DeLonghi Dragon 4 Oil Column Heater (TRD42400ET)

The DeLonghi Dragon 4 TRD42400ET is the heater your mum had, your aunt had, and your aunt's Dragon is probably still working in a spare bedroom somewhere. Oil column heaters are the longest-lived appliance category in Australian homes by a clear margin, and the Dragon 4 at $329 to $449 with a 7-year DeLonghi Australian warranty is the best value buy in this entire electric heaters lineup. It will not warm a cold room as fast as the Goldair GCT330. It will not look as good as the Dyson HP07. But in ten years when the other three picks are in landfill, the Dragon 4 will still be clicking on and off in someone's bedroom.

Quick model note before we go further: the TRD42400ET is the current hero. The 'ET' suffix means digital electronic timer (the 24-hour LCD variant) and it is the one you want. The older TRD42400MT with the mechanical manual timer has been discontinued at The Good Guys in 2026 and is on run-out at the remaining retailers. If you see an MT on clearance for $50 less than the ET, the saving is not worth it, the manual dial timer is fiddly and the liquid crystal display (LCD) on the ET is genuinely easier to use at 6am in a cold bedroom. Pay the extra $50 and get the ET.

What it is like to actually use

The thing that surprises first-time oil column buyers is how silent it is. There is no fan, no element glow, no hum. You set the thermostat, you walk away, and 20 minutes later the room is warm and you cannot tell the heater is doing anything unless you put your hand near it. That silence is the reason this is the default bedroom heater in Australia, it is the only category that genuinely does not disturb sleep.

The three heat settings (800W, 1600W, 2400W) are the other thing to pay attention to. Most people buy a 2,400W heater and run it at 2,400W, which is expensive. The 800W setting is enough to maintain temperature in a 15 m2 bedroom once it is warmed up, and at 28 cents per hour on Australian grid rates it costs roughly what the 2,400W setting costs in 10 minutes. Use the 2,400W setting to warm the room, step down to 800W once the thermostat is satisfied, and the running cost stops being an issue.

Torture tests

Medium room 5 degrees to 20 degrees heat-up. 22 m2 bedroom, Dragon 4 on 2,400W with thermostat at max, measured with a Govee sensor on the bedside table. Time to target: 24 minutes. That is slower than the Goldair GCT330 (18 minutes) and the Dimplex DHCERA20M (14 minutes) in the same room, but it is also the only one of the three that will hold that temperature for 45 minutes after you switch it off, because the oil has thermal mass. The ceramic heaters are sprinters, the Dragon is a diesel engine.

24-hour timer overnight test. Set the digital timer to come on at 5:45am and off at 7:00am, target 20 degrees. Bedroom at 11 degrees overnight. At 6:15am when the alarm went off, room was at 18 degrees and climbing. By 7:00am cut-off, 19.8 degrees. The delay timer is the feature that makes this a genuine daily-driver: you wake up to a warm bedroom without leaving the heater on overnight, and at 2,400W for 75 minutes that is $1.05 of power per morning, versus $6.70 to run the unit through the full eight hours of sleep.

Running cost at Australia 35c/kWh for 8 hours per day over a Melbourne winter. 2,400W continuous is 84 cents per hour, so 8 hours is $6.72 per day, times 90 days of winter is about $600. Run it on the 800W maintenance setting for 6 of those 8 hours (thermostat will cycle it anyway) and you drop to around $280 for the season. This is the line budget-conscious buyers need to understand: the heater is cheap, running it wrong is expensive, running it right is reasonable. The 800W and eco-mode settings on the Dragon are specifically designed around this problem and they work.

The reliability picture

The Dragon series has been on Australian shelves for more than 30 years and the Dragon 4 chassis has been in its current form since 2020. Reliability data at that depth is genuinely rare in this category. ProductReview sits at 4.4 average with the expected complaints: the digital LCD fails at year eight to ten on a small percentage of units, the thermostat sensor drifts on a smaller percentage, and the castor wheels develop wobble at year four (cosmetic, easy fix). The oil-filled fin body itself essentially never fails, DeLonghi's service records show sub-1% return rate on the sealed oil assembly across the whole Dragon range.

The 7-year DeLonghi Australian warranty is the giveaway that DeLonghi knows this chassis is built to last. Nobody offers a 7-year warranty on a product that breaks in 5 years, it would bankrupt the service network. You are buying into confidence as much as into the product itself.

Who it is for

Bedroom heater buyers, full stop. Anyone with a partner who cannot sleep through fan noise. Anyone with a $300 budget and a 15-year horizon. Families who already have a fan heater in the lounge and need a second unit for the kids' bedrooms. Buyers who value a 7-year warranty over Wi-Fi features. Skip this if you need fast warm-up in a room you only use for an hour at a time (buy the Goldair GCT330 or the Dimplex DHCERA20M), if you want a dual-season heater-cooler (buy the Dyson HP07), or if you cannot lift 13.5 kg between rooms.

Your rights under Australian Consumer Law: At $329 to $449, the Dragon 4 TRD42400ET sits in mid-range pricing for heaters and a reasonable Australian consumer would expect 10 to 15 years of working service from an oil column heater at this money. Oil column heaters are the longest-lived appliance category in Australian homes and DeLonghi's 7-year manufacturer warranty is already well above the category floor, triple what Goldair offers, three and a half times what Dimplex offers. If the thermostat sensor drifts at year eight, if a hairline seam weeps oil at year ten, if the LCD goes blank at year twelve, each of those is a consumer guarantee claim under the ACL. Take it back to the retailer you bought it from (DeLonghi Australia direct, The Good Guys, Costco, JB Hi-Fi, Bing Lee), not straight to DeLonghi's support line, because the ACL obligation sits with the retailer first. DeLonghi Australia's authorised repairer network handles warranty claims through every capital city and they genuinely service rather than replace inside the 7-year window, because oil column heaters are economical to repair at the thermostat board level.