Rheem Mini-Tank 2.5 Gallon
A slim 2.5 gallon plug-in tank from Rheem for one sink. It matches the Ariston on warranty but costs more.
Amazon $218.99$218.99
The Rheem Mini-Tank 2.5 Gallon is the better mini tank water heater overall, rated 2.8 to 2.3. The Rheem Mini-Tank 2.5 Gallon leads on features. The ThermoMate ES250 2.5 Gallon wins on value. The ThermoMate ES250 2.5 Gallon costs $19 less ($199.99 vs $218.99).
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 Rheem Mini-Tank 2.5 Gallon for features (plugs into an outlet, relief valve included, wall bracket included vs plugs into an outlet, relief valve included).
- Choose the ThermoMate ES250 2.5 Gallon for value ($80 per gallon ($199.99, 2.5 gal) vs $87.60 per gallon ($218.99, 2.5 gal)).
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 | Rheem Mini-Tank 2.5 Gallon | ThermoMate ES250 2.5 Gallon |
|---|---|---|
| Overall rating | 2.8/5 | 2.3/5 |
| Value 30% | 3 $87.60 per gallon ($218.99, 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
| Rheem Mini-Tank 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) | 15 min at 60 °F rise | - |
| Thermostat range | 50 to 140 °F | 50 to 149 °F |
| Price per gallon | $87.60 | $80 |
| Installation | ||
| Dimensions (H x W x D) | 17 x 10.9 x 10.9 in | 12.9 x 12.9 x 11.5 in |
| Weight | 17.6 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 | - |