Dreo OH521 Oil-Filled Radiator
#3 in RadiatorsFull review
For a bedroom or living room that needs silent, steady heat held at a set temperature. The OH310 does the same job for less.
Amazon $135.92$135.92
The Dreo OH521 Oil-Filled Radiator is the better space heater overall, rated 3.7 to 3.0. The Dreo OH521 Oil-Filled Radiator leads on safety, thermostat and controls. The De'Longhi ComforTemp EW7707CM wins on warranty. The De'Longhi ComforTemp EW7707CM costs $5.97 less ($129.95 vs $135.92).
De'Longhi ComforTemp EW7707CM
#10 in RadiatorsFull review
For a quiet bedroom or office that needs steady background heat for hours. Buyers who want a set temperature or timer should look at the digital Dragon.
Amazon $129.95$129.95
Prices were last checked October 30, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Dreo OH521 Oil-Filled Radiator for safety (ETL listed, tip-over shutoff, overheat shutoff vs overheat shutoff; no safety listing published), thermostat (holds a set temperature vs adjustable thermostat dial, no set temperature) and controls (eco mode, timer, remote; no app vs eco mode; no timer).
- Choose the De'Longhi ComforTemp EW7707CM for warranty (3-year warranty vs 1-year warranty).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every radiators space heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Dreo OH521 Oil-Filled Radiator | De'Longhi ComforTemp EW7707CM |
|---|---|---|
| Overall rating | 3.7/5 | 3.0/5 |
| Value 25% | 31 $91 per kW ($135.92, 1,500 W) | 34 $87 per kW ($129.95, 1,500 W) |
| Safety 25% | 100 ETL listed, tip-over shutoff, overheat shutoff | 45 overheat shutoff; no safety listing published |
| Thermostat 15% | 100 holds a set temperature | 60 adjustable thermostat dial, no set temperature |
| Warranty 15% | 0 1-year warranty | 50 3-year warranty |
| Controls 10% | 75 eco mode, timer, remote; no app | 25 eco mode; no timer |
| Low setting 10% | 67 down to 600 W | 50 lowest setting not published (neutral score used) |
Specifications
| Dreo OH521 Oil-Filled Radiator | De'Longhi ComforTemp EW7707CM | |
|---|---|---|
| Heating | ||
| Heat settings | 600 to 1,500 W | 1,500 W |
| Type | Radiator (no fan) | Radiator (no fan) |
| Element | Oil-filled | Oil-filled |
| Oscillates | No | No |
| Controls | ||
| Thermostat | Digital | Dial |
| Eco mode | Yes | Yes |
| Timer | Yes | No |
| Remote | Yes | No |
| App | No | No |
| Safety | ||
| Safety listing | ETL | None published |
| Tip-over shutoff | Yes | - |
| Overheat shutoff | Yes | Yes |
| Cool-touch housing | - | No |
| Build | ||
| Cord | 6 ft | - |
| Dimensions | 18.5 x 7.68 x 28.54 in | 13.78 x 5.9 x 24.9 in |
| Weight | 20.6 lb | 23.4 lb |
| Warranty | 1 year | 3 years |
| Released | 2023-10 | - |