Ad — This article contains paid affiliate links to Amazon. We may earn a commission if you buy through them. As an Amazon Associate I earn from qualifying purchases.
The DeLonghi Dragon 4 TRD40820T is worth considering if you want an oil-filled radiator with straightforward controls for a room you occupy for several hours. Its appeal is the style of heat delivery and the timer, rather than a promise of unusually cheap electricity.
This is a research-based buying guide, not a hands-on review. We have not measured this model’s warm-up time, thermostat accuracy or noise. Product details were checked on 20 October 2026; check the exact variant and seller before ordering.
DeLonghi Dragon 4 TRD40820T: the essentials
De’Longhi identifies the TRD40820T EX:2 as a 2kW Dragon 4 oil-filled radiator with a mechanical timer. The suffix matters: Dragon 4 listings include different outputs and control types. Use the manufacturer’s support page to match the product to its documentation.
| Your priority | Buying judgement |
|---|---|
| Longer occupied periods | A sensible format to shortlist if you prefer gradual warmth. |
| Immediate heat for a short stop | Compare a fan heater before paying for a radiator. |
| Simple timing controls | Check the mechanical timer layout and instructions. |
| Lowest electricity bill | Compare actual kWh and usage; oil is not a source of free heat. |
Check the Dragon 4 TRD40820T listing on Amazon UK (paid link)
Who should consider it?
Start with your routine. A study used throughout the afternoon is a different job from a spare room visited for ten minutes. For longer sessions, a radiator can make sense if you value heat delivery without a constantly moving stream of warm air. Think about the space it occupies when stored as well as when it is in use.
Check the room’s heat demand before deciding that 2kW is enough. Draughts, glazing, external walls, ceiling height and outdoor temperature all matter. A room-area claim on a retailer page is not a heat-loss assessment. If your existing 2kW heater struggles in the same conditions, changing to another 2kW resistance heater does not create more sustained heat output.
What does a 2kW Dragon 4 cost to run?
At an illustrative electricity rate of 25p/kWh, two kilowatts running continuously for one hour costs 50p. Four hours at full output uses 8kWh and costs £2. Over 30 such days that is £60. These are calculations, not a prediction for your home or a current tariff quote.
If the element runs for half of a four-hour session, the same example becomes 4kWh and £1 per day. That 50% assumption may be too optimistic for a cold or draughty room. A thermostat’s cycling pattern changes with the temperature you choose and the heat escaping from the room. See our guide to 2kW electric heater running costs for the underlying calculation.
Does stored warmth save electricity?
Oil and metal can release stored heat after the element switches off, but that heat was paid for while the radiator warmed up. Dimplex’s explanation of direct-acting electric heating describes how thermal mass changes heat delivery. Controls and your heating schedule are more useful comparisons than claims that one resistance heater produces substantially more heat per kWh.
Checks before you buy
Confirm the model code, wattage, UK plug, dimensions, timer type and return terms on the live listing. Make sure the controls are readable where you intend to place it. Check whether moving and storing a radiator suits your household, and read the supplied instructions before first use.
Keep portable heaters clear of curtains and furniture, use a suitable wall socket, and switch off before sleeping or leaving the heater unattended. Follow the manual and Electrical Safety First’s portable heater advice. A timer does not replace supervision.
Our buying verdict
Shortlist the Dragon 4 if its radiator format and mechanical timer match your routine. Choose based on the exact model and controls you will use; do not buy it on a “free residual heat” claim. For brief warm-ups or a smaller storage footprint, compare other formats in our oil-filled radiator versus fan heater comparison.
View the exact Dragon 4 model and current seller terms (paid link) · Browse our Heating guides.
Frequently asked questions
Is the Dragon 4 cheaper to run than a 2kW fan heater?
At the same tariff, two heaters consuming 2kWh cost the same. Different controls, comfort preferences and operating hours can change how much energy you actually use.
Can I use the timer to heat an empty room?
Do not treat scheduled operation as permission to leave a portable heater unattended. Follow the exact model’s manual and the safety advice above.
