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Have you started to notice a smell from your oil filled heater? This may be nothing to worry about, or it could indicate a serious defect with the unit.
This article runs through possible causes, and how to deal with them.
Types Of Smells Reported By Owners
A variety of smells are reported by worried owners of an oil filled heater. Some are more indicative of problems than others. I’ll give some possible causes, each of which will be detailed in a later section.
Some smells are due to a slight burning of the paint coating. This may happen with first use, but shouldn’t occur afterward:
- Chemical smell
- A smell of burning plastic
- A rubbery smell (but not burning rubber)

A smell of burning oil may be more serious. However, don’t always assume that it’s a leak. We’ll explain what to look out for.
A fishy smell can indicate electrical problems. Alternatively, someone may have splattered food on the fins of the radiator.
Smells On First Use Of A New Heater
Some manufacturers mention in the manual that you can expect a smell when you first turn on your new heater. There are two reasons for initial smells.
Chemical smells from paint coating
The fins on your heater are covered with a light coating of metallic paint. You may get smells from a slight burning of this paint when you first use the heater.
People tend to perceive this as a chemical, plastic, or rubbery smell.
However, this shouldn’t continue to happen after more than a few prolonged uses of the heater. If it’s still happening after continued use, you should check the rest of this article for more ideas as to what’s going on.
Oily smells from external residue
The oil in these heaters should be completely encased within the unit. You shouldn’t be able to smell the oil at all.
However, it’s possible that tiny droplets of oil were splashed on the unit during manufacture. This can give you a slight smell of burning oil when you first turn on the heater.
Again, this should go away in a short while. However, I wouldn’t take a chance with a smell of oil. I would give the fins a thorough cleaning before turning it on again. If there is still a smell of oil, then check out our section on oil leaks.
Smells From Dust Or Spills
It’s common to leave your heater at the side of the room in warm weather. Of course, it sits there gathering dust. That may be what you smell burning when you turn it on.
Alternatively, someone may have dropped food or liquid on the fins. Even a fizzy drink splattering near the heater will leave a residue on the surface. When it dries on the metal, turning on the heater will start cooking it.
The solution is to give the unit a good wipe when you are about to use it again. Dust typically accumulates at the top of the appliance between the fins and at the bottom of the unit – as you can see here!

Smells From Oil Leaks
The worst (but rare) problem with an oil filled heater is an oil leak.
I mentioned that a slight smell of oil could be an innocuous leftover from the manufacturing process. So you may not need to be so worried if it’s the first use, although you should still check the unit thoroughly.
You can run your hands along the bottom of the heater to feel for an oily residue. If nothing is apparent, then wipe the unit and monitor it further.
If the oily smell persists, then the unit is defective. It also can be dangerous. If the unit is within warranty, then you should bring it back to the retailer.
If it’s an older unit, then you should dispose of or recycle the heater. Unfortunately, getting rid of these units isn’t always straightforward. We have an article on how to recycle or dispose of your oil filled heater.

Do Oil Filled Heaters Leak?
Leaks are rare, but they do happen. An Australian newspaper gave an account in 2018 by a mother who turned on a DeLonghi heater in her children’s bedroom. Eventually, she smelled petrol fumes and returned to the room.
I was greeted with a horrible haze of smoke and an overwhelming foul smell.
The Morning Bulletin, 2018 (no longer available online)
A year before, the Sunday Times (a British national newspaper) reported a similar leak from the Mellerware brand. That same year, the Australian product safety board investigated the Moretti brand for spraying oil.
Smells From Electrical Issues Or Overheating
A fishy smell from any electrical appliance can indicate that connections are loose and are burning the socket, the wires, or the lead. Another sign is that the plug is very hot.
You should turn the power off and remove the plug from the socket. The problem may be with your socket or with the wiring in the heating unit. If it’s the latter and your heater is within warranty, then you can take it back to the retail unit.
If it’s outside the warranty, it’s unlikely that having an electrician repair the unit is cost-effective. You’re better off replacing it.
Just be sure that you don’t continue to use the defective unit.
How To Stop Smells From Your Oil Filled Heater
We discussed the less serious issues of dust and spillages. One solution is to keep the cardboard box after purchase, instead of immediately recycling it. Then store the unused heater in the box.
We’ve mentioned cleaning the unit by dusting or wiping it down. This is a good idea when it’s been in a back room during the summer.
How To Prevent Leaks
There’s nothing you can do about a new unit that leaks. Just send it right back to the retailer.
However, the heater can be damaged over time. One likely cause of a leak is a fractured joint through a bang or corrosion.
I’ve never suffered a leak. But I’ve certainly allowed my heaters to fall over at times. This is usually when I’m pulling or rolling the unit from room to room. One way to avoid this problem is to carry the heater instead of rolling it.
Another cautionary measure is to check for rust when you bring your heater out of summer storage. You’ll be looking for signs of discoloration. This is hardly likely to happen when the unit is within warranty, but an older heater may start to degrade.
There’s nothing much you can do about corrosion. It’s just a sure sign that it’s time to get rid of your old oil filled heater.