De’Longhi Dragon 4 TRD40820T Review: 52p an Hour, and Which Model You Are Buying
The Dragon 4 is the oil-filled radiator people mean when they say they bought a good one. It is also sold in at least four boxes that share the name, and the reviews you will read are mostly of a different one from the one in front of you. Here is what three independent sources found, what the 2 kW model actually costs to run at this autumn’s price cap, and the £90 spread we found on a single day.
Where the reviews line up
Three sources, none of them selling it. Mumsnet Reviews put a Dragon 4 in a real room and timed it with a thermometer. The MoneySavingExpert forum spent two pages arguing about whether it is worth the money, which is the argument that actually matters here. And ProductReview.com.au has 67 rated owners on the TRD4 series — the only rating block we found anywhere with a sample size attached to it.
They agree on three things. It heats a room quickly and then shuts up. Mumsnet felt the difference within ten minutes and measured 16 °C to 18 °C in an hour; an Australian owner reports the thermostat cutting out in fifteen to twenty minutes; T3, testing the American sibling, calls it completely silent after a couple of minutes of pops and crackles. The thermostat is genuinely good — accurate and it holds, which is the thing cheap radiators get wrong. And the build feels like the price: enclosed elements, folding castors, a carry handle, and ten years of warranty from three separate retailers.
They also agree on the uncomfortable part. It is a 2 kW electric heater, and no design can change what that costs. The MSE thread makes the point bluntly — a 2 kW radiator is a 2 kW radiator, all of them are about 100% efficient at the plug, and a £50 unit from Screwfix turns the same electricity into the same heat. What you are paying De’Longhi for is how fast the heat spreads, how accurately it stops, and how long the thing lasts. That is a real product, but it is not a cheaper one to run.
At the price cap from 1 October 2026, 26.32p a unit, the top setting costs 52.6p an hour. The middle step is 29.0p and the low step 23.7p. Four hours an evening on full for a week is £14.74 — less in practice, because the thermostat cycles the element off, but nobody publishes by how much.
Buy on model number, not on the name. The 2 kW TRD40820T has eight fins, a mechanical knob and a wind-up timer, and weighs about 14 kg. The digital TRD40820E adds a child lock and an ECO mode. The 2.5 kW TRDX41025E is a ten-fin machine weighing 17.5 kg — and it is the one Mumsnet and Ideal Home actually tested. Two of the three videos below are of a 2.5 kW unit too. Read the reviews, then check the code on the box.
The three reviews this summary is built from
- Mumsnet Reviews87/100, tested by the site’s content editor with a thermometer in a real room. The 2.5 kW model, not the 2 kW.
- MoneySavingExpert forumTwo pages, around a dozen replies, opened August 2023. The only source that asks whether it is worth £175.
- ProductReview.com.au3.7/5 from 67 reviews of the TRD4 series, 69% positive. Australian owners, not UK buyers.
Before the review: four radiators, one name
“Dragon 4” covers several different machines and the reviews get mixed up constantly. TRD40820T is the 2 kW, eight-fin, mechanical model with a 24-hour analogue timer — the one this page is about, and the one most UK shops sell. TRD40820E is the same 2 kW output with a digital panel, a child lock and an ECO function, in a slightly taller cabinet. TRD41025T and TRDX41025E are 2.5 kW, ten-fin units with a 1000/1400/2500 W step ladder. TRD40615E is a 1500 W North American version. If a review quotes 17.5 kg or 68p an hour, it is not testing the radiator in this article.
Specification at a glance
| Spec | Figure | Confidence |
|---|---|---|
| Model | De’Longhi Dragon 4 TRD40820T (sold as TRD40820T EX:2) | De’Longhi GB product page, 18 Sep 2026 |
| Maximum power | 2000 W | De’Longhi |
| Power settings | Three: 900 W · 1100 W · 2000 W | De’Longhi publishes 2000 W max and 900 W min only; the 1100 W middle step is Appliances Direct’s figure |
| Cost per hour, 1 Oct 2026 cap | 23.7p · 29.0p · 52.6p at the three settings | Our arithmetic on Ofgem’s 26.32 p/kWh direct-debit cap. Continuous draw, no thermostat cycling |
| Cost per hour, current quarter | 23.5p · 28.7p · 52.2p | Ofgem, 26.11 p/kWh to 30 Sep 2026 |
| Fins | 8 | De’Longhi. The 2.5 kW models have 10 |
| Room size | Up to 60 m³ — roughly 24 m² of floor at a 2.4 m ceiling | De’Longhi. One retailer prints “60 m²”, which is a unit error, not a bigger radiator |
| Thermostat | Adjustable room thermostat, mechanical knob | De’Longhi; three retailers agree |
| Timer | 24-hour mechanical (analogue) timer | De’Longhi. On the digital models owners report it is a single countdown, not a repeating daily schedule |
| Weight | 14.1 kg (De’Longhi) · 15.1 kg (Big One Electricals) · 17.5 kg is the 2.5 kW model | Two figures for the same model number, a kilo apart |
| Dimensions | 440 × 160 × 650 mm (W × D × H) | De’Longhi GB. The digital TRD40820E is 495 × 160 × 665 mm — a different cabinet |
| Safety features | Overheat safety cut-out, safety thermostat, anti-frost protection, enclosed elements, cord storage | De’Longhi and three retailers |
| Not on this model | Child lock and ECO function — listed for the digital TRD40820E, not for the TRD40820T | Compared across De’Longhi’s own two pages |
| Mobility | Pre-assembled folding castors, integrated carry handles | De’Longhi |
| Supply | 220–240 V, 50 Hz, 13 A plug. 1.38 m cable | De’Longhi; cable length from Trading Depot |
| Warranty | 10 years | Appliances Direct, Trading Depot and Big One Electricals all say 10. De’Longhi’s own page does not print a number |
| Manufacturer’s own caveat | “Only suitable for well insulated spaces or occasional use” | De’Longhi’s ecodesign wording, on both its GB and international pages |
| RRP | £174.99 | De’Longhi GB, 18 Sep 2026 — out of stock on its own shop |
| Live prices, 18 Sep 2026 | £145.00 Trading Depot (in stock) · £204.91 Debenhams · £114.95 Big One Electricals (sold out) | A £90 spread on one day. See the price note below |
The price check, and what we could not price
On 18 September 2026 the same model number ran from £114.95 at Big One Electricals (marked down from £144.95, but sold out) through £145.00 at Trading Depot, in stock with £7.95 delivery, to £204.91 at Debenhams — which is £30 above De’Longhi’s own £174.99 RRP. Appliances Direct listed it out of stock in every variant and would not show a price.
We could not get an Argos, Currys or B&Q price for this model. Argos sells Dragon 4s but the two listings we found are the 2.5 kW version, and its product pages would not return price or rating data to us. The Currys URL for a Dragon 4 oil-filled radiator redirected to the heating category, which usually means the line has been dropped. No B&Q listing surfaced at all. Rather than guess, we are telling you the three prices we actually read.
Mumsnet Reviews
This is the closest thing to a proper hands-on test we could find in the UK, and it is worth reading for one reason above all others: it puts numbers on the heat-up. The reviewer felt a noticeable change in room temperature within ten minutes of switching on, and measured the room going from 16 °C to 18 °C over an hour. Two degrees an hour is a modest, believable figure — and it is the kind of thing manufacturers never publish, because “warms your room 25% faster” sounds better than “two degrees”.
The test unit was the TRDX41025E, the 2.5 kW Pro, at £170 at the time. That matters for everything cost-related: the 37p-to-85p-an-hour range quoted is a 2500 W top step at 2025 prices, not the 2 kW machine at this autumn’s cap. It also explains the 17.5 kg weight, which is three kilos heavier than the radiator most UK shops are selling as a Dragon 4.
The criticisms are specific and they hold for the whole family. The thermostat maxes out at 28 °C. The timer is fiddly to set up the first time, with no digital display to tell you what you have done. And it is too big to tuck under a desk — this is a whole-room heater with a chimney effect, not a personal one, and it works by convecting warm air upwards. The reviewer’s overall conclusion is that it is highly effective and relatively expensive to operate, which is a fair summary of every oil-filled radiator ever made. Noise is not addressed at all.
Watch: Delonghi Dragon-4 TRD4 1025T Oil Filled Radiator Review
A review of the 1025T, the 2.5 kW ten-fin model — the same generation Mumsnet tested, so it is the closest visual match to this source. Confirmed by search listing only; we did not open it.
Watch on YouTube ↗MoneySavingExpert forum
Every review of this radiator tells you it heats a room well. This thread is the only source we found that asks the question you are actually asking, and the answer it arrives at is not flattering. The physics argument runs through the whole thread: a 2 kW radiator is a 2 kW radiator, electric resistance heating is essentially 100% efficient at the plug whatever the badge says, and a £50 oil-filled radiator from Screwfix converts a kilowatt-hour into exactly as much heat as a £175 one. One poster puts it as bluntly as you can: “half that De’L price should do all this.”
That is correct, and it is the right starting point — but the thread does not stop there, and the Dragon owners in it are not converts to the cheap option. They praise build quality, an accurate thermostat, and fast room heating. Those are the three things a design premium can genuinely buy you in a heater: not more heat per unit, but heat that arrives where you are sooner and stops when it should. If your cheap radiator’s thermostat overshoots by three degrees, it costs you money every night. That is the honest case for paying more, and it is a narrower case than the marketing makes it.
Two details worth carrying away. One poster mentions a minor LED whine when the display is dimmed — a digital-panel complaint, so it does not apply to the mechanical TRD40820T. And one owner says simply that they have not used their Dragons “since the price of leccy went stratospheric”, which is the most honest line in the thread. Note that no running-cost figures at all are quoted in the discussion, and nobody compares it with running the central heating; the numbers on this page are ours, from Ofgem’s published cap.
Watch: Delonghi dragon 4 radiator review
A short owner-style review of the Dragon 4 rather than a manufacturer film — the nearest thing in video to the tone of this forum thread. Confirmed by search listing only; we did not open it.
Watch on YouTube ↗ProductReview.com.au
We would rather have given you a UK rating block, and we tried. Every British retailer page we could reach either had no ratings on it or would not render them, and a score without a sample size is not evidence. This one has 67 reviews behind it and a published sentiment split, so it is what we are using — with the obvious health warning that these are Australian buyers of the whole TRD4 range, in a different climate, on different electricity tariffs, and not necessarily on the 2 kW model at all.
3.7 out of 5 is a mid-table score, and it is a more useful number than the five-star blocks you see on shop listings. The 69/21/10 split tells you roughly one buyer in five is unhappy. What they are unhappy about is consistent: running costs. One household reports a winter quarterly bill going from $400 to $900 after buying several units — an extreme case, several radiators, but it is the complaint that recurs. The second complaint is the timer: on the digital models it is a single 24-hour countdown rather than a repeating daily schedule, which several owners called poor at this price, and it is worth knowing before you buy that the timer is less clever than the badge suggests.
Two more that do not show up in the editorial tests. Some owners hear clicking or beeping during heating cycles and find it wakes them — which sits awkwardly against T3 calling the same family completely silent, and the truth is probably that the relay click and the digital-panel beep are real and the airflow is not. And a few report a persistent oil smell even after following the manufacturer’s break-in run. On the other side, the positives match everything else on this page exactly: heats fast enough to hit the thermostat cut-out in 15 to 20 minutes, silent in the sense that matters — no fan — and reassuring around children because the elements are enclosed. Several note the heat goes upward, with little radiating sideways, which is the chimney design doing what it is designed to do and is worth knowing if you planned to sit beside it.
Watch: De’longhi Dragon 4 Oil Filled Radiator [+] De’longhi TRD4 1025T Dragon 4 Oil Filled Radiator Review+
An owner walking round the radiator and its controls — the closest we have to the buyer’s-eye view this rating block represents. Confirmed by search listing only; we did not open it.
Watch on YouTube ↗Strengths and weak points
What holds up
- Fast to useful warmth: two degrees in an hour measured, thermostat cut-out in 15 to 20 minutes reported.
- The thermostat is accurate and holds — the one thing a premium heater can genuinely do better.
- No fan, so no fan noise. T3 found it silent after a couple of minutes of expansion pops.
- Ten-year warranty from three separate retailers, on a category where two years is normal.
- Enclosed elements, overheat cut-out, safety thermostat and anti-frost protection.
- 14 kg on folding castors with carry handles — heavy, but genuinely movable room to room.
- The oil keeps giving heat back for a while after you switch it off.
What people complain about
- 52.6p an hour on full at the October 2026 cap. No design changes that.
- A £50 radiator produces the same heat from the same kilowatt-hour, and the MSE thread will not let you forget it.
- The timer is a basic 24-hour dial, fiddly to set and not a repeating weekly schedule.
- No child lock and no ECO mode on the mechanical TRD40820T — you need the digital version for those.
- Clicking and beeping on heating cycles bothers some owners; a few report a lingering oil smell.
- Heat goes up, not sideways. It is a room heater, not something to sit next to.
- De’Longhi’s own label says it suits “well insulated spaces or occasional use”.
- Price is all over the place: £114.95 to £204.91 on one day for one model number.
Who it actually suits
Buy it if you need to heat one room — a home office, a spare bedroom, a back room the central heating never quite reaches — for a few hours a day, and you want it silent and safe enough to leave running with children in the house. On the 900 W setting at 23.7p an hour it is a reasonable way to keep one room liveable without firing the boiler for the whole house. The ten-year warranty and the thermostat accuracy are what justify the premium over a supermarket radiator, and at Trading Depot’s £145 rather than Debenhams’ £204.91 that premium is defensible.
Look elsewhere if you are trying to heat a draughty or poorly insulated room all winter — De’Longhi says so itself on the label, and at 52.6p an hour the bill will tell you the same thing by February. Look elsewhere too if you want a programmable weekly schedule, if you need a child lock (buy the digital TRD40820E instead), or if you simply want the cheapest way to get 2 kW of heat into a room, in which case the forum is right and a £50 unit will do it. And if a review you are reading quotes 17.5 kg, 2500 W or 68p an hour, put it down — that is a different radiator.
What we could not check
- Any editorial test of this exact model. T3 tested the 1500 W American TRD40615E, Mumsnet and Ideal Home the 2.5 kW. Nobody we found has tested the 2 kW TRD40820T itself.
- A Which? test. None surfaced. Nothing on this page is Which?-backed.
- Noise in decibels. No source gives a figure for any Dragon 4. “Silent” and “it clicks and beeps” are both owner impressions, and they conflict.
- Duty cycle. Our costs per hour assume the element draws continuously. Once the room is warm the thermostat cycles it off, so real cost is lower — but no source publishes by how much, so we will not invent a number.
- Argos, Currys and B&Q prices. Argos lists only the 2.5 kW and its pages would not render data for us; the Currys product URL redirected to a category page; no B&Q listing appeared. Idealo and PriceRunner both blocked us.
- Warranty registration. Three retailers say ten years. Whether that requires registering the product, and within what window, is stated by none of them or by De’Longhi.
- Tip-over cut-out. Ideal Home lists one on the 2500 W model. No source lists one for the TRD40820T, so we cannot tell you it has one.
- The weight, honestly. De’Longhi says 14.145 kg for this model; Big One Electricals says 15.1 kg for the same model number. We have printed both.
- The “25% faster” claim. It is De’Longhi’s own comparison with the Dragon 3, repeated by retailers. Nobody independent has measured it.
- The videos’ channels — and the videos themselves. On this run we did not open youtube.com. All three videos were confirmed the way our rules allow when YouTube will not load: the exact watch URL and its title appeared in two differently-worded search result sets each. No channel name appeared in any snippet, so we cannot tell you who made them, and we have not watched them. Two of the three are of the 2.5 kW 1025T, not this model.
Sources and prices last checked 18 September 2026. The 52.6p an hour is Ofgem’s 26.32 p/kWh direct-debit cap for 1 October to 31 December 2026 — it changes every quarter, and your region and tariff will move it. Check the model number on the box against the one in the review you are reading.