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
The Camplux ME40 4 Gallon is the better mini tank water heater overall, rated 3.5 to 3.2. The Camplux ME40 4 Gallon leads on features. The Camplux ME40 4 Gallon costs $11 less ($209.99 vs $220.99).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
ThermoMate ES400 4 Gallon
A 4 gallon plug-in tank for a kitchen sink. Ariston and EcoSmart sell 4 gallon tanks for less with longer warranties.
Amazon $220.99$220.99
Which should you buy?
- Choose the Camplux ME40 4 Gallon for features (plugs into an outlet, relief valve included, wall bracket included vs plugs into an outlet, relief valve included).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 2.5 to 4 gallon mini tank water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Camplux ME40 4 Gallon | ThermoMate ES400 4 Gallon |
|---|---|---|
| Overall rating | 3.5/5 | 3.2/5 |
| Value 30% | 66 $52.50 per gallon ($209.99, 4 gal) | 60 $55.25 per gallon ($220.99, 4 gal) |
| Warranty 30% | 30 3-year tank, 2-year parts | 24 3-year tank, 1-year parts |
| Heating power 15% | 20 1,440 W element | 20 1,440 W element |
| Features 15% | 100 plugs into an outlet, relief valve included, wall bracket included | 75 plugs into an outlet, relief valve included |
| Tank size 10% | 100 4 gal tank | 100 4 gal tank |
Specifications
| Camplux ME40 4 Gallon | ThermoMate ES400 4 Gallon | |
|---|---|---|
| Heating | ||
| Tank capacity | 4 gal | 4 gal |
| Element | 1,440 W | 1,440 W |
| Voltage | 120 V | 120 V |
| Current | - | 12 A |
| Electrical connection | Plug-in | Plug-in |
| Thermostat range | 50 to 149 °F | 50 to 149 °F |
| Price per gallon | $52.50 | $55.25 |
| Installation | ||
| Dimensions (H x W x D) | 19.2 x 11.8 x 10.4 in | 14.5 x 14.5 x 12.9 in |
| Weight | 18.2 lb | 19.8 lb |
| Water connections | 1/2" NPT | 1/2" NPT |
| Relief valve included | Yes | Yes |
| Wall bracket included | Yes | - |
| Warranty | ||
| Tank | 3 years | 3 years |
| Parts | 2 years | 1 year |