I own two Delonghi oil-filled heaters. I bought them a few years ago, used them intermittently, then put them in storage. When fuel oil bills skyrocketed, I brought them out to start using again.

What motivated me to start using them again was when bill for heating oil for my little house jumped to over $300 a month. Using two Delonghi heaters set on "low" for sixteen hours a day, it has dropped to less than $50. That's a $250 a month in savings, in the coldest months.

My experience has been that oil filled heaters work great, if you know how to use them. Oil filled electric heaters aren't just "plug and play." If you use them as recommended, they're powerful, economic and effective. If you don't, you'll have the problems people complain about in some of these reviews.

How to use 'em:

1) Always TEMPER them before use. A lot of people skip this step, but you shouldn't. To temper them, before using them in your house, plug them in OUTSIDE of your house, in a well ventilated area such as a shop or shed (or a basement, if you don't have a shop). Set the heat on "high" and turn the dial ALL THE WAY UP to the highest temperature. Then leave them for several hours. It's true that this will "waste" a little electricity. (Leaving it that way for 24 hours may cost you a couple of bucks). But it's essential to do this because doing so burns off the coating the manufacturers put on to prevent them from rusting in the warehouse.

The directions say to do this for "two hours or more." I've found that it takes anywhere from two to twenty hours to burn the whole coating off. Once it's gone, the smell is gone forever. IF YOU SKIP THIS STEP, your heater will smell bad in the house every time it gets above a certain temperature (and the coating starts burning off). People who complain about a bad smell are often unaware of this step, or haven't tempered their heater long enough. When it's done being tempered, the smell should be totally gone, absolutely no smell.

2) I had a friend who complained about how ineffective her heater was. It turned out she was trying to use it in a 400 square foot area, with the door open! And the area was uninsulated. And she was shutting it on and off to "save power." You have to use common sense. If the room is uninsulated, insulate it. If the door's open, close it. If it's too big, get two or three heaters. And don't shut them on and off.... leave the heater ON. See point 4 below.

3) Don't expect instant heat. Oil filled heaters are great at MAINTINING the temperature in a room, but It takes a long time for oil filled heaters to RAISE the temperature when the room is cold. (If you have central heating, turn it on in the morning for about 15 minutes to take the chill of off the air. Then turn it off and turn your oil filled heaters on for the rest of the day. If you don't have central heating, set your oil filled heaters on high for a couple of hours, then lower them to low once the place is warmed up.)

4) Once the room does get warm, leave the heater ON. My friend said she was shutting hers off after it got warm to "save electricity." Then she'd come back two or three hours later, find the room cold, and turn it on and complain because it took hours to heat the room up again. Don't do what she did. Don't turn it on and off, on and off. That's what the thermostat is for. To use the thermostat on any oil filled heater, turn the dial to the HIGHEST setting, wait till the room gets toasty, then turn it DOWN just till you hear a soft click. No further. After you do this, it'll come on whenever the room drops below that temperature, and will shut itself off when the room is warm. Using the thermostat this way saves electricity more effectively than you could, and maintains a warm room while doing so.

5) I've seen comments on these posting boards like:

"My heater had a bad smell for weeks." Of course it did -- you didn't temper it. It was burning off a little of the coating each time it got hot. Start over. Take it out to a shed or shop, set up on high heat, turn the thermostat way up, and temper it to finish burning it off. Then there will be no smell at all. (If there is, you may have an oil leak, in which case, yes, return it to the place you bought it. But this is usually not the reason for the smell.)

"I took my heater out of the box, turned it on, waited four hours and it barely got warm, so I shipped it right back to the manufacturer." My comment would be, you were thinking of it as if it were a little space heater, the kind that gets burning hot to the touch. That's not how oil filled heaters work. They WARM the air gradually. They take time, when the room is very cold. They're among the best ways to keep a room warm and toasty economically, when used correctly. But you have to learn how they work and don't expect them to be what they're not.

Give them time, and learn how to use them, use common sense, and oil filled heaters will keep your home balmy and warm, using minimal electricity, and there will not be any smell at all.

We have been using two of these to heat our master and kid's bedroom during cold Chicago nights. We recently moved to a house, which is of course more difficult to keep warm compared to our previous 2 bedroom condo. That's where these heaters come in. We drop the furnace thermostat to low setting so it only kicks in at most once during the night. One of these heaters is powerful enough to keep a large bedroom pretty cozy at only Min power setting (700W; max is 1500W) and the thermostat fixed at 3 (goes all the way up to 6). In the morning raise the furnace thermostat up and turn the Delonghi heaters off and we are ready to start the day.

Pros:
* Allows me to control the temperature of the bedrooms pretty accurately. Learning the correct settings for my house took only a few tries.
* Cheap to use compared to heating an entire house, while occupying only two rooms during cold nights. Even if it runs at 1500W non-stop one of these would only use about $4 of electricity a day and that amount of heat would turn your bedroom into a Turkish bath.
* really lightweight. If I need to carry the heaters downstairs, say. I can carry two of them at once.

Cons:
* Impossible to see the thermostat in dim light.
* the wheels are somewhat flimsy in my opinion.

Tips:
* Heating a space from a really cold state would take a long time with these. These devices are best if they are used to maintain the temperature.
* Bring the space you want to heat to the temperature you like. Lower the thermostat on the heater until it clicks (turns off) and leave it there. That is probably the setting you want. Adjust as you like. To conserve energy set it to the Min setting. Power at min, thermostat at 3 is what I use for our large bedroom.
* I didn't "temper" the heater before using. I didn't have the smell issue in first use that others claim.
* I don't understand why forced air is a thing for heating houses. Radiators should definitely be the way to go. Think of the heat retention properties of cast iron vs. aluminum pans. same logic. heating air vs. heating solid mass.

I bought two of these to heat an insulated 250 square foot sunroom. When temps are cold, say in the 20 to 30 degree range, it'll take a good 3-4 hours to heat up using 2. They're nice because they're completely silent, but they are slow to heat. It is what it is, and I knew this before buying. The last thing I wanted was a loud heater fan blowing while I'm relaxing in the room. They will do a great job of maintaining the heat once you get the room to temp.

At 1500 watts apiece, be careful if you're using 2 at once. I've popped the breaker a couple times. One nice feature is you can switch it to 800 watts, 700 watts or 1500 watts. I can run 2 on the lower wattage and heat different parts of the room and not pop the breaker.

Overall, they're well constructed, nicely designed, and nicely sized.

I have only central AC for heating in my apartment, which is very noisy and kinda expensive for the winter. Not sure about the electric consumption with this item yet, but I really love its quietness, silent to be accurate. As for the smell, I was a little worried at the beginning, since it did off gas during the first 3-5 hours. But after that, it became odor free. So I guess it's coating or something. I live in the east coast, and it kept my studio apartment at 70-75 for all day long. Love it!