The 4 Best Oil-Filled Heaters That Efficiently Warm Large Rooms

Researched & Written by Craig

Are you looking for a quiet, efficient way to heat your home? Fed up of noisy space heaters that run up your energy costs, or just don’t want to turn on the whole-house heating system? Well, these oil-filled heaters may just be what you need.

When shopping online, I know how hard it can be to find the right product. There’s so many options, and it can be tricky to know which is the right one.

With that in mind, I’ve gone through the best oil-filled heaters that pack enough power to handle a large room. I’ve reviewed each in detail below, with recommendations for best overall, best value, most powerful, and the best for peace of mind.

Not sure which one you need? Don’t worry. I’ve put together a quick buyer’s guide and related questions after the reviews. I’ve highlighted each aspect of these heaters, and what to look for in a good one. Once you know what features to look for, it’s easier to know the right model for you.

Need a Quick Recommendation?

If you’re just looking for a quick-link to my top tip, then it’s got to be this PELONIS heater.

The controls are so sleek, clear, and easy to use.

I’ve written about it in much more detail below, but essentially it’s just the best all-rounder available.

It’s unbeaten in functionality – with super clear digital controls boasting the most settings of any model, AND an included remote control. It’s heating made easy.

The design is sleek and contemporary – it’ll be perfect in any modern home. It often becomes a great talking point among guests, especially given how silent it is! (Though all oil-filled heaters are).

The customer reviews? Outstanding. It’s currently at 4.2/5 on Amazon – not just because of how good it is, but also because of it’s price point. It’s an absolute steal for something of this quality.

Overview of the Top Models

After going through dozens of oil-filled heaters, I’ve narrowed the best down to these four. Each is recommended for a unique reason – which you can see in the table.

Image Heater Name Chosen Because.. Heat Settings Height Price
PELONIS Oil Heater Best Overall 5 25.6" Medium
Honeywell HZ-789 EnergySmart Best Warranty 3 24.4" Medium
DeLonghi Full Room Oil Heater Most Power 3 27.2" High
COSTWAY Oil Heater Best Value 3 25.5" Low

The Best Oil Filled Heaters for Large Rooms

Top Model Overall:
PELONIS Oil Filled Heater + Remote Control

My absolute top oil-filled heater recommendation.

This PELONIS model is my top choice for oil-filled heaters.

And if I’m honest, it wasn’t even that close.

While there is a lot to be said for raw power or quality, I personally value an all-rounder package that scores high marks across the board. Especially for such a fair price point like this one.

The design is professional and sleek, while still showing off the digital LCD controls on the side. These make it easy to see what you’re doing and get the heater set up just how you want it.

This heater is the only one on this list to offer pre-set temperature readings. There are 5 options, from 65F (18C) to 85F (29.5C) that you can ‘set and forget’. The ‘eco’ mode works great to save you money. It uses high power to get you to the heat you want, then uses low whenever possible to maintain it.

Want a quick adjustment on the fly? No problem! Grab the included remote-control to change the temperature, or even put a timer on.

Pros Cons
Great Looking Modern Design1-Year Warranty
Remote Control Included
Easy to Use - Digital Controls + 5 Heat Settings
Fantastic Price Point
Eco-Mode

Our Verdict

To sum it up, I’ve picked this model because it simply ticks every box. And it does it so well.

The functionality is second to none. With clear digital controls, the most settings out of any model I’ve reviewed, AND a remote control – you’ll never need to stress about getting the temperature right. They’ve made it so easy to use.

Enjoy having a talking point among friends? The sleek and dark design with 6 fins just exudes quality. While the completely silent operation keeps things subtle.

Bearing all of this in mind, PELONIS really could’ve charged a high price point.

But they haven’t.

All of these benefits for what I can only call a mid to low price point is an absolute steal.

Most Powerful /Child-Friendly:
DeLonghi Dragon 4

It's called 'Dragon' for a reason! For powerful and safe-to-touch heat.

Next up is the powerhouse. This is the DeLonghi ‘Dragon 4’

They called it a “Full Room” heater for a reason.

DeLonghi have been in the heating game for a long time, and they’ve really gone the distance on this model. It’s 25% larger than their previous ‘Dragon’ model, and at over 27 inches high it’s the tallest on this list.

Not to mention the heaviest. The extra height and patented steel design mean this is no lightweight.

It’s for good reason, though. While the fins of the other heaters get hot, the unique design on this model keeps it cool. Perfect if you’ve got any curious kids or pets.

Instead, all of that great heat is channeled out the top of the heater, meaning the surface is safe to touch.

My one gripe with the model is the sacrifice on functionality. The controls are manual – so while it’s got a timer, it’s one of those finicky rotating clocks and not digitally controlled. And even though the design is unique and power unmatched, the price point could be a bit lower.

Pros Cons
One of the Most Powerful HeatersHigh Price Point
Patented Steel DesignManual Controls
25% Larger Than Their Last Model (Dragon 3)1 Year Warranty
Designed for Rooms up to 250sq. ft

Our Verdict

DeLonghi’s ‘Dragon’ is for those who need plenty of heating power.

It’s the most powerful model on this list, with the largest size and weight – meaning more oil. (That also means it will retain heat the longest!).

Another huge selling point is safety. They’ve designed the exterior to be touch-safe, even at maximum temperature. While most other heater manufacturers promise this, heaters with only fins can burn an unsuspecting little hand or paw.

If either of these are a crucial bonus that you’re looking for, then I wouldn’t hesitate to recommend the DeLonghi to you.

However, if these would just be ‘nice perks’, then I’d consider the other alternatives that won’t hit your budget quite as hard.

Unbeatable Value:
COSTWAY Oil Filled Radiator

Unbelievable value for a low price.

Next up we’re hitting the opposite side of the spectrum with these COSTWAY models.
As I write this, their 25.5″ (height) model is the cheapest large room option on the market. It’s currently half the price of the DeLonghi! While still being a fantastic heater.

Let’s cover what we’re losing out on first. The design (and color) are very basic. The controls are also a far throw from modern – I’d go for calling it “90’s sheek”. 3 power settings and a basic temperature ‘gauge’ is the only functionality we’ve got to work with.

But. That price point.

Say you’re just heating a garage, basement,  or somewhere you wouldn’t be bringing guests. Or say you’re just a sucker for a great value deal. Then you’re why I made sure this was on the top 4 list.

Despite lacking in looks and functions, this heater performs. Although the link below goes to the whole range, I’m looking at the maximum sized 25.5″ model. It’s got the same capacity as a heater the other models on this list (barring maybe the DeLonghi) for a much reduced price tag. You just can’t ignore that.

Pros Cons
Lowest Price Point90's Looks
Powerful, Capable HeaterManual Controls

Our Verdict

This COSTWAY model is the definition of no-frills.

It looks a bit of a plain-jane, and the controls are a bit of a 90’s throwback… but so is the price.

It’s a completely capable, powerful heater for easily the lowest price tag on (at the time of writing).

There’s also a full range of these in the link below – with smaller (and even cheaper) models on offer. Definitely worth a look!

Great All-Rounder:
Honeywell EnergySmart Heater

Just missed out on the top overall spot - Honeywell EnergySmart.

Last up, we have the Honeywell EnergySmart Heater.

Honeywell are a huge brand, and they’re great at backing up their name. This heater is the only one I’ve reviewed that doesn’t have a basic one year warranty. It’s got a 3-year warranty instead!

That says a lot for reliability, and a better commitment to their customers than most.

While it’s called ‘EnergySmart’, I’ve not found the ‘eco’ mode to be any better than the other models. That said, it’s still a fully working mode that will save you plenty on your bills! I was just looking for something ‘extra special’ in that department given the name.

Outside of this, all the standard modern features are there. Digital Controls. Safety Switches. Programmable Timers. While it doesn’t blow you away in any respects, it’s a great all-rounder option.

 

Pros Cons
3 Year WarrantyNot As Functional As Top Pick
Great Looks
Easy to Use Controls
Good Price Point

Our Verdict

Sometimes, the right appliance for you can simply be based on gut feeling. For that reason, I know some people might not have liked the other top recommendations on this list.

For that reason – I’ve also included this Honeywell model. It’s another great option in terms of looks, digital functionality, and from a known brand.

It’s huge 3-year warranty makes it a real outlier in terms of customer support and reliability – fantastic if you really value peace of mind.

It only really lost out on the top spot due lacking in a remote control, and a higher price point (as I write this) than the PELONIS. That said, it’s still a fantastic all-rounder with all the functionality you can ask for.

If you’re a Honeywell fan, or perhaps you just like this design better than the others – don’t hesitate in picking one up.

Oil-Filled Heaters: Frequently Asked Questions

How do Oil Filled Heaters Work?

Oil filled heaters work using heat-conserving oil. That is, oil that is super absorbant of any heat that we warm it up with. They’re completely sealed, which means no replacement or maintenance needed. They do take a while to heat up, but once hot are fantastic at keeping that heat going with minimal extra energy. This makes them fantastic for energy-efficient, and also a great option for bedrooms (switch it off when you go to sleep and let the room gradually get warm). They’re best suited for larger spaces than normal heaters and operate completely silently.

Are Oil Filled Heaters Safe?

Yes, oil-filled heaters are completely safe. In-fact, one of their biggest selling points is that, while they are heaters, their exterior remains safe to touch. (Making them perfect for kids or pets). The oil is so well sealed they should never need maintained or replaced. It’s also customary for modern models to include safety shut-off features – including tip-off and overheating protection.

Are Oil Heaters Safe to Leave on Overnight?

Yes, oil heaters are also completely safe to leave on overnight. The safety features I mentioned above have you covered in case of emergency, and they’re not otherwise dangerous. Just make sure not to leave them covered with anything – especially flammable material! The only ‘unsafe’ part might be the effect 24/7 heating has on your energy bills!

Which Heater is Right For Me?

When it comes to appliances like these heaters, there isn’t a huge amount of variation in models. If you’re set on getting an oil-filled heater because of their silence, reliability, and energy efficiency – then the typical model is the easier part.

That said, it does help to consider the differences between models. Keep the following aspects in mind:

  • Size/Power. Almost all full-sized oil heaters use the same amount of power – 1500W. However, some are better at heating than others. These heaters are a rare case where size really does matter. A bigger, heavier size means more heat-conducting oil, which means more heat and longer-lasting heat.
  • Ease of Use. Are you fine to just turn it on and adjust it as you go? Or, would you really appreciate a thermostat which manages itself to achieve a specific temperature? Although digital controls can make the price increase, they often save you more money than they add to the price! By unlocking ‘eco-mode’ models, you can save a ton of energy thanks to the heater keeping itself on low power once the room is warm.
  • Looks. Most heaters look similar, so it’s mainly go with your gut here. One outlier is the model on this list by DeLonghi – which has a patented custom steel design. Instead of fins, it has a cool, solid exterior which can be much safer around kids.
  • Price. Let’s be blunt, this is the #1 factor for most! You do tend to get what you pay for with these kinds of heaters – unless it’s been bumped up because of a brand. That said, almost all heaters have similar capabilities – it’s just the functionality and modern perks (like timers and digital controls) that you’re paying for.
How to Get The Most From Oil Filled Heater

Spending a few minutes making sure you get the most out of your heater can save you hundreds in the long run.

From someone who’s spent many hours working and researching these heaters – here’s a few tips:

  1. Take advantage of eco modes! By automatically switching to low power, the heater will naturally keep your bills lower. (Low power is often 1/3-1/2 of high power).
  2. Insulate as best you can. That means checking for any drafts (use a candle and see if it flickers if not sure). Also just insulate where you can – a bit of sealant around a window frame can go a long way.
  3. Place it well. Smack bang in the middle of a big room may not be the best place. If everyone using the room is often in one area, keep it close to there. Or, if there’s just one entrance, having it near the door can help keep the cold air out and the warm air in. Avoid placing a heater behind, or under, any materials with a lot of fabric (clothes/drapes).

Conclusion

Oil-filled heaters are a fantastic option if you’re looking to silently and efficiently heat one room.

Heat is what absolutely guzzles your energy bills during the colder months – especially if it’s a whole-house heating system. A one-room heater is magnitudes more efficient, and an oil-filled heater is one of the most efficient of those efficient options!

I hope this guide has helped you find a heater that will keep you relaxed and warm throughout the winter. If you’re still looking for your “one” try checking out the bestsellers on Amazon for inspiration.

Or, if you’d consider other options, I’ve written a detailed guide comparing all the different types of cheapest electric heaters to run. It’s completely free, click on this link to check it out and consider my other top alternative – infrared heaters.

Have a great day!

-Craig