DeLonghi Dragon Digital Oil Filled Radiator: Review, Pros & Cons

Summary

A 1500 W, six-fin oil-filled column heater with a digital panel, 24-hour timer, ECO mode and a 41 °F anti-freeze setting. It is silent, holds heat for hours after you switch it off and is the best-tested oil-filled radiator in the US, but it can take up to an hour to warm a room and its case reaches 180 °F, so keep it away from children and pets.

Strengths

Silent: there is no fan, and Wirecutter and WIRED both describe the operating noise as completely silent or inaudible.
Holds heat after shutdown: Wirecutter measured it keeping a room between 80 and 90 °F for four hours with no electricity.
Even, non-drying warmth: the oil mass radiates and convects without blowing dust around the room.
Real capacity: T3 heated a 160 sq ft office with temperatures near 0 °F outside.
Build: all-metal construction that is sturdier than plastic rivals, with the wheels already mounted.
Strong test position: Wirecutter, WIRED and T3 all rank this model at the top of the oil-filled category.

Weaknesses

Slow warm-up: sometimes half an hour or more before you feel warmth, and an hour may only raise the room a few degrees.
Hot surfaces: Wirecutter measured the case at 180 °F and the interior fins at 230 °F, and Consumer Reports warns the exhaust outlet can cause pain or burn.
Top-heavy and large: about 25 lb and 2 ft tall, and too tall to fit under a desk.
First-use smell and creaking: run it at full power for two hours with ventilation, and expect popping as the oil heats.
Tip-over protection is disputed: DeLonghi does not list it and Consumer Reports records none on the analog sibling, though WIRED claims a 45-degree trigger.
The published 23.2 sq ft working capacity is a data error and should be ignored.

Verified specifications

Heating power	1500 W maximum, 700 W minimum, across three steps (MAX / MED / MIN / OFF).
Power	120 V, 60 Hz.
Fins
Weight	25.61 lb.
Dimensions	about 16.4 in long × 10.3 in deep × 26.1 in tall.
Controls	electronic digital panel with LED display, room thermostat and safety thermostat.
Temperature	settable from 50 °F to 82 °F (10 °C to 28 °C), plus a 41 °F (5 °C) anti-freeze setting.
Timer	delayed start and delayed stop, up to 24 hours.
Functions	ECO mode, key lock (child lock) and thermal cut-off.
Construction	steel body with permanently sealed diathermic oil that never needs refilling; no fan.
Castors	pre-assembled, with front and rear grab handles.
On power-up the unit resumes the settings it last used.

Full research notes and sources

Slow heat, long tail

Every independent test hits the same wall. Wirecutter found it can take half an hour or more before you feel warmth, and that after an hour the room may be only a few degrees warmer. WIRED measured about an hour before the room temperature stabilizes, and Consumer Reports, on the near-identical analog sibling, called it very slow at heating a seated person. If you need a room warm in ten minutes, a fan-forced ceramic heater is the better tool.

The payoff comes after warm-up. Wirecutter measured the TRD40615E holding a room between 80 and 90 °F for four hours with no electricity. WIRED’s routine is to run it for an hour before bed, switch it off and stay warm through the night. DeLonghi’s own FAQ describes the radiator releasing stored heat slowly once it is switched off.

Heat, safety and placement

The surface heat is the real caveat. Wirecutter’s infrared readings put the exterior case at 180 °F and the hard-to-reach interior fins at 230 °F after four hours, and Consumer Reports found the exhaust outlet hot enough to cause pain or burn. This is a heavy, top-heavy object that must sit where a child, a pet and a laundry basket cannot reach it. Tip-over protection is unresolved: DeLonghi lists a child lock and a thermal cut-off but not a tip-over switch, Consumer Reports records none for the sibling, and WIRED lists a 45-degree trigger. Do not assume it is there.

Running costs

There are no consumables: no filters, no fluid, no batteries and no remote, so electricity is the whole bill. Wirecutter puts a typical 1500 W heater at just under $1.55 for an eight-hour workday at average US rates. A Reddit calculation for a 1500 W oil-filled radiator run 12 hours a day at $0.25/kWh comes to about $135 a month if it never cycles; ECO mode exists to make it cycle instead. A 1500 W unit at 120 V is a 12.5 A load, so do not put it on an extension cord or share a power strip. Owners often add a smart plug for scheduling rather than use the built-in timer, though the manual documents both a delayed start and a delayed stop.

Warranty and upkeep

The oil is permanently sealed and never needs refilling, and maintenance is limited to dusting between the fins with the unit unplugged. The manual forbids opening the appliance yourself and directs any repair to DeLonghi. Warranty terms conflict: DeLonghi’s product page states a 2-year included warranty, while Wirecutter and Consumer Reports list 1 year and a 2022 DeLonghi home-appliance warranty document specifies one year of parts and labor. Treat 1 year as the conservative baseline and confirm the term in writing at purchase.

Which model this is

This page covers the black TRD40615EBK, sold by DeLonghi US as the same platform as the white TRD40615E-6A and the analog TRD40615T-6A. The instruction books for the TRD40615E-6A and the TRD40615EBK are both 15 pages and state 120 V, 60 Hz, 1500 W. Do not merge it with the EU 2.0 kW and 2.5 kW Dragon 4 Pro codes, the newer US TRD50615E, or the Radia S and ComfortTemp lines. The Amazon listing is ASIN B07WSJZH1G.