Ariston POU 12 Gallon
A 12 gallon tank for a bathroom or kitchenette, with six years on parts and tank. Larger tanks cost little more.
Amazon $313$313
The Ariston POU 12 Gallon is the better mini tank water heater overall, rated 2.9 to 2.4. The ThermoMate ES2000 18 Gallon wins on tank size and value. The Ariston POU 12 Gallon costs $86.70 less ($313 vs $399.70).
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 ES2000 18 Gallon
An 18 gallon hardwired tank for a shower or washer. The GE 18 gallon costs less, plugs in and carries an eight-year warranty.
Amazon $399.70$399.70
Which should you buy?
- Choose the ThermoMate ES2000 18 Gallon for tank size (18 gal tank vs 12 gal tank) and value ($22.21 per gallon ($399.70, 18 gal) vs $26.08 per gallon ($313, 12 gal)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 12 to 20 gallon mini tank water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Ariston POU 12 Gallon | ThermoMate ES2000 18 Gallon |
|---|---|---|
| Overall rating | 2.9/5 | 2.4/5 |
| Value 30% | 15 $26.08 per gallon ($313, 12 gal) | 33 $22.21 per gallon ($399.70, 18 gal) |
| Warranty 30% | 83 6-year tank, 6-year parts | 0 warranty not published, scored as none |
| Heating power 15% | 29 1,500 W element | 29 1,500 W element |
| Features 15% | 35 relief valve included | 35 relief valve included |
| Tank size 10% | 0 12 gal tank | 75 18 gal tank |
Specifications
| Ariston POU 12 Gallon | ThermoMate ES2000 18 Gallon | |
|---|---|---|
| Heating | ||
| Tank capacity | 12 gal | 18 gal |
| Element | 1,500 W | 1,500 W |
| Voltage | 120 V | 120 V |
| Current | 12.5 A | - |
| Electrical connection | - | Hardwired |
| Recovery (maker figure) | 7 gal/hr at 90 °F rise | - |
| Thermostat range | 90 to 160 °F | 90 to 150 °F |
| Price per gallon | $26.08 | $22.21 |
| Installation | ||
| Dimensions (H x W x D) | 22.5 x 15.8 x 15.8 in | 25.8 x 19.2 x 19.2 in |
| Weight | - | 56 lb |
| Water connections | 3/4" NPT | 3/4" NPT |
| Relief valve included | Yes | Yes |
| Wall bracket included | No | - |
| Warranty | ||
| Tank | 6 years | - |
| Parts | 6 years | - |