Can Diesel Fuel be Used in a Kerosene Heater? Risks and Benefits

Kerosene is one of the most common and popular fuels around the world, and is regularly used in heaters, cooking appliances and more. Although it’s no longer quite as popular in North America as it used to be, it is still a reliable standby for various types of portable heaters.

Every prepper, naturally, will want to keep a sizable stash of kerosene on hand to keep their heaters working, but what happens if you run out of kerosene?

Some folks say that it is possible to use diesel fuel as an alternate to kerosene in normal kerosene heaters. Is it true? Is it possible? Can diesel really be used in a kerosene heater?

Yes, diesel fuel can be used safely in a kerosene heater with just a little bit of isopropyl alcohol as an additive.

This is definitely great information to know since it provides you with more flexibility using the same appliance, whatever it is.

As it turns out, kerosene is really just a form of diesel fuel itself and that easily explains why common diesel fuel, also known as No.2 diesel, will still work in a kerosene heater.

Of course, there is plenty more you should know before you try this yourself, so keep reading and I’ll tell you all about it…

Why Burn Diesel in a Kerosene Heater at All?

The simplest answer is that you are simply out of kerosene fuel. Having alternate liquid fuel types for any sort of vehicle, tool or appliance is only a good thing when it comes to preparedness.

Just like how some generators can accept both gasoline and propane, or even additional fuels besides, it’s good to know you can rely on a diesel as a backup to your usual supply of kerosene.

Now, from a performance perspective, there’s no great reason to use diesel instead of kerosene.

Diesel does not put out quite as much heat as kerosene, although they are very close, and it tends to produce a little more odor and also burn up wicks quicker than kerosene.

But make no mistake, your heater will work normally and safely, and you’ll definitely stay warm!

Is it Safe to Use Diesel in an Indoor Kerosene Heater?

Yes, it is safe to use diesel in an indoor kerosene heater if the heater is otherwise used in a safe manner.

Diesel doesn’t make any given heater in any given environment more or less safe. Said another way, as long as you have taken all reasonable precautions to provide ventilation and prevent accidental fires, you can safely use diesel in your indoor kerosene heater.

But the reverse is also true. If you’re using your kerosene heater in an unsafe way, or operating it in an unsafe location or during times of heightened fire risk or with poor circulation, using diesel isn’t going to make it any safer…

Which Kind of Diesel Can Be Used to Replace Kerosene?

You can use common, garden variety No.2 diesel fuel of the type which you typically use in motor vehicles. Preferably, you’ll use high-quality, Ultra-low-sulfur diesel, or ULSD.

Now, if you research this topic for any length of time, you have it by now probably come across at least one or two sources urging you to seek out No.1 diesel for use in kerosene heaters thanks to its superior performance characteristics.

I don’t want to be the one to let the cat out of the bag, but No.1 diesel is basically just kerosene!

That is indeed why it works so much better in a kerosene heater, but this is not a difference that is so great you should go out of your way to find No.1 diesel.

If you have it handy, great, but if not you can just use regular diesel from the pump with one simple additive which we will get into in a moment.

How Do You Use Diesel in a Kerosene Heater?

You use diesel fuel in a kerosene heater the exact same way that you would use kerosene. All the safety, handling and fueling procedures are exactly the same.

However, there is one thing you’ll need to add to the diesel to ensure an even burn and proper functionality.

That additive is a common 91% isopropyl alcohol. And it takes very, very little, too: you should add about 5 ml of isopropyl alcohol to every pint of diesel before using it to fuel your kerosene heater.

Simply add the isopropyl alcohol, stir vigorously for about a minute, and then you are ready to use it in your heater. That’s it!

Can All Types of Kerosene Heater Use Diesel?

Yes. All types of kerosene heater, be they portable or not, radiant or not, can use diesel fuel safely as described above. Torpedo-style kerosene heaters included, but they might need extra maintenance after using diesel. See below.

Do You Need to Modify a Heater to Accept Diesel?

No, not really. Any functional and well-maintained kerosene heater can use diesel fuel as described above without any modifications to the heater itself, and nor should you try to modify it beyond normal function!

That is a whole lot more likely to introduce an unsafe condition than the use of the diesel itself.

That being said, you can get somewhat better performance and better longevity out of your kerosene heater if you switch out a fiberglass wick for a cotton one.

Fiberglass wicks tend to attract moisture and carbonize significantly quicker than cotton wicks when diesel fuel is burned.

But, once again the difference is marginal in the scheme of things and wicks are quite cheap and easy to replace, so you don’t need to fiddle with it if you don’t want to or you are in a bind for time.

Do You Need to Do Anything to Your Heater After Burning Diesel in It?

No. Not usually, anyway. Any kerosene heater that burns diesel as fuel will still be ready to accept kerosene in the future when more is obtained. There are no special modifications to be made one way or the other after using diesel.

That said, certain types of kerosene heater, and torpedo heaters in particular, might be prone to clogging up and getting grimy if you use diesel that is not properly mixed with isopropyl alcohol.

This might make your next scheduled maintenance interval a bit more of a pain in the butt, but that’s the worst that could happen.

What are the Advantages of Using Diesel in a Kerosene Heater?

The biggest advantage to using diesel as opposed to kerosene in your kerosene heater is that diesel is often significantly cheaper, even when you factor in the tiny cost of alcohol to cut it with. In many places, diesel is also more widely available than your regular kerosene.

And of course, if you don’t have kerosene, the fact that you have diesel fuel means you are still in business as opposed to just being out of gas!

What are the Drawbacks of Using Diesel in a Kerosene Heater?

There aren’t too many drawbacks to using diesel fuel in your kerosene heater. We’ve already touched on most of them.

Ideally, you will use diesel fuel with a cotton wick as mentioned above because cotton wicks last longer and work a little better compared to fiberglass wicks.

Also you’ll need to contend with a somewhat dirtier heater with certain designs, particularly torpedo heaters.

This isn’t much to worry about at the time, but it does make maintenance somewhat more aggravating. Possibly the single biggest drawback to using diesel is that diesel, as opposed to true kerosene, smells significantly worse.

You’ll definitely notice an increase in odor, even though the total emissions will be pretty much the same assuming the heater is functioning properly.

And then there’s the fact that diesel does not put out quite as much heat as kerosene, although this difference is so small as to be virtually not worth mentioning under typical circumstances.