check the circuit.
Final Verdict: Best Tankless Water Heater Low Power Consumption
The GE GE04SNLPDG is the best low-power tankless water heater for most sinks. The Eemax FlowCo is the simplest unit, and the LECLOC C3500 has the clearest display.
Best overall: GE Appliances GE04SNLPDG 3.5kW 120V Point-of-Use Tankless Water Heater Check Latest Price
Simplest: Eemax SPEX3512 FlowCo 3.5kW 120V Point-of-Use Tankless Water Heater Check Latest Price
Best display: LECLOC C3500 3.5kW 120V Under-Sink Tankless Water Heater Check Latest Price
Small loads, small heaters: match the wattage to the faucet.
Looking for something else? Browse all of our Water Heaters guides and the wider Heating & Cooling section.
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