ThermoMate ES800 8 Gallon
An 8 gallon plug-in tank short enough for an under-counter space. The warranty is short, and the Ariston 8 gallon costs less if you can hardwire.
Amazon $269.99$269.99
The ThermoMate ES800 8 Gallon is the better mini tank water heater overall, rated 2.9 to 2.6. The ThermoMate ES800 8 Gallon leads on tank size and value. The ThermoMate ES700 6.5 Gallon costs $30 less ($239.99 vs $269.99).
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 ES700 6.5 Gallon
A 6.5 gallon plug-in tank with a freeze setting for cabins and garages. GE sells a 6 gallon tank with a much longer warranty for about the same price.
Amazon $239.99$239.99
Which should you buy?
- Choose the ThermoMate ES800 8 Gallon for tank size (8 gal tank vs 6.5 gal tank) and value ($33.75 per gallon ($269.99, 8 gal) vs $36.92 per gallon ($239.99, 6.5 gal)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 6 to 10 gallon mini tank water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | ThermoMate ES800 8 Gallon | ThermoMate ES700 6.5 Gallon |
|---|---|---|
| Overall rating | 2.9/5 | 2.6/5 |
| Value 30% | 43 $33.75 per gallon ($269.99, 8 gal) | 33 $36.92 per gallon ($239.99, 6.5 gal) |
| Warranty 30% | 24 3-year tank, 1-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% | 75 plugs into an outlet, relief valve included | 75 plugs into an outlet, relief valve included |
| Tank size 10% | 50 8 gal tank | 12 6.5 gal tank |
Specifications
| ThermoMate ES800 8 Gallon | ThermoMate ES700 6.5 Gallon | |
|---|---|---|
| Heating | ||
| Tank capacity | 8 gal | 6.5 gal |
| Element | 1,440 W | 1,440 W |
| Voltage | 120 V | 120 V |
| Current | 12 A | 12 A |
| Electrical connection | Plug-in | Plug-in |
| Thermostat range | 50 to 149 °F | 50 to 149 °F |
| Price per gallon | $33.75 | $36.92 |
| Installation | ||
| Dimensions (H x W x D) | 17.7 x 17.7 x 15.4 in | 17.7 x 17.7 x 14.6 in |
| Weight | 27 lb | 26.5 lb |
| Water connections | 1/2" NPT | 1/2" NPT |
| Relief valve included | Yes | Yes |
| Warranty | ||
| Tank | 3 years | 3 years |
| Parts | 1 year | - |