Camplux ME40 4 Gallon
A narrow 4 gallon plug-in tank that fits where wider tanks don’t. Its tank warranty is shorter than the major brands.
Amazon $209.99$209.99
4 gal1,440 WPlug-in
3.2/5
A 4 gallon plug-in tank for a kitchen sink. Ariston and EcoSmart sell 4 gallon tanks for less with longer warranties.
- 4 galTank
- 1,440 WElement
- Plug-inPower
- 3 yearsTank warranty
Check price at Amazon$220.99
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Plugs into a standard outlet
- Thick 30 mm foam insulation helps the tank hold heat
- Relief valve included
Cons
- Three-year tank and one-year parts warranty
- Costs more than 4 gallon tanks with longer warranties
The ThermoMate ES mini tank family
Every ThermoMate ES mini tank model we rank, smallest first. Ratings compare each against its own size.
| Model | Tank | Rating | Price |
|---|---|---|---|
| ThermoMate ES250 2.5 Gallon | 2.5 gal | 2.3/5 | $199.99 |
| ThermoMate ES400 4 Gallon (this one) | 4 gal | 3.2/5 | $220.99 |
| ThermoMate ES700 6.5 Gallon | 6.5 gal | 2.6/5 | $239.99 |
| ThermoMate ES800 8 Gallon | 8 gal | 2.9/5 | $269.99 |
How it scores
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.
Specifications
| Model number | ES400 |
|---|---|
| Heating | |
| Tank capacity | 4 gal |
| Element | 1,440 W |
| Voltage | 120 V |
| Current | 12 A |
| Electrical connection | Plug-in |
| Thermostat range | 50 to 149 °F |
| Price per gallon | $55.25 |
| Installation | |
| Dimensions (H x W x D) | 14.5 x 14.5 x 12.9 in |
| Weight | 19.8 lb |
| Water connections | 1/2" NPT |
| Relief valve included | Yes |
| Warranty | |
| Tank | 3 years |
| Parts | 1 year |
Alternatives in this size
Stiebel Eltron SHC 4
A 4 gallon plug-in tank for a kitchen sink or as a booster on a long pipe run, with a six-year tank warranty. Cheaper 4 gallon tanks match its warranty and heat faster.
Amazon $239$239
4 gal1,300 WPlug-in
GE 2.5 Gallon Point of Use
A 2.5 gallon plug-in tank with an eight-year tank and parts warranty, the best-covered small tank here. Good for a single sink where you want it to last.
Amazon $205.26$205.26
2.5 gal1,500 WPlug-in
Compare
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