Ariston Andris RS 2.5 Gallon
A low-priced 2.5 gallon plug-in tank for a single sink, with a six-year tank warranty. It is the value pick among the small tanks.
Amazon $159.99$159.99
The Ariston Andris RS 2.5 Gallon is the better mini tank water heater overall, rated 3.2 to 2.3. The Ariston Andris RS 2.5 Gallon leads on value and features. The Ariston Andris RS 2.5 Gallon costs $40 less ($159.99 vs $199.99).
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 ES250 2.5 Gallon
#10 in 2.5 to 4 GallonFull review
A compact 2.5 gallon plug-in tank with a freeze setting, suited to a cabin or garage sink. The warranty is short for the price.
Amazon $199.99$199.99
Which should you buy?
- Choose the Ariston Andris RS 2.5 Gallon for value ($64 per gallon ($159.99, 2.5 gal) vs $80 per gallon ($199.99, 2.5 gal)) and 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 | Ariston Andris RS 2.5 Gallon | ThermoMate ES250 2.5 Gallon |
|---|---|---|
| Overall rating | 3.2/5 | 2.3/5 |
| Value 30% | 42 $64 per gallon ($159.99, 2.5 gal) | 15 $80 per gallon ($199.99, 2.5 gal) |
| Warranty 30% | 56 6-year tank, 2-year parts | 17 3-year tank, parts warranty not published |
| 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% | 0 2.5 gal tank | 0 2.5 gal tank |
Specifications
| Ariston Andris RS 2.5 Gallon | ThermoMate ES250 2.5 Gallon | |
|---|---|---|
| Heating | ||
| Tank capacity | 2.5 gal | 2.5 gal |
| Element | 1,440 W | 1,440 W |
| Voltage | 120 V | 120 V |
| Current | 12 A | 12 A |
| Electrical connection | Plug-in | Plug-in |
| Recovery (maker figure) | 6.8 gal/hr at 90 °F rise | - |
| Thermostat range | 65 to 161 °F | 50 to 149 °F |
| Price per gallon | $64 | $80 |
| Installation | ||
| Dimensions (H x W x D) | 14.2 x 14.2 x 10.8 in | 12.9 x 12.9 x 11.5 in |
| Weight | 15.5 lb | 15.4 lb |
| Water connections | 1/2" NPT | 1/2" NPT |
| Relief valve included | Yes | Yes |
| Wall bracket included | Yes | - |
| Warranty | ||
| Tank | 6 years | 3 years |
| Parts | 2 years | - |