Did you run out of kerosene and wonder if you can use diesel in your heater?
Or maybe you just want to save money by using cheaper diesel or even biodiesel you made yourself.
Whatever the reason, here’s what you need to know about using diesel in a kerosene heater.
Can You Use Diesel in a Kerosene Heater?
Yes, you can use diesel in your kerosene heater. Kerosene heaters are multi-fuel heaters and can run off several different fuels, including diesel. You can even use pure vegetable oil in a kerosene heater! However, some types of fuel will perform better in a kerosene heater.
Which Type of Diesel Can I Use in My Kerosene Heater?
Any diesel fuel will work in a kerosene heater. However, the type of diesel you use could affect performance.
You want to use either #1 diesel in your heater or ULSD heating oil as a general rule. It doesn’t matter whether it is dyed red or not, but red diesel is taxed less and thus cheaper than clear diesel.
This type of diesel is very close to kerosene. The paraffin wax has been removed, so it burns cleaner than diesel #2. It is more viscose than #2 diesel, so it draws up the wick better and is less likely to have gelling problems in cold weather.
Diesel #2 is less refined than diesel #1. It will work in a kerosene heater but not burn as cleanly or easily as diesel #1. However, it is cheaper and also has more energy capacity.
Red Dyed Diesel
Red dyed diesel also goes by many other names, including farm and off-road diesel. It can be either #1 or #2 diesel.
Why is it dyed red?
There is no difference between dyed diesel and clear diesel you buy at the pump. The dye is there for tax reasons: diesel used for on-road vehicles is taxed at a higher rate than the diesel used for off-road vehicles.
Red diesel is much cheaper than clear diesel because it doesn’t have a road tax. You can legally use it in a heater. However, you cannot legally use red diesel in your vehicle.
It used to be that red-dyed diesel could contain more sulfur than clear diesel. However, this is no longer the case. As of 2014, all red diesel for off-road vehicles must also be ultra-low sulfur diesel (ULSD), which means it must contain less than 15ppm of sulfur.
Diesel Heating Oil
Here’s where things get confusing. Like off-road diesel, heating oil is also dyed red. This is to distinguish it from the taxed diesel for on-road vehicles. However, heating oil is not always the same as red-dyed diesel for tractors and other off-road vehicles.
Heating oil is exempt from the Clean Air Act and can contain more than 15ppm of sulfur. Some home heating oil might contain high amounts of sulfur and could stink if used in an unvented kerosene heater!
But most home heating oil is ULSD. That is because NY and many other states in the Northeast now have laws that home heating oil cannot have more than 15ppm sulfur. As a result, almost all diesel heating oil sold in the Northeast is ULSD and won’t stink in your kerosene heater.
Yes, you can use biodiesel in your kerosene heater. If you buy biodiesel, it will be made of 5% organics and 95% diesel. It functions just as well in a kerosene heater as regular diesel. If you make your biodiesel, the burn quality will depend on the purity and viscosity of the final product.
Potential Problems When Burning Diesel Fuel in a Kerosene Heater
Wick Burning Issues
Diesel is thicker than kerosene and also has a higher burning temperature. Because of this, you might have some issues getting your wick lit and burning evenly when using diesel fuel. It’s even trickier when using biodiesel.
You’ll have to keep the wick down much lower than normal. Your wick will burn much faster, and you’ll need to replace it sooner. Looser cotton wicks do better when burning diesel in a kerosene heater. Avoid fiberglass wicks as these don’t work well with diesel.
Even though diesel has more energy than kerosene, it isn’t always the most efficient fuel to run in a kerosene heater. The first reason is that kerosene is generally more refined and burns better. Likewise, diesel does not always combust completely and thus is less efficient.
When using biodiesel in a forced air kerosene heater, you may have some issues when the fan is on. The biodiesel may not burn fast enough, and the heat output could suffer. You may have to fiddle with the fan settings to get it burning efficiently.
Diesel fuel, especially #2 diesel, starts to gel up at cold temperatures. It is not recommended for furnaces with outdoor fuel tanks.
You might have issues getting it fired up indoors if your home is already below freezing. And, if the heater is put in freezing temperatures, the diesel left inside it can gel in the heater. Don’t be surprised if you need to clean your heater sooner than normal because of this.
Using additives can prevent the diesel from gelling inside the kerosene heater. More on that later.
Is It Safe to Use Diesel in a Kerosene Heater?
Yes, it is generally safe to use diesel in a kerosene heater. However, if not careful, you could end up with more fumes or carbon monoxide.
Diesel #1 is not as pure as K-1 kerosene, so it will not burn as cleanly. However, you should not get dangerous fumes from burning diesel in your heater. However, it can be tricky to get diesel burning well in a heater designed for kerosene. You might end up with the wick burning, which will produce fumes.
Also Read: Why Does My Kerosene Heater Smell Bad?
In general, kerosene and diesel will produce similar amounts of carbon monoxide. However, getting diesel burning completely in a kerosene heater can be tricky, especially if you have a fiberglass wick. As a result, there may be less complete combustion and more CO.
Remember that CO gas is produced with all fuels. You must follow proper venting requirements and have a carbon monoxide detector in your home. Because heater venting requirements are usually listed with kerosene in mind, you may want to increase the amount of venting to play it safe.
Diesel Additives for Heaters
You don’t have to add anything to diesel before using it in a kerosene heater. However, a lot of people report better results with additives.
Some options are:
- Isopropyl alcohol: Add 40ml (a bit more than 1/8 cup) of 91% isopropyl alcohol per 5 gallon can of diesel. I’ve also seen much higher amounts of alcohol to diesel recommended, e.g., 80ml of alcohol per gallon.
- Kerosene: You can mix kerosene and diesel in any ratio and have it burn in your heater. Most people recommend using a 1:4 ratio (1 part kerosene to 4 parts diesel).
Don’t forget that you should always have a backup for emergency preparedness. See these other emergency home heating options.
Do you use diesel in your kerosene heater? What tips can you share? Let us know in the comments section below.