Best EcoSmart Tankless Water Heaters Reviewed

EcoSmart tankless water heaters provide efficient, on-demand hot water without the bulk of traditional tank models. With various options available, selecting the right model can significantly impact your energy savings and comfort.

EcoSmart Tankless Water Heater Comparison

Product	Best for	Power (kW)	GPM	Dimensions	Energy Efficiency	Price
EcoSmart ECOS 27 Tankless Electric Water Heater	Best Overall	27	2.7 to 6.6	19 x 4.25 x 9.25 inches	96%	Check price
EcoSmart ECOS 18 Tankless Electric Water Heater	Best for Small Homes	18	1.8 to 4.3	19 x 4.25 x 9.25 inches	96%	Check price
Ecosmart ECO 36 36kw Electric Tankless Water Heater	Best for Large Homes	36	—	—	99.8%	Check price
EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW	Most Durable	8	—	12 x 8 x 4 inches	—	Check price
EcoSmart POU 4T 3.5kW 120v Thermostatic Point of Use Tankless Water Heater	Best Point of Use	3.5	—	—	—	Check price

Our Top EcoSmart Tankless Water Heater Picks

1

Best Overall

EcoSmart ECOS 27 Tankless Electric Water Heater

Best for: Households needing consistent hot water for multiple fixtures

The ECOS 27 offers 27 kW power with self modulating technology that keeps water temperature within 1 degree of the setpoint. It delivers 2.7 to 6.6 gallons per minute, enough for simultaneous use in bathrooms and kitchens. Its compact size saves space and it heats water only on demand, improving energy efficiency.

• Power (kW)27
• GPM2.7 to 6.6
• Dimensions19 x 4.25 x 9.25 inches
• Energy Efficiency96%

Pros

• Consistent hot water without running out
• 96% thermal energy efficiency
• Compact wall-mount design

Cons

• Requires 112.5 amps breaker, so professional installation likely

Skip it if: Skip if your home needs less than 18 kW or lower flow rates.

Check price on Amazon

2

Best for Small Homes

EcoSmart ECOS 18 Tankless Electric Water Heater

Best for: Small homes or point-of-use applications requiring moderate hot water flow

The ECOS 18 provides 18 kW with patented self modulating technology for efficient temperature control within 1 degree. It produces between 1.8 and 4.3 gallons per minute, good for a bathroom or small sink. The compact size and energy savings make it ideal for low-flow needs.

• Power (kW)18
• GPM1.8 to 4.3
• Dimensions19 x 4.25 x 9.25 inches
• Energy Efficiency96%

Pros

• Endless on-demand hot water
• Up to 96% thermal efficiency
• Small footprint for wall or point-of-use installation

Cons

• Limited to lower flow rates than larger models

Skip it if: Skip if your household demand exceeds 4.3 GPM or 18 kW capacity.

Check price on Amazon

3

Best for Large Homes

Ecosmart ECO 36 36kw Electric Tankless Water Heater

Best for: Large homes or commercial use needing high flow and power

The ECO 36 delivers 36 kW and is 99.8% energy efficient, making it the most powerful and efficient option here. It features a digital temperature display and requires a 150 amp breaker setup. Its compact design fits wall mount installations but demands high electrical capacity.

• Power (kW)36
• GPM—
• Dimensions—
• Energy Efficiency99.8%

Pros

• Highest power and efficiency
• Digital temperature display
• Compact and sleek design

Cons

• High power needs require substantial electrical upgrade

Skip it if: Skip if your electrical panel cannot support a 150 amp breaker.

Check price on Amazon

4

Most Durable

EcoSmart ECO 8 Tankless Water Heater, Electric, 8-kW

Best for: Point-of-use or minimal hot water needs with durable design

The ECO 8 is an 8 kW unit known for high durability and ease of use. It suits minimal hot water requirements like a single sink or small appliance. Its compact size fits tight spaces but lacks advanced modulation technology.

• Power (kW)8
• GPM—
• Dimensions12 x 8 x 4 inches
• Energy Efficiency—

Pros

• Highly durable construction
• Simple operation
• Compact size

Cons

• Lower power limits flow rate and simultaneous use

Skip it if: Skip if you need more than minimal hot water or flow rate.

Check price on Amazon

5

Best Point of Use

EcoSmart POU 4T 3.5kW 120v Thermostatic Point of Use Tankless Water Heater

Best for: Low-flow, point-of-use spots like a single sink or small appliance

The POU 4T provides 3.5 kW power ideal for point-of-use or low-flow needs. It heats water on demand, saving energy and space with a unit 90% smaller than traditional tanks. Suitable for places needing quick hot water without a full home system.

• Power (kW)3.5
• GPM—
• Dimensions—
• Energy Efficiency—

Pros

• Compact size for point-of-use
• Energy efficient on-demand heating
• Consistent hot water supply

Cons

• Low power limits use to single fixtures

Skip it if: Skip if you need hot water for multiple fixtures or higher flow.

Check price on Amazon

How to Choose the Right EcoSmart Tankless Water Heater

Choose an EcoSmart tankless water heater by matching its power output and flow rate to your household’s hot water demand. The key is to find a model that delivers enough gallons per minute (GPM) for your simultaneous fixtures without wasting energy.

Start by estimating your peak hot water use in GPM. For example, a shower typically uses 1.5 to 2.5 GPM, while a dishwasher uses about 1.5 GPM. Add up the flow rates of fixtures you expect to run at the same time to get a target GPM.

Next, check the EcoSmart models’ power ratings in kilowatts (kW). Higher kW means more heating capacity and higher flow rates at a set temperature rise. For most homes, the EcoSmart ECO 27 with 27 kW suits multiple simultaneous uses. Smaller models like the ECO 8 or ECOS 18 fit smaller households or point-of-use needs.

Energy efficiency ratings matter for cost savings. EcoSmart models typically exceed 99% energy factor, so choose based on size and flow rather than efficiency differences. All electric models avoid standby heat loss common in tank heaters.

1. 1. Calculate your peak GPM
   List fixtures used simultaneously and add their flow rates.
2. 2. Choose a model with a power rating that meets or exceeds your GPM need at your inlet wa
3. 3. Confirm voltage compatibility with your home’s electrical system.

Sizing and Heat Output for Your Home

Sizing a tankless water heater depends on your household’s gallons per minute (GPM) demand and the temperature rise needed. The temperature rise is how much the heater must raise the incoming water to reach your desired hot water temperature.

To find your GPM, add the flow rates of fixtures you expect to use at the same time. For example, a shower at 2.0 GPM plus a kitchen faucet at 1.0 GPM equals 3.0 GPM total.

Know your inlet water temperature, which varies by region and season. Cold water entering the heater in winter can be as low as 40°F. If you want your hot water at 120°F, the heater must provide an 80°F rise. Higher temperature rises reduce the flow rate a given heater can supply.

1. 1. Measure your peak simultaneous GPM need by adding fixture flow rates.
2. 2. Determine your inlet water temperature for accurate temperature rise calculation.
3. 3. Select a heater model rated for that GPM at your calculated temperature rise.
4. 4. For large households, consider installing multiple units to meet high demand without ov

For example, the EcoSmart ECO 27 can deliver about 3.0 GPM with an 80°F rise, enough for a shower and a faucet running together. Larger models like the ECO 36 support higher flow rates for bigger households.

Proper sizing ensures efficient operation and steady hot water supply. Oversizing wastes electricity and costs more upfront; undersizing reduces comfort and can shorten heater lifespan.

For detailed recommendations on electric tankless water heaters, see our best electric tankless water heater buying guide.

Understanding Running Costs of EcoSmart Tankless Water Heaters

Running costs for EcoSmart tankless water heaters depend on their power rating, usage time, and your electricity rate. The formula to calculate operating cost is watts divided by 1,000, multiplied by hours used, then multiplied by your cost per kWh. For example, a 27-kW heater running for one hour at $0.17 per kWh costs 27 × 1 × 0.17 = $4.59.

Energy consumption varies with how much hot water you use and the temperature rise needed. Higher flow rates or colder incoming water increase power use. Tankless heaters only heat water on demand, so standby losses are minimal compared to tank heaters.

EcoSmart models have digital controls to adjust temperature precisely, reducing wasted energy. Using a lower temperature setting saves power. Also, the electric resistance elements operate only when hot water is needed, so running costs reflect actual usage rather than continuous heating.

Safety and Certification of EcoSmart Tankless Water Heaters

EcoSmart tankless water heaters meet UL and ETL safety certification standards, ensuring they comply with electrical safety requirements. These certifications confirm the heaters have been tested for risks like electric shock and fire hazards.

Safety features include automatic shut-off mechanisms that activate if the heater detects overheating or a fault. This protects the unit and prevents damage to your home’s electrical system.

1. Hire a licensed electrician
   Ensure the heater is connected to a dedicated circuit rated for its power draw, typically 240 V and up to 150 amps for larger models.
2. Verify proper grounding
   A secure ground connection prevents electric shock and allows safety devices to operate correctly.
3. Install according to local codes
   Check local electrical and plumbing codes to comply with all safety regulations.

Are EcoSmart tankless water heaters safe? Yes, when installed properly and used as directed. Their built-in safety features combined with certification provide reliable protection.

EcoSmart Tankless Water Heaters: What Competitors Leave Out

EcoSmart tankless water heaters stand out primarily for their self-modulating technology. This system adjusts the energy use in real time, matching the water temperature and flow demand. It reduces electricity consumption without sacrificing performance.

The compact design of EcoSmart models is another unique advantage. Their small footprint makes them ideal for tight spaces, including closets or utility rooms where larger units would not fit. This space-saving feature often makes installation simpler and more flexible.

Warranty coverage on EcoSmart units is competitive. Most models come with a lifetime warranty on the heating element and a 5-year warranty on parts. This surpasses many competitors, which typically offer shorter warranties or limit coverage to specific components.

The self-modulating feature delivers energy savings by preventing unnecessary power use during low-demand periods. This keeps your electric bills lower over time compared to models that run at full power regardless of need.

EcoSmart’s compact size also means less installation hassle and more options for placement. If your home has limited mechanical space, these units fit where others cannot without custom modifications.

Frequently Asked Questions