Ecosmart US EcoSmart ECOS 18 Tankless vs Ecosmart US Performance 18kW SM 3.5GPM Electric Tankless Water Heater: Spec Comparison
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You are comparing the ecosmart us ecosmart ecos 18 tankless vs performance 18kw sm 3 5gpm. Both units are electric tankless water heaters from EcoSmart US with an 18 kW power rating. They share the same fuel type and voltage requirements. The main difference lies in their flow rates and physical dimensions. The ECOS 18 offers variable flow, while the Performance model lists a fixed 3.5 GPM rate. You need to check which size and flow suit your home's hot water needs.
Key differences
| Aspect | EcoSmart ECOS 18 Electric Tankless | Ecosmart US 18kW Electric Tankless |
|---|---|---|
| Flow Rate | 1.8 to 4.3 GPM | 3.5 GPM |
| Dimensions | 19 x 4.25 x 9.25 inches | 20 x 7 x 7 inches |
| Weight | 9.3 pounds | 11 pounds |
| Color | White | Gray |
| Temperature Control | within 1 degree | not listed |
Which one should you choose?
Choose EcoSmart ECOS 18 Electric Tankless if
- You need a unit with precise temperature control within 1 degree.
- You have limited space and prefer a narrower profile.
- You want a lighter unit for easier wall mounting.
Choose Ecosmart US 18kW Electric Tankless if
- You prefer a fixed flow rate of 3.5 GPM.
- You do not mind a slightly larger footprint.
- You are open to a refurbished unit that works like new.
Verdict: Choose the ECOS 18 if you value precise temperature consistency and a compact, lightweight design. Pick the Performance 18kW SM if you prefer a straightforward fixed flow rate and are comfortable with a refurbished unit. Both deliver 18 kW of power for on-demand hot water.
Ecosmart ECOS 18 vs Performance 18kW
Flow rate capacity
The Performance 18kW SM lists a specific flow rate of 3.5 GPM in its key specs, while the attributes section claims 5.0 GPM. This discrepancy makes the exact output unclear. The ECOS 18 provides a defined range of 1.8 to 4.3 GPM depending on inlet water temperature. You get a predictable performance window with the ECOS model. The Performance unit’s higher stated GPM might suit higher demand, but the conflicting data requires caution. If you need steady, known output, the ECOS 18 offers clearer specifications for planning your hot water usage.
Temperature precision
The ECOS 18 features patented self-modulating technology that keeps water temperature within 1 degree of your selected setting. This ensures consistent performance without sudden hot or cold shocks. The Performance 18kW SM data does not mention any specific temperature control accuracy or modulation technology. You cannot verify if it maintains similar stability. For users who value precise temperature consistency, the ECOS 18 provides a distinct advantage through its documented control system. The lack of this detail for the Performance model makes the ECOS the safer choice for comfort.
Physical dimensions
The ECOS 18 measures 19 inches in height, 9.25 inches in width, and 9.25 inches in length. It is compact and designed for wall mounting or point-of-use installation. The Performance 18kW SM is slightly taller at 20 inches but narrower, measuring 7 inches in both width and length. The Performance unit has a more square footprint, which might fit better in tight vertical spaces. The ECOS 18 is wider but shorter. Your available installation space will determine which form factor works best. Both are small compared to traditional tanks, but their shapes differ.
Weight and build
The ECOS 18 weighs 9.3 pounds, making it very lightweight and easy to handle during installation. The Performance 18kW SM weighs 11 pounds. The slight weight difference is negligible for most users, but the ECOS 18 is marginally lighter. Both units are electric and require 240V power. The Performance unit is listed as refurbished, which may affect internal component condition, though it is certified to work like new. The ECOS 18 is presented as a standard new unit. Weight alone does not dictate durability, but the lighter ECOS model is easier to maneuver.
Warranty coverage
The ECOS 18 includes a five-year limited warranty on leaks and a one-year parts warranty. This provides clear protection for major components and structural integrity. The Performance 18kW SM data does not list any warranty information. You cannot know the coverage terms for this unit. For long-term peace of mind, the ECOS 18 offers documented warranty support. The lack of warranty data for the Performance model is a significant gap. You should prioritize the unit with known warranty terms to protect your investment against potential defects.
Which tankless heater suits your needs
You want precise temperature stability
The ECOS 18 maintains water temperature within 1 degree of your selection. This patented self-modulating technology ensures consistent performance. You get reliable hot water without sudden fluctuations. The unit monitors water temperature and controls flow rates continuously. This precision makes it ideal for users who value steady heat output over maximum volume.
You need compact installation space
The ECOS 18 measures 19 x 4.25 x 9.25 inches. It weighs only 9.3 pounds. This small footprint allows installation in tight spots or at point-of-use locations. You save significant space compared to traditional tank heaters. The compact design fits easily on walls where larger units would not fit.
You prefer refurbished value
The Performance 18kW SM is a refurbished unit tested to work like new. It includes functionality testing, cleaning, and inspection. You get all relevant accessories with this certified product. It may arrive in a generic box. This option offers a 3.5 GPM flow rate at a potentially lower entry point for basic electric heating needs.
The products compared
EcoSmart ECOS 18 Electric Tankless
Best for: Single bathroom point-of-use installation
- Fuel Type
- Electric
- Flow Rate
- 1.8 to 4.3 GPM
- Wattage
- 18 kW
- Voltage
- 240 V
- Temperature Control
- within 1 degree
- Dimensions
- 19 x 4.25 x 9.25 inches
View on Amazon: EcoSmart ECOS 18 Electric Tankless Affiliate link
This electric tankless water heater delivers 18 kW of power at 240 volts. It provides 1.8 to 4.3 GPM depending on inlet temperature. The unit maintains water temperature within 1 degree of your selection. It measures 19 x 4.25 x 9.25 inches and weighs 9.3 pounds. This compact design suits bathrooms or point-of-use installations where space is limited.
Pros
- 18 kW heating capacity for on-demand hot water
- Temperature control within 1 degree of selected setting
- Compact dimensions of 19 x 4.25 x 9.25 inches
- 96% thermal energy efficiency rating
Cons
- Flow rate maxes out at 4.3 GPM
- Requires 75 amp electrical circuit
- Only one year parts warranty coverage
Good fit if
- You need hot water for a single bathroom
- You have a dedicated 240V 75A electrical circuit
- You want to save space with a wall-mounted unit
Skip if
- You need to run multiple showers simultaneously
- Your inlet water temperature is extremely cold
- You cannot install a 75A breaker
Verdict: EcoSmart ECOS 18 Electric Tankless is a compact solution for single-fixture use. It fits well in bathrooms where you have the necessary electrical capacity.
Ecosmart US 18kW Electric Tankless
Best for: Single bathroom electric heating
- Fuel Type
- Electric
- Flow Rate
- 3.5 GPM
- Wattage
- 18 kW
- Dimensions
- 20 x 7 x 7 inches
- Weight
- 11 pounds
View on Amazon: Ecosmart US 18kW Electric Tankless Affiliate link
This Ecosmart US unit is a refurbished 18 kW electric tankless water heater. It delivers a flow rate of 3.5 GPM. The compact gray design measures 20 x 7 x 7 inches and weighs 11 pounds. It is suitable for you if you need a reliable, space-saving electric option for a single bathroom or small sink. The refurbished status ensures it works like new.
Pros
- 18 kW heating capacity for consistent hot water
- Compact 7-inch width fits tight spaces
- Lightweight 11-pound build for easy mounting
- Refurbished and certified to work like new
Cons
- Lower flow rate of 3.5 GPM limits simultaneous use
- Refurbished condition may arrive in a generic box
- Electric model requires adequate electrical circuit capacity
Good fit if
- You need a compact unit for a single bathroom
- You prefer electric heating for easier installation
- You want a certified refurbished device for value
Skip if
- You require high flow rates for multiple fixtures
- You need a brand-new unit with original packaging
- You have limited electrical service capacity
Verdict: Ecosmart US Performance 18kW Electric is a compact electric heater for single-bathroom use. Its 3.5 GPM flow suits low-demand households needing space-saving efficiency.
Specifications side by side
| Spec | EcoSmart ECOS 18 Electric Tankless | Ecosmart US 18kW Electric Tankless |
|---|---|---|
| Fuel Type | Electric | Electric |
| Flow Rate | 1.8 to 4.3 GPM | 3.5 GPM |
| Wattage | 18 kW | 18 kW |
| Voltage | 240 V | not stated |
| Temperature Control | within 1 degree | not stated |
| Dimensions | 19 x 4.25 x 9.25 inches | 20 x 7 x 7 inches |
| Weight | 9.3 pounds | 11 pounds |
| Color | White | Gray |
| Model | ECOS 18 | Performance 18KW SM 3.5GPM Electric |
Frequently asked questions
Which unit is smaller for tight spaces?
The ECOS 18 has a slightly larger footprint but is lighter. It measures 9.25 by 9.25 by 19 inches and weighs 9.3 pounds. The Performance 18kW is narrower and shorter in width. It measures 7 by 7 by 20 inches and weighs 11 pounds. You should check your cabinet dimensions carefully. The narrower unit may fit better in tight corners.
Do both heaters require the same electrical setup?
Yes, both models operate on 240V power. They both use 18 kW of wattage to heat water. This means they draw similar amounts of electricity. You will need adequate circuit capacity for either unit. The electrical requirements are identical for both the ECOS 18 and the Performance 18kW. Check your home's panel capacity before installation.
What is the difference in color options?
The ECOS 18 comes in a white finish. The Performance 18kW model is available in gray. This is the only visible difference between the two units. Choose the color that matches your utility room or bathroom decor. The color does not affect performance or heating efficiency. It is purely a cosmetic distinction between the two models.
Can I use these for multiple bathrooms?
These units are best for single bathroom point-of-use installation. They are designed for low-demand households. The Performance 18kW lists a 3.5 GPM flow rate. This suits one fixture well. Using them for multiple simultaneous bathrooms may reduce water pressure. Consider a higher-capacity model if you need to supply more than one shower at once.
How heavy are these tankless water heaters?
The ECOS 18 weighs 9.3 pounds. The Performance 18kW weighs 11 pounds. Both units are relatively light for easy mounting. You can install them on standard wall studs. The weight difference is minor. Ensure your mounting surface can support at least 11 pounds. Both models are compact enough for most residential utility spaces.
Is the flow rate clearly defined for the ECOS 18?
The ECOS 18 data does not list a specific GPM rating. The Performance 18kW lists 3.5 GPM in its specs. This makes direct flow comparison difficult. The ECOS 18 is rated for single-fixture use. You should expect lower flow output from the ECOS 18. Check your local water pressure and temperature to estimate actual flow.